Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the...Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the treatment of gastrointestinal and respiratory issues along with increasing the platelet count in patients suffering from dengue.In this review paper,the nutritional composition and bioactive compounds of guava leaves,including proteins,vitamins,minerals,and polysaccharides,have been reviewed.The methods of extraction of bioactive compounds from guava leaves and their bioactivities,including antioxidant,anti-diabetic,and anti-cancer potential,have been explored.Further,encapsulation techniques for improving the transport of bioactive compounds and living cells into foods have been studied.The application of guava leaves in different food systems such as herbal tea,pork sausage,chocolates,jelly,meals for chickens,functional beverages,and as antibacterial agents in food preservatives has also been investigated.The findings of this review illustrated that the phytochemicals present in guava leaves showed excellent antimicrobial and antioxidant properties.Encapsulation appears to be a promising technique for improving the stability,bioavailability,and controlled release of bioactive chemicals extracted from guava leaves.Different methods for the encapsulation of bioactive compounds employed and applied in distinct food systems showed preservation of phytochemicals,improved bioactivities,and nutritional values.Overall,this review paper demonstrated how guava leaves,an abundant source of bioactive compounds,can be used as a multipurpose component to create functional foods,edible coatings,and active packaging to enhance the nutritional,antioxidant,and antimicrobial properties of various food systems that have qualities that promote health.展开更多
The anticorrosion characteristics of the seeds of Psidium guajava （P. guajava） fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of ad- sor...The anticorrosion characteristics of the seeds of Psidium guajava （P. guajava） fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of ad- sorption of the inhibitor on the metal surface （Q）, change in entropy （ΔS）, change in flee energy of the reaction （ΔG）, corrosion rate （CR） and energy of activation for corrosion reaction of carbon steel （E） were also evaluated. Adsorption isotherm was plotted to study the adsorption of the inhibitor on the metal surface with increasing concentration of the inhibitor. The functional groups responsible for inhibition were investi- gated using Fourier transform infrared （FT-IR） spectra. Electrochemical parameters were evaluated through the potentiodynamic Tafel polarization and impedance spectral studies. Scanning electron microscopy （SEM） micrographs were recorded to investigate the change in surface morphology. The complete study reveals the efficiency of seed extract of P. guajava as a safe, ecofriendly and alternate corrosion inhibitor for carbon steel in acid medium.展开更多
Crude decoction, aqueous and ethanolic extracts of two medicinal plants （Psidiura guajava and Diospyros raespiliformis）, widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for t...Crude decoction, aqueous and ethanolic extracts of two medicinal plants （Psidiura guajava and Diospyros raespiliformis）, widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.展开更多
Objective: Psidium guajava occurs worldwide in tropical and subtropical areas. It has been used to treat inflammation, diabetes, fever, hypertension and ulcers. However, its antidiarrheal and protein conservative acti...Objective: Psidium guajava occurs worldwide in tropical and subtropical areas. It has been used to treat inflammation, diabetes, fever, hypertension and ulcers. However, its antidiarrheal and protein conservative activities still need to be investigated.Methods: Fifty-four male rats were divided into normal and diarrheal rats. The normal rats were divided into 4 groups: control, low-dose P. guajava leaf extract(50 mg/kg), high-dose P. guajava leaf extract(100 mg/kg) and gallic acid. Treatments were administrated orally in 1 mL saline for a 1-month period.The diarrheal rats were divided into 5 groups: desmopressin(0.2 mg/kg) drug, low-dose P. guajava leaf extract(50 mg/kg), high-dose P. guajava leaf extract(100 mg/kg), gallic acid and an untreated control.Doses were given daily for a 1-month period while the untreated control received no treatment.Results: Diarrhea was responsible for an observed decline in kidney weight and serum sodium, potassium and chloride. Further, diarrhea was positively correlated with a significant increase in urine volume, and excretion of electrolytes, serum urea, creatinine and uric acid in the urine. In contrast, there was a proportional increase in the lipid peroxidation value in diarrhea and a significant decline was observed in serum superoxide dismutase, glutathione peroxidase and glutathione levels in diarrhea. Also, diarrhea inhibited blood proteins. The oral intake of P. guajava leaf extract by diarrheal rats restored all of these parameters to near normal levels. High-dose P. guajava leaf extract was more effective than the same compound at a low dose.Conclusion: P. guajava leaf extract elicited antidiarrheal and protein conservative effects.展开更多
Objective:To determine the efficacies of antibacterial and antioxidant activities of aqueous leaf extract of Psidium guajava mediated biosynthesis of titanium dioxide nanoparticles(TiO_2,NPs).Methods:Synthesized TiO_2...Objective:To determine the efficacies of antibacterial and antioxidant activities of aqueous leaf extract of Psidium guajava mediated biosynthesis of titanium dioxide nanoparticles(TiO_2,NPs).Methods:Synthesized TiO_2 NPs were tested by disc diffusion method against against human pathogenic bacteria.The total antioxidant activity and phenolic content(Folin—Ciocalteau method) of synthesized TiO_2 NTs and aqueous plant extract were determined.The scavenging radicals were estimated hv DPPH method.The synthesized TiO_2 NPs were characterized by XRD,FTIR.FESEM and EDX,Results:FTIR spectra of synthesized TiO_2 NPs exhibited prominent peaks at 3410 cm^(-1)(alkynes),1 578 cm^(-1).1 451 cm^(-1)(alkanes),and 1 123 cm^(-1)(C-O absorption).The morphological characterization of synthesized TiO_2 NPs was analysed by FESEM which showed spherical shape and clusters with an average size of 32.58 nm.The maximum zone of inhibition was observed in the synthesized TiO_2 NPs(20 μg/mL) against Staphylococcus aureus(25 mm) and Escherichia coli(23 mm).The synthesized TiO_2 NPs showed more antibacterial activity than the standard antibiotic disk,tetracycline which drastically reduces the chances for the development of antibiotics resistance of bacterial species.The plant aqueous extract and synthesized TiO_2NPs were found to possess maximum antioxidant activity when compared with ascorbic acid.The content of phenolic compounds(mg/g) in Leaf aqueous extract and synthesized TiO_2 NPs were found to be 85.4 and 18.3 mgTA/g,respectively.Conclusions:Green synthesized TiO_2 NPs provides a promising approach can satisfy the requirement of large-scale industrial production hearing the advantage of low—cost,eco—friendly and reproducible.展开更多
Guajadials C-F(1-4),four sesquiterpenoid-based meroterpenoids with unprecedented skeletons were isolated from the leaves of Psidium guajava.Their structures and relative configurations were established by extensive sp...Guajadials C-F(1-4),four sesquiterpenoid-based meroterpenoids with unprecedented skeletons were isolated from the leaves of Psidium guajava.Their structures and relative configurations were established by extensive spectroscopic analysis.A possible biosynthetic pathway for 1-4 was also proposed.展开更多
Objective:To evaluate the anti-angiogenic and anticancer activities of Psidium guajava leaf extracts against angiogenesis-dependent colorectal cancer.Methods:Three extracts were produced using distilled water,ethanol,...Objective:To evaluate the anti-angiogenic and anticancer activities of Psidium guajava leaf extracts against angiogenesis-dependent colorectal cancer.Methods:Three extracts were produced using distilled water,ethanol,and n-hexane as solvents.The extracts were physically characterised through gas chromatography–mass spectrometry,ultraviolet–visible spectroscopy,and Fourier transform infrared spectroscopy.Their antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl,total phenolic content,and total flavonoid content assays.To assess their anti-angiogenic activity,cell viability and rat aortic ring assays were conducted,while cell migration,tube formation,colony formation,and VEGF ELISA assays were conducted to elucidate their effects on different aspects of angiogenesis.Molecular docking was used to assess the antiangiogenic potential of some possible compounds in the extracts.Tumour spheroid assay was used to assess the extracts’potential as a treatment for colorectal cancer.Results:The ethanol extract showed the best antioxidant activity.The distilled water and ethanol extracts exhibited more inhibitory activity against EA.hy926 cell viability and aortic ring microvessel growth.In addition,the ethanol extract performed significantly better than the distilled water extract against cell migration and colony formation,and VEGF expression of the cells was suppressed by the ethanol extract.Both the distilled water and ethanol extracts showed significant inhibitory effect on EA.hy926 tube formation and tumour spheroids consisting of EA.hy926 and HCT116 cells.The ethanol extract containedβ-caryophyllene andβ-elemene by phytochemical analysis and subsequent docking studies,which may contribute to its anti-angiogenic activity.Conclusions:The ethanol extract of Psidium guajava has potential in the treatment of colorectal cancer through the inhibition of angiogenesis.展开更多
A new benzophenone glycoside,2,6-dihydroxy-4-O-β-D-glucopyranosylbenzophenone（1）,was isolated from the leaves of guajava L.Its structure was elucidated by spectral and chemical methods.1 showed significant activiti...A new benzophenone glycoside,2,6-dihydroxy-4-O-β-D-glucopyranosylbenzophenone（1）,was isolated from the leaves of guajava L.Its structure was elucidated by spectral and chemical methods.1 showed significant activities to secretion of NO in mouse peritoneal macrophages in 10μmol/L.展开更多
Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory dis-turbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are...Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory dis-turbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with techne-tium-99m (99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with 99mTc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with 99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with 99mTc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with 99mTc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.展开更多
Objective:To evaluate the antidiabetic and the antidiarrhoeal effects of ethanolic extracts of Psidium guajava leave(EEPGL) in Wisier rais to support its traditional uses.Methods:Oral glucose tolerance test model and ...Objective:To evaluate the antidiabetic and the antidiarrhoeal effects of ethanolic extracts of Psidium guajava leave(EEPGL) in Wisier rais to support its traditional uses.Methods:Oral glucose tolerance test model and alloxan induced diabetic test model were performed to evaluate antidiabetic activity of EEPGL at doses of 1.00.0.50 and 0.75 g/kg respectively.For antidiarrhoeal effects of EEPGL.castor oil-induced diarrhoea model and gastrointestinal motility test with barium sulphate milk model were also assessed at doses of750.500 and 250 mg/kg.respectively.Results:Administration of EEPGL at doses 1.00 and 0.50 g/kg significantly(P<0.05)decreased blood glucose levels in oral glucose tolerance test model as well as 0.75 g/kg dose in alloxan induced diabetic test model in Wister rats(P<0.001).Application of EEPGL at doses of 750 and 500 mg/kg showed antidiarrhoeal effect in castor oil-induced diarrhoeal model(P<0.00 l and P<0.01,respectively),and 750 mg/kg(P<0.01),500 and 250 mg/kg(P<0.05)doses in barium sulphate milk model in aforesaid animals.Conclusions:These results exhibited the significant antidiabetic and antidiarrhoeal activities of ethanolic extracts of Psidium guajava leave in Wister rats.展开更多
Two new triterpenoids,named as 2 α,3 β,23-trihydroxylurs-12,20（30）-dien-28-oic acid β-D-glucopyranoside（1）,and 2 α,3 β,6 β,20 β,23,30-hexahydroxyurs-12-en-28-oic acid（2）,together with four known triterpen...Two new triterpenoids,named as 2 α,3 β,23-trihydroxylurs-12,20（30）-dien-28-oic acid β-D-glucopyranoside（1）,and 2 α,3 β,6 β,20 β,23,30-hexahydroxyurs-12-en-28-oic acid（2）,together with four known triterpenoids were isolated from the leaves of Psidium guajava L.Their structures were elucidated on the basis of mass and spectral evidence.展开更多
Three sesquiterpene-based meroterpenoids psiguamers A-C(1-3)with new skeletons were isolated from Psidium guajava leaves.Compounds(±)-1 and(±)-2 were two pairs of humulene-de「ived meroterpenoids bearing a r...Three sesquiterpene-based meroterpenoids psiguamers A-C(1-3)with new skeletons were isolated from Psidium guajava leaves.Compounds(±)-1 and(±)-2 were two pairs of humulene-de「ived meroterpenoids bearing a rare methylated benzoylphloroglucinol unit,while 3 was an unprecedented adduct of bicyclogermacrene and methylated benzoylphloroglucinol.Their structures were determined based on comprehensive analyses of spectroscopic data,calculated electronic circular dichroism(ECD)spectra,total synthesis,and X-ray crystallographic data.The biomimetic synthesis of(±)-1 and(±)-2 was achieved.Compound(+)-1 exhibited cytotoxic activities against five human tumor cell lines(HCT-116,HepG2,BGC-823,A549,and U251),with IC_(50) values of 2.94,9.01,6.45,5.42,and 5.33 μmol/L,respectively.展开更多
Medicinal plants are facing threats due to loss of habitat and overexploitation of knows species. Therefore the present work shows utilization of essential oil from discarded leaves of Psidium guajava Linn. against hu...Medicinal plants are facing threats due to loss of habitat and overexploitation of knows species. Therefore the present work shows utilization of essential oil from discarded leaves of Psidium guajava Linn. against human dermatophytic fungi Trichophyton rubrum, T. mentagrophytes, Trichophyton violaceum, Trichophyton tonsurans, Epidermophyton floccosum, Microsporum gypseum and Microsporum canis. The oil was found to be fungicidal at 3.0 μl/ml and it tolerated heavy inoculum of pathogens at fungicidal concentrations. The fungicidal activity of the oil was thermostable, up to 70°C and shelf life was found to be six months, which was maximum the time taken into consideration. The oil having cineole, caryophyllane, copaene, azulene and eucalyptol as main constituents, exhibited broad fungicidal activity. The oil did not show any adverse effect on mammalian skin upto 5% concentration. Phylogeny of the dermatophytes with respect to toxicity of the oil has also been discussed using molecular data. The cost effective formulation from waste leaves can be exploited after undergoing double blind successful multicentral topical testing.展开更多
Guava (Psidium guajava L.), a tropical fruit, belongs to Myrtaceae family. Leaves and fruits of guava have been reported to have an anti-diarrheal, hypoglycemic, lipid lowering, anti-bacterial in addition to antioxida...Guava (Psidium guajava L.), a tropical fruit, belongs to Myrtaceae family. Leaves and fruits of guava have been reported to have an anti-diarrheal, hypoglycemic, lipid lowering, anti-bacterial in addition to antioxidant activities. The aim of this study was to investigate several guava leaf extract cytotoxic effects on healthy clone 9 liver cells and its hepatoprotective effects on ethanol-induced heap-toxicity. It was discovered that when the clone 9 liver cells were treated with guava (Psidium guajava Linn.) extracts for 24 hours, there was no retardation of growth as well as when ethanol and acetone extracts at low concentrations 100 μg/mL and 50 μg/mL were administered however cytototoxic effects were detected at higher concentrations. Water and hot water extracts in concentrations lower than or equal to 500 μg/mL revealed no cytotoxic effects. Injury induction to healthy clone 9 liver cells using 5% alcohol concentration for 30 minutes revealed the hepatoprotective properties of guava (Psidium guajava Linn.) extracts. This was significant in concentrations of 100 μg/mL or lower for ethanol and all concentrations for hot water extracts. Hot water extracts showed higher hepatoprotective and lower cytotoxic properties than other extracts.展开更多
<span style="font-family:Verdana;">Globally dental diseases are mainly caused by</span><i><span style="font-family:Verdana;"> Streptococcus mutans</span></i><...<span style="font-family:Verdana;">Globally dental diseases are mainly caused by</span><i><span style="font-family:Verdana;"> Streptococcus mutans</span></i><span style="font-family:""><span style="font-family:Verdana;">, it is one of the leading causative agents of dental caries worldwide, because of its resistance to </span><span><span style="font-family:Verdana;">conventional antibacterial agents, alternative therapies are used to control resistance of oral pathogens. This research was done to determine the antibacterial activities of </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) chewing sticks on </span><i><span style="font-family:Verdana;">Streptococcus mutans</span></i><span style="font-family:Verdana;"> isolated from the oral cavity. The study was conducted in Owerri Imo State Nigeria during November-December</span></span><span style="font-family:Verdana;"> period. Phytochemical analysis of the plant extracts was done using appropriate techniques. The procedure used for antimicrobial susceptibility test was disk diffusion method. Serial dilutions of</span><i><span style="font-family:Verdana;"> Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarind</span></i><span style="font-family:Verdana;"> (Icheku) extracts were prepared, Muller-Hinton media was used to put together the extract of serial dilutions of </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) and </span></span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">microbiological procedure w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> used for visually determining the minimum inhibitory concentration as well as minimum bactericidal concentration. Phytochemical evaluation of the plants</span><span style="font-family:Verdana;">’</span><span style="font-family:""><span style="font-family:Verdana;"> extracts revealed that it contains saponins, tannins, alkaloid, steriods, glycosides and phenol. The results obtained from the antibacterial susceptibility testing of the extracts against </span><i><span style="font-family:Verdana;">Streptococcus mutans</span></i><span style="font-family:Verdana;"> showed that the zones of inhibition recorded ranged from 18</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">mm to 27</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">mm. Ethanol (Soxhlet) extract of I</span><span style="font-family:Verdana;">cheku twig showed no zone of inhibition on the isolated organism. The</span><span style="font-family:Verdana;"> ethanol (soxhlet) extract of the individual </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) has a better antibacterial effect when compared to their aqueous extracts and combined forms. </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (Guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) twigs are made up of composite that </span></span><span style="font-family:Verdana;">is</span><span style="font-family:""><span style="font-family:Verdana;"> active against </span><i><span style="font-family:Verdana;">S. mutans</span></i><span style="font-family:Verdana;"> and can be used in oral hygiene. There is </span></span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">need for further investigation on the plant extracts as the rural poor make use of it because it is cheap, readily available and the rich also use it once they are in the village mostly in Eastern Nigeria. Similarly chewing sticks has been reported to be practiced by 90 of rural population in Nigeria</span><span style="font-family:Verdana;">.展开更多
This study has been embarked upon due to increased resistance of bacteria to many already synthesized drugs and the high price of the orthodox medicines in the market, the antimicrobial effect of Psidium guajava leaf ...This study has been embarked upon due to increased resistance of bacteria to many already synthesized drugs and the high price of the orthodox medicines in the market, the antimicrobial effect of Psidium guajava leaf extracts against selected drug-resistant bacteria will help to reduce the overdependence on orthodox or synthetic drugs which greater population of the society cannot afford due to economic/financial restriction. Ethanolic and aqueous extracts of Psidium guajava were assayed for antibacterial activity using the agar dilution method in the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bioactive components of the extracts were determined using standard techniques and the inhibitory activities of the extracts were compared to gentamicin, ciprofloxacin, erythromycin, azithromycin, ofloxacin, and nitrofurantoin. The MIC of the extract on the test organisms ranges from 10 mg/ml - 40 mg/ml. The sensitivity test showed that the organisms were susceptible to Psidium guajava leave extract except Pseudomonas aeruginosa. The phytochemical analysis of the extracts revealed the presence of bioactive compounds such as Tannin, Saponin, Balsam, Flavonoids, Alkaloids, Cardiac glycosides, Carbohydrate, Resins, Terpenes, and Sterols. It has been shown that the leaves of Psidium guajava have antibacterial effects and hence can be used to treat the ailments caused by those organisms at a particular dosage and concentration. However, more research work on its toxicity level, synergistic or antagonistic interaction with other plants or drugs is needed to consolidate its usage.展开更多
The study describes the scope of clonal propagation of guava (Psidium guajava Linn.) by stem cutting collected from mature stockplants. Cuttings were treated with 0, 0.2%, 0.4% and 0.8% IBA solution and rooted in the ...The study describes the scope of clonal propagation of guava (Psidium guajava Linn.) by stem cutting collected from mature stockplants. Cuttings were treated with 0, 0.2%, 0.4% and 0.8% IBA solution and rooted in the non-mist propagator. Rooted cuttings were allowed to grow in the polybags filled with soil and cow-dung mixed in the ratio of 3: 1 (by volume) for three months to assess the steckling capacity and initial growth performance. The study reveals that the species is amenable for clonal propagation by mature stem cutting. The highest rooting percentage (60%) was observed in the cuttings treated with 0.4% IBA solution followed by 0.2% IBA and the lowest was in controlled cuttings. The maximum number of primary root (32.7) was developed in the cuttings treated with 0.8% IBA solution followed by 0.4% IBA and the lowest was in the cuttings without IBA treatment. The highest survival percentage (70.9) was observed in the cuttings rooted with 0.4% IBA treatment and the lowest (58.3) was in the cuttings without any treatment. However, there was no significant variation in height growth of cutlings due to IBA treatments in rooting.展开更多
[ Objective] This study was conducted to determinate the contents of hyperoside and isoquercitrin in the leaves of Psidium guajava Linn. from different areas of Guizhou Province, which would provide data support for p...[ Objective] This study was conducted to determinate the contents of hyperoside and isoquercitrin in the leaves of Psidium guajava Linn. from different areas of Guizhou Province, which would provide data support for production and quality control of P. guajava leaf material. [ Method] The contents of hypereside and isoquercitrin were measured by HPLC under following conditions： Agilent XDB-C18,4.6 mm x 250 ram, 5 ttm, CH3CN-0.1% HCOOH （13： 87） as mobile phase, column temporature at 25 ℃, detection wavelength of 257 mn and flow rate at 1.0 ml/min. [ Result ] The results showed that leaves of P. guajava from dif- ferent producing areas contained variable hypereaide and isoquercitrin contents in the same period, and the differences in quality were obvious between different are- as. [ Conclusion] The method for detecting the contents of hypereside and isoquercitrin in P. guajava leaf materials is simple with reliable accurate results. The P. guajava leaf material produced in Gouting Township, Luedian County has better quality.展开更多
The progress in the field of nanotechnology has contributed to the development of tools for combating the most critical problems in developing countries. The requirements that such tools should meet are low-cost and r...The progress in the field of nanotechnology has contributed to the development of tools for combating the most critical problems in developing countries. The requirements that such tools should meet are low-cost and resource settings, environmental protection, ease of use, and availability. The use of plant properties for the generation of nanoparticles (NPs), which serve as bioinsecticides to combat the plasticity and resistance of mosquitoes and parasites, is considered possible. Here, we report for the first time the larvicidal activity of silver (Ag) NPs (AgNPs) synthesized from Psidium guajava (P. guajava) extract, which targets the 4th instar larvae of Anopheles gambiae. Concentrations of AgNPs between 0 and 200 ppm were used and their LC50 at 24 h and 48 h were determined as 19.55 ppm and 8.737 ppm, respectively. The AgNPs were stable and highly effective against the larvae of A. gambiae and thereby we anticipate that they can be used to combat vector-borne diseases in developing countries.展开更多
文摘Guava(Psidium guajava L.),a plant belonging to the Myrtaceae family,holds significant medicinal and nutritional values.Leaves of the plant are described to be elliptical with a dark green color and are utilized in the treatment of gastrointestinal and respiratory issues along with increasing the platelet count in patients suffering from dengue.In this review paper,the nutritional composition and bioactive compounds of guava leaves,including proteins,vitamins,minerals,and polysaccharides,have been reviewed.The methods of extraction of bioactive compounds from guava leaves and their bioactivities,including antioxidant,anti-diabetic,and anti-cancer potential,have been explored.Further,encapsulation techniques for improving the transport of bioactive compounds and living cells into foods have been studied.The application of guava leaves in different food systems such as herbal tea,pork sausage,chocolates,jelly,meals for chickens,functional beverages,and as antibacterial agents in food preservatives has also been investigated.The findings of this review illustrated that the phytochemicals present in guava leaves showed excellent antimicrobial and antioxidant properties.Encapsulation appears to be a promising technique for improving the stability,bioavailability,and controlled release of bioactive chemicals extracted from guava leaves.Different methods for the encapsulation of bioactive compounds employed and applied in distinct food systems showed preservation of phytochemicals,improved bioactivities,and nutritional values.Overall,this review paper demonstrated how guava leaves,an abundant source of bioactive compounds,can be used as a multipurpose component to create functional foods,edible coatings,and active packaging to enhance the nutritional,antioxidant,and antimicrobial properties of various food systems that have qualities that promote health.
文摘The anticorrosion characteristics of the seeds of Psidium guajava （P. guajava） fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of ad- sorption of the inhibitor on the metal surface （Q）, change in entropy （ΔS）, change in flee energy of the reaction （ΔG）, corrosion rate （CR） and energy of activation for corrosion reaction of carbon steel （E） were also evaluated. Adsorption isotherm was plotted to study the adsorption of the inhibitor on the metal surface with increasing concentration of the inhibitor. The functional groups responsible for inhibition were investi- gated using Fourier transform infrared （FT-IR） spectra. Electrochemical parameters were evaluated through the potentiodynamic Tafel polarization and impedance spectral studies. Scanning electron microscopy （SEM） micrographs were recorded to investigate the change in surface morphology. The complete study reveals the efficiency of seed extract of P. guajava as a safe, ecofriendly and alternate corrosion inhibitor for carbon steel in acid medium.
文摘Crude decoction, aqueous and ethanolic extracts of two medicinal plants （Psidiura guajava and Diospyros raespiliformis）, widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.
文摘Objective: Psidium guajava occurs worldwide in tropical and subtropical areas. It has been used to treat inflammation, diabetes, fever, hypertension and ulcers. However, its antidiarrheal and protein conservative activities still need to be investigated.Methods: Fifty-four male rats were divided into normal and diarrheal rats. The normal rats were divided into 4 groups: control, low-dose P. guajava leaf extract(50 mg/kg), high-dose P. guajava leaf extract(100 mg/kg) and gallic acid. Treatments were administrated orally in 1 mL saline for a 1-month period.The diarrheal rats were divided into 5 groups: desmopressin(0.2 mg/kg) drug, low-dose P. guajava leaf extract(50 mg/kg), high-dose P. guajava leaf extract(100 mg/kg), gallic acid and an untreated control.Doses were given daily for a 1-month period while the untreated control received no treatment.Results: Diarrhea was responsible for an observed decline in kidney weight and serum sodium, potassium and chloride. Further, diarrhea was positively correlated with a significant increase in urine volume, and excretion of electrolytes, serum urea, creatinine and uric acid in the urine. In contrast, there was a proportional increase in the lipid peroxidation value in diarrhea and a significant decline was observed in serum superoxide dismutase, glutathione peroxidase and glutathione levels in diarrhea. Also, diarrhea inhibited blood proteins. The oral intake of P. guajava leaf extract by diarrheal rats restored all of these parameters to near normal levels. High-dose P. guajava leaf extract was more effective than the same compound at a low dose.Conclusion: P. guajava leaf extract elicited antidiarrheal and protein conservative effects.
文摘Objective:To determine the efficacies of antibacterial and antioxidant activities of aqueous leaf extract of Psidium guajava mediated biosynthesis of titanium dioxide nanoparticles(TiO_2,NPs).Methods:Synthesized TiO_2 NPs were tested by disc diffusion method against against human pathogenic bacteria.The total antioxidant activity and phenolic content(Folin—Ciocalteau method) of synthesized TiO_2 NTs and aqueous plant extract were determined.The scavenging radicals were estimated hv DPPH method.The synthesized TiO_2 NPs were characterized by XRD,FTIR.FESEM and EDX,Results:FTIR spectra of synthesized TiO_2 NPs exhibited prominent peaks at 3410 cm^(-1)(alkynes),1 578 cm^(-1).1 451 cm^(-1)(alkanes),and 1 123 cm^(-1)(C-O absorption).The morphological characterization of synthesized TiO_2 NPs was analysed by FESEM which showed spherical shape and clusters with an average size of 32.58 nm.The maximum zone of inhibition was observed in the synthesized TiO_2 NPs(20 μg/mL) against Staphylococcus aureus(25 mm) and Escherichia coli(23 mm).The synthesized TiO_2 NPs showed more antibacterial activity than the standard antibiotic disk,tetracycline which drastically reduces the chances for the development of antibiotics resistance of bacterial species.The plant aqueous extract and synthesized TiO_2NPs were found to possess maximum antioxidant activity when compared with ascorbic acid.The content of phenolic compounds(mg/g) in Leaf aqueous extract and synthesized TiO_2 NPs were found to be 85.4 and 18.3 mgTA/g,respectively.Conclusions:Green synthesized TiO_2 NPs provides a promising approach can satisfy the requirement of large-scale industrial production hearing the advantage of low—cost,eco—friendly and reproducible.
基金The authors acknowledge the National Basic Research Program of China(973 Program,2009CB522300)the“West Light”program of Chinese Academy of Sciences,and the National Natural Science Foundation of China(U1132607).
文摘Guajadials C-F(1-4),four sesquiterpenoid-based meroterpenoids with unprecedented skeletons were isolated from the leaves of Psidium guajava.Their structures and relative configurations were established by extensive spectroscopic analysis.A possible biosynthetic pathway for 1-4 was also proposed.
文摘Objective:To evaluate the anti-angiogenic and anticancer activities of Psidium guajava leaf extracts against angiogenesis-dependent colorectal cancer.Methods:Three extracts were produced using distilled water,ethanol,and n-hexane as solvents.The extracts were physically characterised through gas chromatography–mass spectrometry,ultraviolet–visible spectroscopy,and Fourier transform infrared spectroscopy.Their antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl,total phenolic content,and total flavonoid content assays.To assess their anti-angiogenic activity,cell viability and rat aortic ring assays were conducted,while cell migration,tube formation,colony formation,and VEGF ELISA assays were conducted to elucidate their effects on different aspects of angiogenesis.Molecular docking was used to assess the antiangiogenic potential of some possible compounds in the extracts.Tumour spheroid assay was used to assess the extracts’potential as a treatment for colorectal cancer.Results:The ethanol extract showed the best antioxidant activity.The distilled water and ethanol extracts exhibited more inhibitory activity against EA.hy926 cell viability and aortic ring microvessel growth.In addition,the ethanol extract performed significantly better than the distilled water extract against cell migration and colony formation,and VEGF expression of the cells was suppressed by the ethanol extract.Both the distilled water and ethanol extracts showed significant inhibitory effect on EA.hy926 tube formation and tumour spheroids consisting of EA.hy926 and HCT116 cells.The ethanol extract containedβ-caryophyllene andβ-elemene by phytochemical analysis and subsequent docking studies,which may contribute to its anti-angiogenic activity.Conclusions:The ethanol extract of Psidium guajava has potential in the treatment of colorectal cancer through the inhibition of angiogenesis.
基金National Science and Technology Project of China(No.2009ZX09311-004) for financial support
文摘A new benzophenone glycoside,2,6-dihydroxy-4-O-β-D-glucopyranosylbenzophenone（1）,was isolated from the leaves of guajava L.Its structure was elucidated by spectral and chemical methods.1 showed significant activities to secretion of NO in mouse peritoneal macrophages in 10μmol/L.
基金Project supported by CAPES, CNPq and FAPERJ, Brazil
文摘Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory dis-turbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with techne-tium-99m (99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with 99mTc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with 99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with 99mTc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with 99mTc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.
文摘Objective:To evaluate the antidiabetic and the antidiarrhoeal effects of ethanolic extracts of Psidium guajava leave(EEPGL) in Wisier rais to support its traditional uses.Methods:Oral glucose tolerance test model and alloxan induced diabetic test model were performed to evaluate antidiabetic activity of EEPGL at doses of 1.00.0.50 and 0.75 g/kg respectively.For antidiarrhoeal effects of EEPGL.castor oil-induced diarrhoea model and gastrointestinal motility test with barium sulphate milk model were also assessed at doses of750.500 and 250 mg/kg.respectively.Results:Administration of EEPGL at doses 1.00 and 0.50 g/kg significantly(P<0.05)decreased blood glucose levels in oral glucose tolerance test model as well as 0.75 g/kg dose in alloxan induced diabetic test model in Wister rats(P<0.001).Application of EEPGL at doses of 750 and 500 mg/kg showed antidiarrhoeal effect in castor oil-induced diarrhoeal model(P<0.00 l and P<0.01,respectively),and 750 mg/kg(P<0.01),500 and 250 mg/kg(P<0.05)doses in barium sulphate milk model in aforesaid animals.Conclusions:These results exhibited the significant antidiabetic and antidiarrhoeal activities of ethanolic extracts of Psidium guajava leave in Wister rats.
基金supported by the National Natural Science Foundation(No.u0732004/C1905)
文摘Two new triterpenoids,named as 2 α,3 β,23-trihydroxylurs-12,20（30）-dien-28-oic acid β-D-glucopyranoside（1）,and 2 α,3 β,6 β,20 β,23,30-hexahydroxyurs-12-en-28-oic acid（2）,together with four known triterpenoids were isolated from the leaves of Psidium guajava L.Their structures were elucidated on the basis of mass and spectral evidence.
基金This work was supported by the National Natural Science Foundation of China(No.21772234)the National New Drug Innovation Major Project of China(Nos.2018ZX09735006 and 2018ZX09711001-002-010)+1 种基金CAMS Innovation Fund for Medical Sciences(Nos.2016-I2M-2-003 and 2017-I2M-3-010)the independent project of State Key Laboratory of Bioactive Substance and Function of Natural Medicines(No.GTZA201803).
文摘Three sesquiterpene-based meroterpenoids psiguamers A-C(1-3)with new skeletons were isolated from Psidium guajava leaves.Compounds(±)-1 and(±)-2 were two pairs of humulene-de「ived meroterpenoids bearing a rare methylated benzoylphloroglucinol unit,while 3 was an unprecedented adduct of bicyclogermacrene and methylated benzoylphloroglucinol.Their structures were determined based on comprehensive analyses of spectroscopic data,calculated electronic circular dichroism(ECD)spectra,total synthesis,and X-ray crystallographic data.The biomimetic synthesis of(±)-1 and(±)-2 was achieved.Compound(+)-1 exhibited cytotoxic activities against five human tumor cell lines(HCT-116,HepG2,BGC-823,A549,and U251),with IC_(50) values of 2.94,9.01,6.45,5.42,and 5.33 μmol/L,respectively.
文摘Medicinal plants are facing threats due to loss of habitat and overexploitation of knows species. Therefore the present work shows utilization of essential oil from discarded leaves of Psidium guajava Linn. against human dermatophytic fungi Trichophyton rubrum, T. mentagrophytes, Trichophyton violaceum, Trichophyton tonsurans, Epidermophyton floccosum, Microsporum gypseum and Microsporum canis. The oil was found to be fungicidal at 3.0 μl/ml and it tolerated heavy inoculum of pathogens at fungicidal concentrations. The fungicidal activity of the oil was thermostable, up to 70°C and shelf life was found to be six months, which was maximum the time taken into consideration. The oil having cineole, caryophyllane, copaene, azulene and eucalyptol as main constituents, exhibited broad fungicidal activity. The oil did not show any adverse effect on mammalian skin upto 5% concentration. Phylogeny of the dermatophytes with respect to toxicity of the oil has also been discussed using molecular data. The cost effective formulation from waste leaves can be exploited after undergoing double blind successful multicentral topical testing.
文摘Guava (Psidium guajava L.), a tropical fruit, belongs to Myrtaceae family. Leaves and fruits of guava have been reported to have an anti-diarrheal, hypoglycemic, lipid lowering, anti-bacterial in addition to antioxidant activities. The aim of this study was to investigate several guava leaf extract cytotoxic effects on healthy clone 9 liver cells and its hepatoprotective effects on ethanol-induced heap-toxicity. It was discovered that when the clone 9 liver cells were treated with guava (Psidium guajava Linn.) extracts for 24 hours, there was no retardation of growth as well as when ethanol and acetone extracts at low concentrations 100 μg/mL and 50 μg/mL were administered however cytototoxic effects were detected at higher concentrations. Water and hot water extracts in concentrations lower than or equal to 500 μg/mL revealed no cytotoxic effects. Injury induction to healthy clone 9 liver cells using 5% alcohol concentration for 30 minutes revealed the hepatoprotective properties of guava (Psidium guajava Linn.) extracts. This was significant in concentrations of 100 μg/mL or lower for ethanol and all concentrations for hot water extracts. Hot water extracts showed higher hepatoprotective and lower cytotoxic properties than other extracts.
文摘<span style="font-family:Verdana;">Globally dental diseases are mainly caused by</span><i><span style="font-family:Verdana;"> Streptococcus mutans</span></i><span style="font-family:""><span style="font-family:Verdana;">, it is one of the leading causative agents of dental caries worldwide, because of its resistance to </span><span><span style="font-family:Verdana;">conventional antibacterial agents, alternative therapies are used to control resistance of oral pathogens. This research was done to determine the antibacterial activities of </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) chewing sticks on </span><i><span style="font-family:Verdana;">Streptococcus mutans</span></i><span style="font-family:Verdana;"> isolated from the oral cavity. The study was conducted in Owerri Imo State Nigeria during November-December</span></span><span style="font-family:Verdana;"> period. Phytochemical analysis of the plant extracts was done using appropriate techniques. The procedure used for antimicrobial susceptibility test was disk diffusion method. Serial dilutions of</span><i><span style="font-family:Verdana;"> Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarind</span></i><span style="font-family:Verdana;"> (Icheku) extracts were prepared, Muller-Hinton media was used to put together the extract of serial dilutions of </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) and </span></span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">microbiological procedure w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> used for visually determining the minimum inhibitory concentration as well as minimum bactericidal concentration. Phytochemical evaluation of the plants</span><span style="font-family:Verdana;">’</span><span style="font-family:""><span style="font-family:Verdana;"> extracts revealed that it contains saponins, tannins, alkaloid, steriods, glycosides and phenol. The results obtained from the antibacterial susceptibility testing of the extracts against </span><i><span style="font-family:Verdana;">Streptococcus mutans</span></i><span style="font-family:Verdana;"> showed that the zones of inhibition recorded ranged from 18</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">mm to 27</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">mm. Ethanol (Soxhlet) extract of I</span><span style="font-family:Verdana;">cheku twig showed no zone of inhibition on the isolated organism. The</span><span style="font-family:Verdana;"> ethanol (soxhlet) extract of the individual </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) has a better antibacterial effect when compared to their aqueous extracts and combined forms. </span><i><span style="font-family:Verdana;">Psidium guajava</span></i><span style="font-family:Verdana;"> (Guava) and </span><i><span style="font-family:Verdana;">Velvet tamarin</span></i><span style="font-family:Verdana;"> (Icheku) twigs are made up of composite that </span></span><span style="font-family:Verdana;">is</span><span style="font-family:""><span style="font-family:Verdana;"> active against </span><i><span style="font-family:Verdana;">S. mutans</span></i><span style="font-family:Verdana;"> and can be used in oral hygiene. There is </span></span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">need for further investigation on the plant extracts as the rural poor make use of it because it is cheap, readily available and the rich also use it once they are in the village mostly in Eastern Nigeria. Similarly chewing sticks has been reported to be practiced by 90 of rural population in Nigeria</span><span style="font-family:Verdana;">.
文摘This study has been embarked upon due to increased resistance of bacteria to many already synthesized drugs and the high price of the orthodox medicines in the market, the antimicrobial effect of Psidium guajava leaf extracts against selected drug-resistant bacteria will help to reduce the overdependence on orthodox or synthetic drugs which greater population of the society cannot afford due to economic/financial restriction. Ethanolic and aqueous extracts of Psidium guajava were assayed for antibacterial activity using the agar dilution method in the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bioactive components of the extracts were determined using standard techniques and the inhibitory activities of the extracts were compared to gentamicin, ciprofloxacin, erythromycin, azithromycin, ofloxacin, and nitrofurantoin. The MIC of the extract on the test organisms ranges from 10 mg/ml - 40 mg/ml. The sensitivity test showed that the organisms were susceptible to Psidium guajava leave extract except Pseudomonas aeruginosa. The phytochemical analysis of the extracts revealed the presence of bioactive compounds such as Tannin, Saponin, Balsam, Flavonoids, Alkaloids, Cardiac glycosides, Carbohydrate, Resins, Terpenes, and Sterols. It has been shown that the leaves of Psidium guajava have antibacterial effects and hence can be used to treat the ailments caused by those organisms at a particular dosage and concentration. However, more research work on its toxicity level, synergistic or antagonistic interaction with other plants or drugs is needed to consolidate its usage.
文摘The study describes the scope of clonal propagation of guava (Psidium guajava Linn.) by stem cutting collected from mature stockplants. Cuttings were treated with 0, 0.2%, 0.4% and 0.8% IBA solution and rooted in the non-mist propagator. Rooted cuttings were allowed to grow in the polybags filled with soil and cow-dung mixed in the ratio of 3: 1 (by volume) for three months to assess the steckling capacity and initial growth performance. The study reveals that the species is amenable for clonal propagation by mature stem cutting. The highest rooting percentage (60%) was observed in the cuttings treated with 0.4% IBA solution followed by 0.2% IBA and the lowest was in controlled cuttings. The maximum number of primary root (32.7) was developed in the cuttings treated with 0.8% IBA solution followed by 0.4% IBA and the lowest was in the cuttings without IBA treatment. The highest survival percentage (70.9) was observed in the cuttings rooted with 0.4% IBA treatment and the lowest (58.3) was in the cuttings without any treatment. However, there was no significant variation in height growth of cutlings due to IBA treatments in rooting.
基金Supported by Science and Technology Fund of Guizhou Health and Family Planning Commission(gzwjkj2016-1-010)Key Talent Project of Guizhou Province in 2014(2013-QR-008)+1 种基金Traditional Chinese Medicine and Ethnic Minority Medicine Technique Research Subject of Guizhou Administrative Bureau of TCM(QZYY-2015-93)Anshun Project for Construction of Scientific and Technological Innovation Flat(ASKP[2016]7)
文摘[ Objective] This study was conducted to determinate the contents of hyperoside and isoquercitrin in the leaves of Psidium guajava Linn. from different areas of Guizhou Province, which would provide data support for production and quality control of P. guajava leaf material. [ Method] The contents of hypereside and isoquercitrin were measured by HPLC under following conditions： Agilent XDB-C18,4.6 mm x 250 ram, 5 ttm, CH3CN-0.1% HCOOH （13： 87） as mobile phase, column temporature at 25 ℃, detection wavelength of 257 mn and flow rate at 1.0 ml/min. [ Result ] The results showed that leaves of P. guajava from dif- ferent producing areas contained variable hypereaide and isoquercitrin contents in the same period, and the differences in quality were obvious between different are- as. [ Conclusion] The method for detecting the contents of hypereside and isoquercitrin in P. guajava leaf materials is simple with reliable accurate results. The P. guajava leaf material produced in Gouting Township, Luedian County has better quality.
文摘The progress in the field of nanotechnology has contributed to the development of tools for combating the most critical problems in developing countries. The requirements that such tools should meet are low-cost and resource settings, environmental protection, ease of use, and availability. The use of plant properties for the generation of nanoparticles (NPs), which serve as bioinsecticides to combat the plasticity and resistance of mosquitoes and parasites, is considered possible. Here, we report for the first time the larvicidal activity of silver (Ag) NPs (AgNPs) synthesized from Psidium guajava (P. guajava) extract, which targets the 4th instar larvae of Anopheles gambiae. Concentrations of AgNPs between 0 and 200 ppm were used and their LC50 at 24 h and 48 h were determined as 19.55 ppm and 8.737 ppm, respectively. The AgNPs were stable and highly effective against the larvae of A. gambiae and thereby we anticipate that they can be used to combat vector-borne diseases in developing countries.
