Acer rubrum is an important garden color-leafed plant.Its leaves will turn red in autumn,which is of great orna-mental value.The leaf color change in Acer rubrum is closely associated with anthocyanins accumulation.In...Acer rubrum is an important garden color-leafed plant.Its leaves will turn red in autumn,which is of great orna-mental value.The leaf color change in Acer rubrum is closely associated with anthocyanins accumulation.In anthocyanin synthesis and accumulation,various transcription factor families play significant regulatory roles,including the basic(region)leucine zipper(bZIP).However,there is no report on the systematic identification and functional analysis of the bZIPs in Acer rubrum.In this study,137 bZIPs distributed on 29 chromosomes of Acer rubrum were identified and renamed according to their locations on the chromosomes.According to the constructed bZIP phylogenetic tree of Arabidopsis thaliana and Acer rubrum,bZIPs were divided into 13 groups.Two pairs of bZIP genes were involved in tandem duplication,and 106 segmental duplication gene pairs were found.Cis-acting elements in the promoter region of these bZIP genes were analyzed.The results of promoter analysis showed that many elements were closely related to light conditions,hormone responses,and abiotic stress factors.Among them,the cis-acting elements related to light response were most abundant and prominent.The results of anthocyanin determination showed that anthocyanin contents in the leaves of Acer rubrum increased significantly under low temperature with light.In addition,gene expression analysis showed that compared to other ArbZIPs,ArbZIP137,ArbZIP136,ArbZIP114,ArbZIP130,and ArbZIP14 showed a more pronounced increase in gene expression both under low-temperature conditions and under light conditions.From the correlation analysis,there was a high correlation between ArbZIPs and several anthocyanin-regulated transcription factors,including ArMYBs,ArbHLH and ArWD40s.Conclusively,the bZIP genes in Acer rubrum were identified and analyzed,providing a foundational basis for future studies on their function and significantly enhancing our understanding of the color mechanism of Acer rubrum.展开更多
Objective: To evaluate vasorelaxant and vasoconstriction effects of Zingiber officinale var. rubrum(ZOVR)on live rats and isolated aortic rings of spontaneously hypertensive rats(SHRs).Methods: Extracts of ZOVR were s...Objective: To evaluate vasorelaxant and vasoconstriction effects of Zingiber officinale var. rubrum(ZOVR)on live rats and isolated aortic rings of spontaneously hypertensive rats(SHRs).Methods: Extracts of ZOVR were subjected to in-vivo antihypertensive screening using noninvasive blood pressures in SHRs. The most potent extract, ZOVR petroleum ether extract(ZOP) was then fractionated using n-hexane, chloroform and water. Isolated thoracic aortic rings were harvested and subjected to vascular relaxation studies of n-hexane fraction of ZOP(HFZOP) with incubation of different antagonists such as Nω-nitro-L-arginine methyl ester(L-NAME, 10 μmol/L), indomethacin(10 μmol/L), methylene blue(10 μmol/L), atropine(1 μmol/L), glibenclamide(10 μmol/L), prazosin(0.01 μmol/L), and propranolol(1 μmol/L).Results: During the screening of various ZOVR extracts, ZOP produced the most reduction in blood pressures of SHRs and so did HFZOP. HFZOP significantly decreased phenylephrine-induced contraction and enhanced acetylcholine-induced relaxation. L-NAME, indomethacin, methylene blue, atropine, and glibenclamide significantly potentiated the vasorelaxant effects of HFZOP. Propranolol and prazosin did not alter the vasorelaxant effects of HFZOP. HFZOP significantly suppressed the Ca2+-dependent contraction and influenced the ratio of the responses to phenylephrine in Ca2+-free medium.Conclusion: This study demonstrates that ZOP may exert an antihypertensive effect in the SHR model. Its possible vascular relaxation mechanisms involve nitric oxide and prostacyclin release, activation of cGMP-KATP channels, stimulation of muscarinic receptors, and transmembrane calcium channel or Ca2+release from intracellular stores. Possible active compounds that contribute to the vasorelaxant effects are 6-gingerol, 8-gingerol and 6-shogaol.展开更多
Objective: To investigate the fungistatic activity and synergistic effects of natural products and their constituents, including traditional oriental medicines(TOMs).Methods: Fungistatic activities of TOMs prepared by...Objective: To investigate the fungistatic activity and synergistic effects of natural products and their constituents, including traditional oriental medicines(TOMs).Methods: Fungistatic activities of TOMs prepared by hot-water(115 ℃) or ethanol(70%; 40 ℃) extraction were determined by their minimum inhibitory concentration.To assess possible synergistic effects, minimum inhibitory concentrations of various combinations were evaluated.Results: By evaluating antifungal susceptibility of Trichophyton rubrum, which is a major causative fungus for several types of dermatophytosis, we confirmed that ethanol extracts were more active than hot-water extracts in 25 of the 36 TOMs, suggesting that the constituents with high hydrophobicity tend to contribute significantly to fungistatic activity.We selected four TOMs with high fungistatic activity, including Aucklandiae radix, Gentianae macrophyllae radix, Scutellariae radix, and Galla rhois, and their synergistic effects were investigated through the combination studies between TOMs or TOM-conventional drug terbinafine.In combinations between four TOMs, partial synergistic effects were observed in Aucklandiae radix–Galla rhois and Gentianae macrophyllae radix–Galla rhois combinations, as supported by the lowest fractional inhibitory concentration index value of 0.66 for both combinations.Furthermore, Galla rhois showed the strongest synergistic effect on growth inhibition of Trichophyton rubrumwith a fractional inhibitory concentration index value of 0.50 in combination with terbinafine.Conclusions: Our findings indicate that the combination of TOMs and TOM-terbinafine may be effective on treatment for chronic and recurrent dermatophytosis by improving fungistatic activity and led to decrease systemic toxicity in clinical practice.展开更多
BACKGROUND Facial cosmetic procedures become popular for people with a desire to have a younger appearance,and cosmetic technology has developed rapidly over the past several decades.However,increasing complications r...BACKGROUND Facial cosmetic procedures become popular for people with a desire to have a younger appearance,and cosmetic technology has developed rapidly over the past several decades.However,increasing complications related to cosmetic injections have been reported,and infection is one of the most serious problems and can cause anxiety and facial injury.We here report a case of Majocchi’s granuloma(MG)caused by Trichophyton rubrum after facial injection of hyaluronic acid.CASE SUMMARY A 37-year-old woman presented to our hospital with a history of red papules,nodules,and abscesses on her left zygomatic arch for 2 mo.She had received a cosmetic injection of hyaluronic acid on the left side of her face prior to the appearance of the lesions.MG caused by Trichophyton rubrum after facial injection of hyaluronic acid was diagnosed based on morphology and molecular biological identification.In vitro antifungal susceptibility testing was conducted according to the Clinical and Laboratory Standards Institute M38-A2 method.Minimal inhibitory concentrations were used to evaluate the antifungal susceptibility.The antifungal agents and their minimal inhibitory concentrations for the strain were terbinafine(<0.5μg/mL),itraconazole(0.06μg/mL),amphotericin B(0.25μg/mL),fluconazole(32μg/mL),voriconazole(0.125μg/mL),posaconazole(0.125μg/mL),and isavuconazole(0.06μg/mL).We initially administered 250 mg/d oral terbinafine for 2 mo,but the patient still had painful papules,nodules and abscesses on her face.Then,we adjusted the treatment to itraconazole 400 mg/d for 8 wk based on the in vitro antifungal susceptibility testing results.The skin lesions improved significantly,and there was no recurrence during follow-up.CONCLUSION This case revealed that facial injection of hyaluronic acid may cause serious MG.Antifungal susceptibility testing should be considered in the treatment of MG caused by Trichophyton rubrum.展开更多
To meet minimum spring flows, water management districts in Florida sought to make both agriculture and urban landscapes water efficient, which includes tree farms. Acer rubrum L. (red maple) trees are endemic to Cent...To meet minimum spring flows, water management districts in Florida sought to make both agriculture and urban landscapes water efficient, which includes tree farms. Acer rubrum L. (red maple) trees are endemic to Central Florida and native to the eastern portion of the United States. Urban and suburban expansion has increased use of A. rubrum in landscape plantings and their production in nurseries. In Florida A. rubrum is planted around stormwater retention areas, but also in urban landscapes. To provide a basis for irrigation allocations both during production and in landscapes, daily actual evapotranspiration (ET<sub>A</sub>) for three red maple trees were measured with weighing lysimeters, beginning with rooted cuttings and continuing until trees averaged 8 m in height. Empirical models were derived to calculate ET<sub>A</sub> based on crown horizontal projected area or trunk caliper, adjusted daily by changes in reference evapotranspiration (ETo). Water use efficiency, based on carbon sequestered in above ground wood mass, was calculated at the end of five growing seasons. Average ET<sub>A</sub> to produce these maples was 29,107 L over 4.75 years, with an average water use efficiency of 1 kg dry mass of wood per 709 L of water lost by transpiration.展开更多
OBJECTIVE ″-omics″study represents an unbiased perspective to examine the bio-system to discover the novel biomarker(s)which might be overlooked when targeted analysis is performed instead.Urine,due to its ease of c...OBJECTIVE ″-omics″study represents an unbiased perspective to examine the bio-system to discover the novel biomarker(s)which might be overlooked when targeted analysis is performed instead.Urine,due to its ease of collection,minimal invasion involved and rich information of the downstream metabolites,has been extensively studied.Fermentum rubrum(Hongqu,HQ capsules)is a well-known traditional medicine with the claimed slimming effect which could be related to the reduction in the deposition of total cholesterol and glycerides.Lack in sufficient clinical evidence is always one of the leading reasons that hamper traditional medicines from gaining world-wide recognition.In our pursuit of scientific support for HQ capsules in managing obesity,we aim to examine the alteration of urinary metabolites in this small-scale human clinical research.METHODS 6 Chinese subjects were included and exposed to short-term administration of HQ capsules for 3d,twice daily,two capsules each dosing.The urine samples were collected for three days prior to the dosing and on the day following the last dosing.In total,96 urine samples were collected and then separated on hydrophilic interaction chromatography(HILIC)and analyzed by Agilent 6550 ESI-Quadrupoletime-of-flight(QTOF)mass spectrometer.RESULTS Under positive mode,two compounds were found to be present only in post-dosing urine,and one compound was significantly lowered in post-dosing samples.Those two compounds might be associated with the administered HQ capsules,which is formulated with multiherbal constituents.CONCLUSION Further elucidation on the structures of these compounds is needed to enable better understanding of the mechanism of HQ capsules in managing obesity.展开更多
In this experiment,the biological characteristics,the number of spikes per plant,the average number of panicles,the average spike length,and the average yield per plant of the wild Ribes rubrum Linn. were observed and...In this experiment,the biological characteristics,the number of spikes per plant,the average number of panicles,the average spike length,and the average yield per plant of the wild Ribes rubrum Linn. were observed and determined and the analytic hierarchy process( AHP)was applied to evaluate the economic value of 8 different sources of excellent plants of R. rubrum Linn. The results indicated that " RXF02", " RXF03" and " RXM05" performed well in the number of spikes per plant,average number of panicles,average yield per plant,and cold resistance,and the comprehensive scores were 9. 68,9. 44 and 9. 41,respectively.展开更多
Objective: One appealing strategy to overcome and prevent resistant problem is the use of combined two or more antibacterial substances. Lawsone methyl ether(LME) is the naphthoquinone found in the leaves of Impatiens...Objective: One appealing strategy to overcome and prevent resistant problem is the use of combined two or more antibacterial substances. Lawsone methyl ether(LME) is the naphthoquinone found in the leaves of Impatiens balsamina. The objective of this study is to determine the interaction of LME with some antibiotics(ampicillin, tetracycline, norfloxacin, and clotrimazole) and a natural compound, artocarpin against methicillin-resistant Staphylococcus aureus(MRSA), Candida albicans, and Trychophyton rubrum.Methods: A broth microdilution method was used to determine the minimum inhibition concentration(MIC). Synergistic effects were evaluated at their own MIC using the checkerboard method and time-kill assay.Results: LME showed moderate antibacterial activity against MRSA with MIC value of 15.6 μg/mL, and exhibited strong antifungal activities against T. rubrum and C. albicans with MIC values of 7.8 and 3.9 μg/m L,respectively. The interaction of LME with the natural compound artocarpin against MRSA produced a synergy with fractional inhibitory concentration index(FICI) value of 0.31, while the combination of LME and clotrimazole exhibited synergy against C. albicans and T. rubrum with FICI values of 0.38 and 0.24, respectively. The time-kill assays confirmed that the compounds in combination enhanced their antimicrobial activities against the resistant microorganisms with different degrees.Conclusion: LME in combination with clotrimazole exhibited synergy effect against C. albicans and T.rubrum. In combination with artocarpin, it showed synergy effect against MRSA.展开更多
Background:Trichophyton rubrum represents the most common infectious fungus responsible for dermatophytosis in human,but the mechanism involved is still not completely understood.An appropriate model constructed to si...Background:Trichophyton rubrum represents the most common infectious fungus responsible for dermatophytosis in human,but the mechanism involved is still not completely understood.An appropriate model constructed to simulate host infection is the prerequisite to study the pathogenesis of dernlatophytosis caused by T..rubrum.In this study,we intended to develop a new T.rubrum infection model in vitro,using the three-dimensional reconstructed epidermis-EpiSkin,and to pave the way for further investigation of the mechanisms involved in T.rubrum infection.Methods:The reconstructed human epidermis(RHE)was infected by inoculating low-dose(400 conidia)and high-dose(4000 conidia)T.rubrum conidia to optimize the infection dose.During the various periods after infection,the samples were processed for pathological examination and scanning electron microscopy(SEM)observation.Results:The histological analysis of RHE revealed a fully differentiated epidermis with a functional stratum corneum,which was analogous to the normal human epidermis.The results of hematoxylin and eosin staining and the periodic acid-Schiff staining showed that the infection dose of 400 conidia was in accord with the pathological characteristics of host dermatophytosis caused by T.rubrum.SEM observations further exhibited the process of 77 ruhrum infection in an intuitionistic way,Conclusions:We established the T.rubrum infection model on RHE in vitro successfully.It is a promising model fbr further investigation of the mechanisms involved in T.rubrum infection.展开更多
基金This study was funded by the National Natural Science Foundation of China(Project No.32271914)the Natural Science Foundation of Anhui Province(2108085MC110).
文摘Acer rubrum is an important garden color-leafed plant.Its leaves will turn red in autumn,which is of great orna-mental value.The leaf color change in Acer rubrum is closely associated with anthocyanins accumulation.In anthocyanin synthesis and accumulation,various transcription factor families play significant regulatory roles,including the basic(region)leucine zipper(bZIP).However,there is no report on the systematic identification and functional analysis of the bZIPs in Acer rubrum.In this study,137 bZIPs distributed on 29 chromosomes of Acer rubrum were identified and renamed according to their locations on the chromosomes.According to the constructed bZIP phylogenetic tree of Arabidopsis thaliana and Acer rubrum,bZIPs were divided into 13 groups.Two pairs of bZIP genes were involved in tandem duplication,and 106 segmental duplication gene pairs were found.Cis-acting elements in the promoter region of these bZIP genes were analyzed.The results of promoter analysis showed that many elements were closely related to light conditions,hormone responses,and abiotic stress factors.Among them,the cis-acting elements related to light response were most abundant and prominent.The results of anthocyanin determination showed that anthocyanin contents in the leaves of Acer rubrum increased significantly under low temperature with light.In addition,gene expression analysis showed that compared to other ArbZIPs,ArbZIP137,ArbZIP136,ArbZIP114,ArbZIP130,and ArbZIP14 showed a more pronounced increase in gene expression both under low-temperature conditions and under light conditions.From the correlation analysis,there was a high correlation between ArbZIPs and several anthocyanin-regulated transcription factors,including ArMYBs,ArbHLH and ArWD40s.Conclusively,the bZIP genes in Acer rubrum were identified and analyzed,providing a foundational basis for future studies on their function and significantly enhancing our understanding of the color mechanism of Acer rubrum.
基金supported by the Fundamental Research Grant Scheme,Ministry of Higher Education,Malaysia(203/PFARMASI/6711408)MyPhD(MyBrain programme),Ministry of Higher Education,Malaysia.
文摘Objective: To evaluate vasorelaxant and vasoconstriction effects of Zingiber officinale var. rubrum(ZOVR)on live rats and isolated aortic rings of spontaneously hypertensive rats(SHRs).Methods: Extracts of ZOVR were subjected to in-vivo antihypertensive screening using noninvasive blood pressures in SHRs. The most potent extract, ZOVR petroleum ether extract(ZOP) was then fractionated using n-hexane, chloroform and water. Isolated thoracic aortic rings were harvested and subjected to vascular relaxation studies of n-hexane fraction of ZOP(HFZOP) with incubation of different antagonists such as Nω-nitro-L-arginine methyl ester(L-NAME, 10 μmol/L), indomethacin(10 μmol/L), methylene blue(10 μmol/L), atropine(1 μmol/L), glibenclamide(10 μmol/L), prazosin(0.01 μmol/L), and propranolol(1 μmol/L).Results: During the screening of various ZOVR extracts, ZOP produced the most reduction in blood pressures of SHRs and so did HFZOP. HFZOP significantly decreased phenylephrine-induced contraction and enhanced acetylcholine-induced relaxation. L-NAME, indomethacin, methylene blue, atropine, and glibenclamide significantly potentiated the vasorelaxant effects of HFZOP. Propranolol and prazosin did not alter the vasorelaxant effects of HFZOP. HFZOP significantly suppressed the Ca2+-dependent contraction and influenced the ratio of the responses to phenylephrine in Ca2+-free medium.Conclusion: This study demonstrates that ZOP may exert an antihypertensive effect in the SHR model. Its possible vascular relaxation mechanisms involve nitric oxide and prostacyclin release, activation of cGMP-KATP channels, stimulation of muscarinic receptors, and transmembrane calcium channel or Ca2+release from intracellular stores. Possible active compounds that contribute to the vasorelaxant effects are 6-gingerol, 8-gingerol and 6-shogaol.
基金supported by the Grant K17281 from Korea Institute of Oriental Medicine(KIOM),provided by the Ministry of Science,ICT and Future Planning(MISP),Republic of Korea
文摘Objective: To investigate the fungistatic activity and synergistic effects of natural products and their constituents, including traditional oriental medicines(TOMs).Methods: Fungistatic activities of TOMs prepared by hot-water(115 ℃) or ethanol(70%; 40 ℃) extraction were determined by their minimum inhibitory concentration.To assess possible synergistic effects, minimum inhibitory concentrations of various combinations were evaluated.Results: By evaluating antifungal susceptibility of Trichophyton rubrum, which is a major causative fungus for several types of dermatophytosis, we confirmed that ethanol extracts were more active than hot-water extracts in 25 of the 36 TOMs, suggesting that the constituents with high hydrophobicity tend to contribute significantly to fungistatic activity.We selected four TOMs with high fungistatic activity, including Aucklandiae radix, Gentianae macrophyllae radix, Scutellariae radix, and Galla rhois, and their synergistic effects were investigated through the combination studies between TOMs or TOM-conventional drug terbinafine.In combinations between four TOMs, partial synergistic effects were observed in Aucklandiae radix–Galla rhois and Gentianae macrophyllae radix–Galla rhois combinations, as supported by the lowest fractional inhibitory concentration index value of 0.66 for both combinations.Furthermore, Galla rhois showed the strongest synergistic effect on growth inhibition of Trichophyton rubrumwith a fractional inhibitory concentration index value of 0.50 in combination with terbinafine.Conclusions: Our findings indicate that the combination of TOMs and TOM-terbinafine may be effective on treatment for chronic and recurrent dermatophytosis by improving fungistatic activity and led to decrease systemic toxicity in clinical practice.
基金the Scientific Research Project of Peking University Shenzhen Hospital,No. JCYJ2018011the"San-ming"Project of Medicine in Shenzhen,No. SZSM201812059。
文摘BACKGROUND Facial cosmetic procedures become popular for people with a desire to have a younger appearance,and cosmetic technology has developed rapidly over the past several decades.However,increasing complications related to cosmetic injections have been reported,and infection is one of the most serious problems and can cause anxiety and facial injury.We here report a case of Majocchi’s granuloma(MG)caused by Trichophyton rubrum after facial injection of hyaluronic acid.CASE SUMMARY A 37-year-old woman presented to our hospital with a history of red papules,nodules,and abscesses on her left zygomatic arch for 2 mo.She had received a cosmetic injection of hyaluronic acid on the left side of her face prior to the appearance of the lesions.MG caused by Trichophyton rubrum after facial injection of hyaluronic acid was diagnosed based on morphology and molecular biological identification.In vitro antifungal susceptibility testing was conducted according to the Clinical and Laboratory Standards Institute M38-A2 method.Minimal inhibitory concentrations were used to evaluate the antifungal susceptibility.The antifungal agents and their minimal inhibitory concentrations for the strain were terbinafine(<0.5μg/mL),itraconazole(0.06μg/mL),amphotericin B(0.25μg/mL),fluconazole(32μg/mL),voriconazole(0.125μg/mL),posaconazole(0.125μg/mL),and isavuconazole(0.06μg/mL).We initially administered 250 mg/d oral terbinafine for 2 mo,but the patient still had painful papules,nodules and abscesses on her face.Then,we adjusted the treatment to itraconazole 400 mg/d for 8 wk based on the in vitro antifungal susceptibility testing results.The skin lesions improved significantly,and there was no recurrence during follow-up.CONCLUSION This case revealed that facial injection of hyaluronic acid may cause serious MG.Antifungal susceptibility testing should be considered in the treatment of MG caused by Trichophyton rubrum.
文摘To meet minimum spring flows, water management districts in Florida sought to make both agriculture and urban landscapes water efficient, which includes tree farms. Acer rubrum L. (red maple) trees are endemic to Central Florida and native to the eastern portion of the United States. Urban and suburban expansion has increased use of A. rubrum in landscape plantings and their production in nurseries. In Florida A. rubrum is planted around stormwater retention areas, but also in urban landscapes. To provide a basis for irrigation allocations both during production and in landscapes, daily actual evapotranspiration (ET<sub>A</sub>) for three red maple trees were measured with weighing lysimeters, beginning with rooted cuttings and continuing until trees averaged 8 m in height. Empirical models were derived to calculate ET<sub>A</sub> based on crown horizontal projected area or trunk caliper, adjusted daily by changes in reference evapotranspiration (ETo). Water use efficiency, based on carbon sequestered in above ground wood mass, was calculated at the end of five growing seasons. Average ET<sub>A</sub> to produce these maples was 29,107 L over 4.75 years, with an average water use efficiency of 1 kg dry mass of wood per 709 L of water lost by transpiration.
基金The project supported by Temasek Polytechnic DRP project grant
文摘OBJECTIVE ″-omics″study represents an unbiased perspective to examine the bio-system to discover the novel biomarker(s)which might be overlooked when targeted analysis is performed instead.Urine,due to its ease of collection,minimal invasion involved and rich information of the downstream metabolites,has been extensively studied.Fermentum rubrum(Hongqu,HQ capsules)is a well-known traditional medicine with the claimed slimming effect which could be related to the reduction in the deposition of total cholesterol and glycerides.Lack in sufficient clinical evidence is always one of the leading reasons that hamper traditional medicines from gaining world-wide recognition.In our pursuit of scientific support for HQ capsules in managing obesity,we aim to examine the alteration of urinary metabolites in this small-scale human clinical research.METHODS 6 Chinese subjects were included and exposed to short-term administration of HQ capsules for 3d,twice daily,two capsules each dosing.The urine samples were collected for three days prior to the dosing and on the day following the last dosing.In total,96 urine samples were collected and then separated on hydrophilic interaction chromatography(HILIC)and analyzed by Agilent 6550 ESI-Quadrupoletime-of-flight(QTOF)mass spectrometer.RESULTS Under positive mode,two compounds were found to be present only in post-dosing urine,and one compound was significantly lowered in post-dosing samples.Those two compounds might be associated with the administered HQ capsules,which is formulated with multiherbal constituents.CONCLUSION Further elucidation on the structures of these compounds is needed to enable better understanding of the mechanism of HQ capsules in managing obesity.
基金Supported by Key Project of Heilongjiang Forest Industry Administration(sgzjY 2013019)
文摘In this experiment,the biological characteristics,the number of spikes per plant,the average number of panicles,the average spike length,and the average yield per plant of the wild Ribes rubrum Linn. were observed and determined and the analytic hierarchy process( AHP)was applied to evaluate the economic value of 8 different sources of excellent plants of R. rubrum Linn. The results indicated that " RXF02", " RXF03" and " RXM05" performed well in the number of spikes per plant,average number of panicles,average yield per plant,and cold resistance,and the comprehensive scores were 9. 68,9. 44 and 9. 41,respectively.
基金supported by The Thailand Research Fund (Grant No. DBG6180031)
文摘Objective: One appealing strategy to overcome and prevent resistant problem is the use of combined two or more antibacterial substances. Lawsone methyl ether(LME) is the naphthoquinone found in the leaves of Impatiens balsamina. The objective of this study is to determine the interaction of LME with some antibiotics(ampicillin, tetracycline, norfloxacin, and clotrimazole) and a natural compound, artocarpin against methicillin-resistant Staphylococcus aureus(MRSA), Candida albicans, and Trychophyton rubrum.Methods: A broth microdilution method was used to determine the minimum inhibition concentration(MIC). Synergistic effects were evaluated at their own MIC using the checkerboard method and time-kill assay.Results: LME showed moderate antibacterial activity against MRSA with MIC value of 15.6 μg/mL, and exhibited strong antifungal activities against T. rubrum and C. albicans with MIC values of 7.8 and 3.9 μg/m L,respectively. The interaction of LME with the natural compound artocarpin against MRSA produced a synergy with fractional inhibitory concentration index(FICI) value of 0.31, while the combination of LME and clotrimazole exhibited synergy against C. albicans and T. rubrum with FICI values of 0.38 and 0.24, respectively. The time-kill assays confirmed that the compounds in combination enhanced their antimicrobial activities against the resistant microorganisms with different degrees.Conclusion: LME in combination with clotrimazole exhibited synergy effect against C. albicans and T.rubrum. In combination with artocarpin, it showed synergy effect against MRSA.
基金supported by the grants from Guangdong Natural Science Foundation(No.030313137)the Special Fund for Young Scientists of Third AffiliatedHospital of Sun Yat-sen University(No.A1286).
文摘Background:Trichophyton rubrum represents the most common infectious fungus responsible for dermatophytosis in human,but the mechanism involved is still not completely understood.An appropriate model constructed to simulate host infection is the prerequisite to study the pathogenesis of dernlatophytosis caused by T..rubrum.In this study,we intended to develop a new T.rubrum infection model in vitro,using the three-dimensional reconstructed epidermis-EpiSkin,and to pave the way for further investigation of the mechanisms involved in T.rubrum infection.Methods:The reconstructed human epidermis(RHE)was infected by inoculating low-dose(400 conidia)and high-dose(4000 conidia)T.rubrum conidia to optimize the infection dose.During the various periods after infection,the samples were processed for pathological examination and scanning electron microscopy(SEM)observation.Results:The histological analysis of RHE revealed a fully differentiated epidermis with a functional stratum corneum,which was analogous to the normal human epidermis.The results of hematoxylin and eosin staining and the periodic acid-Schiff staining showed that the infection dose of 400 conidia was in accord with the pathological characteristics of host dermatophytosis caused by T.rubrum.SEM observations further exhibited the process of 77 ruhrum infection in an intuitionistic way,Conclusions:We established the T.rubrum infection model on RHE in vitro successfully.It is a promising model fbr further investigation of the mechanisms involved in T.rubrum infection.
