Cyanea nozakii Kishinouye （C. nozakii）, a giant cnidarian of the class Scyphomedusae, order Semaeostomeae and family Cyaneidae, is widely distributed in the East China Sea, the Yellow Sea and the Bohai Sea, and is a...Cyanea nozakii Kishinouye （C. nozakii）, a giant cnidarian of the class Scyphomedusae, order Semaeostomeae and family Cyaneidae, is widely distributed in the East China Sea, the Yellow Sea and the Bohai Sea, and is abundant from late summer to early autumn. Venom produced by C. nozakii during mass agglomerations can contaminate seawater resulting in death of the halobios and seriously damage commercial fisheries. Swimmers and fishermen commonly suffer painful stings from this j ellyfish, resulting in local edema, tingling, breathing difficulties, depressed blood pressure and even death. Such effects arise from the complex mixture of biologically active molecules that make up jellyfish venom. In the present study, the hemolytic activity of venom from tentacles of C. nozakii and factors affecting its activity were assayed. The HUso （defined as the amount of protein required to lyse 50% of erythrocytes） of the venom against dove and chicken erythrocytes was 34 and 59 gg/mL, respectively. Carboxylmethyl chitosan and glycerol could increase hemolytic activity at concentrations greater than 0.06% and 0.2 mol/L, respectively.展开更多
Blooms of Phaeocystis globosa have been reported accountable for massive fi sh mortality worldwide.The toxigenic mechanisms of P.globosa,however,remain largely unclear due to the multiple structures and/or synergistic...Blooms of Phaeocystis globosa have been reported accountable for massive fi sh mortality worldwide.The toxigenic mechanisms of P.globosa,however,remain largely unclear due to the multiple structures and/or synergistic or antagonistic ef fects of hemolytic compounds.External stressors could lead to the regulation of photoprotective or antioxidative defense system,as well as the potential hemolytic activity.Therefore,the light-induced photosynthetic system,including the accessory photosynthetic growth,the relative electron transfer rate(ETR),photosynthetic e ffi ciency(F_(v)/F_(m)),quantum yield of photosystem II(Yield),together with the hemolytic activity of P.globosa were investigated under variable environmental conditions in the present study.Results confirmed that hemolytic activity of P.globosa was initiated by the light,but inhibited by low temperature(16℃),high light intensity(>100μmol/(m^(2)·s)),and iron-limited conditions.Interestingly,the hemolytic activity was not impacted by photosynthetic electron inhibitors(Diuron,atrazine,paraquat,and dibromothymoquinone),which signifi cantly inhibited the photosynthetic activity of P.globosa.The correlated response of hemolytic and photosynthetic activity of P.globosa under those environmental factors suggested that the hemolytic compounds of P.globosa would be involved in the photosynthetic process but not in the electron transfer chain of P.globosa.展开更多
Functionalized carbon nanotubes have already demonstrated great biocompatibility and potential for drug delivery.We have synthesized acid oxidized and non-covalently PEGlyated single-walled carbon nanotubes(SWNTs),whi...Functionalized carbon nanotubes have already demonstrated great biocompatibility and potential for drug delivery.We have synthesized acid oxidized and non-covalently PEGlyated single-walled carbon nanotubes(SWNTs),which were previously prepared for drug delivery purposes,and explored their potential for detoxification in the bloodstream.Our investigations of the binding of SWNTs to a pore-forming toxin pyolysin show that SWNTs prevented toxin-induced pore formation in the cell membrane of human red blood cells.Quantitative hemolysis assay and scanning electron microscopy were used to evaluate the inhibition of hemolytic activity of pyolysin.According to Raman spectroscopy data,human red blood cells,unlike HeLa cells,did not internalize oxidized SWNTs.Molecular modeling and circular dichroism measurements were used to predict the 3-D structure of pyolysin(domain 4)and its interaction with SWNTs.The tryptophan-rich hydrophobic motif in the membrane-binding domain of pyolysin,a common construct in a large family of cholesterol-dependent cytolysins,shows high affinity for SWNTs.展开更多
Two species of jellyfish, Cyanea nozakii Kishinouye and Nemopilema nomurai Kishinouye, have occurred offcoastal areas of the northeastern China Sea, Yellow Sea, and Bohai Sea in recent years. They influence marine eco...Two species of jellyfish, Cyanea nozakii Kishinouye and Nemopilema nomurai Kishinouye, have occurred offcoastal areas of the northeastern China Sea, Yellow Sea, and Bohai Sea in recent years. They influence marine ecosystem safety and fishery production, and also pose a risk to human health. The current study examined the hemolytic and cytotoxic activities of crude venoms extracted from the nematocysts of C. nozakii and N. nomurai. The results showed that there were more nematocysts on tentacles from C. nozakii than on tentacles of the same length from N. nomurai. The protein concentration per nematocyst extracted from N. nomurai was higher than that from C. nozakii. Both nematocyst venoms showed dose-and timedependent hemolytic activity on erythrocytes from chicken, pigeon, and sheep, with sheep erythrocytes being the most sensitive, with EC 50 values of 69.69 and 63.62 μg/m L over a 30-min exposure with N. nomurai and C. nozakii nematocyst venoms, respectively. A cytotoxic assay of both jellyfish venoms on A431 human epidermal carcinoma cells resulted in IC 50 values of 68.6 and 40.9 μg/mL after 24-h incubation, respectively, with venom from C. nozakii showing stronger cytotoxic activity than that from N. nomurai. The results of current study indicate that nematocyst venom from C. nozakii had stronger hemolytic and cytotoxic activities than that from N. nomurai and, thus, C. nozakii might be more harmful to the health of humans and other species than are N. nomurai when they appear in coastal waters.展开更多
Vibrio parahaemolyticus (VP) is one of the pathogenic vibrios endangering net-cage cultured Pseudosciaena crocea,Fennerpenaeus chinensis, and shellfish in coastal areas of China. Several types of hemolysins produced b...Vibrio parahaemolyticus (VP) is one of the pathogenic vibrios endangering net-cage cultured Pseudosciaena crocea,Fennerpenaeus chinensis, and shellfish in coastal areas of China. Several types of hemolysins produced by Vp have been characterized as major virulence factors.They are thermostable direct hemolysin (TDH),TDH-related hemolysin (TRH) and thermolabile hemolysin (TLH). In this study, we cloned tdh, trh, and tlh genes from the genome DNA of VP by polymerase chain reaction (PCR).We ligated the three genes into prokaryotic expression vector pET-28a (+),and transformed the recombinant plasmids into Es-cherichia coli BL21 (DE3). The expression of recombinant proteins was induced by isopropyl-β-D-thiogalacto-pyranoside (IPTG). The recombinant proteins were expressed in a form of inclusion bodies and thus purified with Ni-NTA affinity chromatography. Western blotting results showed that recombinant proteins,TDH, TRH and TLH, could be recognized by rabbit anti-VP serum. The three purified proteins were renatured by gradient dialysis.The renatured proteins exhibited hemolytic activity except for TLH in the presence of phosphatidylcholine. These results not only are helpful for better understanding these genes' functions under a single factor level, but also provide evidence for VP vaccine engineering.展开更多
In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel ...In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well.展开更多
The present work is the first report of the biochemical characterization of the venom from nematocysts of the jellyfish Rhopilema esculentum Kishinouye. The nematocysts were isolated by autolysis and centrifugation an...The present work is the first report of the biochemical characterization of the venom from nematocysts of the jellyfish Rhopilema esculentum Kishinouye. The nematocysts were isolated by autolysis and centrifugation and separated by flow cytometry. Four types of nematocysts were identified： mastigophores, euryteles, and atrichous and holotrichous isorhiza. SDS-PAGE and amino acid analyses demonstrated that most of the proteins in the nematocyst extract were between 10 kDa and 40 kDa, and that glutamic acid was the main amino acid. A hemolytic activity assay showed that the activity of the nematocyst venom （RNV） was strongest in Tris-HCl buffer （50 mmol/L, pH 7.8, 5% glycerol, 0.5 mmol/L EDTA, 0.1 mol/L NaC1）. The hemolytic activity was related to protein concentration and the HU50 against chicken erythrocytes was 0.91 μg/mL.展开更多
Artificial sweeteners are man-made substitutes for diet that needs low sugars or caloric intake. Recent studies have shown that AS consumption is possibly associated with metabolic disturbances and intestinal flora di...Artificial sweeteners are man-made substitutes for diet that needs low sugars or caloric intake. Recent studies have shown that AS consumption is possibly associated with metabolic disturbances and intestinal flora disturbances. Erythritol is a kind of 4-carbon sugar substitute in the form of sugar alcohol, which may contribute to the prevention of gingivitis by inhibit the biofilm formation of oral bacteria. Despite these studies, the data on how erythritol affects commensal flora causing pathogenicity to remain limited. In this study, microbiota (Escherichia coli) models were used to investigate the effects of different concentration of erythritol on the metabolism of bacteria, especially on Escherichia coli’s growth, transformation efficiency and hemolytic activity. The results showed that sweeteners decreased the bacteria’s ability to normally grow in higher concentration, and form biofilms to varying degrees. And the addition of erythritol in low concentration may have an effect of promote the growth of Escherichia coli. Habitual consumption of artificial sweeteners in the diet continues to increase was associated with the maintenance of micro-ecological equilibrium in gut.展开更多
Natural products from medicinal plants serve as an invaluable resource for drug discovery and development.However,low-abundance natural products are often understudied due to the challenges of obtaining sufficient qua...Natural products from medicinal plants serve as an invaluable resource for drug discovery and development.However,low-abundance natural products are often understudied due to the challenges of obtaining sufficient quantities for pharmacological testing in cells or animals.Additionally,their complex stereochemistry and functional groups make chemical synthesis and purification difficult.In this study,we showcased the power of biosynthetic approaches to explore these underexplored compounds,using the low-abundance polyphyllin trillin 6′-O-glucoside from Paris polyphylla as an example.We identified two trillin 6′-O-glucosyltransferases required for its biosynthesis and successfully reconstructed the entire pathway in Nicotiana benthamiana.We demonstrated that trillin 6′-O-glucoside exhibits anti-bacterial activity comparable to major polyphyllins like polyphyllinsⅠ,Ⅱ,and Ⅶ.Notably,it also showed much lower hemolytic activity,a common side effect of those major polyphyllins.Together,our study underscores the advantages of employing biosynthetic approaches to explore natural products that exist in low or trace abundances yet possess equally important pharmacological activities.展开更多
Objective:To isolate and characterize the saponin from Persian Gulf brittle star(Ophiocoma erinaceus)and to evaluate its hemolytic and cytotoxic potential. Methods:In an attempt to prepare saponin from brittle star,co...Objective:To isolate and characterize the saponin from Persian Gulf brittle star(Ophiocoma erinaceus)and to evaluate its hemolytic and cytotoxic potential. Methods:In an attempt to prepare saponin from brittle star,collected samples were minced and extracted with ethanol,dichloromethane,n-buthanol.Then,concentrated n-butanol extract were loaded on HP-20 resin and washed with dionized water,80%ethanol and 100%ethanol respectively.Subsequently,detection of saponin was performed by foaming property,fourier transform infrared spectroscopy and hemolytic analysis on thin layer chromatography.The cytotoxic activity on HeLa cells was evaluated through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide(MTT)assay and under invert microscopy.Results:The existence of saponin in Ophiocoma erinaceus were approved by phytochemical method.The presence of C-H bond,C-O-C and OH in fourier transform infrared spectrum of fraction 80%ethanol is characteristic feature in the many of saponin compounds.Hemolytic assay revealed HD_(50) value was 500μg/mL.MTT assay exhibited that saponin extracted in IC_(50) value of 25μg/mL inducsd potent cytotoxic activity against HeLa cells in 24 h and 12.5μg/mL in 48 h,meanwhile in lower concentration did not have considerable effect against HeLa cells.Conclusions:These findings showed that only 80%ethanol fraction Persian Gulf brittle star contained saponin like compounds with hemolytic activity which can be detected simply by phytochemical that can be appreciable for future anticancer research.展开更多
Objective To explore and analyze the reducing hemolytic effects of PEGylated puerarin (PEG-PUE) on erythrocytes induced by PUE in glucose-6-phosphate dehydrogenase (G6PD)-deficient rats. Methods The rat model with G6P...Objective To explore and analyze the reducing hemolytic effects of PEGylated puerarin (PEG-PUE) on erythrocytes induced by PUE in glucose-6-phosphate dehydrogenase (G6PD)-deficient rats. Methods The rat model with G6PD-deficiency was established via sc injecting 1% acetylphenyl-hydrazine. Then the G6PD-deficient erythrocyte suspension obtained from this rat model was used to evaluate the hemolytic effects of PUE and the reducing hemolytic effects of PEG-PUE via hemolytic activity and erythrocyte osmotic fragility assay. Results It was found that PUE could cause a serious hemolysis to the erythrocyte suspension with the increase of drug concentration and the prolongation of drug incubation time, the hemolytic rate of PUE was up to 40%, while the addition of PEG-PUE to the erythrocyte suspension revealed no significant hemolysis. Additionally, the result of erythrocyte osmotic fragility indicated that PEG-PUE exerted a slight effect on the erythrocyte membranes, and the NaCl concentration that induced 50% hemolysis (32 mmol/L) was about one-third PUE. Conclusion These results demonstrate that PEG-PUE could play a significant role in reducing the side effect of hemolysis induced by PUE. The low hemolytic activity of PEG-PUE makes it a favorable candidate for in vivo tests and PEG-PUE could also provide the useful insight for the further formulation development as an innovative drug.展开更多
Titanium dioxide(TiO_(2))nanoparticles(NPs)are one of the nanomaterials that have been widely used in cosmetics,pharmaceuticals and biomedical applications which include drug delivery,cancer treatment,biosensors,and g...Titanium dioxide(TiO_(2))nanoparticles(NPs)are one of the nanomaterials that have been widely used in cosmetics,pharmaceuticals and biomedical applications which include drug delivery,cancer treatment,biosensors,and genetic engineering.In this study,TiO_(2) NPs have been synthesized via hydrothermal method.The samples were calcinated at different temperatures such as 450 and 500℃.The structural,functional group,morphological and elemental composition analyses of the synthesized materials were conducted by various techniques such as X-ray diffraction(XRD),Fourier transform infrared(FTIR)analysis,Raman spectroscopy,field emission scanning electron microscopy(FESEM)and elemental dispersive X-ray(EDX)analysis.Various concentrations(25,50,75 and 100μg/mL)of synthesized TiO_(2) NPs were evaluated for their antimicrobial activity against the gram-positive and gram-negative bacteria.The maximum zone of inhibition was observed in the synthesized TiO_(2) NPs(100μg/mL)against Staphylococcus aureus(15 mm),Bacillus Subtilis(16 mm),Escherichia coli(18 mm)and Pseudomonas aeruginosa(17 mm),and the results indicated that the antimicrobial activities of the TiO_(2) NPs were tested against pathogenic bacteria.Overall,the results indicated that TiO_(2) nanoparticles could elicit the viability of lymphocytes at all investigated concentrations(50,100,250 and 500μg/mL).Hence,we concluded that the in-vitro hemolytic and antibacterial activities of TiO_(2) NPs,indicated the good potential biomedical applications.展开更多
In this study,kefir grains and kefir produced from contaminated grains were investigated in terms of food safety.For this aim,traditional kefir grains were collected from distinct parts of Turkey,and their pathogenici...In this study,kefir grains and kefir produced from contaminated grains were investigated in terms of food safety.For this aim,traditional kefir grains were collected from distinct parts of Turkey,and their pathogenicity was examined.Typical and non-typical colonies were isolated on Violet Red Bile Agar and identified for the first time at species level.Antibiotic resistance and hemolytic activity of the isolates were also determined.Coliform and pathogenic bacteria was found in 19 out of 30 kefir grains tested(63.33%).Although Hafnia paralvei was the predominant group,Klebsiella oxytoca,Citrobacter freundii,Serratia liquefaciens,and Escherichia coli were also identified among the 27 strains as the pathogenic bacteria.It was found that the bacterial count of kefir produced from two kefir grains containing pathogenic bacteria was 8.44 log CFU/mL and 8.20 log CFU/mL at the end of the 10th day.All isolates were sensitive to ciprofloxacin,nalidixic acid,meropenem,and ertapenem but resistant to ampicillin and vancomycin.Furthermore,all strains were found to beβ-hemolytic in that study.As a result,it was determined that traditionally produced kefir can be risky in terms of food safety due to contaminated kefir grains and this risk continues throughout consumption.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.41376004,41406152)the Key R&D program of Shandong Province(Nos.2015GSF115022,2015GSF115034)the China Postdoctoral Science Foundation(No.2013M531654)
文摘Cyanea nozakii Kishinouye （C. nozakii）, a giant cnidarian of the class Scyphomedusae, order Semaeostomeae and family Cyaneidae, is widely distributed in the East China Sea, the Yellow Sea and the Bohai Sea, and is abundant from late summer to early autumn. Venom produced by C. nozakii during mass agglomerations can contaminate seawater resulting in death of the halobios and seriously damage commercial fisheries. Swimmers and fishermen commonly suffer painful stings from this j ellyfish, resulting in local edema, tingling, breathing difficulties, depressed blood pressure and even death. Such effects arise from the complex mixture of biologically active molecules that make up jellyfish venom. In the present study, the hemolytic activity of venom from tentacles of C. nozakii and factors affecting its activity were assayed. The HUso （defined as the amount of protein required to lyse 50% of erythrocytes） of the venom against dove and chicken erythrocytes was 34 and 59 gg/mL, respectively. Carboxylmethyl chitosan and glycerol could increase hemolytic activity at concentrations greater than 0.06% and 0.2 mol/L, respectively.
基金Supported by the National Key R&D Program of China(Nos.2016YFC1402104,2019YFC1407900)the Special Foundation for National Science and Technology Basic Research Program of China(No.2018FY100201)+3 种基金the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(No.420LH004)the National Natural Science Foundation of China(No.41276091)the Program of Bureau of Science and Technology of Zhoushan(No.2019C8103)a Tang scholarship provided to Mengmeng TONG。
文摘Blooms of Phaeocystis globosa have been reported accountable for massive fi sh mortality worldwide.The toxigenic mechanisms of P.globosa,however,remain largely unclear due to the multiple structures and/or synergistic or antagonistic ef fects of hemolytic compounds.External stressors could lead to the regulation of photoprotective or antioxidative defense system,as well as the potential hemolytic activity.Therefore,the light-induced photosynthetic system,including the accessory photosynthetic growth,the relative electron transfer rate(ETR),photosynthetic e ffi ciency(F_(v)/F_(m)),quantum yield of photosystem II(Yield),together with the hemolytic activity of P.globosa were investigated under variable environmental conditions in the present study.Results confirmed that hemolytic activity of P.globosa was initiated by the light,but inhibited by low temperature(16℃),high light intensity(>100μmol/(m^(2)·s)),and iron-limited conditions.Interestingly,the hemolytic activity was not impacted by photosynthetic electron inhibitors(Diuron,atrazine,paraquat,and dibromothymoquinone),which signifi cantly inhibited the photosynthetic activity of P.globosa.The correlated response of hemolytic and photosynthetic activity of P.globosa under those environmental factors suggested that the hemolytic compounds of P.globosa would be involved in the photosynthetic process but not in the electron transfer chain of P.globosa.
基金by Dr.Tang’s startup fund from University of Waterloo and by grants from the Natural Science and Engineering Research Council(NSERC)of Canada.
文摘Functionalized carbon nanotubes have already demonstrated great biocompatibility and potential for drug delivery.We have synthesized acid oxidized and non-covalently PEGlyated single-walled carbon nanotubes(SWNTs),which were previously prepared for drug delivery purposes,and explored their potential for detoxification in the bloodstream.Our investigations of the binding of SWNTs to a pore-forming toxin pyolysin show that SWNTs prevented toxin-induced pore formation in the cell membrane of human red blood cells.Quantitative hemolysis assay and scanning electron microscopy were used to evaluate the inhibition of hemolytic activity of pyolysin.According to Raman spectroscopy data,human red blood cells,unlike HeLa cells,did not internalize oxidized SWNTs.Molecular modeling and circular dichroism measurements were used to predict the 3-D structure of pyolysin(domain 4)and its interaction with SWNTs.The tryptophan-rich hydrophobic motif in the membrane-binding domain of pyolysin,a common construct in a large family of cholesterol-dependent cytolysins,shows high affinity for SWNTs.
基金Supported by the NSFC-Shandong Joint Funds Project(No.U1606404)the National Natural Science Foundation of China(No.41606140)the National Special Research Fund for Non-Profit Marine Sector(No.201005018)
文摘Two species of jellyfish, Cyanea nozakii Kishinouye and Nemopilema nomurai Kishinouye, have occurred offcoastal areas of the northeastern China Sea, Yellow Sea, and Bohai Sea in recent years. They influence marine ecosystem safety and fishery production, and also pose a risk to human health. The current study examined the hemolytic and cytotoxic activities of crude venoms extracted from the nematocysts of C. nozakii and N. nomurai. The results showed that there were more nematocysts on tentacles from C. nozakii than on tentacles of the same length from N. nomurai. The protein concentration per nematocyst extracted from N. nomurai was higher than that from C. nozakii. Both nematocyst venoms showed dose-and timedependent hemolytic activity on erythrocytes from chicken, pigeon, and sheep, with sheep erythrocytes being the most sensitive, with EC 50 values of 69.69 and 63.62 μg/m L over a 30-min exposure with N. nomurai and C. nozakii nematocyst venoms, respectively. A cytotoxic assay of both jellyfish venoms on A431 human epidermal carcinoma cells resulted in IC 50 values of 68.6 and 40.9 μg/mL after 24-h incubation, respectively, with venom from C. nozakii showing stronger cytotoxic activity than that from N. nomurai. The results of current study indicate that nematocyst venom from C. nozakii had stronger hemolytic and cytotoxic activities than that from N. nomurai and, thus, C. nozakii might be more harmful to the health of humans and other species than are N. nomurai when they appear in coastal waters.
基金supported by National High Technology Research and Development Program of China grant(2006AA1003062006AA100307)
文摘Vibrio parahaemolyticus (VP) is one of the pathogenic vibrios endangering net-cage cultured Pseudosciaena crocea,Fennerpenaeus chinensis, and shellfish in coastal areas of China. Several types of hemolysins produced by Vp have been characterized as major virulence factors.They are thermostable direct hemolysin (TDH),TDH-related hemolysin (TRH) and thermolabile hemolysin (TLH). In this study, we cloned tdh, trh, and tlh genes from the genome DNA of VP by polymerase chain reaction (PCR).We ligated the three genes into prokaryotic expression vector pET-28a (+),and transformed the recombinant plasmids into Es-cherichia coli BL21 (DE3). The expression of recombinant proteins was induced by isopropyl-β-D-thiogalacto-pyranoside (IPTG). The recombinant proteins were expressed in a form of inclusion bodies and thus purified with Ni-NTA affinity chromatography. Western blotting results showed that recombinant proteins,TDH, TRH and TLH, could be recognized by rabbit anti-VP serum. The three purified proteins were renatured by gradient dialysis.The renatured proteins exhibited hemolytic activity except for TLH in the presence of phosphatidylcholine. These results not only are helpful for better understanding these genes' functions under a single factor level, but also provide evidence for VP vaccine engineering.
基金Supported by the Award Foundation of Scientific Research for Excellent Young and Middle-age Scientist of Shandong Province (No. 2006BS07003)the Knowledge Innovation Project of Chinese Academy of Sciences (KZCX2-YW-R-104)
文摘In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well.
基金Supported by Qingdao Science and Technology Project (No. 08-1-3-51- JCH)the Award Foundation of Scientific Research for Excellent Young and Middle-Age Scientist of Shandong Province (No.2006BS 07003)
文摘The present work is the first report of the biochemical characterization of the venom from nematocysts of the jellyfish Rhopilema esculentum Kishinouye. The nematocysts were isolated by autolysis and centrifugation and separated by flow cytometry. Four types of nematocysts were identified： mastigophores, euryteles, and atrichous and holotrichous isorhiza. SDS-PAGE and amino acid analyses demonstrated that most of the proteins in the nematocyst extract were between 10 kDa and 40 kDa, and that glutamic acid was the main amino acid. A hemolytic activity assay showed that the activity of the nematocyst venom （RNV） was strongest in Tris-HCl buffer （50 mmol/L, pH 7.8, 5% glycerol, 0.5 mmol/L EDTA, 0.1 mol/L NaC1）. The hemolytic activity was related to protein concentration and the HU50 against chicken erythrocytes was 0.91 μg/mL.
文摘Artificial sweeteners are man-made substitutes for diet that needs low sugars or caloric intake. Recent studies have shown that AS consumption is possibly associated with metabolic disturbances and intestinal flora disturbances. Erythritol is a kind of 4-carbon sugar substitute in the form of sugar alcohol, which may contribute to the prevention of gingivitis by inhibit the biofilm formation of oral bacteria. Despite these studies, the data on how erythritol affects commensal flora causing pathogenicity to remain limited. In this study, microbiota (Escherichia coli) models were used to investigate the effects of different concentration of erythritol on the metabolism of bacteria, especially on Escherichia coli’s growth, transformation efficiency and hemolytic activity. The results showed that sweeteners decreased the bacteria’s ability to normally grow in higher concentration, and form biofilms to varying degrees. And the addition of erythritol in low concentration may have an effect of promote the growth of Escherichia coli. Habitual consumption of artificial sweeteners in the diet continues to increase was associated with the maintenance of micro-ecological equilibrium in gut.
基金supported by the National Key Research and Development Program of China(2020YFA0908000)CAMS Innovation Fund(CI2023E002,CI2021A05101,CI2021B014,CI2021A05104 and CI2023E005TS06)+1 种基金Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CI2023D008)Fundamental Research Funds for the Central Public Welfare Research Institutes(ZZ14-YQ-051,ZZ14-YQ-052,ZZ17-YQ-047,ZZ15-ND-10,ZZ16-ND-10-12,ZZ17-ND-10-02,ZZ17-ND-10-16 and ZZ16-XRZ-103)。
文摘Natural products from medicinal plants serve as an invaluable resource for drug discovery and development.However,low-abundance natural products are often understudied due to the challenges of obtaining sufficient quantities for pharmacological testing in cells or animals.Additionally,their complex stereochemistry and functional groups make chemical synthesis and purification difficult.In this study,we showcased the power of biosynthetic approaches to explore these underexplored compounds,using the low-abundance polyphyllin trillin 6′-O-glucoside from Paris polyphylla as an example.We identified two trillin 6′-O-glucosyltransferases required for its biosynthesis and successfully reconstructed the entire pathway in Nicotiana benthamiana.We demonstrated that trillin 6′-O-glucoside exhibits anti-bacterial activity comparable to major polyphyllins like polyphyllinsⅠ,Ⅱ,and Ⅶ.Notably,it also showed much lower hemolytic activity,a common side effect of those major polyphyllins.Together,our study underscores the advantages of employing biosynthetic approaches to explore natural products that exist in low or trace abundances yet possess equally important pharmacological activities.
文摘Objective:To isolate and characterize the saponin from Persian Gulf brittle star(Ophiocoma erinaceus)and to evaluate its hemolytic and cytotoxic potential. Methods:In an attempt to prepare saponin from brittle star,collected samples were minced and extracted with ethanol,dichloromethane,n-buthanol.Then,concentrated n-butanol extract were loaded on HP-20 resin and washed with dionized water,80%ethanol and 100%ethanol respectively.Subsequently,detection of saponin was performed by foaming property,fourier transform infrared spectroscopy and hemolytic analysis on thin layer chromatography.The cytotoxic activity on HeLa cells was evaluated through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide(MTT)assay and under invert microscopy.Results:The existence of saponin in Ophiocoma erinaceus were approved by phytochemical method.The presence of C-H bond,C-O-C and OH in fourier transform infrared spectrum of fraction 80%ethanol is characteristic feature in the many of saponin compounds.Hemolytic assay revealed HD_(50) value was 500μg/mL.MTT assay exhibited that saponin extracted in IC_(50) value of 25μg/mL inducsd potent cytotoxic activity against HeLa cells in 24 h and 12.5μg/mL in 48 h,meanwhile in lower concentration did not have considerable effect against HeLa cells.Conclusions:These findings showed that only 80%ethanol fraction Persian Gulf brittle star contained saponin like compounds with hemolytic activity which can be detected simply by phytochemical that can be appreciable for future anticancer research.
基金Ministry of National Science and Technology Support Program "Twelfth Five-Year Plan" (2011BAI01B08)
文摘Objective To explore and analyze the reducing hemolytic effects of PEGylated puerarin (PEG-PUE) on erythrocytes induced by PUE in glucose-6-phosphate dehydrogenase (G6PD)-deficient rats. Methods The rat model with G6PD-deficiency was established via sc injecting 1% acetylphenyl-hydrazine. Then the G6PD-deficient erythrocyte suspension obtained from this rat model was used to evaluate the hemolytic effects of PUE and the reducing hemolytic effects of PEG-PUE via hemolytic activity and erythrocyte osmotic fragility assay. Results It was found that PUE could cause a serious hemolysis to the erythrocyte suspension with the increase of drug concentration and the prolongation of drug incubation time, the hemolytic rate of PUE was up to 40%, while the addition of PEG-PUE to the erythrocyte suspension revealed no significant hemolysis. Additionally, the result of erythrocyte osmotic fragility indicated that PEG-PUE exerted a slight effect on the erythrocyte membranes, and the NaCl concentration that induced 50% hemolysis (32 mmol/L) was about one-third PUE. Conclusion These results demonstrate that PEG-PUE could play a significant role in reducing the side effect of hemolysis induced by PUE. The low hemolytic activity of PEG-PUE makes it a favorable candidate for in vivo tests and PEG-PUE could also provide the useful insight for the further formulation development as an innovative drug.
基金Funding was provided by the Department of Science and Technology(DST)PURSE-Phase-Ⅱ.
文摘Titanium dioxide(TiO_(2))nanoparticles(NPs)are one of the nanomaterials that have been widely used in cosmetics,pharmaceuticals and biomedical applications which include drug delivery,cancer treatment,biosensors,and genetic engineering.In this study,TiO_(2) NPs have been synthesized via hydrothermal method.The samples were calcinated at different temperatures such as 450 and 500℃.The structural,functional group,morphological and elemental composition analyses of the synthesized materials were conducted by various techniques such as X-ray diffraction(XRD),Fourier transform infrared(FTIR)analysis,Raman spectroscopy,field emission scanning electron microscopy(FESEM)and elemental dispersive X-ray(EDX)analysis.Various concentrations(25,50,75 and 100μg/mL)of synthesized TiO_(2) NPs were evaluated for their antimicrobial activity against the gram-positive and gram-negative bacteria.The maximum zone of inhibition was observed in the synthesized TiO_(2) NPs(100μg/mL)against Staphylococcus aureus(15 mm),Bacillus Subtilis(16 mm),Escherichia coli(18 mm)and Pseudomonas aeruginosa(17 mm),and the results indicated that the antimicrobial activities of the TiO_(2) NPs were tested against pathogenic bacteria.Overall,the results indicated that TiO_(2) nanoparticles could elicit the viability of lymphocytes at all investigated concentrations(50,100,250 and 500μg/mL).Hence,we concluded that the in-vitro hemolytic and antibacterial activities of TiO_(2) NPs,indicated the good potential biomedical applications.
文摘In this study,kefir grains and kefir produced from contaminated grains were investigated in terms of food safety.For this aim,traditional kefir grains were collected from distinct parts of Turkey,and their pathogenicity was examined.Typical and non-typical colonies were isolated on Violet Red Bile Agar and identified for the first time at species level.Antibiotic resistance and hemolytic activity of the isolates were also determined.Coliform and pathogenic bacteria was found in 19 out of 30 kefir grains tested(63.33%).Although Hafnia paralvei was the predominant group,Klebsiella oxytoca,Citrobacter freundii,Serratia liquefaciens,and Escherichia coli were also identified among the 27 strains as the pathogenic bacteria.It was found that the bacterial count of kefir produced from two kefir grains containing pathogenic bacteria was 8.44 log CFU/mL and 8.20 log CFU/mL at the end of the 10th day.All isolates were sensitive to ciprofloxacin,nalidixic acid,meropenem,and ertapenem but resistant to ampicillin and vancomycin.Furthermore,all strains were found to beβ-hemolytic in that study.As a result,it was determined that traditionally produced kefir can be risky in terms of food safety due to contaminated kefir grains and this risk continues throughout consumption.
