Aim To evaluate the inhibitory effect of chitosan-cysteine conjugate onenzymatic degradation and hypogly-cemic enhancement effect of insulin. Methods Chitosan-cysteineconjugate was synthesized. The protective effect o...Aim To evaluate the inhibitory effect of chitosan-cysteine conjugate onenzymatic degradation and hypogly-cemic enhancement effect of insulin. Methods Chitosan-cysteineconjugate was synthesized. The protective effect of the conjugate against degradation of insulin byα-chymotrypsin and trypsin was evaluated in vitro. Insulin enteric- microspheres were prepared byusing O_1 /Q_2 emulsion solvent evaporation method. The hypoglycemic enhancement effect of theconjugate was studied by oral administration of insulin solution or enteric-microspheres to rats.Results The thiol group content of the synthesized conjugate was about 200 μmol·g^(-1) polymer,which showed a strong protective effect on insulin from enzymatic degradation in vitro. Almost allthe insulin incubated in a-chymotrypsin solution or trypsin solution without chitosan-cysteineconjugate was degraded entirely within 1 h and 5 h respectively, whereas above 75% of insulinremained in the same content of the enzymatic solution containing 4 mg·mL^(-1) conjugate. The drugloading of insulin enteric-microspheres was about 7% . In vivo experiment, chitosan-cysteineconjugate (85 μg·kg^(-1)) prolonged the hypoglycemic time of insulin solution orenteric-microspheres when administered simultaneously with the absorption enhancer SNAC. ConclusionChitosan-cysteine conjugate has a marked inhibitory effect on the enzymatic degradation of insulinin vitro, and it displays a significant hypoglycemic enhancement effect on insulin oral formulationin vivo.展开更多
Sea cucumber and cordyceps sinensis are used as both food and traditional medicines in Asia. This study was carried out in order to investigate the hpyerglycemic effect of a mixture of sea cucumber (Apostichopusjapon...Sea cucumber and cordyceps sinensis are used as both food and traditional medicines in Asia. This study was carried out in order to investigate the hpyerglycemic effect of a mixture of sea cucumber (Apostichopusjaponicas) and cordyceps sinensis (Cor-dyceps militaris) (SCC) in diabetic rat and explore the mechanism underlining such an effect. The diabetic model rat was induced with intraperitoneal injection of streptozotocin (STZ). The diabetic model rats were randomly divided into control group (0.9% NaC1), low dose group (300 mg SCC.(kg body weight)-1) and high dose group (1200 mg SCC (kg body weight)-l). Sodium chloride and SCC were intragastrically administered once a day for 35 d. Changes in fasting serum glucose and serum insulin content, oral glucose tolerance and liver and muscle glycogen content were routinely evaluated. Pancreas tissue and β-cells of islets were observed under both optical and transmission electronic microscope, respectively. The abundance of glucose metabolism-relating genes in gastrocnemius and epididymal adipose tissue was determined with either reverse transcription PCR (RT-PCR) or western blotting. Results showed that SCC significantly decreased fasting serum glucose content, improved glucose tolerance and increased serum insulin and glycogen content; repaired STZ-injured β-cells of diabetic rat, and increased the expression of phosphatidylinositol 3 kinase (PI(3)K), protein kinase B (PKB) and glucose transporter 4 (Glut4) encoding protein in both gastroenemius and adipose tissue, and Glut4 encoding gene in peripheral tissue. Our findings demonstrated that SCC exerted an anti-hyperglycemic effect by repairing β-cells and promoting insulin-mediated signal transduction pathway in insulin-sensitive gastrocnemius and adipose tissue.展开更多
Objective The aim of the present study was to investigate the hypoglycemic effects of silkworm extract(SE)on experimental type 2 diabetes mellitus(T2DM)rats.Methods SE was prepared by dissolving freeze-dried silkworm ...Objective The aim of the present study was to investigate the hypoglycemic effects of silkworm extract(SE)on experimental type 2 diabetes mellitus(T2DM)rats.Methods SE was prepared by dissolving freeze-dried silkworm powder in 70%(v/v)aqueous ethanol.T2DM rats were induced by feeding them a high fat diet and an intraperitoneal injection of streptozotocin(STZ).The blood glucose,free fatty acid(FFA),malondialdehyde(MDA),tumor necrosis factor alpha(TNF-α)and superoxide dismutase(SOD)levels were detected by enzyme-linked immunosorbent assay(ELISA).The quality of SE was controlled by high performance liquid chromatography(HPLC;Agilent 1260,Agilent,USA).Hematoxylin-eosin(HE)staining was performed for histological evaluation.Antibody expression was assessed via immunohistochemistry(IHC)staining.Results SE could improve insulin resistance and islet cell function by reducing FFA,MDA and TNF-αlevels and increasing SOD level.In addition,pancreatic HE staining analysis revealed that SE has a protective effect on isletβ-cells.Conclusions The present study indicates that SE has hypoglycemic as well as pancreatic protective effects in T2DM model rats.展开更多
Cassava peel has a lot of nutrients which can be utilized as fertilizer in agriculture. However, high cellulose contents may cause difficulty for organic digestion and slow down the nutrient absorption for plants. Thi...Cassava peel has a lot of nutrients which can be utilized as fertilizer in agriculture. However, high cellulose contents may cause difficulty for organic digestion and slow down the nutrient absorption for plants. This study aims to reach the microorganisms or their combination for biodegradating the cassava peel waste. The initial result shows that after 21 days the glucose concentration in all samples was the highest during experiment times. The reducing glucose produced in mg/mL by the selected bacteria was 9.32, higher than the selected fungie of 1.57 mg/mL. The percentage degradation of cassava peel weigh was the highest for fungi which was 52% of weigh, respectively. Meanwhile, bacteria only degradated about 31.6% after 4 weeks. However, the combination between bacteria and fungi provides the highest glucose concentration, 19.29 mg/mL and digests 62% of the mass cassava in experiment. This study suggests that biodegradation of agro-wastes in the environment to reduce biomass waste pollution is very promising.展开更多
Anoectochilus chapaensis Gagnep. (Orchidaceae), an indigenous and valuable Chinese folk medicine, has been widely used in China to treat diabetes. However, few reports are available about its constituents and activi...Anoectochilus chapaensis Gagnep. (Orchidaceae), an indigenous and valuable Chinese folk medicine, has been widely used in China to treat diabetes. However, few reports are available about its constituents and activity. The present experiment was conducted to investigate the active fractions from A. chapaensis in diabetic rat model induced by high-fat diet plus streptozotocin. The total EtOH extract from the whole herbs ofA. chapaensis, half of which was partitioned in sequence with petrol ether (PE), ethyl acetate (EtOAc), n-BuOH and H2O, thus yielding four fractions, all of them were orally administered with an identical dose amount to 4 g/kg dried crude herbs once a day for consecutive two weeks to further investigate the antihyperglycemic activity. The EtOAc fraction caused a significant fall in the non-fasting blood glucose level of diabetic rats from (402.66±82.26) to (226.26±62.10) mg/dl, which may be attributed to ameliorating insulin resistance, modulating the activity of enzymatic antioxidants, reducing the content of NO, etc. Much more intact β cells in the islets of Langerhans in EtOAc fraction-treated groups than the negative control were observed, which greatly supported the morphological and functional elucidation. The OGTT evidenced that EtOAc fraction could promote the endurance capacity of acute glucose increase in diabetic rats. The EtOAc fraction of A. chapaensis contains some hypoglycemic and antioxidant principles with the potential to be developed further for the treatment of diabetes specifically associated with an insulin resistance state.展开更多
文摘Aim To evaluate the inhibitory effect of chitosan-cysteine conjugate onenzymatic degradation and hypogly-cemic enhancement effect of insulin. Methods Chitosan-cysteineconjugate was synthesized. The protective effect of the conjugate against degradation of insulin byα-chymotrypsin and trypsin was evaluated in vitro. Insulin enteric- microspheres were prepared byusing O_1 /Q_2 emulsion solvent evaporation method. The hypoglycemic enhancement effect of theconjugate was studied by oral administration of insulin solution or enteric-microspheres to rats.Results The thiol group content of the synthesized conjugate was about 200 μmol·g^(-1) polymer,which showed a strong protective effect on insulin from enzymatic degradation in vitro. Almost allthe insulin incubated in a-chymotrypsin solution or trypsin solution without chitosan-cysteineconjugate was degraded entirely within 1 h and 5 h respectively, whereas above 75% of insulinremained in the same content of the enzymatic solution containing 4 mg·mL^(-1) conjugate. The drugloading of insulin enteric-microspheres was about 7% . In vivo experiment, chitosan-cysteineconjugate (85 μg·kg^(-1)) prolonged the hypoglycemic time of insulin solution orenteric-microspheres when administered simultaneously with the absorption enhancer SNAC. ConclusionChitosan-cysteine conjugate has a marked inhibitory effect on the enzymatic degradation of insulinin vitro, and it displays a significant hypoglycemic enhancement effect on insulin oral formulationin vivo.
基金supported by National Marine Public Welfare Scientific Research Project of China (No.201105029)the National Key Technology S&D Program (No.2012BAD33B07)Program for Changjiang Scholars and Innovative Research Team in University (IRT1188)
文摘Sea cucumber and cordyceps sinensis are used as both food and traditional medicines in Asia. This study was carried out in order to investigate the hpyerglycemic effect of a mixture of sea cucumber (Apostichopusjaponicas) and cordyceps sinensis (Cor-dyceps militaris) (SCC) in diabetic rat and explore the mechanism underlining such an effect. The diabetic model rat was induced with intraperitoneal injection of streptozotocin (STZ). The diabetic model rats were randomly divided into control group (0.9% NaC1), low dose group (300 mg SCC.(kg body weight)-1) and high dose group (1200 mg SCC (kg body weight)-l). Sodium chloride and SCC were intragastrically administered once a day for 35 d. Changes in fasting serum glucose and serum insulin content, oral glucose tolerance and liver and muscle glycogen content were routinely evaluated. Pancreas tissue and β-cells of islets were observed under both optical and transmission electronic microscope, respectively. The abundance of glucose metabolism-relating genes in gastrocnemius and epididymal adipose tissue was determined with either reverse transcription PCR (RT-PCR) or western blotting. Results showed that SCC significantly decreased fasting serum glucose content, improved glucose tolerance and increased serum insulin and glycogen content; repaired STZ-injured β-cells of diabetic rat, and increased the expression of phosphatidylinositol 3 kinase (PI(3)K), protein kinase B (PKB) and glucose transporter 4 (Glut4) encoding protein in both gastroenemius and adipose tissue, and Glut4 encoding gene in peripheral tissue. Our findings demonstrated that SCC exerted an anti-hyperglycemic effect by repairing β-cells and promoting insulin-mediated signal transduction pathway in insulin-sensitive gastrocnemius and adipose tissue.
基金supported by the Xiamen City Health and Family Planning Commission and the Xiamen Municipal Bureau of Science and Technologythe funding support from the Leading Project of Fujian. P. R. C. (No. 2019D018)the Xiamen Science and Technology Project (No. 3502Z20174058)。
文摘Objective The aim of the present study was to investigate the hypoglycemic effects of silkworm extract(SE)on experimental type 2 diabetes mellitus(T2DM)rats.Methods SE was prepared by dissolving freeze-dried silkworm powder in 70%(v/v)aqueous ethanol.T2DM rats were induced by feeding them a high fat diet and an intraperitoneal injection of streptozotocin(STZ).The blood glucose,free fatty acid(FFA),malondialdehyde(MDA),tumor necrosis factor alpha(TNF-α)and superoxide dismutase(SOD)levels were detected by enzyme-linked immunosorbent assay(ELISA).The quality of SE was controlled by high performance liquid chromatography(HPLC;Agilent 1260,Agilent,USA).Hematoxylin-eosin(HE)staining was performed for histological evaluation.Antibody expression was assessed via immunohistochemistry(IHC)staining.Results SE could improve insulin resistance and islet cell function by reducing FFA,MDA and TNF-αlevels and increasing SOD level.In addition,pancreatic HE staining analysis revealed that SE has a protective effect on isletβ-cells.Conclusions The present study indicates that SE has hypoglycemic as well as pancreatic protective effects in T2DM model rats.
文摘Cassava peel has a lot of nutrients which can be utilized as fertilizer in agriculture. However, high cellulose contents may cause difficulty for organic digestion and slow down the nutrient absorption for plants. This study aims to reach the microorganisms or their combination for biodegradating the cassava peel waste. The initial result shows that after 21 days the glucose concentration in all samples was the highest during experiment times. The reducing glucose produced in mg/mL by the selected bacteria was 9.32, higher than the selected fungie of 1.57 mg/mL. The percentage degradation of cassava peel weigh was the highest for fungi which was 52% of weigh, respectively. Meanwhile, bacteria only degradated about 31.6% after 4 weeks. However, the combination between bacteria and fungi provides the highest glucose concentration, 19.29 mg/mL and digests 62% of the mass cassava in experiment. This study suggests that biodegradation of agro-wastes in the environment to reduce biomass waste pollution is very promising.
基金National Natural Science Foundation of China(Grant No.81001628)Guangdong Natural Science Foundation(Grant No.S2013010014771)
文摘Anoectochilus chapaensis Gagnep. (Orchidaceae), an indigenous and valuable Chinese folk medicine, has been widely used in China to treat diabetes. However, few reports are available about its constituents and activity. The present experiment was conducted to investigate the active fractions from A. chapaensis in diabetic rat model induced by high-fat diet plus streptozotocin. The total EtOH extract from the whole herbs ofA. chapaensis, half of which was partitioned in sequence with petrol ether (PE), ethyl acetate (EtOAc), n-BuOH and H2O, thus yielding four fractions, all of them were orally administered with an identical dose amount to 4 g/kg dried crude herbs once a day for consecutive two weeks to further investigate the antihyperglycemic activity. The EtOAc fraction caused a significant fall in the non-fasting blood glucose level of diabetic rats from (402.66±82.26) to (226.26±62.10) mg/dl, which may be attributed to ameliorating insulin resistance, modulating the activity of enzymatic antioxidants, reducing the content of NO, etc. Much more intact β cells in the islets of Langerhans in EtOAc fraction-treated groups than the negative control were observed, which greatly supported the morphological and functional elucidation. The OGTT evidenced that EtOAc fraction could promote the endurance capacity of acute glucose increase in diabetic rats. The EtOAc fraction of A. chapaensis contains some hypoglycemic and antioxidant principles with the potential to be developed further for the treatment of diabetes specifically associated with an insulin resistance state.