Objective： To explore the effects and mechanisms of poly （ADP-ribose） polymerase （PARP） inhibitor 3-aminobenzamide on nerve lesions in streptozotocin-diabetic rats. Methods： Experimental rats were divided into n...Objective： To explore the effects and mechanisms of poly （ADP-ribose） polymerase （PARP） inhibitor 3-aminobenzamide on nerve lesions in streptozotocin-diabetic rats. Methods： Experimental rats were divided into normal control group（NC group）, diabetic control group （DC group ）and diabetic group treated with 3-aminobenzamide （DT group ）.Nerve conduction velocity （NCV）, serum superoxide dismutase （SOD） activity and serum malondialdehyde （MDA） concentration,phosphocreatine （Pcr） ,creatine （Cr） concentration in sciatic nerves were evaluated after 4 weeks. Results： SOD,Pcr activity,and NCV were higher （P 〈 0.05） and MDA concentration were significantly lower in DT group, compared with DC group （P 〈 0.01 ）. Meanwhile, ATP and Cr in sciatic nerves were similar in DT group, compared with DC group （P 〉 0.05）. Conclusion： 3-aminobenzamide could alleviate the established functional and metabolic abnormalities of early DPN in the streptozotocin-induced diabetic rat models,which pro- vided a novel approach for prevention and treatment of diabetic neuropathy.展开更多
Objective:To achieve a primary pharmacological screening contained in the aqueous extract of Berberis vulgaris(B.vulgaris) and to examine the hypoglycaemic effect and biochemical parameters of aqueous and saponins ext...Objective:To achieve a primary pharmacological screening contained in the aqueous extract of Berberis vulgaris(B.vulgaris) and to examine the hypoglycaemic effect and biochemical parameters of aqueous and saponins extract on groups of rats rendered diabetic by injection of streptozotocin.Methods:The phytochemicol tests to detect the presence of different compounds were based on the visual observation of color change or formation of precipitate after the addition of specific reagents.Diabetes was induced in rats by intraperitoneal(i.p.) injection of streptozotocin(STZ) at a dose of 65 mg/kg bw.The fasting blood glucose levels were estimated by glucose oxidase-peroxidase reactive strips(Dextrostix,Bayer Diagnostics).Blood samples were taken by cutting the tip of the tail.Serum cholesterol and serum triglycerides were estimated by enzymatic DHBS colorimetric method.Results:Administration of 62.5 and 2S.0 mg/kg of saponins and aqueous extract respectively in normal rats group shows a significant hypoglycemic activity(32.33%and 40.17%respectively) during the first week.However,diabetic group treated with saponin extract produced a maximum fall of 73.1%and 76.03%at day 1 and day 21 compared to the diabetics control.Also,blood glucose levels of the diabetic rats treated with aqueous extract showed decrease of 78.79%on the first day and the effect remains roughly constant during 3 week. Both extracts also declined significantly biochemical parameters(20.77%-49.00%).The control in the loss of body weight was observed in treated diabetic rats as compared to diabetic controls. Conclusions:These results demonstrated significant antidiabetic effects and showed that serum cholesterol and serum triglycerides levels were decreased,significantly,consequently this plant might be of value in diabetes treatment.展开更多
Objective:To study the antidiabetic activity of Gynura procumbens(G.procumbens)used in the traditional management of diabetes in Southern Asia.Methods:G.procumbens leaves were extracted sequentially with graded percen...Objective:To study the antidiabetic activity of Gynura procumbens(G.procumbens)used in the traditional management of diabetes in Southern Asia.Methods:G.procumbens leaves were extracted sequentially with graded percentage of ethanol in water(95%,75%,50%,25%and 0%),and the extracts were tested for antidiabetic activity using acute(7 h),subcutaneous glucose tolerance test and sub-chronic(14 d)test in non-diabetic and streptozotocin-induced diabetic rats.The extracts were further subjected to phytochemical studies.Results:In acute dose(1 g/kg),the extracts significantly lowered fasting blood glucose(FBG)in streptozotocin-induced diabetic rats(P<0.05).However,the FBG-lowering effect of the 25%extract compared to the other extracts,was rapid(47%after 2 h)and the highest:53%,53%and 60%in the 3rd,5th,and 7th h,respectively(P<0.05),comparable only to the effect of metformin.Furthermore,the extracts suppressed peak FBG in subcutaneous glucose tolerance test,but only the 0%and 25%extracts,and metformin sustained the decrease until the 90th min(P<0.05).Moreover,in the 14 days study,the 25%extract exerted the highest FBG-lowering effect,namely 49.38%and 65.43%on days 7 and 14,respectively(P<0.05),similar to the effect of metformin(46.26%and 65.42%).Total flavanoid and phenolic contents in the extracts were found to decrease with increase in polarity of extraction solvents.The composition of reference compounds(chlorogenic acid,rutin,astragalin and kaempferol-3-O-nrtinoside)followed a similar trend.Conclusions:G.procumbens contains antidiabetic principles,most extracted in 25%ethanol.Interaction among active components appears to determine the antidiabetic efficacy,achieved likely by a metformin-like mechanism.展开更多
Objective To evaluate the effect of low-dose insulin [1 U/(kg·d)] in combination with selenium [180 g/(kg·d)] on general physiological parameters and glucose transporter (GLUT4) level in skeletal muscle of s...Objective To evaluate the effect of low-dose insulin [1 U/(kg·d)] in combination with selenium [180 g/(kg·d)] on general physiological parameters and glucose transporter (GLUT4) level in skeletal muscle of streptozotocin (STZ)-induced diabetic rats. Methods Diabetic rats were treated with insulin,selenium,and insulin and selenium in combination for four weeks. The level of blood glucose was determined using One Touch SureStep Blood Glucose meter and the level of GLUT4 in skeletal muscle was examined by immunoblotting and immunohistochemistry. Results Our data showed that insulin in combination with selenium could significantly lower blood glucose level and restore the disturbance in GLUT4 level in skeletal muscle. Treatment with insulin was only partially effective in restoring diabetic alterations. Conclusion It can be concluded that there is a synergistic action between insulin and selenium,and that treatment of diabetic rats with combined doses of insulin and selenium is effective in the normalization of blood glucose level and correction of altered GLUT4 distribution in skeletal muscle of diabetic rats.展开更多
Objective:To investigate the antidiabetic activity of Ocimum tenuiflorum L.(O.tenuiflorum) leaves used in the traditional medicine management of diabetes in Malaysia.Methods:O.tenuiflorum leaves were extracted sequent...Objective:To investigate the antidiabetic activity of Ocimum tenuiflorum L.(O.tenuiflorum) leaves used in the traditional medicine management of diabetes in Malaysia.Methods:O.tenuiflorum leaves were extracted sequentially with hexane,chloroform,ethyl acetate,methanol,and water.The extracts were evaluated in terms of antidiabetic activity by using acute,subcutaneous glucose tolerance,and sub-chronic tests in streptozotocininduced diabetic rats.The extracts were also subjected to phytochemical analyses.Results:With an acute dose(1 g/kg),the methanol extracts showed significant reduction(31%) in fasting blood glucose(FBG) of the streptozotocin-induced diabetic rats.The FBG-decreasing effect of ethyl acetate extract was more rapid than that of the other extracts;the decreasing rates were 20%after 2 h,21%after 3 h,and 8%after 5 and 7 h.After 7 h(31%),the effect of methanol extract on FBG was significantly lower than that of metformin.In the subcutaneous glucose tolerance test,only methanol and hexane extracts showed the similarity of metformin in diabetic rats.After 14 days,the effects of these extracts were similar to those of metformin(63.33%).The total flavonoid and phenolic contents of extracts decreased as the polarity of the extraction solvent increased.Conclusions:The results obtained provide support for a possible use of O.tenuiflorum leaves in managing hyperglycemia and preventing the complications associated with it in type 2 diabetic.展开更多
Objective: To study the antidiabetic and antioxidant activities of nipa palm vinegar(NPV) used in traditional Malay medicine for treating diabetes. Methods: NPV was extracted using liquid-liquid extraction method and ...Objective: To study the antidiabetic and antioxidant activities of nipa palm vinegar(NPV) used in traditional Malay medicine for treating diabetes. Methods: NPV was extracted using liquid-liquid extraction method and the obtained samples were subjected to antidiabetic studies using normal and streptozotocin-induced diabetic rat models whereas antidoxidant activities were investigated via in vitro antioxidant tests namely 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid free radicals scavenging activities and the reducing power assay. Results: Single administration of NPV and its extracts were not effective in both normal and diabetic rats. In intraperitoneal glucose tolerance test, NPV and its aqueous extract showed significant blood glucose lowering effect. In the sub-acute study, compared with the diabetic control, aqueous extract of NPV showed the most notable blood glucose lowering effect(56.6%) and a significant improvement in serum insulin levels(79.8%, P<0.05). To assess NPV's antioxidant activity, three in vitro antioxidant tests were employed: 2,2-diphenyl-1-picryhydrazyl and 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid free radical-scavenging assays, and the reducing power assay. Ethyl acetate extract had the greatest antioxidant potential and content of phenolic and flavonoid compounds. A linear positive correlation between the antioxidant parameters was observed. Chemical profiling analysis of aqueous extract of NPV revealed the presence of acetic acid(35.25%), the main active constituent which significantly contributed to the observed antidiabetic activity. Conclusions: Aqueous extract of NPV possesses antihyperglycaemic activities comparable to the metformin, while the ethyl acetate extract precipitated significant antioxidant effects attributable to its high phenolic content. These findings suggest that antioxidant compounds of NPV do not contribute much towards the overall observed antidiabetic effect.展开更多
The loss of balance between the antagonistic activities of angiotensin II AT1/AT2 receptors has been impli-cated as a major mediator in the development of hypertension and progressive nephropathy in expe-rimental diab...The loss of balance between the antagonistic activities of angiotensin II AT1/AT2 receptors has been impli-cated as a major mediator in the development of hypertension and progressive nephropathy in expe-rimental diabetes. The present study was designed to investigate the potential of garlic to modulate the level of expression of the AT2 receptor in the adrenal and renal tissues of diabetic rats. Three groups of rats were studied after 8 weeks following diabetes induction: normal, streptozotocin-induced diabetic (control diabetic), and garlic-treated diabetic rats. A polyclonal antibody of proven specificity to the AT2 receptor, as verified by Western blotting and emplo- yed in immunohistochemical assays, indicated that compared to normal rats, the highest adrenocortical AT2 receptor expression was significantly shifted from the zona glomerulosa to the zona fasciculate/ reticularis, and was significantly reduced in adrenomedul- lary chromaffin cells of control diabetic rats. In the kidney, STZ treatments were associated with a signi- ficant decrease in AT2 receptor expression throughout glomeruli and all cortical and medullary tubular segments. Compared to control diabetic rats, the labeling of the AT2 receptor in the garlic-treated diabetic group was restored among adrenocortical zona glomerulosa cells and adrenomedullary chromaffin cells and significantly reduced in the zona fasiculata, and was also restored in glomeruli and throughout renal cortical and medullary tubular segments, to le- vels comparable to those observed in normal rats. The capacity of garlic to modulate diabetes-induced AT2 receptor down-regulation may be implicated in restoring the recuperative processes mediated by AT2 receptors, which interfere with the development of hypertension and nephropathy.展开更多
Leaf and root extracts of Smallanthus sonchifolius (yacon), have antihyper-glycemic activity and antioxidant properties. The present study aims to compare the in vivo hepatic antioxidant activity of hydroalcoholic ext...Leaf and root extracts of Smallanthus sonchifolius (yacon), have antihyper-glycemic activity and antioxidant properties. The present study aims to compare the in vivo hepatic antioxidant activity of hydroalcoholic extracts of yacon leaves and roots in rats with streptozotocin-induced diabetes in terms of their in vitro antioxidant capacity. Rats were treated during 14 days with 1060 mg·Kg<sup>-1</sup> root extract or 400 mg·Kg<sup>-</sup><sup>1</sup> leaf extract. The latter was richer in phenolics and possessed a much higher in vitro antioxidant activity. Both extracts prevented hyperglycemia in diabetic rats. The liver of diabetic rats presented increased levels of protein carbonyls and ROS and decreased activities of antioxidant enzymes. Treatment with both root and leaf extracts restored the protein carbonyl levels to normality. The root extract also restored the ROS levels to normality, but the leaf extract was not effective. The root extract was also more effective in restoring the activity of at least two important antioxidant enzymes (glucose 6-phosphate dehydrogenase and glutathione peroxidase). In terms of the antioxidant load (which was 17 times lower in the root extract treatment), the in vivo action of the root extract was more effective than the leaf extract in reducing the hepatic oxidative stress that accompanies diabetes.展开更多
文摘Objective： To explore the effects and mechanisms of poly （ADP-ribose） polymerase （PARP） inhibitor 3-aminobenzamide on nerve lesions in streptozotocin-diabetic rats. Methods： Experimental rats were divided into normal control group（NC group）, diabetic control group （DC group ）and diabetic group treated with 3-aminobenzamide （DT group ）.Nerve conduction velocity （NCV）, serum superoxide dismutase （SOD） activity and serum malondialdehyde （MDA） concentration,phosphocreatine （Pcr） ,creatine （Cr） concentration in sciatic nerves were evaluated after 4 weeks. Results： SOD,Pcr activity,and NCV were higher （P 〈 0.05） and MDA concentration were significantly lower in DT group, compared with DC group （P 〈 0.01 ）. Meanwhile, ATP and Cr in sciatic nerves were similar in DT group, compared with DC group （P 〉 0.05）. Conclusion： 3-aminobenzamide could alleviate the established functional and metabolic abnormalities of early DPN in the streptozotocin-induced diabetic rat models,which pro- vided a novel approach for prevention and treatment of diabetic neuropathy.
文摘Objective:To achieve a primary pharmacological screening contained in the aqueous extract of Berberis vulgaris(B.vulgaris) and to examine the hypoglycaemic effect and biochemical parameters of aqueous and saponins extract on groups of rats rendered diabetic by injection of streptozotocin.Methods:The phytochemicol tests to detect the presence of different compounds were based on the visual observation of color change or formation of precipitate after the addition of specific reagents.Diabetes was induced in rats by intraperitoneal(i.p.) injection of streptozotocin(STZ) at a dose of 65 mg/kg bw.The fasting blood glucose levels were estimated by glucose oxidase-peroxidase reactive strips(Dextrostix,Bayer Diagnostics).Blood samples were taken by cutting the tip of the tail.Serum cholesterol and serum triglycerides were estimated by enzymatic DHBS colorimetric method.Results:Administration of 62.5 and 2S.0 mg/kg of saponins and aqueous extract respectively in normal rats group shows a significant hypoglycemic activity(32.33%and 40.17%respectively) during the first week.However,diabetic group treated with saponin extract produced a maximum fall of 73.1%and 76.03%at day 1 and day 21 compared to the diabetics control.Also,blood glucose levels of the diabetic rats treated with aqueous extract showed decrease of 78.79%on the first day and the effect remains roughly constant during 3 week. Both extracts also declined significantly biochemical parameters(20.77%-49.00%).The control in the loss of body weight was observed in treated diabetic rats as compared to diabetic controls. Conclusions:These results demonstrated significant antidiabetic effects and showed that serum cholesterol and serum triglycerides levels were decreased,significantly,consequently this plant might be of value in diabetes treatment.
基金Supported by a grant from the Ministry of Agriculture and Agrobased Industries,Malaysia(Grant No.304/PFARMASl/650581/K123)
文摘Objective:To study the antidiabetic activity of Gynura procumbens(G.procumbens)used in the traditional management of diabetes in Southern Asia.Methods:G.procumbens leaves were extracted sequentially with graded percentage of ethanol in water(95%,75%,50%,25%and 0%),and the extracts were tested for antidiabetic activity using acute(7 h),subcutaneous glucose tolerance test and sub-chronic(14 d)test in non-diabetic and streptozotocin-induced diabetic rats.The extracts were further subjected to phytochemical studies.Results:In acute dose(1 g/kg),the extracts significantly lowered fasting blood glucose(FBG)in streptozotocin-induced diabetic rats(P<0.05).However,the FBG-lowering effect of the 25%extract compared to the other extracts,was rapid(47%after 2 h)and the highest:53%,53%and 60%in the 3rd,5th,and 7th h,respectively(P<0.05),comparable only to the effect of metformin.Furthermore,the extracts suppressed peak FBG in subcutaneous glucose tolerance test,but only the 0%and 25%extracts,and metformin sustained the decrease until the 90th min(P<0.05).Moreover,in the 14 days study,the 25%extract exerted the highest FBG-lowering effect,namely 49.38%and 65.43%on days 7 and 14,respectively(P<0.05),similar to the effect of metformin(46.26%and 65.42%).Total flavanoid and phenolic contents in the extracts were found to decrease with increase in polarity of extraction solvents.The composition of reference compounds(chlorogenic acid,rutin,astragalin and kaempferol-3-O-nrtinoside)followed a similar trend.Conclusions:G.procumbens contains antidiabetic principles,most extracted in 25%ethanol.Interaction among active components appears to determine the antidiabetic efficacy,achieved likely by a metformin-like mechanism.
基金supported by the National Basic Research Program of China (973Program) ( No.2007CB512005)the National Natural Science Foundation of China (No.30770785)+1 种基金the Cultivation Fund of the Key Scientific and Technological Innovation Pro-ject of the Ministry of Education of China (No.705045)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20050698012)
文摘Objective To evaluate the effect of low-dose insulin [1 U/(kg·d)] in combination with selenium [180 g/(kg·d)] on general physiological parameters and glucose transporter (GLUT4) level in skeletal muscle of streptozotocin (STZ)-induced diabetic rats. Methods Diabetic rats were treated with insulin,selenium,and insulin and selenium in combination for four weeks. The level of blood glucose was determined using One Touch SureStep Blood Glucose meter and the level of GLUT4 in skeletal muscle was examined by immunoblotting and immunohistochemistry. Results Our data showed that insulin in combination with selenium could significantly lower blood glucose level and restore the disturbance in GLUT4 level in skeletal muscle. Treatment with insulin was only partially effective in restoring diabetic alterations. Conclusion It can be concluded that there is a synergistic action between insulin and selenium,and that treatment of diabetic rats with combined doses of insulin and selenium is effective in the normalization of blood glucose level and correction of altered GLUT4 distribution in skeletal muscle of diabetic rats.
文摘Objective:To investigate the antidiabetic activity of Ocimum tenuiflorum L.(O.tenuiflorum) leaves used in the traditional medicine management of diabetes in Malaysia.Methods:O.tenuiflorum leaves were extracted sequentially with hexane,chloroform,ethyl acetate,methanol,and water.The extracts were evaluated in terms of antidiabetic activity by using acute,subcutaneous glucose tolerance,and sub-chronic tests in streptozotocininduced diabetic rats.The extracts were also subjected to phytochemical analyses.Results:With an acute dose(1 g/kg),the methanol extracts showed significant reduction(31%) in fasting blood glucose(FBG) of the streptozotocin-induced diabetic rats.The FBG-decreasing effect of ethyl acetate extract was more rapid than that of the other extracts;the decreasing rates were 20%after 2 h,21%after 3 h,and 8%after 5 and 7 h.After 7 h(31%),the effect of methanol extract on FBG was significantly lower than that of metformin.In the subcutaneous glucose tolerance test,only methanol and hexane extracts showed the similarity of metformin in diabetic rats.After 14 days,the effects of these extracts were similar to those of metformin(63.33%).The total flavonoid and phenolic contents of extracts decreased as the polarity of the extraction solvent increased.Conclusions:The results obtained provide support for a possible use of O.tenuiflorum leaves in managing hyperglycemia and preventing the complications associated with it in type 2 diabetic.
基金financially supported by Research University Grant of Universiti Sains Malaysia(1001/PFARMASI/815080)
文摘Objective: To study the antidiabetic and antioxidant activities of nipa palm vinegar(NPV) used in traditional Malay medicine for treating diabetes. Methods: NPV was extracted using liquid-liquid extraction method and the obtained samples were subjected to antidiabetic studies using normal and streptozotocin-induced diabetic rat models whereas antidoxidant activities were investigated via in vitro antioxidant tests namely 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid free radicals scavenging activities and the reducing power assay. Results: Single administration of NPV and its extracts were not effective in both normal and diabetic rats. In intraperitoneal glucose tolerance test, NPV and its aqueous extract showed significant blood glucose lowering effect. In the sub-acute study, compared with the diabetic control, aqueous extract of NPV showed the most notable blood glucose lowering effect(56.6%) and a significant improvement in serum insulin levels(79.8%, P<0.05). To assess NPV's antioxidant activity, three in vitro antioxidant tests were employed: 2,2-diphenyl-1-picryhydrazyl and 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid free radical-scavenging assays, and the reducing power assay. Ethyl acetate extract had the greatest antioxidant potential and content of phenolic and flavonoid compounds. A linear positive correlation between the antioxidant parameters was observed. Chemical profiling analysis of aqueous extract of NPV revealed the presence of acetic acid(35.25%), the main active constituent which significantly contributed to the observed antidiabetic activity. Conclusions: Aqueous extract of NPV possesses antihyperglycaemic activities comparable to the metformin, while the ethyl acetate extract precipitated significant antioxidant effects attributable to its high phenolic content. These findings suggest that antioxidant compounds of NPV do not contribute much towards the overall observed antidiabetic effect.
文摘The loss of balance between the antagonistic activities of angiotensin II AT1/AT2 receptors has been impli-cated as a major mediator in the development of hypertension and progressive nephropathy in expe-rimental diabetes. The present study was designed to investigate the potential of garlic to modulate the level of expression of the AT2 receptor in the adrenal and renal tissues of diabetic rats. Three groups of rats were studied after 8 weeks following diabetes induction: normal, streptozotocin-induced diabetic (control diabetic), and garlic-treated diabetic rats. A polyclonal antibody of proven specificity to the AT2 receptor, as verified by Western blotting and emplo- yed in immunohistochemical assays, indicated that compared to normal rats, the highest adrenocortical AT2 receptor expression was significantly shifted from the zona glomerulosa to the zona fasciculate/ reticularis, and was significantly reduced in adrenomedul- lary chromaffin cells of control diabetic rats. In the kidney, STZ treatments were associated with a signi- ficant decrease in AT2 receptor expression throughout glomeruli and all cortical and medullary tubular segments. Compared to control diabetic rats, the labeling of the AT2 receptor in the garlic-treated diabetic group was restored among adrenocortical zona glomerulosa cells and adrenomedullary chromaffin cells and significantly reduced in the zona fasiculata, and was also restored in glomeruli and throughout renal cortical and medullary tubular segments, to le- vels comparable to those observed in normal rats. The capacity of garlic to modulate diabetes-induced AT2 receptor down-regulation may be implicated in restoring the recuperative processes mediated by AT2 receptors, which interfere with the development of hypertension and nephropathy.
文摘Leaf and root extracts of Smallanthus sonchifolius (yacon), have antihyper-glycemic activity and antioxidant properties. The present study aims to compare the in vivo hepatic antioxidant activity of hydroalcoholic extracts of yacon leaves and roots in rats with streptozotocin-induced diabetes in terms of their in vitro antioxidant capacity. Rats were treated during 14 days with 1060 mg·Kg<sup>-1</sup> root extract or 400 mg·Kg<sup>-</sup><sup>1</sup> leaf extract. The latter was richer in phenolics and possessed a much higher in vitro antioxidant activity. Both extracts prevented hyperglycemia in diabetic rats. The liver of diabetic rats presented increased levels of protein carbonyls and ROS and decreased activities of antioxidant enzymes. Treatment with both root and leaf extracts restored the protein carbonyl levels to normality. The root extract also restored the ROS levels to normality, but the leaf extract was not effective. The root extract was also more effective in restoring the activity of at least two important antioxidant enzymes (glucose 6-phosphate dehydrogenase and glutathione peroxidase). In terms of the antioxidant load (which was 17 times lower in the root extract treatment), the in vivo action of the root extract was more effective than the leaf extract in reducing the hepatic oxidative stress that accompanies diabetes.
