南非传统草药Sutherlandia抗糖尿病作用的研究

目的:观察南非传统草药Sutherlandia水提物对糖脂代谢的影响。方法:腹腔注射链脲佐菌素(STZ)并高脂饲料喂养诱导2型糖尿病大鼠模型。随机分为正常组、模型组、吡格列酮组、Sutherlandia组。观察体质量、口服糖耐量试验(OGTT)、血甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白-胆固醇(LDL-C)、高密度脂蛋白-胆固醇(HDL-C)指标的改变,Western Blot法检测各组大鼠骨骼肌胰岛素受体底物(IRS-1)表达情况。结果:与正常组比较,模型组大鼠体质量降低,OGTT、TG、TC、LDL-C指标明显升高(P<0.05),多饮、多食、多尿症状明显,IRS-1蛋白表达明显降低(P<0.05);治疗后,与模型组比较,Sutherlandia组及吡格列酮组的体质量未见明显增长,Sutherlandia组及吡格列酮组血糖、TG、TC均明显降低(P<0.05或P<0.01),二者之间无统计学差异,Sutherlandia组及吡格列酮组骨骼肌中IRS-1蛋白表达明显升高(P<0.05),二者之间无统计学差异。结论:腹腔注射STZ并高糖高脂饲料喂养诱导2型糖尿病大鼠模型存在糖脂代谢紊乱;南非传统草药Sutherlandia可明显降低其血糖水平,改善血脂代谢,提高胰岛素水平;Sutherlandia可提高IRS-1骨骼肌中的表达水平,进而改善胰岛素抵抗,降低血糖,其确切的作用途径有待进一步深入研究。

Testicular oxidative stress and apoptosis status in streptozotocin-induced diabetic rats after treatment with rooibos(Aspalathus linearis),honeybush(Cyclopia intermedia),and sutherlandia(Lessertia frutescens)infusions

Objective:To investigate the testicular oxidative stress and apoptosis status,as well as the sperm functional parameters in streptozotocin(STZ)induced diabetic rats following treatment with rooibos(Aspalathus linearis),honeybush(Cyclopia intermedia)and sutherlandia(Lessertia frutescens)infusions.Methods:Diabetes was induced by injecting fourteen-week-old adult male Wistar rats(250-300 g)with a single intraperitoneal injection of STZ(45 mg/kg body weight).Fifty rats were randomly divided into five groups:the vehicle group received 0.1 M citrate buffer,the diabetic control group received 45 mg/kg STZ,the diabetic+rooibos group received 45 mg/kg STZ+2.0%rooibos,the diabetic+honeybush group received 45 mg/kg STZ+4.0%honeybush,and the diabetic+sutherlandia group received 45 mg/kg STZ+0.2%sutherlandia.Rats were sacrificed 7 weeks after induction of diabetes mellitus.The testes and epididymides were harvested and weighed after induction.Spermatozoa were retrieved from the cauda epididymis for motility,concentration,and morphology analysis,and the testis was used for all biochemical assays.Oxidative stress was determined by measuring malondialdehyde levels,catalase,and superoxide dismutase activities,while apoptotic biomarkers were evaluated by Western blotting assays.Results:After induction of diabetes,rats in the diabetic control group,diabetic+rooibos group,diabetic+honeybush group,and diabetic+sutherlandia group presented with significantly elevated blood glucose levels as compared with the vehicle group(P<0.001).Rats in the diabetic control group had a reduction in sperm progressive motility,while rats in the diabetic+rooibos group and the diabetic+sutherlandia group displayed an increase in progressive motility as compared with the diabetic control group.The diabetic control animals showed a 40.0%decrease in sperm concentration when compared to the vehicle group,and there were no significant differences in sperm kinematic and speed parameters between the groups.In addition,the percentage of morphologically normal spermatozoa was increased by 13.0%,16.0%,and 15.0%after treatment with rooibos,honeybush,and sutherlandia,respectively and the rats in the diabetic+infusion groups also displayed an increase in superoxide dismutase activity when compared to the diabetic control group.Conclusions:Rooibos,honeybush and sutherlandia infusions may partly alleviate diabetes-induced sperm function impairment by reducing oxidative stress.

An in vitro evaluation of the antioxidant and antidiabetic potential of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts

Objective: To evaluate the antioxidant and antidiabetic activities of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts using the in vitro model.Methods: The antioxidant activities of aqueous, decoction, ethanol and hydro-ethanol extracts of the plant were determined using seven different assays; the antidiabetic potential was evaluated through the inhibition of key carbohydrate hydrolysing enzymes(aamylase and a-glucosidase), while the modes of the enzymes inhibition were assessed using enzyme kinetic analysis.Results: The ethanol extract exhibited the best scavenging activity(IC_(50): 0.47, 0.36,0.20, 0.29 and 0.01 mg/m L) against the tested radicals like 1,1-diphenyl-2-picrylhydrazyl,2, 20-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), nitric oxide, hydroxyl and superoxide anion, respectively. It also showed the best reducing power efficiency when compared with the standard(silymarin), while the decoction extract displayed the strongest metal chelating potential(IC_(50): 0.71 mg/m L). The ethanol(IC_(50): 5.52 mg/m L)and decoction(IC_(50): 0.05 mg/m L) extracts exhibited mild and strong inhibitory effects on the specific activities of a-amylase and a-glucosidase respectively, through an uncompetitive and non-competitive mode of action.Conclusions: The observed properties might be linked to the presence of active principles as shown by the results of the phytochemical analyses of the extracts. This research has validated the folkloric application of Sutherlandia montana as a potential antidiabetic agent, which is evident from the inhibition of specific activities of key enzymes involved in carbohydrate metabolism.

Descriptive histomorphological evaluation of the testis and caudal epididymis following treatment with rooibos(Aspalathus linearis),honeybush(Cyclopia intermedia)and sutherlandia(Lessertia frutescens)in healthy and streptozotocin-induced diabetic rats

Objective:To evaluate the testis and the cauda epididymis after treating both healthy and diabetic rats with rooibos(Aspalathus linearis),honeybush(Cyclopia intermedia),and sutherlandia(Lessertia frutescens),respectively.Methods:Ninety male Wistar rats were randomly divided into nine groups(n=10 per group).Fifty rats were randomized to receive tap water,0.1 M citrate buffer,2.0%fermented rooibos,4.0%fermented honeybush,or 0.2%unfermented sutherlandia.Diabetes was induced via a single intraperitoneal injection of streptozotocin(STZ)at 45 mg/kg in 40 rats.The diabetic rats were randomized to receive tap water,2.0%fermented rooibos,4.0%fermented honeybush,or 0.2%unfermented sutherlandia.Rats were sacrificed after seven weeks of diabetic induction.Blood was collected for hormonal assay,while the testes and caudal epididymis were retrieved for histomorphological evaluations.Results:Diabetic rats treated with 2.0%fermented rooibos exhibited a significant increase in fasting plasma glucose(FPG)versus the vehicle group(P=0.002),and a 3.6%decrease compared to the diabetic control group(P>0.05).Diabetic rats treated with honeybush or sutherlandia showed 23.6%and 15.4%decrease in FPG when compared to the diabetic control group,respectively(both P>0.05).The diabetic control rats had a significant decrease in the percentage of histologically normal seminiferous tubules compared to the control group(P=0.049).There was 21.0%,14.0%,and 5.4%rise in the percentage of normal seminiferous tubules in diabetic rats receiving rooibos,honeybush or sutherlandia,respectively,compared to the diabetic control group.The infusion control groups(rooibos,honeybush and sutherlandia)showed normal seminiferous tubules,presence of spermatozoa in the epididymal lumen,and had normal overall architecture.Both testicular and epididymal morphology were altered in the diabetic control group,but these disruptions were mildly ameliorated by rooibos,honeybush,and sutherlandia.Conclusions:The detrimental effects of diabetes on the histomorphological architecture of the testis and epididymis are mildly ameliorated by the infusions(2.0%fermented rooibos,4.0%fermented honeybush,and 0.2%unfermented sutherlandia).

几种因素对纸荚豆不定根生长的影响研究

为建立纸荚豆不定根培养体系,本研究利用从纸荚豆无菌种子诱导的不定根探究了吲哚丁酸(IBA)、蔗糖浓度和培养时期对纸荚豆不定根增殖生长的影响。结果表明:在3 mg/L的IBA下,不定根根长、根数及生物量最高;蔗糖浓度对不定根生长也有很大影响,在蔗糖浓度为30 g/L时,不定根可达到最优的生长效果;当培养周期为50 d时,不定根生物量达到最大值。