Modulation of antioxidant status in streptozotocin-induced diabetic male wistar rats following intake of red palm oil and/or rooibos

Objective:To investigate the role of red palm oil(RPO),rooibos tea extract(RTE)and their combined treatment(RPO+RTE)on antioxidant status in streptozotocin(STZ)-induced diabetic rats.Methods:Diabetes mellitus was induced by a single administration of streptozotocin(50 mg/kg)and the rats were treated for 7 weeks.Antioxidant enzymes[calalase(CAT),glutathione peroxidase(GPx),superoxide dismutase(SOD)],antioxidant capacity[trolox equivalence antioxidant capacity(TEAC),oxygen radical absorbance capacity(ORAC)]as well as total protein,albumin,globulin,total glutathione,conjugated diene and thiobarbituric acid reactive substances(TBARS)were investigated.Results:Treatment with RPO,RTE and RPO+RTE significantly(p>0.05)improved liver SOD and plasma ORAC in the diabetic rats.Similarly,diabetic rats treated with RTE and RPO+RTE enhanced liver GPx.A significant(P<0.05)increase in the plasma TBARS in the diabetic control group was observed when compared with the normal control group.Treatment of diabetic rats with RTE and RPO+RTE reduced plasma TBARS to a level not significantly different at P<0.05 from the normal control group.Conclusions:The results revealed the anti-oxidative potentials of red palm oil,rooibos and their combination in diabetic conditions and hence,they could be useful in the management of diabetes and its complications.

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.

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).

Effects of Dietary Green Rooibos on Physical Endurance in Swimming Mice

Green rooibos made from unfermented rooibos leaves contains high amounts of aspalathin. Dietary green rooibos is expected to increase physical endurance and decrease physical fatigue, because aspalathin has antioxidant activity and stimulates glucose uptake in muscle tissue. The aim of this study was to validate the effects of green rooibos and aspalathin by using a swimming mouse model. Dietary green rooibos and aspalathin tended to increase swimming time in mice. This beneficial effect might be induced by increased glycogen accumulation in the liver and skeletal muscles.

科伊桑人的Rooibos

两位非洲学生,从遥远的故乡为我带来了Rooibos。她们梳着脏辫,用带着浓郁口音的英语告诉我面前这些碎碎的类似草干之类的东西,就是我一直在找的Rooibos。我很诧异,这种我们翻译为'如意波斯茶'或者'路易波斯茶'的茶,看起来并不像茶。事实上,它也算不上茶,而是一种草本植物。Rooibos的发现,与中国茶的发现中融入了佛道等宗教元素有很大不同。