Evaluation of antidiabetic activity of plants used in Western Sudan

Objective: To investigate the traditional antidiabetic uses of some indigenous Sudanese plants on streptozotocin-induced diabetes rats. Methods: Diabetic rats were treated with a 400 mg/kg dose of aqueous extracts of five plant species orally for 2 h(acute) or 14 days(chronic). In acute model blood glucose levels were monitored at specific intervals. In the chronic model blood samples were collected from overnight fasted diabetic rats on day 15 to estimate blood glucose level. And the body weight, serum lipid profile and activities of liver and kidney enzymes were measured. Histopathological observations of liver sections were also studied.Results: In the case of acute treatment, aqueous extracts of Tinospora bakis(T. bakis), Nauclea latifolia(N. latifolia) and Randia nilotica(R. nilotica) at 400 mg/kg significantly lowered(P < 0.05) blood glucose levels in diabetic rats whereas, chronic treatment of diabetic rats with 400 mg/kg of T. bakis, N. latifolia, R. nilotica and Mitragyna inremis proved to have significant(P < 0.05) antihyperglycemic effect and have the capacity to correct the metabolic disturbances associated with diabetes. Histopathological studies showed that the aqueous extracts of these four plants reinforced the healing of liver. However, Striga hermonthica aqueous extract did not exert any antihyperglycemic effect to diabetic rats. Conclusions: This study demonstrated that T. bakis, N. latifolia, R. nilotica and Mitragyna inremis have therapeutic value in diabetes and related complications and thus supporting the traditional uses of these plants in Sudanese traditional medicine.

西非产阔叶乌檀中三萜和甾醇类成分的研究

目的:研究非洲民间药物——茜草科植物阔叶乌檀Nauclea latifolia Smith的化学成分。方法:采用硅胶、Sepha-dex LH-20柱色谱等方法分离化合物,根据波谱数据和理化常数确定其结构。结果:从阔叶乌檀甲醇提取物中分离得到12个非生物碱类化合物,其中8个为三萜及其皂苷类,即24-烯-环阿尔廷酮(1),熊果醛(2),奎诺酸(3),铁冬青酸(4),3β,19α,23,24-四羟基乌苏烷三萜(5),pyrocincholic acid 3β-O-β-D-fucopyranoside(6),quinovic acid 3β-O-β-D-glucopyranoside(7),quinovicacid-3β-O-D-glucopyranosyl-(28→1)-β-D-glucopyranosyl ester(8);甾醇类4个,即β-谷甾醇(9),豆甾-3,6-二酮(10),豆甾-4-烯-6β-醇-3-酮(11),胡萝卜苷(12)。结论:除化合物4,9,12外,所有化合物均首次从该植物中分离得到,其中化合物2,6,10,11为首次从乌檀属中分离得到。