Oral hypoglycemic activity of water extract from Ya-Tevada, Malvastrum Coromandelianum Garcke, equivalent to insulin injection

Water extract from whole plant of Ya-Tevada, Malvastrum coromandelianum Garcke; Malvaceae, showed strong hypoglycemic activity when given orally. Feeding the spray-dried crude water extract as low as 50 and 100mg/kg body weight (bw) to streptozotocin-induced male Wistar Rats, reduced significantly non-fasting blood glucose from approx. 350–450mg/dL within one hour after administration to a level of blood glucose in normal non-diabetic rats which is about 150mg/dL, equivalent to i.p. injection of Insulin (Humulin R®) 5U/kg bw. The hypoglycemic effect lasted for at least 5 hours. This strong hypoglycemic activity of this plant extract would fulfill the search for an oral hypoglycemic agent equivalent to insulin injection. Feeding the extract at repeated doses of 50, 100 and 500mg/kg bw/day for 30 days suppressed only fasting blood glucose to a level equivalent to a level shown in the group of diabetic rats injected with insulin 5 U/kg bw/day and the group of normal rats fed water. Previous report showed no chronic toxic effect upon feeding this water extract at daily doses of 0.2, 2.0 and 20g/kg bw for 6 months in male and female Wistar rats [1]. This largest dose is 400 times the effective hypoglycemic dose of 50mg. This agent also showed antibacterial activity against Staphylococcus aureus both methicillin-sensitive and methicillin-resistant and good wound healing effect. Thus, water extract of this plant showed great potential as oral hypoglycemic agent to be used in diabetic condition.

Acknowledgements: Fac Pharm Sci, and Fac Vet Sci, Chulalongkorn U., Bangkok 10900, Thailand.

Reference: 1. Attawish, A, et al. (1998), Bull. Dept. Med. Sci. 40: 261–271.