Antidiabetic and Antiinflammatory Activities of Ursolic Acid (3 - beta-3hyrdoxy-urs-12-ene -8-oic-acid), a Triterpenoid from Leaves of Stachytarpheta jamaicensis (L) Vahl (Verbennaceae)

Abstract

Background: Ursolic acid, a pentacyclic terpenoid carboxylic acid widely found in medicinal plants has been reported to have multifarious biological activities such as antiinflammatory, anticancer, antidiabetic, and antioxidant activities. Aim: To evaluate the antidiabetic and antiinflammatory activities of Ursolic acid isolated from dichloromethane: methanol extract of leaves of Stachytarpheta jamiacensis (L) Vahl (Verbenaceae) in alloxan-induced diabetic rats. Methods: A dichloromethane: methanol (1:1) leaves extract was prepared by cold maceration. Dichloromethane fraction obtained from the dichloromethane: methanol extract was subjected to column chromatography and eluted with different solvents of increasing polarity to isolate the bioactive compounds. The structure of the isolated compound was elucidated using spectroscopic techniques (IR, 1HNMR, 13CNMR, MS). Phytochemical analysis of the isolate and acute toxicity study was done following standard procedures. The anti-diabetic potential was assessed by determining fasting blood glucose level on hyperglycemic rats at the dose of 25 and 50 mg/kg for a period of 14days. The isolated compounds’ antiinflammatory activity was investigated using egg albumin-induced rat paw edema in mice at dose of 10 and 20 mg/kg body weight. Results: Ursolic acid (3-beta-3hyrdoxy-urs-12-ene -8- oic-acid) isolated from dichloromethane: methanol extract of Stachytarpheta jamaicensis showed significant (p<0.05) reduction (72.79 and 79.77%) in fasting blood glucose levels at the dose of 25 and 50 mg/kg respectively in treated diabetic animals when compared with the diabetic control. A 77.77 % reduction was observed for standard drug (glibenclamide). Ursolic acid at 20 mg/kg exhibited a maximum inhibition (75.00%, p<0.05) of carrageenan-induced ear edema in mice. It showed positive for terpenoids.  There was no death recorded in the acute toxicity test at doses of up to 5000 mg/kg. Conclusion: The results demonstrate that ursolic acid isolated from dichloromethane: methanol extract of Stachytarpheta jamaicensis (L) Vahl possesses significant anti-diabetic and anti-inflammatory activity.