Full Length Research Paper

Gastroprotective effects of leaf extracts of Carpolobia lutea (polygalaceae) G. Don. in rats

Lucky L. Nwidu¹* and Paul A. Nwafor²

¹Department of Pharmacology and Toxicology, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.

²Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Uyo, Akwa Ibom state, Nigeria.

*Corresponding author. E-mail: menelucky@yahoo.com. Tel: +2348033417432.

Accepted 6 November, 2008

The preliminary screening of the gasroprotective effects of Carpolobia lutea leaf extracts was investigated through bioactivity guided gradient extraction. Experimentally induced gastric ulceration was affected using ulcerogens such as indomethacin, ethanol, reserpine in 0.5% acetic acid, stress, serotonin and diethylthiocarbamate in rats. The median lethal dose (LD 50) of the ethanol extract was also investigated intraperitoneally in mice. Preliminary phytochemi-cal screening of the ethanol extract was conducted. The acute toxicity shows the median lethal dose to be 3850.0 mg/kg. The phytochemical screening of C. lutea revealed that alkaloids, saponins, tannins, anthraquinone, cardiac glycosides, flavoniods were presents. The ethanol extract gave a preventive ratios (PRs) of 3.08, 90.09, 22.17, 70.00, 43.44 and 51.58; the ethyl acetate extract gave 57.50, 100.00, 83.33, 63.61, 84.80, and 68.79; the chloroform extract gave 4.85, 45.05, -13.80, 46.37, 35.88 and 70.29; n-hexane extract gave 38.02, 34.83, 55.50, 100.00, 68.49 and 31.30 PRs respectively for the indomethacin, ethanol, reserpine in 0.5% acetic acid, stress, serotonin and diethylthiocarbamate induced ulceration in rats. The PRs of cimetidine are 90.26, 66.67, 91.82, and 49.97 respectively for indomethacin, reserpine in 0.5% acetic acid, stress and serotonin induced ulceration in rats. The ethyl acetate extract (770 mg/kg) consistently and effectively reduced the ulcer index significantly (p<0.01 - 0.001) than the ethanol, chloroform and n-hexane extracts of C. lutea in all the experimentally induced ulcer models studied. C. lutea could be exploited in the treatment of peptic ulcer in man justifying its ethnomedical use as stomach medicine.

Key words: Carpolobia lutea, gradient bioactivity guided extraction, gastroprotectives, gastric ulcers