www.ejbps.com 1 Nwidu et al. European Journal of Biomedical and Pharmaceutical Sciences DARRHOEAL PROTECTIVE ACTIVITY OF HOT AQUEOUS STEM- BARK EXTRACT OF CARPOLOBIA LUTEA IN RATS. Lucky Legbosi Nwidu*, Moses Bariweni and Iyele Kamenebali Department of Pharmacology and Toxicology, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. Article Received on 03/11/2015 Article Revised on 25/11/2015 Article Accepted on 16/12/2015 ABSTRACT The objective is to scrutinize the darrhoeal protective activity of Carpolobia lutea (CL) Hot aqueous stem-bark extract (HASE) in rodents. The diarrhoeal protective effect of CL HASE (12.5-50 mg/kg p.o.) was scrutinize using experimental models of castor-oil induced diarrhoea in wistar rats and its effect compared to standard drugs. CL HASE (12.5-50 mg/kg p.o.) produced a dose-dependent decrease in normal and castor oil-induced intestinal transit, castor oil- induced diarrhoea and enteropooling compared to the vehicle treated group. The 25.0 mg/kg CL HASE significantly reduced (p< 0.05 - 0.001) the number, total number, the weight and total weight of stool from the control values of 7.83± 0.42 , 10.50 ± 1.09, 3.83 ± 0.42 and 5.85 to 0.0, 1.50 ± 0.43, 0.0 and 0.81 ± 0.03 respectively. It reduces intestinal fluid by 58.79 % and weight by 58.6% compared to morphine (5 mg/kg s.c.) of 24.73% and 46.04 % inhibition respectively. It reduces diarrhoea scores of 27.46 ± 4.00 to 1.67 ± 0.76 in a dose dependent significant manner (p < 0.001). The protection of 93.92% by 25.0 mg/kg CL HASE was reversed significantly (p < 0.001) by isosorbide dinitrate (150 mg/kg p.o.), yohimbine (1 mg/kg s.c.) and diphenoxylate (0.5 mg/kg p.o.) to 91.51 %, 60.67 % and 87.84 % respectively. Preliminary phytochemical screening reveal the presence of saponins, alkaloids, cardiac glycosides and tannins. In the acute toxicity study, no mortality was observed orally up to 5 000 mg/kg in rats, but an LD 50 of 125.05 mg/kg i.p. in mice. The study indicate that CL HASE possess antidiarrhoeal activity mediated via the stimulation of mucosal α- adrenergic receptors and inhibition of nitric oxide pathway. KEYWORDS: Diarrhoeal protective effect, ethanolic stembark extract, Carpolobia lutea. European Journal of Biomedical AND Pharmaceutical sciences http://www.ejbps.com ISSN 2349-8870 Volume: 2 Issue: 1 01-19 Year: 2015 Research Article ejbps, 2015, Volume 2, Issue 1, 01-19. *Correspondence for Author Dr. Lucky Legbosi Nwidu Department of Pharmacology and Toxicology, Faculty of Pharmacy, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.