GASTRO-INTESTINAL MUCOSAL PROTECTIVE PROPERTIES AND TOXICITY STUDIES ON THE METHANOL ROOT EXTRACT OF WALTHERIA INDICA LINN. (STERCULIACEAE) IN LABORATORY ANIMALS

GASTRO-INTESTINAL MUCOSAL PROTECTIVE PROPERTIES AND TOXICITY STUDIES ON THE METHANOL ROOT EXTRACT OF WALTHERIA INDICA LINN. (STERCULIACEAE) IN LABORATORY ANIMALS

Abstract:

Many countries worldwide including Nigeria use different parts of Waltheria indica (leaves, stem-barks, roots and whole plants) to treat various ailments. In Nigeria, Waltheria indica is used to treat gastro-intestinal ulcers, pain, inflammation, diarrhoea, conjunctivitis, anaemia and erectile dysfunction. The aim of this study was to evaluate the gastro-intestinal mucosal protective properties and ascertain the toxicity profile of the methanol root extract of Waltheria indica. Preliminary phytochemical screening was carried out on the extract and the oral median lethal dose (LD50) of the extract was estimated using modified Lorke’s (1983) method in rats followed by sub-acute toxicity study using OECD 407, 2008 guidelines where haematological and biochemical indices as well as histology examination of selected organs were carried out. The gastro-protective effect of the extract (250, 500 and 1,000 mg/kg) was evaluated using indomethacin-induced ulcer and pylorus ligation-induced ulcer models in Wistar rats and the extracts effect on isolated guinea pig ileum and rabbit jejunum was also determined. Phytoconstituents like alkaloids, cardiac glycosides, flavonoids, saponin glycoside, tannins and triterpenes were present in the methanol root extract of Waltheria indica and the oral LD50 was estimated to be greater than 5,000 mg/kg with no significant effect on the weekly body weights of the rats and relative organ weight ratio of the stomach, intestine, liver, kidney and heart. There was no significant effect on haematological parameters and renal function indices. However, there was statistically significant increase (p ≤ 0.05) in alanine transaminase, total bilirubin and conjugated bilirubin at doses of (250 mg/kg), (250, 500 and 1,000 mg/kg) and (1,000 mg/kg) respectively. Histology examination of the liver, showed polymorphonuclear infiltration at doses of (250 and 1,000 mg/kg) and moderate hepatocellular necrosis at (500 mg/kg) with tubular necrosis observed in the kidney at 1,000 mg/kg extract dose. There was significant vii (p ≤ 0.05) and dose dependent protection against indomethacin-induced ulcers in rats. The extract also significantly (p ≤ 0.05) and dose dependently protected the rats against pylorus ligation-induced ulcer. The methanol root extract, neither contracted nor relaxed the guinea pig ileum and rabbit jejunum respectively. These findings, suggest that the methanol root extract of Waltheria indica, may be considered relatively safe and it possesses gastro-intestinal mucosal protective properties. This supports the folklore claims for the use of the plant in the management of peptic ulcer disease.

GASTRO-INTESTINAL MUCOSAL PROTECTIVE PROPERTIES AND TOXICITY STUDIES ON THE METHANOL ROOT EXTRACT OF WALTHERIA INDICA LINN. (STERCULIACEAE) IN LABORATORY ANIMALS