Synergistic Gastroprotective Effects of the Leaf and Root Extracts of Chromolaena odorata against Ethanol-induced Gastric Ulceration in Wistar Rats

Abstract

Gastric ulceration remains an important gastrointestinal disorder associated with disruption of mucosal defence, oxidative stress, and inflammation. Although Chromolaena odorata has recognised medicinal properties, comparative evidence on the gastroprotective effects of its leaf and root extracts, particularly when used in combination, remains limited.This study investigated the synergistic gastroprotective effects of methanol leaf and root extracts of Chromolaena odorata against ethanol-induced gastric ulceration in Wistar rats. Fresh leaves and roots were collected from Rumuolumeni, Port Harcourt, Rivers State, Nigeria, authenticated, air-dried, pulverised, and separately extracted with 80% methanol by cold maceration, yielding 11.72% and 8.56%, respectively. Forty (40) Wistar rats were randomly assigned to eight groups of five and pretreated orally for 14 days with distilled water, omeprazole (20 mg/kg), leaf extract (200 or 400 mg/kg), root extract (200 or 400 mg/kg), or combined leaf and root extracts (200 mg/kg each), followed by absolute ethanol (5 mL/kg). Phytochemical screening showed alkaloids, flavonoids, tannins, saponins, phenols, glycosides, terpenoids, steroids, anthraquinones, and reducing sugars. Ethanol significantly reduced haemoglobin, packed cell volume, gastric pH, superoxide dismutase and catalase, while increasing white blood cell count, malondialdehyde, total acidity and ulcer index (p < 0.05). Extract treatment significantly ameliorated these alterations. Histological examination revealed marked mucosal disruption, erosion, ulceration and inflammatory cell infiltration in the ulcer control, whereas treated groups showed improved mucosal integrity. The leaf extract generally outperformed the root extract, while the combined extract produced the greatest gastroprotection, with 87.77% ulcer inhibition compared with 84.97% for omeprazole. C. odorata therefore demonstrates promising gastroprotective activity. Further studies are recommended to isolate the active constituents and establish the mechanisms and safety of the extracts.