Gastroprotective Effect and Safety Assessment of Zanthoxylum Zanthoxyloides (Lam) Waterm Root Bark Extract

Problem statement: Gastrointestinal ulcers account significantly for morbidity and mortality in Ghana. The study therefore investigated the gastroprotective effect of an ethanolic root bark extract of Zanthoxylum zanthxyloides and its safety for us. Approach: Gastric ulceration was induced in Sprague-Dawley rats with Indomethacin (25 mg kg^-1, p.o) and was treated with 150, 250, or 500 mg kg^-1 of the extract, or 20 mg kg^-1 Esomeprazole. The number of ulcers per stomach, Ulcerative Index and Curative Ratio were determined. A histological study of the gastric mucosa was also performed. The extract’s effect on an isolated guinea-pig ileum preparation was investigated to elucidate its possible mechanism of action. Safety assessments involving, organ weight to body weight ratio determination, hematological analysis and liver function tests were performed. Results: The extract significantly decreased (p≤0.001) the number of ulcers per stomach and the Ulcerative Index (similar to Esomeprazole) and significantly increased (p≤0.001) the Curative Ratio in a dose-dependent manner. It completely corrected the architectural distortions caused by gastric ulceration and inhibited significantly (p≤0.001) the contractile responses of the isolated guinea-pig ileum to Acetylcholine, Nicotine and Histamine in a manner comparable to reference antagonists. The extract had no significant effect (p>0.05) on organ weight to body ratio and hematological profile. Plasma levels of Alanine transaminase and Alkaline phosphatase decreased significantly (p≤0.001) in extract and Esomeprazole-treated ulcerated rats. Levels of Gamma-glutamyl transferase, Total bilirubin (direct and indirect) however increased significantly (p≤0.01-0.001). Conclusion/Recommendations: Per the findings, the ethanolic root bark extract of Zanthoxylum zanthoxyloides has gastroprotective effect in Sprague-Dawley rats working possibly via antimuscarinic or antihistaminic mechanism. It however has a potential of causing cholestasis hence liver function should be monitored.