Solanum nigrum (SLN), commonly known as African nightshade, is used as a vegetable as well as in the management and treatment of various ailments including gastric ulcers. We analyzed, both grossly and microscopically using H&E, Masson’s trichrome and PSA staining methods, the protective effects of aqueous leaf extracts of three Kenyan SLN genotypes namely S. scabrum (SSB), S. sarrachoides (SSR) and S. villosum (SVL) on ethanol-induced gastric lesions in rats. There was evidence of gastro-protection by all the three genotypes with the SSB showing the highest ulcer inhibition score (76.37 %) followed by SSR (72.51 %) and SVL (63.30 %). SLN-pretreated rats showed less areas of gastric mucosal surface erosion. Additionally in the pretreated animals, the depth of the ulcers were markedly reduced, reaching only the gastric pit region except in those treated with SVL where the ulcers penetrated slightly more deeply to affect the gastric glands. Compared with controls, the mean microscopic ulcer index decreased 5.07, 3.55 and 2.37-fold in rats pretreated with SSB, SSR and SVL extracts respectively. Results of this work show extracts of the three SLN genotypes to have antiulcerogenic potential but at varied strengths, thus confirming earlier reports that phytoconstituents and hence the efficacy of a medicinal plant may be influenced by genetic factors.
KEY WORDS: Gastric ulcer; Inhibition; Kenyan; Solanum nigrum.