Anti-microbial activity of <i>Psidium guajava</i> stem bark extract on albino rats

The anti-microbial activity of guava stem bark extract (GSBE) on albino rats was carried out. GSBE was exposed to acute toxicity test (LD50). Assay of the GSBE against some enteropathogenic organisms was tested in vitro. Zone of Inhibition (ZI) was evaluated by doubling dilution techniques in pre-seeded nutrient agar. Anti-diarrhoeal effect of the GSBE was assessed using charcoal meal transit and castor oil induced diarrhoeal models in albino rats. The animal models were divided into four groups (n=5) and administered treatment. Results revealed acute toxicity value > 5000 mg/kg. Significant inhibition of the microbes in concentrationdependent manner was observed. 1000 mg/ kg of the extract produced 39.33±1.16, 31.00±1.00, 29.00±1.00, 25.67±1.53 and 23.33±1.55 mm zones of inhibition for Staphylococcus aureus, Escherichia coli, Salmonella typhi, Campylobacter jejuni and Shigella dysenteriae, respectively. Significant decrease (p<0.05) in the frequency and amount of wet stool output was observed in the diarrhoeal-induced rats and significant inhibition of charcoal meal transit was observed in the motility study. The activities of the GSBE compared favourably with that of the standard control. Hence, the use of guava stem bark extract to manage diarrhoea by local folk is hereby scientifically justified.