Investigation Into The Antibacterial And Antidiarrhoeal Properties Of Water And Ethanolic Extracts Of Psidium Guava Leaves

Abstract

Objective: The water extract (WE) and ethanol extract (EE) of Psidium guava Leaf were carried out for antibacterial and antidiarrhoeal effects using patients stool and animal models. The antibacterial sensitivity tests were based on their zone of inhibition for six species of bacteria which include: Aeromonas hydrophila, 22±4mm; Pseudomonas aeruginosa 18±2mm; Shigella dysenteriae, 17±1mm; Bacillus subtilis, 16±3mm; Staphylococcus aureus, 13±1mm; and Escherichia coli, 12±2mm.
Result: Their minimum inhibitory concentration, MIC, and minimum bactericidal concentration, MBC, were respectively: Aeromonas hydrophila, 3mg/ml and 5mg/ml; Pseudomonas aeruginosa, 6mg/ml and 9mg/ml; Bacillus subtilis, 25mg/ml and 40mg/ml; Staphylococcus aureus, 50mg/ml and 84mg/ml; while Escherichia coil gave 100mg/ml and 132mg/ml, respectively.
Antidiarrhoeal effect of both the water and ethanol extracts, compared with the standard drug diphenoxylate was, clearly showed significant reduction in faecal output and protection from castor oil – induced diarrhoea in the albino rat.
Conclusion: The extracts also significantly (P<0.05) reduced the growth of common pathogenic microorganisms and thus both explain the basis for the use of the plant in traditional medicine as recognized antibacterial and antidiarrhoeal cocortion remedy. Presently, it is uncertain which of the active principles in the psidium guava leaf extract that contribute to the observed antibacterial and antidiarrhoeal effects.



Keywords: Psidium guava; antidiarrhoeal activity; antispamodic; antibacterial activity.

Tropical Journal of Medical Research Vol. 11 (1) 2007: pp. 1-6