Phytochemical and Antibacterial Activity of Psidium Guajava Leaves against Some Selected Species of Gram-Positive and Gram-Negative Bacteria

Abstract

Medicinal plants are regarded as rich sources of traditional medicines and provide lead drugs to the modern medicines. This study focuses on the preliminary phytochemical constituent and antibacterial activity of acetone and alcoholic leaves extract of Psidium guajava against three clinical isolates (Staphylococcus species, E. coli and Klebsiella species). Standard methods of analysis were adopted. The phytochemical constituent tests revealed the presence of tannins, saponins, alkaloids, volatile oil and steroids while flavonoids, cardiac glycosides, and terpenoids were absent in the leaves extracts. The result of antibacterial activity showed that acetone extract exhibited the susceptibility against Staphylococcus species with the mean zone of inhibition of (40.00±0.00), (50.00±0.00), and (40.00±0.00) using the concentration of 50μl, 75μl, and 100μl followed by the Alcoholic extract with a mean zones of inhibition of (15.00±0.00), (20.00±0.00) and (20.00±0.00) using the concentration of 50μl, 75μl, and 100μl respectively. Similarly, both acetone and alcoholic extracts were sensitive to S. aureus species whereas Klebsiella species and E. coli showed resistance to both extract of the leaves. The results obtained from the acetone and alcoholic leaf extract of Psidium guajava could be potentially used as antibacterial agents in the treatment of infections caused by Staphylococcus aureus species.

Keywords: Psidium guajava leave extract, antimicrobial activity, alcohol and acetone.