Phytochemical Properties and Antibacterial Activity of Leaf Extract of Ocimum gratissimum on Salmonella Species

Aim: Ocimum gratissimum is commonly used as food and health purposes. This study is aimed at evaluating the bioactive compounds and antibacterial activity of leaf extract of O. gratissimum against Salmonella species.

Methodology: The Phytochemical screening of O. gratissimum was conducted using standard methods. Screening for antibacterial activity of the leaf extracts against Salmonella species was determined using agar well diffusion method. An in-vivo toxicity study was carried out with albino rats.

Results: The phytochemical screening revealed the presence of saponins, tannins, cardiac glycoside, flavonoid, glycosides, alkaloid, volatile oils and steroids. A zone of inhibition of 14mm was recorded against the organisms using ethanolic extract with a concentration of 100 mg/ml and the lowest was recorded against Salmonella paratyphi with the concentration of 25 mg/ml of the ethanolic extract. Zone of inhibition of 9.00 mm and 10.0mm was recorded against S. typhi and S. paratyphi on a concentration of 100 mg/ml of the aqueous extract. A minimum inhibitory concentration of 100 mg/ml and 25 mg/ml of the aqueous and ethanolic extract of the leaf was recorded. After the toxicity test, no death was recorded after 2 (two) weeks.

Conclusion: The leaf extract of O. gratissimum shows promising potentials in the treatment of infectious diseases associated with Salmonlla typhi and Salmonella paratyphi, due to its antimicrobial activity and low toxicity. However, further studies are needed to non-polar solvents to isolate other bioactive compounds as well as identify the active metabolites responsible for these activities.