Secondary Metabolites Constituents and Antibacterial Screening of Methanolic Leaves Extracts of <i>Senna fistula</i> and <i>Ocimum gratissimum</i>

Abstract

The misuse of antibiotics has contributed largely to the development of resistance strains thereby creating the need for an incessant search and development of newer drugs. This study investigated the secondary metabolites constituents and antibacterial activity of methanolic leaves extracts of Senna fistula (SF) and Ocimum gratissimum (OG). The SF and OG leaves extracts were done using methanol, the phytochemical analysis were done as per standard protocol. The antibacterial activity was determined by agar well diffusion method.

The results showed that the methanolic leaves extracts of SF and OG contain secondary metabolites like flavonoids, tannins, alkaloids, terpenoids, cardiac gylcosides, saponins, phenolic compounds. The antibacterial screening revealed that both Senna fistula and Ocimum gratissimum exhibited strong inhibitory activity against all the tested organisms. Methanolic leaf extract of SF has a stronger antibacterial activity with zones of inhibition of 19.5mm against E coli  and 31.5 mm against Klebsiella than methanolic leaf extract of OG (18 mm against E coli and 28 mm against Klebsiella) in a dose dependent manner.

In conclusion, the methanolic leaves extracts of Senna fistula and Ocimum gratissimum exhibited antibacterial activity which is due to the presence of various secondary metabolites; therefore this study supports its use as an antibiotic agent.

Keywords: Senna fistula, Antibacterial, Terpenoids, Klebsiella, Ocimum gratissimum, Secondary metabolites