Phytochemical Analysis and Antimicrobial Effect of Lemon Grass (Cymbopogon citratus) Obtained From Zaria, Kaduna State, Nigeria

Aim: The research study aimed to extract Cymbopogon citratus leaf using various solvents with view to determine the phytochemical constituents and antimicrobial effect of the plant extracts on some selected microorganisms.

Methodology: The cold maceration and agar well diffusion technique were employed to assess phytochemical properties and the antimicrobial potency of Cymbopogon citratus (Lemongrass) leaf extracts against selected bacterial pathogens using different solvents; ethanol, chloroform, and acetone. All the extracts were subjected to standard phytochemical qualitative screening for the presence or absence of various primary or secondary metabolites. The susceptibility test of the plant extracts on Escherichia coli, Staphylococcus aureus and Salmonella typhi were done using the agar well diffusion method. Tetracycline, Ciprofloxacin and Erythromycin were used as controls. The Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) were determined in three concentrations; 100 mg/ml, 50 mg/ml and 25 mg/ml of each extract.

Mean zone of inhibition was used to measure the antimicrobial potential of leaf extracts against Staphylococcus aureus, Salmonella typhi and Escherichia coli respectively.

Results: Phytochemicals such as flavonoids, carbohydrates, tannins, alkaloids, steroids, and phytosteriods were detected except glycosides and phenol that were absent in the acetone and chloroform leaf extracts. The ethanol leaf extract showed antimicrobial activity at the concentration of 100 mg/ml, and intermediate antimicrobial activity at the concentration of 50 mg/ml against all isolates tested. Acetone and chloroform leaf extracts recorded inactivity against E. coli and S. aureus respectively.

Conclusions: The results of preliminary phytochemical screening of the leaf extracts revealed the presence of phytochemicals which could be used as medical regimens. Lemongrass has demonstrated antimicrobial properties which could be harnessed for the control of pathogens tested.