Antibacterial Efficacy of Crude Extracts from Tamarind (Tamarindus indica) Leaves against Staphylococcus aureus and Klebsiella pneumoniae: An In vitro Study

Infectious diseases are the primary concern for all mankind, and despite the discovery of antibiotics, the battle is still eminent due to the rise in antibiotic resistance, posing the need to develop feasible alternatives. Since plants proved to be sources of inspiration for novel drug compounds from their secondary metabolites, the present study aimed to investigate the effect of the crude extracts from the leaves of Tamarindus indica against selected pathogenic bacteria, as the plant is reported to have uncountable uses in traditional medicine. Maceration technique was employed for subsequent extraction of crude extracts using acetone and ethanol as solvents. Antibacterial activity of each crude extract was evaluated at a concentration of 100, 200 and 300 mg/ml through disk diffusion method. Tetracycline at 2.5 mg/ml and 1 ml of Tween 20 were used as positive and negative controls, respectively. Through serial dilution starting from 300 to 4.6875 mg/ml, minimum inhibitory concentration was also determined. The findings indicated that both acetone and ethanol crude extract showed antibacterial activity at all concentrations on both S. aureus and K. pneumonia, being significantly different from the negative control (P = 0.00), and insignificantly different from the drug (P > 0.05). However, K. pneumoniae showed more sensitivity to the extracts than S. aureus. The MIC value of LAE on S. aureus and K. pneumoniae were 18.75 and 9.375 mg/ml, respectively, whereas on the LEE, both showed MIC value of 18.75 mg/ml. The outcomes of this study indicated that the leaves have antibacterial properties; however, further study on the mechanism of actions and other related properties is required for the safe use of this plant in relation to the health problems.