Antibacterial, Insecticidal and Free radical scavenging activity of methanol extract of Ziziphus rugosa Lam. (Rhamnaceae) fruit pericarp

Introduction:Ziziphus rugosa Lam. belongs to the family Rhamnaceae and is found chiefly in deciduous and semi-evergreen forest of Western Ghats. The present study was undertaken to determine antibacterial, insecticidal and free radical scavenging activity of methanol extract of Ziziphus rugosa Lam. fruit pericarp. Methods: The powdered fruit pericarp of Z. rugosa was extracted with methanol. Antibacterial activity of methanol extract was determined against Escherichia coli and Staphylococcus aureus by Agar well diffusion method. Free radical scavenging activity was determined using DPPH assay. The insecticidal activity of extract was tested against second instar larvae of Aedes aegypti. Results: The extract exhibited dose dependent inhibition of test bacteria. Among bacteria, E. coli was found to be more susceptible to extract than S. aureus. All the concentrations of extract produced over 50% mortality of larvae and the larvicidal effect was found to be dose dependent. The extract caused 100% mortality of larvae at concentration of 50 mg/ml. The extract exhibited concentration dependent radical scavenging activity with an IC50 value of 61.88 µg/ml. The phytochemical analysis of extract showed the presence of alkaloids, saponins, flavonoids and glycosides. Conclusion: The extract, in suitable form, may be used to control bacterial diseases, free radical damage and arboviral diseases. The phytoconstituents present in the extract may be responsible for the tested biological efficacies of extract. Further studies on isolation of active constituents from the extract and their biological activity are under investigation.