ABSTRACT

Ziziphus rugosa Lam. a member of the Rhamnaceae family, is found in the semi-evergreen forests of the Western Ghat region, India. This plant is used in many traditional formulations owing to its benefits in miscarriage, misconception, syphilis, tachycardia, diarrhea, flatulence, dropsy, skin diseases, boils, mouth ulcer and hysteria. Successive extracts of Z. rugosa Lam. leaves were prepared using solvents of increasing polarity ranging from petroleum ether (60-80 °C) to water using the Soxhlet extraction method. The methanol extract of the leaves was used to prepare alkaloid rich fraction as per reported method and the total alkaloid content determined by UV-Vis spectroscopy. The extracts and the ARF were screened for antibacterial activity using selected Gram positive and Gram negative bacterial strains and ciprofloxacin as the reference standard. HR-LCMS was performed to identify the phytoconstituents present in the alkaloid rich fraction. Phytochemical studies of the extracts indicated the presence of tannins, phenolics, alkaloids, saponins, flavonoids and glycosides. The antimicrobial screening data indicated the extracts to exhibit concentration dependent inhibition of the test bacteria. The alkaloid rich fraction exhibited the best activity, significantly better than the solvent extracts across the selected panel of bacteria. The methanol and aqueous extracts showed moderate activity while the dichloromethane, pet ether and the ethyl acetate extracts were weakly active. HR-LCMS studies of the alkaloid rich fraction indicated the presence of several alkaloids detected for the first time in this plant. The observed bioactivity and traditional use warrants more investigations on this plant that would result in isolation and identification of new actives from this plant of immense traditional utility and maximizing its spectrum of utility.