Abstract

The present study was designed to evaluate the phytochemical composition, antimicrobial and radical-scavenging activities of ethanolic extract of Primula denticulata – an important medicinal herb of Kashmir Himalaya. Phytochemical study was performed by using various standard phytochemical methods. Free radical scavenging activities of the extract was assessed by employing different in vitro assays such as DPPH free radical scavenging assay, hydrogen peroxide scavenging activity and lipid per oxidation assay. Calf thymus DNA was also monitored by TBARS formation. The results were compared with standard antioxidant (?-tocopherol). Antibacterial activity of the extract was determined by agar well diffusion method. DPPH free radical scavenging assay and hydrogen peroxide scavenging activity revealed plant extract to be an active radical scavenger. P.denticulata extract also dose dependently inhibited the MDA formation or lipid per oxidation and as such might intercept the free radical chain of oxidation. The leaf extract also prevents calf thymus DNA from oxidative damage induced by hydroxyl radical generated by FeSO ₄ and H ₂ O ₂ in Fenton reaction. The hydroxyl radical quenching ability of polyphenolic compounds of Primula denticulata could be responsible for the protection against oxidative damage to DNA. The ethanolic extract showed anti-microbial activity which was visible as the zones of inhibition formed in the different cultures of Gram positive and Gram negative bacteria as well as in case of fungal cultures. Among all the maximum activity was seen for Escherichia coli with inhibition zone diameter of 23.53 3.71mm followed by Klebsiella pneumoniae with inhibition zone diameter of 20.74 3.33mm. These findings provide evidence that the considered plant possesses antimicrobial and antioxidant properties and may act as possible antioxidant for biological systems susceptible to free radical-mediated reactions.