Curcuma longa (Turmeric): An auspicious spice for antibacterial, phytochemical and antioxidant activities.

ABSTRACT

Turmeric, a recognized spice, is known for miscellaneous health benefits in addition to culinary uses. In this study, in vitro evaluation of turmeric ethanol, methanol and aqueous extracts were mediated by disc diffusion, agar well method and phytochemical analysis. Purification of curcumin from turmeric was assisted by silica gel, TLC and HPLC for evaluation of its antioxidant and DNA protection activity. The sensitivity of alcoholic extracts against bacterial species differed, yet Staphylococcus aureus sub sp. Aureus and Bacillus subtilis both exhibited pronounced inhibition in disc diffusion and agar well method respectively. Overall, the crude ethanol extract of turmeric has an enhanced inhibitory effect on the growth of different bacterial species with a mean of 9.4±1.00 mm compared to 8.8±0.58 mm in case of crude methanol extract. Phytochemical analysis confirmed the presence of carbohydrates, flavonoids, coumarins, steroids, saponnins, tannins and phenols. Purification of curcumin through HPLC gave the main peak with 55% of acetonitrile at a retention time of 61- 65 minutes. Lower concentration of purified curcumin has protective effects on human DNA but increased concentrations instigate damaging effects. Its percentage scavenging ability was highest (91.84%) at 45 µg and per unit increase in the concentration prompted 6 units increase in percentage inhibition with a linear regression, R2= 0.914. All these traits boost its significance in herbal medicine with varied antimicrobial and pharmacological activities.