Phytochemical composition and bioactivity of Asparagus racemosus roots: Impact of processing on antimicrobial and antioxidant potential

This study aimed to evaluate the antimicrobial and antioxidant activity of the processed and unprocessed root extracts of Asparagus racemosus against common microorganisms. The roots were processed by boiling, peeling, and drying, while the unprocessed roots were washed, dried, and powdered. The extracts were subjected to qualitative phytochemical screening methods and extraction in four different solvents: methanol, ethyl acetate, ethanol and water. The total phenolic content, flavonoids, proteins and antioxidant activity were assessed using standard methods, and antimicrobial activity and minimum inhibitory concentration (MIC) were determined using agar-well diffusion and macro-broth dilution methods, respectively. The percent inhibition antioxidant activity of the processed and unprocessed roots was 34.9% and 34.2%, respectively. The total phenolic content was 0.174μg/mg GAE and 46.42μg/mg GAE for unprocessed and processed roots, respectively. The total protein was estimated to be 6539.74 μg/ml. Methanol was found to be the most effective extraction medium for the unprocessed roots, with the highest inhibition zone against Bacillus subtilis and Staphylococcus aureus. TLC profiling of the aqueous extracts of the processed and unprocessed root powder was performed in a chloroformmethanol solvent system. Qualitative analysis revealed major phenolic and saponin content in the alcoholic extracts. The root extracts before and after processing showed minor differences in antimicrobial and antioxidant activity but showed significant differences in total phenolic content and flavonoid content. The major phytochemicals were similar in both root samples. Thus, the present study confirms that the processed root extracts of A. racemosus possessed good nutraceutical potential and antibacterial activity.