Protective Effect of Kickxia ramosissima (Wall.) Janchn Extracts Against Pathogenic Bacterial Strains and Free Radicals

Abstract

Plants are the major source of a wide array of antimicrobials and antioxidants. Present study describes the biochemical exploration of the methanol and chloroform extracts of aerial parts of Kickxia ramosissima (Wall.) Janchn. Main objective of study was to verify the antimicrobial and antioxidant value of its extracts. The crude extracts were subjected to different biological activities to explore the traditional medicinal potential of this herb. Antibacterial and antifungal activities were determined by using agar well diffusion and tube dilution assays, respectively, while antioxidant activity was investigated by DPPH free radical scavenging assay, phosphomolybdate assay and reducing power assay. The results indicated that both the extracts of aerial parts showed varied degree of antimicrobial, antifungal and antioxidant activities. Overall, the methanol extract showed comparatively better activities in various assays. It revealed significantly higher activity against all the tested bacterial strains (Pseudomonas spp. > Staphylococcus aureus > Staphylococcus epidermidis > Klebsiella pneumoniae > Escherichia coli). A maximum fungicidal activity (54.8%) has shown by methanol extract against Aspergillus terreus. The highest radical scavenging activity by DPPH method was found in case of methanol extracts (49.8% and IC50 228.53 µg ml−1) at 250 µg ml−1. In phosphomolybdate method, the highest activity was shown by methanolic extract (0.459 nm) at same concentration. Similarly, the highest activity evaluated by reducing power assay was 0.521 nm at the highest concentration of 250 µg ml−1. In conclusion, Kickxia ramosissima is a potential candidate for further studies to explore active compounds particularly responsible for antibacterial and antifungal and activities.