Phytochemical Analysis, Antioxidant and Antibacterial Activities of Two Traditionally Used Indian Medicinal Plants

Aims: The aim of the present study was to determine the phytochemical constituents, antioxidant and antibacterial activities of crude extracts from leaves of two traditional Indian medicinal plants Catharanthus roseus and Ocimum basilicum.

Study Design: The methanol extracts of the leaves were used to study the antioxidant activity using DPPH and superoxide radical scavenging assays. The disc diffusion method was employed to evaluate the antibacterial activities on four major infective pathogenic agents.

Place and Duration of Study: The study was carried out at Post Graduate & Research Department of Biochemistry, Mohamed Sathak College of Arts and Science (Affiliated to University of Madras), Chennai - 600 119, Tamil Nadu, India during January 2017-August 2017.

Methodology: DPPH and superoxide radical scavenging assays were performed using standard methods. The disc diffusion method was employed to evaluate the antibacterial activities on four major infective pathogenic agents, namely, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis.

Results: Both the extracts exhibited strong DPPH and superoxide radical scavenging activities in a dose-dependent manner. The DPPH scavenging activity by Catharanthus roseus and Ocimum basilicum extracts was found to be 78.62±5.4% and 62.72± 4.2%, respectively. At the concentration of 100 µg/mL, the superoxide radical-scavenging activities of methanol extracts of Catharanthus roseus and Ocimum basilicum were found to be 72.36±3.21 and 68.76±3.16, respectively. Moreover, both the extracts showed a remarkable inhibition of bacterial growth at a concentration of 300 μg/mL compared to the two other doses tested (100 and 200 μg/mL).

Conclusion: Present findings provide experimental evidence that the leaves of Catharanthus roseus and Ocimum basilicum have potential antioxidant and antimicrobial activities which might be used as a functional food and safe remedy for the treatment of infectious diseases. This study also revealed that the plant could be a promising source for development of natural antioxidant and antibacterial agents.