The Antibacterial and Phytochemical Aspects of Viola odorata Linn. Extracts Against Respiratory Tract Pathogens

Abstract

Monitoring of susceptibility of herbal drugs for bacterial pathogens is important for appropriate choice of treatment. The present study was to evaluate the antibacterial activity of various extracts of Viola odorata against selected respiratory tract pathogens i.e. Haemophilus influenzae MTCC 3826, Pseudomonas aeruginosa MTCC 2474, Staphylococcus aureus MTCC 1144, Streptococcus pneumoniae MTCC 655 and Streptococcus pyogenes MTCC 442. Plants were collected from Herbal Nursery, Prem Nagar Ashram, Haridwar, Uttarakhand and authenticated at Botanical Survey of India, Northern Regional Center, Dehradun. Properly washed and shade dried aerial parts of the plant material were crushed and extracted in petroleum ether, acetone, methanol and water by using Soxhlet apparatus. The antibacterial activity was examined by agar well diffusion method and the minimum inhibitory concentration (MIC) by twofold serial dilution method. Erythromycin was used as positive control to determine the sensitivity of the strains. The results showed that methanol extract was more active than other extracts in its antibacterial activity. The zone of inhibition exhibited by methanol extract against tested microorganisms ranged between 16 mm to 24 mm respectively. MIC values were recorded between 3.12 mg/ml to 12.5 mg/ml for all the organisms. Phytochemical analysis of methanolic extract revealed the presence of flavonoids, glycosides, alkaloids, steroids, saponins and tannins. The investigation supports a good response to the use of V. odorata in herbal medicine and as a base for the development of new drugs and phytomedicine in rationale for its use in treatment of respiratory infectious diseases.