Evaluation of Antibacterial, Antifungal and Phytochemical Screening ofSolanum nigrum

The present study aimed at evaluating the antimicrobial potential of aqueous and methanolic extracts of Solanum nigrum, a traditionally used medicinal plant with multiple therapeutic properties. The susceptibility of microbial strains to the two extracts was determined using agar well diffusion method. The bacterial strains employed were Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris and Escherichia coli. The fungal strains used were Penicillium Chrysogenum, Aspergillus fumigatus, Candida albicans and Saccharomyces cerevisiae. Phytochemical screening was performed using standard methods. A dose dependent increase in the antibacterial activity was observed with both the methanol and aqueous extracts. Highest antibacterial activity was exhibited by aqueous extract with Escherichia coli (16 ± 0.23 mm) followed by Staphylococcus aureus (15 ± 0.15 mm) at the concentration of 100 mg/ml plant extract. Methanolic extract showed highest antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa with zone of inhibition (14 ± 0.11 mm) and (14 ± 0.26 mm) at the same concentration (100 mg/ml) respectively. The highest antifungal potential was exhibited by the methanolic extract against Saccharomyces cerevisiae (26 ± 0.27 mm) and Candida albicans (22 ± 0.13 mm), while the aqueous extract exhibits the highest antifungal potential against Saccharomyces cerevisiae (23 ± 0.14 mm) followed by Candida albicans (21 ± 0.10 mm) and Aspergillus fumigatus (16 ± 0.11 mm) at the concentration of 100 mg/ml. Phytochemical analysis revealed the plant is rich in various secondary metabolites like alkaloids, saponins, flavonoids, phenols and volatile oils. Cardenolides and phlobtannins were found absent. The study concludes that the plant possess novel compounds with significant antibacterial and antifungal properties. Isolation and characterization of these novel compounds could provide potent antimicrobial agents to combat pathogenic infections.