In vitro Antibacterial Activity of Manilkara hexandra (Sapotaceae) Seed Extracts and Violacein against Multidrug Resistant Streptococcus mutans

Extracts of the Pongamia pinnata, Manilkara hexandra, and Pyrus pyrifolia seeds prepared by microwave assisted extraction method, and the violet pigment- violacein extracted from Chromobacterium violaceoum were screened for their antibacterial activity against Streptococcus mutans.M. hexandra extracts were able to inhibit both the test strains of S. mutans used in this study with minimum inhibitory concentration (MIC) ranging from 600-800 µg/mL. These extracts exerted bactericidal action against S. mutans with minimum bactericidal concentration (MBC) of 600-900 µg/mL. Acetone extract of M. hexandra seeds registered highest average total activity of 231.20 mL/g. Extraction efficiency was found to have a moderately good correlation with antibacterial activity. Violacein exerted bactericidal action with MIC and MBC of less than 2 µg/mL against both the strains.