Synergistic in vitro antibacterial activity of Tectona grandis leaves with tetracycline.

Abstract

The frontal leaves of Tectona grandis (Verabinaceae) are widely used in the folklore to treat various kinds of infections. The aim of this study was, to formulate new cost effective antimicrobial agent for multi drug resistant organisms, based on the synergistic activity of Tetracycline with methanolic extract of Tectona grandis. The Minimum Inhibition Concentration (MIC) of methanolic extract in combination with Tetracycline using 9 different Gram-positive and Gram-negative bacteria was found to be around 62.5 μg/ml -2000 μg/ml. The synergistic activity was varied using Kirby-Bauer method. It shows maximum synergistic activity against different bacteria both Gram-positive and Gram-negative species. The higher synergistic rate was attained against Salmonella typhimurium(MTCC 98) , Klebsiella pneumonia (MTCC 432), and lowest synergistic shows against Pichia pastoris (MTCC 34), Escherichia coli, (MTCC 729). No synergistic activity was observed in Citrobacter freondii (MTCC 1658)