Phytochemical evaluation and comparative antibiocide efficacy of Aqueous, Ethanolic and equal mixture of aqueous and ethanolic (1:1) bark extract of Lannea coromandelica L. procured from Eastern region of India

The present investigation was evaluating the potential antibacterial activity of three different extracts of the bark of Lannea coromandelica Linn. (LC) tree procured from Eastern India. Extraction of bark separation was carried out using aqueous, ethanol and a mixture of aqueous and ethanol. Microbiocides of all the extracts were separately evaluated against several microorganisms viz. Bacillus substilis, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonus aeruginosa, Escherichia coli and Serratia marcescens by agar diffusion technique. The Minimum Inhibition Concentration (MIC) of all the extracts was carried out by the serial dilution method. The results of MIC ranged from 12.5 to 150 mg/ml (all the three extracts). The concentration dependent (**P < 0.01) potential antimicrobial activity was resulted and at the dose of 200 mg/ml, combined aqueous and ethanol extract of LC (LCAE + LCEE) gave significant results against gram positive bacteria where the maximum zone of inhibition was recorded against Streptococcus pyogenes (17.0± 0.05**) followed by Straphyloccus aureus (13.6 ±0.05**). Further, the same extract showed the maximum relative percentage inhibition against Straphyloccus aureus (178.64%) followed by Streptococcus pyogenes (143.42%). Such variation may be due to the effects of choice of solvent and the quantity of the extracted amount and also the geographical source of the plant part. These results represent scientific evidence to support the traditional medicinal uses of LC bark extracts and indicate a promising potential used against the treatment of infectious diseases caused by pathogenic bacteria and also provide scientific evidence for their efficacy to prepare the alternate newer medicine for antibiotics.