Antibacterial screening of the stem bark and leaf extracts of Litsea glutinosa (Lour.) C.B. Rob - an ethnomedicinally important tree of the Western Ghats

Abstract

Introduction:Litsea glutinosa (Lour.) C.B.Rob., is an aromatic medicinal tree belongs to the family Lauraceae and rarely distributed in the Western Ghats. Ethnomedicinally, the bark is used by the traditional practitioners as a demulcent, emollient and in the treatment of diarrhea and dysentery, and to facilitate wound healing process. The leaf paste is applied to relieve respiratory diseases; cough and also used as a demulcent and an emollient. Methods: The petroleum ether, chloroform and ethanol extracts of stem bark and leaf were screened for potential antibacterial activity using agar well diffusion method against 8 clinical strains isolated from infectious sources belonging to Gram-positive Staphylococcus aureus, Bacillus stubtilis and gram-negative Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi, Salmonella paratyphi and Proteus sp. Minimum Inhibitory Concentration (MIC) of the three sequential extracts of the leaf and stem bark was carried out against clinical isolated strains using two fold agar dilution method. Results: Ethanol extract of stem bark exhibited significant antibacterial activity with 2.5mg/ml MIC against Bacillus subtilis (19.20 ± 1.52), Escherichia coli (16.40 ± 0.55) and Staphylococcus aureus (15.20 ± 0.84) indicating the potent drug for the treatment of diarrhea and dysentery. Among the tree sequential extracts of the leaf the ethanol extract showed potent antibacterial activity against Klebsiella pneumoniae (16.40 ± 0.80) and may acting as a suitable drug for respiratory disorders. Conclusion: The obtained results justify the ethnomedicinal claims of Litsea glutinosa.