In vitro Evaluation of Phytochemicals and Antimicrobial activities of extracts of seeds and leaves of Lawsonia inermis Linn.

In the last two decades, antibiotic resistance has become a severe problem worldwide. This has lead to the search for new, safe and effective antimicrobial agents from alternative natural resources like plant products. Different parts of Lawsonia inermis L. (Family: Lythraceae) like roots, bark, leaves, flowers and seeds are traditionally used for the treatment of various ailments.  Alkaloids, tannin, phenolics, saponin and anthraquinone are present in both types of extracts of leaves of Lawsonia inermis. Glycosides are present in ethanolic extract of leaves and seeds. Terpenoids and flavonoids are not found in leaves but present in seeds. The disc diffusion assay showed that the leaves and seeds of Henna plant have different degrees of bacterial and fungal growth inhibition, depending on the strains.  The aqueous extracts showed broadest antimicrobial activity by inhibiting more or less most of the microbial strains involved. Aqueous extract was more effective than their ethanolic extracts. Klebsiella pneumonie and Serratia  marcescens were the most resistant strains tested. It could be concluded that seeds and leaves of Lawsonia inermis have potential antimicrobial efficacy. All extracts (aqueous or ethanolic) have shown better antimicrobial efficacy against Staphylococcus aureus, Escherichia coli and Aspergillus niger. Differential antimicrobial activity of plant parts against different bacteria might be due to concentration of different active phyto-compounds in different parts. Among those antimicrobial compounds, phenolic compounds, terpenoids, and alkaloids are very important compounds in antimicrobial or antioxidant action.