Chemical composition, antimicrobial activity and cytotoxicity of Murraya paniculata (L.) Jack leaf essential oil from Assam, India: the effect of oil on cellular morphology of micro-organisms.

Murraya paniculata (L.) Jack is commonly cultivated as ornamental plant in Assam and has been used as spice and phytomedicine traditionally for many healthcare purposes. The therapeutic potential and chemical constituents of the essential oil of M. paniculata leaf was investigated against several pathogenic microbial species and human cancer cell lines. 29 chemical compounds were identified by GC-MS analysis from the essential oil representing 97.62% of the oil. The major compound identified was caryophyllene (20.93%). Leaf essential oil exhibited promising antibacterial activity against Mycobacterium smegmatis (MIC = 4 µg/mL) and Pseudomonas aeruginosa (MIC = 4 µg/mL). Best anticancer activity of the oil was observed for HeLa cells (IC 50  = 6.28 μg/mL). Further, scanning electron microscopic studies revealed that the oil kills micro-organisms with the deformation of cellular morphology on treatment of the oil. Thus, the essential oil of M. paniculata leaf can be an excellent alternative for development of new antimicrobials and anticancer chemotherapeutic agents for the pharmaceutical industries.