In vitro comparative study of antimicrobial activity of whole plant and root's bark of Delonix regia (Bojer Ex. Hook)

Medicinal plants are the potent source of biologically active compounds and have always been of field of interest for the effective chemotherapeutic agents and offering a broad spectrum of activity with greater emphasis on preventive action. The present study was aimed at evaluating and comparing the antimicrobial spectrum of various extracts (methanolic, ethanolic, DCM and aqueous) of whole plant and root’s bark of Delonix regia against different pathogenic strains of bacteria and fungi, by adopting the disc diffusion method. Among all studied extracts, methanolic extract of whole plant (seeds, leaves and stem) showed the significant inhibitory response against S. aureus (91.84%), P. aeruginosa (91.05%), B. pumilus (85.75%) and E. coli (78.71 %). The descending sequences of antimicrobial activity of various extracts of whole plant of Delonix regia (seeds, leaves and stem) against studied microorganisms were as follows: methanolic extract, ethanolic extract, DCM extract, and aqueous extract. The results of the present study indicate that methanolic extract of the studied plant is a potentially good candidate for the therapy of antibacterial-resistant bacteria and would therefore require further study.