In vitro comparative study of Bougainvillea spectabilis “stand” leaves and Bougainvillea variegata leaves in terms of phytochemicals and antimicrobial activity

摘要

AIM:To study the qualitative analysis of phytochemicals and antibacterial activity of the ethanolic and methanolic extracts of Bougainvillea spectabilis and Bougainvillea variegata leaves.METHODS:Phytochemical constituents were determined qualitatively by the Harborne method,while antimicrobial activities were determined by measuring the zone of inhibition on Mueller Hinton Agar.RESULTS:The maximum inhibitory effects were obtained against the Gram positive microbe Staphylococcus aureus for the methanolic extracts of both B.spectabilis [(28.54 ± 0.18) mm]and B.variegata [(21.97 ± 0.06) mm].The Gram negative microbes Proteus vulgaris [(16.00 ± 0.15) mm]and Serratia marcescens [(16.00 ± 0.06) mm]gave maximum inhibitory effects for the ethanolic extracts of B.variegata,while Salmonella typhimurium [(17.26 ± 0.12) mm]gave a maximum zone of inhibition for the methanolic extract of B.spectabilis.No inhibitory effects were observed for the extracts of B.spectabilis or B.variegate against Enterococcus faecalis,Vibro cholera or Klebsiella pneumoniae.CONCLUSION:Both B.spectabilis and B.variegata possess significant antimicrobial activity that,following additional studies,could replace commercially known antibiotics.