title: Mechanism of antibacterial action of the alcoholic extracts of Hemidesmus indicus (L.) R. Br. ex Schult, Leucas aspera (Wild.), Plumbago zeylanica L., and Tridax procumbens (L.) R. Br. ex Schult.
abstract: Herbal products derived from Hemidesmus indicus (L.) R. Br. ex Schult, Leucas aspera (Wild.), Plumbago zeylanica L., and Tridax procumbens (L.) R. Br. ex Schult. are widely used in traditional medicine. Though the extracts of these plants were found to be antimicrobial in nature and have the potential to be used in clinics, the mechanism of action of is not reported. The ethanolic extracts of Hemidesmus indicus (L.) R. Br. ex Schult, Hemidesmus indicus ethanolic extract (HIEE), Leucas aspera (Wild.), Leucas aspera ethanolic extract (LAEE), Plumbago zeylanica L., Plumbago zeylanica ethanolic extract (PZEE), and Tridax procumbens (L.) R. Br. ex Schult, Tridax procumbens ethanolic extract (TPEE) were tested for their antibacterial activity against E. coli. Antibacterial activity was analyzed by CFU assay and the effect on the bacterial membrane by fluorescence activated cell sorting and scanning electron microscopy. LAEE, PZEE, and HIEE displayed potent bacterial killing activity in a time and concentration dependent manner. TPEE did not display appreciable antibacterial activity. The antibacterial action involved disruption of membrane potential, inner membrane permeabilization, blebbing and leakage of cellular contents. Our results contribute to the understanding of the antibacterial mechanism of alcoholic extracts of the medicinal plants used in this study.
authors.affiliation: Department of Biochemistry, University of Hyderabad , Hyderabad, India.
authors.forename: Kongari
authors.initials: K
authors.lastname: Saritha
authors.affiliation: Department of Animal Biology, University of Hyderabad , Hyderabad, India.
authors.forename: Angireddy
authors.initials: A
authors.lastname: Rajesh
authors.affiliation: Department of Biochemistry, University of Hyderabad , Hyderabad, India.
authors.forename: Khanapur
authors.initials: K
authors.lastname: Manjulatha
authors.affiliation: Department of Biochemistry, University of Hyderabad , Hyderabad, India.
authors.forename: Oruganti H
authors.initials: OH
authors.lastname: Setty
authors.affiliation: Department of Animal Biology, University of Hyderabad , Hyderabad, India.
authors.forename: Suresh
authors.initials: S
authors.lastname: Yenugu
keywords: antibacterial activity; flow cytometry; herbal products; membrane permeabilization