title: The in vitro pharmacological activities of 12 South African Hermannia species.
abstract: Hermannia species are widely used in traditional medicine in southern Africa, however no extensive study has been conducted on this genus. The acetone extracts of 12 indigenous Hermannia species (flowers, stems and leaves combined) were evaluated for various pharmacological activities. All investigated species displayed promising antimicrobial activity, with Hermannia saccifera being the most active against Staphylococcus aureus (MIC=19.5 microg/ml), Bacillus cereus (MIC=19.5 microg/ml) and Enterococcus faecalis (MIC=125 microg/ml). Time-kill studies on H. saccifera against S. aureus indicated bacteriostatic activity at 1.25, 2.5 and 5.0%, and a concentration of 7.5% achieved complete bactericidal activity after 4h. Ten of the 12 species indicated good free radical scavenging activity, with H. cuneifolia demonstrating the most promising activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH():IC(50)=10.26 microg/ml) and 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS(+)/TEAC: IC(50)=10.32 microg/ml) assays. In addition, all species exhibited moderate anti-inflammatory activity in the 5-lipoxygenase assay with the exception of H. cuneifolia (IC(50)=15.32 microg/ml). Overall, the selected species were low in cytotoxicity, except for H. saccifera and H. trifurca. Several Hermannia species indicated promising in vitro biological activity which relate to their traditional use in treating a number of disease states.
authors.affiliation: Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, Johannesburg, South Africa.
authors.forename: A B
authors.initials: AB
authors.lastname: Essop
authors.forename: R L
authors.initials: RL
authors.lastname: van Zyl
authors.forename: S F
authors.initials: SF
authors.lastname: van Vuuren
authors.forename: D
authors.initials: D
authors.lastname: Mulholland
authors.forename: A M
authors.initials: AM
authors.lastname: Viljoen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D005658:Fungi / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D016859:Lipoxygenase Inhibitors; D019660:Malvaceae / Q000737:chemistry* / Q000145:classification; D016488:Medicine, African Traditional; D008826:Microbial Sensitivity Tests; D008517:Phytotherapy; D010851:Picrates; D010936:Plant Extracts / Q000494:pharmacology; D012997:Solvents; D013019:South Africa; D013451:Sulfonic Acids
chemical_list: D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D016859:Lipoxygenase Inhibitors; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C004931:1,1-diphenyl-2-picrylhydrazyl