title: The antibacterial activity, antioxidant activity and selectivity index of leaf extracts of thirteen South African tree species used in ethnoveterinary medicine to treat helminth infections.
abstract: BACKGROUND
  Diseases caused by bacteria remain a major challenge globally and particularly in sub-Saharan Africa. The plants used in this study have been used in South Africa to treat helminth infections in livestock and humans. In a previous study we found a correlation between antifungal and anthelmintic activity in some cases. In this study we examined other potential uses of these thirteen plant species by determining the antibacterial and antioxidant activity of the leaf acetone extracts.The antibacterial activity was determined by using a serial microdilution method against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis. Bioautography was used to determine the number of antibacterial compounds. The antioxidant activity was determined using the ABTS and DPPH methods.
  
  
  RESULTS
  Maesa lanceolata and Leucosidea sericea with an MIC of 0.02 mg/ml had excellent antibacterial activity against Enterococcus faecalis and Pseudomonas aeruginosa. There was a poor correlation between antioxidant activity and antibacterial activity with R2 = 0.143. This is because antibacterial activity is mainly related to non-polar compounds and antioxidant activity to polar compounds. Maesa lanceolata extracts had a low cytotoxicity with a selectivity index of 5.2, 2.6, 2.6 and 1.3 for P. aeruginosa, E. faecalis, E. coli and S. aureus respectively. Strychnos mitis extracts had a therapeutic index of 1.1 for E. coli.
  
  
  CONCLUSIONS
  This study shows that plant extracts of some species used in ethnoveterinary medicine as anthelmintic may also have excellent antibacterial activity.
authors.forename: Mathew
authors.initials: M
authors.lastname: Adamu
authors.forename: Vinny
authors.initials: V
authors.lastname: Naidoo
authors.affiliation: Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria 0110, South Africa. kobus.eloff@up.ac.za.
authors.forename: Jacobus N
authors.initials: JN
authors.lastname: Eloff
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects; D019448:Ethnobotany; D006374:Helminthiasis, Animal / Q000188:drug therapy*; D008519:Medicine, Traditional; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D013019:South Africa; D019155:Veterinary Drugs
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D010936:Plant Extracts; D019155:Veterinary Drugs