title: The anti-diarrhoeal properties of Breonadia salicina, Syzygium cordatum and Ozoroa sphaerocarpa when used in combination in Swazi traditional medicine.
abstract: OBJECTIVE
  The aim of the study was to determine in vitro activity of the bark of Ozoroa sphaerocarpa R. Fern & A. Fern (Anacardiaceae), Breonadia salicina (Vahl) Hepper & J.I.R. Wood (Rubiaceae) and Syzygium cordatum Hochst ex C Krauss (Myrtaceae) against a diarrhoea-causing pathogen, Escherichia coli; as well as the pharmacological interactions present in their combination.
  
  
  METHODS
  In consultation with traditional healers, the plants were collected from the wild, dried and extracted with dichloromethane:methanol (1:1). Thereafter, antimicrobial activity of the individual plants and their different combinations was tested using a common diarrhoea pathogen, Escherichia coli by employing the minimum inhibitory concentration assay.
  
  
  RESULTS
  Ozoroa sphaerocarpa was the most potent inhibitor of antimicrobial growth (MIC value of 1.2 mg/ml), followed by Syzygium cordatum (MIC value of 1.44 mgl/ml) and lastly Breonadia salicina (MIC value of 10.89 mg/ml). The combination between Syzygium cordatum and Ozoroa sphaerocarpa gave the strongest synergistic interaction (MIC value of 0.33 mg/ml); whilst that between Syzygium cordatum and Breonadia salicina was mildly synergistic (MIC value of 1.00 mg/ml). The triple combination (1:1:1) was also very effective in inhibiting microbial growth (MIC value of 0.44 mg/ml). The combined effect of these plants on toxicity was predominantly synergistic except for the combination of Ozoroa sphaerocarpa and Syzygium cordatum which was predominantly antagonistic (ΣFIC value of 1.48 ± 0.25). The triple combination had a favourable toxicity profile with an IC(50) value of 155.76 ± 11.86 μg/ml.
  
  
  CONCLUSIONS
  This study supports the rationale by traditional healers to use the bark of Syzygium cordatum, Breonadia salicina and Ozoroa sphaerocarpa in combination for the treatment of diarrhoea.
authors.affiliation: Department of Pharmacy and Pharmacology, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa. sguguster@gmail.com
authors.forename: Gugu F
authors.initials: GF
authors.lastname: Sibandze
authors.forename: Robyn L
authors.initials: RL
authors.lastname: van Zyl
authors.forename: Sandy F
authors.initials: SF
authors.lastname: van Vuuren
mesh_terms: D027926:Anacardiaceae; D000890:Anti-Infective Agents / Q000494:pharmacology; D000930:Antidiarrheals / Q000494:pharmacology* / Q000633:toxicity; D003967:Diarrhea / Q000188:drug therapy*; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism; D004927:Escherichia coli Infections / Q000188:drug therapy*; D013541:Eswatini; D020128:Inhibitory Concentration 50; D008519:Medicine, Traditional; D008826:Microbial Sensitivity Tests; D027822:Myrtaceae; D008517:Phytotherapy; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology* / Q000633:toxicity; D019666:Rubiaceae
chemical_list: D000890:Anti-Infective Agents; D000930:Antidiarrheals; D010936:Plant Extracts