Abstract
The genus Scabiosa L., so called because of its traditional use for the treatment of scabies, belongs to the family Caprifoliaceae. This genus is relatively large comprising about 80 species distributed mainly in the Mediterranean, with only nine species occurring naturally in southern Africa. In southern Africa the genus was last revised by Harvey and Sonder (1865), however, the purpose of the current study was to provide a synopsis of the medicinally important species of the genus. In addition, the study aimed to record the ethnomedicinal uses of these species and identify the plants with which Scabiosa columbaria L. is used in combination. The third aim of the study was to evaluate S. columbaria and the plant combinations for antibacterial and anti-inflammatory activities and then assess interactive effects. The fourth aim was to evaluate S. columbaria for its antacid and acid neutralising potential and lastly, to investigate all the plants studied here for their toxicity levels. Herbarium specimens were examined to study the morphological characteristics and the geographical distribution patterns of the medicinal species. For the antibacterial activity, the minimum inhibitory concentration assay was used. The pathogens tested were Neisseria gonorrhoeae (sexual transmitted infections), Bacillus cereus, Enterococcus faecalis and Escherichia coli (gastrointestinal pathogens) and skin pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis). The anti-inflammatory activities were investigated through inhibition of the cyclooxygenase (COX) isoenzymes COX-1 and COX-2, as well as 15-lipoxygenase enzyme (15-LOX). Back titration of sodium hydroxide and Fordtran’s model were used to assess the antacid activities and neutralization potential of the selected plants. Lastly the brine shrimp lethality assay was used to test the toxicity of S. columbaria and plants used in combination. The results indicate that leaf morphology is of diagnostic importance in distinguishing the closely related taxa with differences observed in pubescence density, leaf shape, size and margins...
M.Sc. (Botany)