The phytochemistry and microbial activity of selected indigenous Helichrysum species
| dc.contributor.author | Reddy, Dakshina | |
| dc.date.accessioned | 2008-06-10T07:01:25Z | |
| dc.date.available | 2008-06-10T07:01:25Z | |
| dc.date.issued | 2008-06-10T07:01:25Z | |
| dc.description.abstract | ABSTRACT Helichrysum (Asteraceae) is a large genus consisting of approximately 500 species of which 245 taxa are indigenous to southern Africa. Many Helichrysum species are widely used by the indigenous population to treat various ailments, including coughs, colds, fever, infections, headache, menstrual pain and as a treatment for wounds. Medicinal uses are often not species-specific but often depend on the local availability. Guided by the traditional use and the lack of scientific information, nine species of Helichrysum were selected for this study. The essential oils were obtained through hydrodistillation and methanol and acetone extracts of the plant material were prepared. The essential oil composition was determined using GC-MS. The oil profiles were mostly dominated by the presence of monoterpenes such as a-pinene, 1,8-cineole and p-cymene. Monoterpenes were largely absent in the essential oil of H. felinum, but this oil was rich in sesquiterpenes with high yields of b-caryophyllene. The antimicrobial activity of the essential oils and plant extracts were of interest due to their traditional use as an antiseptic. The antimicrobial activity of the essential oils and extracts was determined by disc diffusion assays and, following this, the most active species were further investigated using the minimum inhibition concentration (MIC) assay. Helichrysum dasyanthum displayed the best activity against B. cereus (MIC = 16 mg/ml) and was the only extract that exhibited activity against all three fungal strains tested (C. neoformans, 1 mm; C. albicans, 3 mm; and A. alternata, 2 mm). The essential oil of H. petiolare and H. felinum exhibited the most pronounced activity against the fungal strains in the disc diffusion assay (C. albicans, 2mm). | en |
| dc.format.extent | 865763 bytes | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | http://hdl.handle.net/10539/4947 | |
| dc.language.iso | en | en |
| dc.subject | Helychrysum | en |
| dc.subject | antimicrobial | en |
| dc.subject | phytochemistry | en |
| dc.title | The phytochemistry and microbial activity of selected indigenous Helichrysum species | en |
| dc.type | Thesis | en |