Thesis (MTech (Horticultural Sciences))--Cape Peninsula University of Technology, 2017. / The increasing demand for medicinal plants has led into serious over-harvesting of wild populations and presents an opportunity for potential profitable cultivation. Production of medicinal plants in controlled environments particularly hydroponic technology provides opportunities for high quality biomass accumulation and optimizes production of secondary metabolites. Water availability and supplies are becoming scarce, thus search for innovative irrigation practices is desirable and vital. The proper irrigation interval and growing media can play a major role in increasing the water use efficiency. Thus, Siphonochilus aethiopicus was cultivated by means of the hydroponic technique, under various substrate combinations and watering regimes.

Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2017. / The exact responses to the concentration of compost tea extract and methods of irrigation application were not previously measured on Hypoxis hemerocallidea and Siphonochilus aethiopicus. Commercial exploitation, habitat loss and degradation, overharvesting, and enhancement of their medicinal properties, have led to this investigation and the need to replenish both these valuable plant species. This is crucial for plant survival, especially in the wild and for use of the traditional medicinal plants. Hypoxis hemerocallidea and Siphonochilus aethiopicus, known as star flower and wild ginger respectively continue to decline, due to overharvesting from their natural habitat. Both these species have tremendous traditional medicinal value among localized African people. To enhance their commercial cultivation, compost tea extracts, in the following ratios (no catalyst added (control1); T 1000:1, T750:1, T500:1, and T250:1L) were applied in equal dosages to determine an optimal compost tea extract ratio. The experiment was conducted in a temperature controlled greenhouse. Mushroom compost (500 g, per brew) was used for all extracts. Brewing was done with no catalyst added (Control 1), and 24 hours later another brew was done with catalyst added, weekly for 20 weeks. The Control treatment received water only. Both species were slow growing and comparatively, the Hypoxis plants responded faster than the Siphonochilus plants. In this investigation, plant growth parameters such as plant height, number of leaves, leaf width, leaf length and leaf colour, were measured and evaluated. Despite the plants positive response to the mushroom compost tea extracts, across all the above plant growth parameters, no significant differences were noted between the treatments during the twenty-week application period. Leaf chlorophyll content peaked in week 11 of the hypoxis plants and was the highest in week 14 of the Siphonochilus plants with no significant interaction between weeks vs. treatment over the twenty-week experiment. The chlorophyll readings indicate that both species increased their chlorophyll production over time. Although the total wet leaf length, root length, corm diameter, leaf weight, corm weight and root weight of Hypoxis were non-significant between treatments, T500:1 total wet weight was significantly higher when compared to the rest of the treatments. The total dry weight analysis of hypoxis was non-significant. Control Calcium level was significantly lower between the control and the treatments of the Hypoxis total dry leaf nutrient analysis. The Hypoxis dried roots nutrient analysis was non-significant across treatments.

Plants used by southern African traditional healers for the treatment of menstrual pains were screened for prostaglandin-synthesis inhibitors and the ability to reduce isolated uterine muscle contraction using the cyclooxygenase (Cox-1) and in vitro uterine bioassays respectively. Prostaglandins are synthesized from arachidonic acid and the enzyme that drives this reaction is cyclooxygenase. The excessive production of prostaglandins by the myometrium and endometrium induces uterine contractions. Inhibition of cyclooxygenase and hence of the prostaglandin biosynthetic pathway may lead to relief of menstrual pain. Nine plants used by traditional healers for menstrual pains were assayed for cyclooxygenase inhibitory activity. Several plant extracts exhibited high inhibitory activity in the assay. The highest activities were obtained with ethanolic extracts of Siphonochilus aethiopicus, Cenchrus cilliaris and Solanum mauritianum. None of the ethanolic plant extracts were able to relax or reduce the contractions of a precontracted guinea pig uterus. Bioassay guided fractionation was used in an attempt to isolate the active compound(s) from the leaves of Siphonochilus aethiopicus. Isolation techniques employed were serial solvent extraction, bulk extraction, silica gel, Sephadex LH20 column, and high pressure liquid chromatography. Biological activity was followed through each purification step using the cyclooxygenase bioassay as a guide with respect to anti-inflammatory activity. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1999.