Philosophiae Doctor - PhD / Typha capensis (T. capensis), commonly known as bulrush, is a medicinal plant found growing in the wetland areas of South Africa. In traditional medicine, rhizome decoctions of T. capensis are used to treat a wide variety of ailments, including venereal disease, dysentery, diarrhoea and low libido in men. Previously, T. capensis rhizomes were shown to be a rich source of antioxidants, such as catechin and epicatechin, inhibiting both reactive oxygen species and reactive nitrogen species. The antioxidant capacity of such plant species serves as a reservoir of electrons to transport them into gold salt for the production of gold nanoparticles through green nanotechnology. Therefore, this study aimed to investigate the application of T. capensis in green nanotechnology and nano-medicine.

Philosophiae Doctor - PhD / Introduction: Typha capensis, commonly referred to as bulrush also called "love reed'' growing in Southern Africa's wetlands, is one of South Africa indigenous medicinal plants that are traditionally used to treat male fertility problems and various other ailments. Previous studies revealed that T. capensis has indeed a beneficial effect on male reproductive functions and aging male symptoms. The T.capensis rhizomes are used in traditional medicine during pregnancy to ensure easy delivery, for venereal diseases, dysmenorrhea, diarrhoea, dysentery, and to enhance the male potency and libido. Typha genuses contain flavones and other phenolic compounds, which exhibit anti-oxidative capacity. Materials and Methods: This study encompasses three parts (part 1: Exposure of different cell lines to crude aqueous extracts of T. capensis rhizomes; part 2: HPLC analysis of Typha capensis crude rhizome extract and exposure of different cell lines to the F1 fraction of the summer season; part 3: Compound identification by means of NMR spectrometric analysis and exposure of different cell lines to bioactive compounds (Quercetin and Naringenin) isolated from T. capensis rhizomes. Part 1: TM3-Leydig cells and LNCaP cells incubated with different concentrations of crude aqueous extract of T. capensis rhizomes (0.01, 0.02, 0.1, 1, 10 and 100 μg/ml) and control (without extract) for 24 and 96 hours, after incubation. The following parameters were evaluated: cell morphology and viability (determined by means of MTT assay). Part 2: The crude extract HPLC profiles were obtained by preparing the extracts for different seasons (Autumn, Winter, Spring, Summer). TM3-Leydig cells, LNCaP cells and PWR-1E cells incubated with different concentrations T. capensis rhizomes extract F1 fraction of the summer season (0.01, 0.02, 0.1, 1, 10 and 100 μg/ml) and control (without extract) for 24 and 96 hours, after incubation. The following parameters were evaluated: cell morphology was observed and recorded, viability (determined by means of MTT assay), testosterone production (testosterone ELISA test), cell early apoptosis (determined by means of Annexin V-Cy3 binding), DNA fragmentation (determined by means of the TUNEL assay). Part 3: NMR spectrometric analysis was performed on a 13C spectra were recorded at 400 MHz. TM3-Leydig cells and LNCaP cells incubated with different concentrations of bioactive compounds (Quercetin and Naringenin) isolated from T. capensis rhizomes, for acute exposure (24, 96 hours) and chronic exposure (96 hours), after incubation, the following parameters were evaluated: cell morphology and viability (determined by means of MTT assay), testosterone production (testosterone ELISA test), cell early apoptosis (determined by means of Annexin V-Cy3 binding) and DNA fragmentation (determined by means of the TUNEL assay). Results: Part 1: for TM3-Leydig cells the results reveal no observable morphological changes and no significant influence on cell viability except at highest concentration indicating cellular stress. However, LNCaP cells showed a decline in cell viability at the incubation period 96 hours (-82.4%) more than 24 hours (-64.7%) indicating more cell death. Part 2: HPLC data showed that the most effective fraction was the F1 fraction from the summer harvest. Results revealed that the T. capensis rhizome extract F1 fraction of the summer season significantly enhanced testosterone production in TM3 cells and was more toxic towards cancer cells (LNCaP cells ) compared to the normal cell lines (TM3-Leydig, PWR-1E cells). Part 3: NMR data showed 2 bioactive compounds which were identified as Quercetin and Naringenin. The assays showed that LNCaP cells are more sensitive to the cytotoxic effects and apoptosis induction of both compounds, whereas, the assays resulted in weak effects toward TM3-Leydig cells. However, testosterone production in TM3-Leydig cells was significantly enhanced at low concentrations of Quercetin and Naringenin at all exposure types (acute and chronic) testosterone beak significantly at around 0.100 and 0.125 μg/ml (P<0.0001), stimulatory activity in a dose-dependent manner. Conclusion: Typha capensis enhanced the production of testosterone and might be useful to treat male infertility and aging male problems. Results further reveal that the F1 fraction from the summer harvest had highest biological activity. This study, for the first time, investigated the effects of bioactive compounds (Quercetin and Naringenin) yeilded from aqueous extraction of Typha capensis rhizomes in cell lines investigating male reproductive functions. Active compounds present in the rhizomes have caused an increased production of testosterone level in TM3-Leydig cells. Furthermore, the active compounds of Typha capensis rhizomes in the high dose had a negative effect on the percentage of DNA fragmentation in LNCaP cells. When compared to the effect of the low dose, the two compounds induced significant apoptosis in cancer cell line (LNCaP) compared with the normal cell line (TM3-Leydig). The isolated compounds are significantly selective towards the cancer cells than the normal cell compared with the exposure of bioactive compounds used in this study.

Magister Scientiae (Biodiversity and Conservation Biology) / South Africa is recognised worldwide for its rich diversity of plants, many of which have been used in ethno-medicine. However, the use of wetland plant species in ethno-medicine required further investigations. This research is aimed at investigating three wetland medicinal, plant species, Centella asiatica, Cyperus longus and Typha capensis based on their geographical, seasonal, mineral nutrient (Fe, Mn, Ca, Mg, K and Na) and secondary metabolite characteristics. Samples of each species were collected from Grabouw, Kelderhoff, Kenilworth, Pringle Bay, University of the Western Cape (UWC) and Worcester within the Western Cape Province of South Africa. Specimen and soil collections were carried out during autumn, spring, summer and winter of 2014. Both plant and soil samples were acid digested and mineral nutrient concentrations in the samples were analysed using an atomic absorption spectrometer (AAS). Secondary metabolites were determined using analytical TLC on normal phase Merck-Silva gel coated aluminium plates as well as by using HPLC separation from crude extracts of C. asiatica, C. longus and T. capensis using LC-MS hardware from Agilent. The elemental analysis of soil samples showed that Ca, K, Mg, Mn and Zn concentrations were predominantly low. Soil mineral concentrations increased progressively from inland (Worcester) towards the coastland in the south (Pringle Bay). Calcium and sodium concentrations, in particular, were higher in soil samples obtained from Grabouw (inland south) and decreased northward towards Worcester. Comparatively, plant mineral concentrations were generally higher than soil concentrations. The high concentration of some of these essential elements, in selected plants is an indication that these plant species could be a good source of essential elements. High concentrations of phytochemicals were found in Centella asiatica during winter, while Cyperus longus and Typha capensis exhibited high concentrations during autumn indicating variation in respect of season. Consequently, harvesting of the studied plants should be done at the season with a relatively high phytochemical concentration. Studies are needed to investigate the extent of pesticide or herbicide contamination in wetland plants to protect the health of users. The LC-MS analyses of the three study species showed that seasonal variation affects metabolite constituents and moreover that these metabolite constituents differ from one locality to another. The seasonal variation of the elements in the studied medicinal plants justified the importance of harvesting seasons in the optimal utilization of the studied plants for medicinal purpose. s, for C. asiatica, anti-bacterial treatments for C. longus and fertility enhancement and birth control for T. capensis.

Magister Scientiae - MSc / The aim of this study was to use plants to determine the degree of heavy metal contamination in water and sediments in order to effectively monitor and provide possible recommendation to improve the water quality in the aquatic ecosystem of the Bottelary River.

The lack of proper wastewater treatment inhibits the social and economic development in many communities. The South African town Wakkerstroom is an example where wastewater is first treated before it is released. Due to the lack of technical expertise and funding to manage the sewage disposal system, a large part of the wastewater goes directly, without any treatment, into a stream feeding the Wakkerstroom wetland. The wetland purifies the wastewater and provides clean water downstream, thus is indispensable for its detoxification capacity. One relatively cheap method to determine the absorption capacity of a wetland with respect to nitrogen loading is to investigate the nitrogen uptake by the wetland vegetation. In this study, the nitrogen uptake of the vegetation in the Wakkerstroom wetland during the growing seasons between the years 2000-2018 was investigated by using harvested biomass and its nitrogen content as a proxy. The interannual variability of Net Primary Production (NPP) was calculated using a Light Use Efficiency (LUE) model for the period 2000-2018. The NPP derived with LUE-modelling was compared to NPP based on an end-of season harvest of biomass in March 2019. The nitrogen content and carbon and nitrogen (C:N) ratio were determined in the harvested biomass by carbon and nitrogen content analysis. The annual nitrogen uptake of the growing seasons between the years 2000-2018 was subsequently determined by multiplying the calculated NPP by the fraction of nitrogen found in the harvested material. The NPPtot based on harvested biomass (NPPharvest) towards the end of the growing season 2018/2019 was estimated to be 2.01 kg‧m-2‧season-1. The NPPtot calculated from LUE modelling (NPPLUE) varied between 0.49-1.64 kg‧m-2 for the growing seasons between 2000-2018. NPPharvest was between 1.2-4 times higher compared to NPPLUE, probably due to overestimation of NPPharvest because of biomass sampling of more than one-year production, or underestimation of NPPLUE due to a low maximum radiation conversion efficiency factor, εmax. The community mean nitrogen (N) content found in the biomass harvested aboveground was 1.29 % for the Phragmites community and 1.00 % for the Typha community. The nitrogen uptake of the vegetation was estimated to vary between 6.10-20.5 g N∙m-2 per growing season between the years 2000-2018. / Bristen på adekvata reningstekniker för att behandla avloppsvatten hämmar den sociala och ekonomiska utvecklingen i många samhällen. Den sydafrikanska staden Wakkerstroom är ett exempel där avloppsvatten först renas innan det släpps ut. På grund av brisen på teknisk kompetens och finansiering att hantera reningsverket som avlägsnar avloppsvatten så läcker en stor del av det orenade avloppsvattnet ut i en våtmark i Wakkerstroom via en närliggande å. Våtmarken är av regional betydelse för sin reningskapacitet då den renar avloppsvattnet och förser användare nedströms med rent vatten. En viktig aspekt för att bestämma en våtmarks reningskapacitet med avseende på kväve (N) är att undersöka växternas kväveupptag i våtmarken. Kväveupptaget hos växterna i våtmarken i Wakkerstroom under växtsäsongerna mellan år 2000–2018 undersöktes genom att använda skördad biomassa och dess kväveinnehåll som proxy. Den årliga variabiliteten hos nettoprimärproduktionen (NPP) beräknades genom att använda en LUE (Light Use Efficiency)-modell för perioden 2000-2018. NPP framtaget med LUE-modellering jämfördes med NPP baserat på biomassa skördad i slutet av växtsäsongen i mars 2019. Kväveinnehållet och kol-kväve (C:N) kvoten bestämdes hos den skördade biomassan genom en kol- och kväveanalys. Det årliga kväveupptaget under växtsäsongerna mellan 2000–2018 togs därefter fram genom att multiplicera beräknad NPP med kvävefraktionen erhållen från den skördade biomassan. NPPtot framtaget med biomassa skördad i slutet av växtsäsongen 2018/2019 (NPPbiomassa) uppskattades vara 2,01 kg‧m-2‧säsong-1. NPPtot beräknat med LUE-modellering (NPPLUE) varierade mellan 0,49–1,64 kg‧m-2 under växtsäsongerna mellan år 2000–2018. NPPbiomassa var 1,2–4 gånger högre i jämförelse med NPPLUE, vilket troligtvis berodde på att NPPbiomassa överskattades på grund av att mer än en årsproduktion av biomassa skördades, eller för att NPPLUE underskattades på grund av ett för lågt värde på den maximala effektivitetsfaktorn εmax valdes. Medelvärdet för kväveinnehållet erhållen i biomassan skördad ovanför vattennivån var 1,29 % för Phragmites-samhället och 1,00 % för Typha-samhället. Kväveupptaget hos växterna varierade mellan 6,10–20,5 g N∙m-2 per växtsäsong mellan år 2000–2018.