Thesis (MSc (Biochemistry))--University of Stellenbosch, 2006. / The phytoestrogenic activity of Cyclopia, used to prepare honeybush tea, was evaluated and compared with that of the endogenous estrogen, 17-β-estradiol (E2) and the known phytoestrogen, genistein. Phytoestrogens are plant polyphenols much in demand in the nutraceutical market as they mediate an estrogenic effect through binding to estrogen receptor (ER) subtypes, ERα and ERβ.

Thesis (Master of Applied Sciences in Chemistry)--Cape Peninsula University of Technology, 2018. / The high demand of omega-3 fish oil nutraceuticals (dietary supplements) is due to the numerous health benefits contributed by the polyunsaturated fatty acids (PUFA’s). The nutraceutical industry is required to follow good manufacturing practice (GMP) standards in order to ensure label claims and prevent adulteration. It is vital that the quality control (QC) procedures will be able to detect adulterated products. It is thus necessary to ensure the analytical techniques are adequate by using validated methods. The qualification or identification of natural fish oils is a difficult task due to overlapping concentration ranges of PUFA’s and other similar properties. Gas chromatography (GC) is the prescribed technique in the nutraceutical industry for analysis of omega-3 fatty acids, but it is time-consuming and costly. Near infrared (NIR) spectroscopy is a rapid and cost-effective technique that can replace the prescribed method if proven equivalent, through validation according to pharmaceutical criteria. In this study, NIR spectroscopy in combination with chemometrics was considered as an alternative method to GC, to identify various commercial fish oils and to quantify the PUFA’s. Identification methods were developed for nine commercial omega-3 fish oils using spectral libraries. Quantitative NIR methods were developed for arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in fish oils expressed as mg.g-1 as well as percentage (%) area using partial least squares (PLS) regression and independent validation by superimposing datasets with mutual properties. Based on the statistics in terms of SEC, R2, SEP and r of the PUFA models, the NIR method was equivalent to the prescribed GC methods and precision results obtained were within the prescribed criteria. NIR spectroscopy and chemometrics can be used for conclusive identification and quantification of omega-3 fish oils, thereby minimizing the risk of adulteration. The method also complied with the prescribed pharmaceutical method validation criteria; therefore, was demonstrated as an alternative method to GC for the nutraceutical industry.

Research on the putative health benefits has indicated that kefir, a traditional fermented milk, might have antimutagenic and antitumor properties. The major objective of the present thesis was to isolate and identify antitumor compounds in cow's milk kefir and investigate the possible mechanisms involved. High speed centrifugation (HSC), molecular weight cut-off filtration (MWCO), size exclusion high performance liquid chromatography (SEC-HPLC) and reverse phase-HPLC (RP-HPLC) were utilized for fractionation of kefir and a cell culture model was developed to screen for the antiproliferative effects of the kefir fractions. The antiproliferative effects of bacteria-free extracts from different fermentation stages of kefir production, as well as bacteria-free extracts from milk and yogurt were compared. The results showed that extracts from an early stage of fermentation (i.e., kefir mother culture) and the final commercial kefir product both exerted dose-dependent inhibition effects on human mammary tumor MCF-7 cells, yogurt extracts showed less potent antiproliferative effects, while pasteurized milk extracts showed no antiproliferative effects. No antiproliferative effects of the kefir extracts were observed on human mammary epithelial cells (HMEC) whereas the yogurt extracts showed antiproliferative action in HMEC cells at a high dose. A fraction of the kefir mother culture isolated by HSC, MWCO and RP-HPLC contained components that inhibited MCF-7 cell growth and had no effect on HMEC cells. Characterization of the bioactive fraction using mass spectrometry (MS) indicated that the main components in the fraction are likely fragments of kefiran and/or ceramide containing compounds such as gangliosides. The growth inhibitory effect may be mainly caused by the induction of TNF-alpha in MCF-7 cells. Whole extracts of kefir depleted glutathione (GSH) in MCF-7 cells, while the SEC-HPLC Fraction 7 and the RP-HPLC Fraction 30 induced GSH produc

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