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The purpose of this study was to assess the effects of dietary fish oil (FO) and rooibos supplementation on semen quality, fatty acids composition and reproductive performance of aged male broiler breeders. Seventy-two 47-week-old Ross broiler breeder roosters were randomly assigned to a 2 × 3 factorial arrangements to include two FO concentrations (0% and 2%) and 3 rooibos concentrations (0%, 1.5% and 3%) for 13 weeks consecutive. The different diets affected semen parameters significantly (p 0.05), except for the semen concentration and abnormality of the sperm. The sperm of the FO and 3% rooibos-treated group showed better motility and viability when compared to the other groups (p 0.05). The susceptibility of semen to lipid peroxidation was increased in roosters fed the rooibos-free diets (p 0.05), but it was reduced (p 0.05) when the diet was supplemented with 1.5% and 3% rooibos. In addition, at 64 weeks, the highest concentration of testosterone was observed in the roosters fed a diet that included 2% FO and 3% rooibos (p 0.05); however, the difference in testosterone levels between Week 52 and Week 64 was not significant (p 0.05). The fertility rate of collected eggs from the FO and 3% rooibos group was higher (p 0.05) than that of the other groups at the end of the experiment. In conclusion, dietary inclusion of FO along with rooibos improved seminal quality and reproduction performance in aged roosters.

Citrullus colocynthis (C. colocynthis) seed is a common and expensive cuisine in West African diet unlike the seeds from Citrullus lanatus (C. lanatus) that are agro waste. The oils from these seeds were comparatively profiled using their physicochemical properties, fatty acids and phenolic contents, in-vitro antioxidant capacity (DPPH, TEAC, FRAP, ORAC), inhibitions of lipid peroxidation and tyrosinase. Toxicities of the oils in mice were also assessed using plasma AST, ALT, cholesterol, HDL-C, liver, heart and kidney (GSH, GPx and SOD) and clastogenic effects in mouse bone marrow. Citrullus lanatus oil contains higher peroxides, saponification, saturated fatty acids and stearic acid (6-fold) levels, with a lower acid value when compared to C. colocynthis. Strong antioxidant capacity, inhibition of lipid peroxidation and tyrosinase by C. lanatus oil extract is proposed to be related to the presence of catechins that are absent in C. colocynthis. The in-vivo study indicated that C. lanatus induced significant increase in ALT while a significant increase of AST was observed in the C. colocynthis treated group. Citrullus lanatus induced a significantly (p 0.05). This work reports for the first time the presence of stearic acid and catechin in C. lanatus oil which is important for its compelling in vitro activity. High doses of both oils could evidently induce toxicological indices in mice.

South Africa, a country considered affluent in nature, ranks third in global biodiversity and encompasses approximately 9% of higher plants on planet Earth. Many indigenous plants have been utilised as herbal medicine, proving successful in treating numerous ailments. From the common cold to pandemic maladies such as COVID-19 in the 21st century and the treatment of incurable diseases, South African inhabitants have found great promise in the healing properties of these plants. Phytomedicine is a rapidly evolving topic, with in-depth bioactive composition analysis, identifying therapeutic action mechanisms, and disease prevention. While we are now poised to take advantage of nature’s medicine cabinet with greater scientific vigour, it remains critical that these practises are done with caution. Overharvesting significantly impacts biodiversity and cultivation practices amidst the beautiful nature of these nutraceuticals. This book chapter focuses on the therapeutic potential of commonly used South African medicinal plants, their ethnopharmacological properties, and how we can conserve this treasure cove we call home for future generations.

Malignant primary brain tumours are reported to be the leading cause of death from solid tumours in children and the third leading cause of death from cancer in adolescents and adults. Current treatment options include surgery, radiation and chemotherapy. Despite these treatment options, patient survival still remains poor. The Amaryllidaceae family contains alkaloids which have shown several biological activities including the treatment of Alzheimer's disease. This study investigates the cytotoxic activity of the methanolic extracts of fourteen plants belonging to the Amaryllidaceae family in brain tumour cell lines. The MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay was used to determine the effects of plant extracts on cell viability while routine antioxidant assays were conducted to determine the antioxidant activities of the extracts. Results showed that of the fourteen extracts, five (Cyrtanthus breviflorus, Amaryllis belladonna, Crinum variabile, Haemanthus pubescens, Nerine filifolia) showed cytotoxicity in all the cell lines tested with IC50 values under 100 µg/mL. Six extracts (Crinum moorei, Clivia miniata, Haemanthus amarylloides, Crossyne guttata, Nerine humilis, and Ammocharis longifolia) showed varying levels of cytotoxicity in the cell lines tested and were unable to induce 50% reduction in cell viability across the cell lines tested at the highest concentration of 100 µg/mL. Furthermore, three plant extracts (Brunsvigia bosmaniae, Boophone disticha, Strumaria truncata) had minimal or no cytotoxic effects on all cell lines tested when compared to control. The extracts also showed varying degrees of antioxidant activity but were not as potent as the positive control. Findings from this study suggest that species of the Amaryllidaceae family may be useful sources of phytochemicals for the treatment of central nervous system cancers and should be further explored in animal models of central nervous system (CNS) and other cancer types.

Fumonisins are a family of potentially carcinogenic mycotoxins produced by Fusarium verticillioides. Several fumonisins have been identified with fumonisin B1 (FB1 ) being the most toxic. The canonical mechanism of FB1 toxicity is centered on its structural resemblance with sphinganine and consequent competitive inhibition of ceramide synthase and disruption of lipidomic profiles. Recent and emerging evidence at the molecular level has identified the disruption of mitochondria and excessive generation of toxic reactive oxygen species (ROS) as alternative/additional mechanisms of toxicity. The understanding of how these pathways contribute to FB1 toxicity can lead to the identification of novel, effective approaches to protecting vulnerable populations. Natural compounds with antioxidant properties seem to protect against the induced toxic effects of FB1 . Rooibos (Aspalathus linearis), endemic to South Africa, has traditionally been used as a medicinal herbal tea with strong scientific evidence supporting its anecdotal claims. The unique composition of phytochemicals and combination of metabolic activators, adaptogens and antioxidants make rooibos an attractive yet underappreciated intervention for FB1 toxicoses. In the search for a means to address FB1 toxicoses as a food safety problem in developing countries, phytomedicine and traditional knowledge systems must play an integral part. This review aims to summarize the growing body of evidence succinctly, which highlights mitochondrial dysfunction as a secondary toxic effect responsible for the FB1 -induced generation of ROS. We further propose the potential of rooibos to combat this induced toxicity based on its integrated bioactive properties, as a socio-economically viable strategy to prevent and/or repair cellular damage caused by FB1 .

Shortage in insulin secretion or degradation of produced insulin is the principal characteristic of the metabolic disorder of diabetes mellitus (DM). However, because the current medications for the treatment of DM have many detrimental side effects, it is necessary to develop more effective antidiabetic drugs with minimal side effects. Alpha-glucosidase and alpha-amylase inhibitors are directly implicated in the delay of carbohydrate digestion. Pharmacologically, these inhibitors could be targeted for the reduction in glucose absorption rate and, subsequently, decreasing the postprandial rise in plasma glucose and the risk for long-term diabetes complications. The main objectives of this research study were to isolate different phytochemical constituents present in the methanolic extract of

Helichrysum species are prominent South African medicinal plants. From the essential oils (EOs) of three Helichrysum species, H. petiolare, H. odoratissimum, and H. cymosum, sixty-three constituent components were identified, with hydrocarbons and oxygenated monoterpenes and sesquiterpenes as major components. The compounds were analyzed by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. In H. petiolare EO, the major components were faurinone (20.66%) and (E)-β-ocimene (17.21%). Faurinone was isolated from this EO for the first time. In H. odoratissimum, 1,8-cineole (17.44%) and α-pinene, and γ-curcumene (15.76%) were the major components whereas, in H. cymosum, α-pinene (29.82%) and (E)-caryophyllene (19.20%) were the major components. In the antibacterial activity study, the EOs were tested against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The EOs were found to possess low antibacterial, anti-tyrosinase, and photoprotection activities and moderate antioxidant capacities, thus establishing these Helichrysum EOs as valuable antioxidant agents.

Skin cells suffer continuous damage from chronic exposure to ultraviolet light (UV) that may result in UV-induced oxidative stress and skin thinning. This has necessitated the formulation of cosmeceutical products rich in natural antioxidants and free radical scavengers. Aspalathus linearis (rooibos) is an endemic South African fynbos plant growing naturally in the Western Cape region. The plant is rich in phenolics and other bioactives with a wide spectrum of health benefits. The chemical study of an acetonic extract of green A. linearis afforded a novel compound named linearthin (1) and two known dihydrochalcones, aspalathin (2) and nothofagin (3). The chemical structure of the novel compound was elucidated based on spectroscopic data analysis. The bio-evaluation of the isolated chalcones in vitro for protection against UVB-induced oxidative stress were systematically assessed by examining cell viability, metabolic activity, apoptosis, and cytotoxicity using HaCaT and SK-MEL-1 skin cells models. It was observed that pre-treatment with tested samples for 4- and 24 h at low concentrations were sufficient to protect skin cells from UVB-induced damage in vitro as evidenced by higher cell viability and improved metabolic activity in both keratinocytes (HaCaT) and melanocytes (SK-MEL-1). The results further show that the pre-treatment regimen employed by this study involved some degree of cellular adaptation as evidenced by higher levels of reduced glutathione with a concomitant decrease in lipid peroxidation and lowered caspase 3 activity. Furthermore, compound 1 was most cytoprotective against UVB irradiation of HaCaT cell line (over 24 h) with an IC50 of 282 µg/mL and SK-MEL-1 cell line with IC50 values of 248.3 and 142.6 µg/mL over 4 and 24 h, respectively. On the other hand, HaCaT cells exposed to 2 over 4 h before UVB irradiation showed the highest degree of cytoprotection with an IC50 of 398.9 µg/mL among the four studied samples. These results show that linearthin (1) and the two glycoside dihydrochalcone of A. linearis have the potential to be further developed as antioxidant cosmeceutical ingredients that may protect skin against UVB-induced damage.

The South African medicinal plant Oncosiphon suffruticosum (L.) Källersjö is an important remedy used to treat chronic, respiratory, and skin ailments. From the essential oil (EO) extracted by the hydrodistillation, sixteen constituent components were identified with oxygenated monoterpenes: camphor (31.21%), filifolone (13.98%), chrysanthenone (8.72%), 1,8-cineole (7.85%), and terpinen-4-ol (7.39%) as predominant constituents. In the antibacterial activity study, the EO was found most susceptible against Pseudomonas aeruginosa with an MIC of 6.4 mg/mL; however, it showed the same activity against Staphylococcus aureus and Escherichia coli with an MIC value of 12.8 mg/mL. The sun protecting factor (SPF) of the EO was found to be 2.299 and thus establishing it as a potentially important cosmeceutical for sunscreen applications. This is the first report investigating the essential oil of O. suffruticosum for its chemical composition and skin-related in vitro biological activities viz antibacterial, antioxidant capacity, antityrosinase, and sun protection factor.

Lipopolysaccharide (LPS), a well-conserved cell wall component of Gram positive bacteria, exerts its toxic effects via inducing oxidative and pro-inflammatory responses. Red palm oil (RPO) is a unique natural product with a balanced ratio of saturated and unsaturated fatty acids, with reported antioxidant and anti-inflammatory effects. In this study, we assess the protective effect and mechanistic action of RPO using a lipopolysaccharide (LPS)-induced hepatic injury model. Male Wistar rats were assigned into four groups (10 animals/group): normal control (NC), RPO, LPS and RPO + LPS. Animals in the RPO and RPO + LPS groups were administered RPO (200 μL/day) for 28 days. On the 27th day of experiment, animals in LPS and RPO + LPS groups were injected with LPS (0.5 mg/kg body weight). Animals were sacrificed 24 h later, and blood and liver tissues harvested for biochemical and molecular analysis. RPO resolved hepatic histological dysfunction induced by LPS, and lowered alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyl transferase activities in the serum. Hepatic malondialdehyde and conjugated dienes, as well as pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6 and TNFα were significantly diminished (p < 0.05) by RPO pre-treatment. Activity of hepatic antioxidant enzymes including superoxide dismutase, glutathione reductase, glutathione peroxidase, as well as glutathione redox status (GSH:GSSG), and markers of antioxidant capacity that decreased as a result of LPS injection were improved by RPO pre-treatment. Mechanistically, RPO up-regulated mRNA expression of redox sensitive transcription factor Nrf2 and its downstream targets GCL and HO-1, while also suppressing the expression of NFκβ and associated inflammatory protein, Iκβ kinase (IκKβ). In conclusion, this study highlights the ameliorating effects of RPO against LPS-induced hepatic injury and revealed the Nrf2/GCL/HO-1 and NFκβ signaling axis as potential contributing mechanisms.

Diabetes mellitus (DM) is a group of systemic metabolic disorders with a high rate of morbidity and mortality worldwide. Due to the detrimental side effects of the current treatment, there is a great need to develop more effective antidiabetic drugs with fewer side effects. Natural products are a well-known source for the discovery of new scaffolds for drug discovery, including new antidiabetic drugs. The genus Helichrysum has been shown to produce antidiabetic natural products. In this investigation, the methanolic extract of H. cymosum and H. pandurifolium resulted in the isolation and identification of eleven known compounds viz 5,8-dihydroxy-7-methoxy-2-phenyl flavanone (1), pinostrobin (2), dihydrobaicalein (3), glabranin (4), allopatuletin (5), pinostrobin chalcone (6), helichrysetin (7), 5-hydroxy-3,7-dimethoxyflavone (8), 3,5-dihydroxy-6,7,8-trimethoxyflavone (9), 3-O-methylquercetin (10), and 3-methylethergalangin (11). The in vitro bio-evaluation of isolated compounds against alpha-glucosidase showed that 10, 5, and 11 demonstrated the highest alpha-glucosidase inhibitory activity with IC50 values of 9.24 ± 0.4, 12.94 ± 0.2, and 16.00 ± 2.4 μM respectively, followed by 7 and 3 with IC50 values of 18.16 ± 1.2 and 44.44 ± 0.2 μM respectively. However, none of these compounds showed a measurable inhibitory effect on alpha-amylase under the experimental conditions used except compound 10 which showed a poor alpha-amylase inhibitory activity with an IC50 value of 230.66 ± 15.8 μM. Additionally, strong total antioxidant capacities were demonstrated by 10, 5 and 7 in ferric-ion reducing antioxidant power assay (374.34 ± 69.7; 334.37 ± 1.7; 279.93 ± 0.8) µmol AAE/mmol. This is the first scientific report to be carried out on alpha-glucosidase inhibitory activities and antioxidant capacities of H. cymosum constituents and a first report on the isolation and identification of methoxyflavanoids from H. pandurifolium. Our findings suggest that these compounds are promising candidates to inhibit alpha-glucosidase as well as oxidative stress related to diabetes. Results from molecular docking provided insight into the observed in vitro alpha-glucosidase inhibitory activities for 5, 7, 10, and 11. It is envisaged that the isolated phytochemicals from these plants may contribute to the development of hypoglycemic lead compounds with anti-diabetic potential.

Graphical abstract, This article presents the potential health benefits of Rooibos to be considered a support during the COVID-19 pandemic. The recent pandemic of COVID-19 has led to severe morbidity and mortality. The highly infectious SARS-CoV-2 is known to prime a cytokine storm in patients and progression to acute lung injury/acute respiratory distress syndrome. Based on clinical features, the pathology of acute respiratory disorder induced by SARS-CoV-2 suggests that excessive inflammation, oxidative stress, and dysregulation of the renin angiotensin system are likely contributors to the COVID-19 disease. Rooibos, a well-known herbal tea, consumed for centuries, has displayed potent anti-inflammatory, antioxidant, redox modulating, anti-diabetic, anti-cancer, cardiometabolic support and organoprotective potential. This article describes how Rooibos can potentially play a supportive role by modulating the risk of some of the comorbidities associated with COVID-19 in order to promote general health during infections.

Fumonisins are a family of potentially carcinogenic mycotoxins produced by Fusarium verticillioides. Several fumonisins have been identified with fumonisin B

Oxidative stress and inflammation are intricately interlinked as aetiological factors in the context of ageing and chronic disease-related accelerated ageing. Previous research by our group has highlighted the anti-oxidant and anti-inflammatory potential of grape-derived polyphenols in the context of acute inflammation and oxidative stress. The aim here was to add to this by assessing efficacy of the treatment (acutely) to address ageing-associated cumulative pro-oxidant and pro-inflammatory changes in an in vitro model. Blood from young and aged humans was analysed for baseline oxidative stress and inflammatory status. Isolated neutrophils were acutely exposed to the polyphenol treatment in vitro. The chemokinetic capacity of treated and control neutrophils in response to fMLP was subsequently determined in a Dunn chamber, using live cell imaging. Neutrophils were also analysed for the expression of selected molecular markers associated with functional capacity and oxidative stress. Results indicate that the aged population had significantly worse oxidative stress and inflammatory profiles (higher plasma conjugated dienes and MPO) than young controls. Neutrophils isolated from both young and aged individuals had improved chemokinetic accuracy and capacity after in vitro polyphenol treatment. Additionally, increased shedding of CD16 and expression of CD66b suggested sites via which the polyphenol achieved improved neutrophil motility. We conclude that grape seed-derived polyphenols facilitated improved neutrophil functionality by acting on the molecular targets elucidated here.

Trihalomethane group of disinfection by-products was used to evaluate the magnitude of physiological changes induced on nutrient levels, oxidative stress and phytosterol content in two tomato cultivars. The tomato cultivars were grown as potted plants in a greenhouse and exposed to the varying concentrations of trihalomethanes and organochlorines via irrigation water for a period of 30 days. The concentration levels of nitrogen, potassium and boron in both cultivars significantly (p

Ethnopharmacological relevance Cyclopia intermedia is indigenous to South Africa and used to prepare honeybush herbal tea. This aromatic herbal tea has been associated with numerous health benefits, mostly based on anecdotal evidence and with very few studies reporting on the antimicrobial activities. Aim The inhibitory effect on the growth of important nosocomial microorganisms and possible association with the antioxidant capacity/content of various solvent extracts of green/unfermented and fermented honeybush plant material were determined in the current study. Materials and methods The agar disk diffusion assay was used as a screening assay for the antimicrobial activity of the various honeybush extracts, while the minimal inhibitory concentration (MIC) values, using the broth micro-dilution method, were determined against Streptococcus pyogenes , Staphylococcus aureus and Candida albicans . Active antimicrobial compounds were then shown using thin layer chromatography bioautography. Total antioxidant capacities and -content were also determined for each extract, while the main phenolic compounds were quantified using HPLC. Results Six of the eight solvent extracts of honeybush showed antimicrobial activity, with the fermented and green methanol extracts being most effective against S. aureus and C. albicans respectively, whilst the green chloroform extract was most potent against S. pyogenes . Thin layer chromatography-bioautography acknowledged the existence of active antimicrobial fractions within these different solvent honeybush extracts. Regardless of the assay, the green honeybush extracts generally exhibited the highest antioxidant capacity when compared to the fermented honeybush. The total polyphenols were also observed to be highest in green extracts when using water and methanol as solvents. In general the mangiferin and hesperidin contents were higher in the green than the fermented extracts of honeybush plant material. Conclusions The inhibitory activity of the various extracts against specific microorganisms was observed to be linearly proportional to the extract concentration. Although the different solvent extracts can only be considered weak antimicrobial agents, three compounds showed specific activity and should be further elucidated in future. It appears the antioxidant capacity of the various solvent herbal extracts did not relate to the antimicrobial activities; however, further work will be required to ascertain this observation. The current data also suggested that the various extracts of honeybush can be considered a good source of a unique blend of natural phytochemical antioxidants and antimicrobial compounds and should be further elucidated.

In this study, procyanidins fractions of dimers and trimers (F1–F2) from the Leucosidea sericea total extract (LSTE) were investigated for their chemical constituents. The total extract and the procyanidins were employed in the synthesis of gold nanoparticles (Au NPs) and fully characterized. Au NPs of 6, 24 and 21 nm were obtained using LSTE, F1 and F2 respectively. Zeta potential and in vitro stability studies confirmed the stability of the particles. The enzymatic activity of LSTE, F1, F2 and their corresponding Au NPs showed strong inhibitory alpha-amylase activity where F1 Au NPs demonstrated the highest with IC50 of 1.88 µg/mL. On the other hand, F2 Au NPs displayed the strongest alpha-glucosidase activity at 4.5 µg/mL. F2 and F2 Au NPs also demonstrated the highest antioxidant activity, 1834.0 ± 4.7 μM AAE/g and 1521.9 ± 3.0 μM TE/g respectively. The study revealed not only the ability of procyanidins dimers (F1 and F2) in forming biostable and bioactive Au NPs but also, a significant enhancement of the natural products activities, which could improve the smart delivery in future biomedical applications.

Skin cells suffer continuous damage from chronic exposure to ultraviolet light (UV) that may result in UV-induced oxidative stress and skin thinning. This has necessitated the formulation of cosmeceutical products rich in natural antioxidants and free radical scavengers. Aspalathus linearis (rooibos) is an endemic South African fynbos plant growing naturally in the Western Cape region. The plant is rich in phenolics and other bioactives with a wide spectrum of health benefits. The chemical study of an acetonic extract of green A. linearis afforded a novel compound named linearthin (1) and two known dihydrochalcones, aspalathin (2) and nothofagin (3). The chemical structure of the novel compound was elucidated based on spectroscopic data analysis. The bio-evaluation of the isolated chalcones in vitro for protection against UVB-induced oxidative stress were systematically assessed by examining cell viability, metabolic activity, apoptosis, and cytotoxicity using HaCaT and SK-MEL-1 skin cells models. It was observed that pre-treatment with tested samples for 4- and 24 h at low concentrations were sufficient to protect skin cells from UVB-induced damage in vitro as evidenced by higher cell viability and improved metabolic activity in both keratinocytes (HaCaT) and melanocytes (SK-MEL-1). The results further show that the pre-treatment regimen employed by this study involved some degree of cellular adaptation as evidenced by higher levels of reduced glutathione with a concomitant decrease in lipid peroxidation and lowered caspase 3 activity. Furthermore, compound 1 was most cytoprotective against UVB irradiation of HaCaT cell line (over 24 h) with an IC50 of 282 µg/mL and SK-MEL-1 cell line with IC50 values of 248.3 and 142.6 µg/mL over 4 and 24 h, respectively. On the other hand, HaCaT cells exposed to 2 over 4 h before UVB irradiation showed the highest degree of cytoprotection with an IC50 of 398.9 µg/mL among the four studied samples. These results show that linearthin (1) and the two glycoside dihydrochalcone of A. linearis have the potential to be further developed as antioxidant cosmeceutical ingredients that may protect skin against UVB-induced damage.

Searching for new natural bioactive capping agents represent an urgent priority in the green synthesis of metal nanoparticles. Additionaly, the biosaftey of metal nanparticles is a major concern especially in medical applications. Recently, the use of pharmacollogicaly active natural products as capping agents has been deployed to avoid toxic effects during the nanoparticles preparation and to enhance their drugability compared with convential drugs. Helichrysum foetidum is a South African medicinal plant used in folk medicine for the treatment of different human pathologies, and it is known to contain a variety of bioactive compounds. Herein, the total extract and two pure chalcones, helichrysetin and helichrysin, isolated from the same plant were successfully used to synthesize quasi-monodispersed gold nanoparticles in the size range of 2–12 nm. The bio-evaluation of samples indicated that the AuNP/capping agent conjugates are biostable, and have different biological profiles from the total extract/pure compounds. The enzymatic inhibition assays showed significant inhibition by the total extract, helichrysetin and their gold nanoparticles. Interestingly, a similar activity was observed for glucose uptake in HEK293 treated cells. On the other hand, all the tested samples relatively demonstrated no cytotoxicity when tested against the HaCaT keratinocytes. In conclusion, the study demonstrated potential enhancement of glucose uptake in mammalian kidney cells, and inhibition of carbohydrate-hydrolysing enzymes by green synthesized gold nanoparticles of H. foetidum. It also provides a therapeutic appraisal of AuNPs/chalcones conjugate towards the development of antidiabetes drugs derived from H. foetidum and its gold nanoparticles.

Epidemiological studies have shown a consistent positive correlation between exposure to particulate matter (PM) and increased mortality largely due to increased rates of cardiovascular morbidity and mortality. Diesel exhaust particles (DEPs) are major constituents of atmospheric PM and have been shown to cause disruption of the endothelial cell monolayer integrity, thereby affecting organ functions. Endothelial cells are very active metabolic components of biological tissue that performs a number of important physiological functions. Therefore, anything that compromises the integrity and functions of the endothelium will lead to organ dysfunction and disease. This review focuses on scientific evidence that link DEP exposure to endothelial cell dysfunction in various pathophysiological conditions affecting the cardiovascular system. The various mechanisms involved in the DEP-induced endothelial cell dysfunction are also addressed together with the preventive and therapeutic approaches to overcoming these challenges.

Medicinal plants of the Plectranthus genus (Lamiaceae) are well known for their ethnomedicinal applications. Plectranthus madagascariensis, which is native to South Africa, is traditionally used in the treatment of respiratory conditions, scabies, and cutaneous wounds. The phytochemical studies of P. madagascariensis led to the isolation of five known royleanone abietanes, namely, 6&beta, 7&alpha, dihydroxyroyleanone (1), 7&alpha, acetoxy-6&beta, hydroxyroyleanone (2), horminone (3), coleon U quinone (4), and carnosolon (5). The relative configuration of compound 2 was established by X-ray analysis. Compounds 1&ndash, 4 showed antimycobacterial activity (Minimum inhibitory concentration for 90% inhibition, MIC90 = 5.61&ndash, 179.60 &mu, M) against Mycobacterium tuberculosis H37Rv. Compound 4 and 5 showed comparable toxicity (Concentration for 50% inhibition, IC50 98.49 &mu, M and 79.77 &mu, M) to tamoxifen (IC50 22.00 &mu, g/mL) against HaCaT cells. Compounds 1&ndash, 5 showed antioxidant activity through single-electron transfer (SET) and/or hydrogen-atom transfer (HAT) with compound 5 being the most active antioxidant agent. Compounds 3 and 5 were isolated for the first time from P. madagascariensis. The observed results suggest P. madagascariensis as an important ethnomedicinal plant and as a promising source of diterpenoids with potential use in the treatment of tuberculosis and psoriasis.

Rooibos (Aspalathus linearis), widely known as a herbal tea, is endemic to the Cape Floristic Region of South Africa (SA). It produces a wide range of phenolic compounds that have been associated with diverse health promoting properties of the plant. The species comprises several growth forms that differ in their morphology and biochemical composition, only one of which is cultivated and used commercially. Here, we established methodologies for non-invasive transcriptome research of wild-growing South African plant species, including (1) harvesting and transport of plant material suitable for RNA sequencing, (2) inexpensive, high-throughput biochemical sample screening, (3) extraction of high-quality RNA from recalcitrant, polysaccharide- and polyphenol rich plant material, and (4) biocomputational analysis of Illumina sequencing data, together with the evaluation of programs for transcriptome assembly (Trinity, IDBA-Trans, SOAPdenovo-Trans, CLC), protein prediction, as well as functional and taxonomic transcript annotation. In the process, we established a biochemically characterized sample pool from 44 distinct rooibos ecotypes (1&ndash, 5 harvests) and generated four in-depth annotated transcriptomes (each comprising on average &asymp, 86,000 transcripts) from rooibos plants that represent distinct growth forms and differ in their biochemical profiles. These resources will serve future rooibos research and plant breeding endeavours.

Antioxidant activities in Mytilus galloprovincialis were determined from samples collected at Scarborough, Hout Bay, Green Point, Milnerton and Bloubergstrand in Cape Town, South Africa. Antioxidant enzyme activity was determined by measuring CAT, SOD and GSH. The total antioxidant capacity was measured using FRAP and ORAC, while the content and lipid peroxidation marker levels of CDs and TBARS. Antioxidant activities and responses in mussels varied between sites with significant correlations for 85% and 71% of all antioxidant measurements made for Fe and Zn, respectively. The oxidative stress results reported here are novel for the region and indicated that mussels in Cape Town do not have (relatively) high levels of antioxidant activities as a result of exposure to metals. The research undertaken suggests that antioxidant responses was an appropriate biomarker of exposure to metals but more environmental parameters should be considered when interpreting antioxidant responses in the natural environment.

A 30-day exposure time experiment was designed to investigate whether the extent of physiological impacts of trihalomethane exposure on two Solanum lycopersicum cultivars correlated with either the number of bromine or chlorine atoms in the trihalomethane molecules, focusing on biomass gain, nutrient concentration, oxidative stress, fatty acids and α-tocopherol contents in membrane lipids. The gain of biomass in tomato seedlings decreased with an increase in the degree of bromination. Concentrations of essential nutrients required for plant growth such as nitrogen, phosphorus, potassium, sulphur and boron decreased in plant dry matter that correlated with the increasing number of chlorine atoms in the trihalomethane molecules. Trihalomethane exposure resulted in an increase in oxidative stress response in both tomato cultivars with parameters such as total phenolic content, ferric reducing antioxidant power, oxygen radical absorbance capacity and the activities of antioxidant peroxidase enzymes, all correlating with an increasing number of chlorine atoms in the trihalomethane molecule; hence, oxidative damage increased with a higher degree of chlorination. However, no such correlations were observed in superoxide dismutase activity, general lipid peroxidation, α-tocopherol content and total soluble proteins. In plant membrane lipids, an increase in the saturated fat hexadecanoic acid was observed in both tomato cultivars that correlated with the degree of chlorination in the trihalomethane molecule. The increase in α-linolenic acid stress signaling correlated with an increase in the degree of chlorination in only one tomato cultivar suggesting variable tolerance between cultivars to chemical action.

Gethyllis multifolia is a South African bulbous geophyte with medicinal properties and on which very limited research has been conducted. This research investigated the effect of drought and shade, which are experienced in the natural habitat, on the antioxidant properties, as well as the isolation of natural compounds from certain plant parts. The total polyphenol, flavonol/flavone and flavanone contents, oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP) and radical cation scavenging ability (ABTS) were measured in the leaves, bulbs and roots (dry weight) of G. multifolia under photo- and drought stress. A significantly higher total polyphenol content was observed in the roots under the photo - and drought stresses when compared to the control. When all the plant parts were compared, the highest total polyphenol content was observed in the drought-stressed roots of G. multifolia . An increased antioxidant capacity was observed in the root system of G. multifolia where the FRAP, ORAC and ABTS were found to be significantly higher during drought stress when compared to the control. Phytochemical investigation of the leaves, bulbs and roots of G. multifolia revealed the presence of tannins, flavonoids, phenolics, saponins, glycosides (phenolic and terpenoid) as well as essential oils, while the test for alkaloids was negative. Further in -depth studies on the roots of G. multifolia led to the isolation of three known flavonoids, of which one was also isolated as its endogenously acetylated derivative. Their structures were elucidated by chemical and spectroscopic methods as 2,3-dihydro-7-hydroxy-2-phenyl-4 H -1-benzopyran-4-one ( 1 ), (1-[2.4-dihydroxyphenyl]-3-phenylpropan-1-one) ( 2 ), 2,3-dihydro-5,7-dihydroxy-2-phenyl-4 H -1-benzopyran-4-one or pinocembrin ( 3 ) and 5,7-diacetoxy-2,3-dihydro-2-phenyl-4 H -1-benzopyran-4-one ( 4 ). This investigation indicated how environmental conditions can be manipulated to enhance the antioxidant properties of certain plant parts for future cultivation of this species and the isolation of the four natural compounds elucidated its medicinal potential and created a platform for future in vivo research.

Previous evidence show foods and beverages rich in polyphenolic compounds to have favourable effects on the cardiovascular system.The current study assessed the modulation of oxidative stress and associated inflammation induced by diesel exhaust particles (DEP - SRM 2975) by pre-treatment of human umbilical vein endothelial cells (HUVECs) with aqueous extracts of rooibos [fermented (FR) as well as green form (GR)] and honeybush [fermented form (FH)].HUVEC are either exposed to DEP (10 µg/ml) for 4 h or pre-treated with 40 and 60 µg/ml of FR or GH or FR, or 50 µg/ml orientin (OR) for 6 h prior to DEP exposure.In vitro antioxidant capacity of the extracts was assessed and the polyphenol contents were also assessed by HPLC. ROS, cell viability, lactate dehydrogenase leakage, lipid peroxidation, GSH:GSSG ratios, conjugated diene and protein carbonyl levels were determined as indices of oxidative stress and cytotoxicity. RT-qPCR and western blot were used to assess inflammatory cytokines and antioxidant genes expression.DEP caused a dose and time-dependent increase in ROS production, significant (p 0.001) increase in protein carbonyl (PC) formation, thiobarbituric acid reactive substances and conjugated dienes levels (p 0.01) and a significant reduction in glutathione (GSH) redox status. Pre-incubation with either the herbal extracts or orientin attenuated these effects. The significant increase in IL-1α, IL-6, IL-8, VCAM-1 and ATF4 gene expression caused by DEP (10 µg/ml) were also attenuated by the presence of the FR, GR and FH extracts, and OR . Pre-treatment with the rooibos extracts or flavone orientin enhanced cell viability, reduced LDH leakage, enhanced mRNA expression of NQO1 and Nrf2, but repressed CYP1B1 mRNA induced by DEP. Western blot showed both the herbal tea extracts and orientin to enhance NQO1 and γGSC protein induction by DEP.Taken together, the herbal extracts offer protection against DEP-induced oxidative stress and inflammatory response.

Alcohol intake is associated with variation in many biochemical markers and metabolic processes implicated in car- diovascular disease (CVD) and other non-communicable diseases associated with advanced aging. Some changes are beneficial, while others may be harmful in relation to individual differences in genetic background. The objective of this study was to compare the effects of alternative moderate consumption of red wine and brandy on the lipid profile in the same experimental population of healthy adults and to identify genetic risk factors that may contribute to differences in response. An 8-week ran- domised crossover intervention study of red wine versus brandy consumption was performed in 37 healthy volunteers (19 males and 18 females) between the ages of 26 and 71 years. The assessments included anthropometric measurements, biochemical determinations and genetic analysis using a multi-gene CVD test. The level of total glutathione as an indicator of antioxidant capacity was significantly decreased only after the brandy intervention when compared to the baseline (p = 0.002). Both the brandy and wine intervention resulted in a significant increase in HDL-cholesterol (p < 0.001). Significant differential effects were shown in relation to genetic variation in the APOE (p = 0.027) and MTHFR (p = 0.048) genes, known to be associated with hyper-responsiveness to alcohol intake. Novel findings included a statistically significant increase of both total cholesterol (p = 0.016) and triglyceride (p = 0.022) levels with alcohol intake only in individuals who tested positive for the low-penetrance H63D and/or C282Y mutations in the HFE gene. This study confirmed the well-established protective effect of moderate alcohol consumption on the lipid profile, especially red wine. Since the genetic background influences the effect of alcohol on biochemical parameters of CVD risk, safe limits of wine and brandy consumption may in future be based partly on the genetic profile.

This study investigated the antioxidative effect of rooibos herbal tea and a rooibos-derived commercial supplement ontert-butyl hydroperoxide- (t-BHP-) induced oxidative stress in the liver. Forty male Wistar rats consumed fermented rooibos, unfermented rooibos, a rooibos-derived commercial supplement, or water for 10 weeks, while oxidative stress was induced during the last 2 weeks via intraperitoneal injection of 30 µmole oft-BHP per 100 g body weight. None of the beverages impaired the body weight gain of the respective animals. Rats consuming the rooibos-derived commercial supplement had the highest (P<0.05) daily total polyphenol intake (169 mg/day) followed by rats consuming the unfermented rooibos (93.4 mg/day) and fermented rooibos (73.1 mg/day). Intake of both the derived supplement and unfermented rooibos restored thet-BHP-induced reduction and increased (P<0.05) the antioxidant capacity status of the liver, while not impacting on lipid peroxidation. The rooibos herbal tea did not affect the hepatic antioxidant enzymes, except fermented rooibos that caused a decrease (P<0.05) in superoxide dismutase activity. This study confirms rooibos herbal tea as good dietary antioxidant sources and, in conjunction with its many other components, offers a significantly enhanced antioxidant status of the liver in an induced oxidative stress situation.

cope To determine the effect of Rooibos (Aspalathus linearis) on glucocorticoid biosynthesis and inactivation in vivo and in vitro. Methods and results Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) analyses of in vivo studies showed that human Rooibos consumption increased cortisone plasma levels in males (p = 0.0465) and reduced cortisol:cortisone ratios in males and females (p = 0.0486) at risk for cardiovascular disease. In rats, corticosterone (CORT) (p = 0.0275) and deoxycorticosterone (p = 0.0298) levels as well as the CORT:testosterone ratio (p = 0.0009) decreased following Rooibos consumption. The inactivation of cortisol was investigated in vitro by expressing 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) and type 2 (11βHSD2) in CHO-K1 cells. Rooibos inhibited 11βHSD1, which resulted in a significant reduction in the cortisol:cortisone ratio (p < 0.01). No significant effect was detected on 11βHSD2. In vitro studies in adrenal H295R cells showed that Rooibos and rutin, one of the more stable flavonoid compounds present in Rooibos, significantly reduced the levels of cortisol and CORT in cells stimulated with forskolin to mimic a stress response. Conclusion In vivo studies demonstrate that Rooibos significantly decreased glucocorticoid levels in rats and steroid metabolite ratios linked to metabolic disorders—cortisol:cortisone in humans and CORT:testosterone in rats. Results obtained at cellular level elucidate possible mechanisms by which these effects were achieved.

Gethyllis multifolia and Gethyllis villosa are winter-growing, summer-blooming, deciduous and bulbous geophytes that grow naturally in the semi-arid ‘Succulent Karoo Biome’ of South Africa. G. multifolia is threatened in its natural habitat and resides in the ‘Vulnerable’ category of the ‘Red Data List of Southern African Plants’. Previous investigations suggested that G. multifolia is more sensitive to drought stress than G. villosa and that both species adopted certain morphological changes in their leaves during shade stress. Current models indicate that this biome is being exposed to increasingly drier conditions and shading from encroaching indigenous plant species. In this study, the photosynthetic gas exchange responses of both species to drought and shade stresses were investigated and the ‘Vulnerable’ conservation status of G. multifolia. This investigation found that during drought stress G. villosa had a more enhanced photosynthetic performance than G. multifolia which appears not to be related to foliar adaptations such as specific leaf mass (SLM), but to the G. villosa's leaves maintaining their stomatal conductance (Gs), photosynthetic light compensation (LCP) and photon yields. Furthermore, during shade stress G. villosa also had an improved photosynthetic performance by not altering its photosynthetic LCP during reduced light conditions. It can be concluded that G. multifolia has a lower capacity than G. villosa to adapt its photosynthetic apparatus to changing environments such as increasing drought and shaded conditions. This may be a contributing factor to the threatened conservation status of G. multifolia.

Reactive oxygen species (ROS) are involved in many physiological functions of mammalian sperm. Numerous endogenous antioxidants belonging to both enzymatic and non-enzymatic groups can remove excess ROS and prevent oxidative stress (OS). This study compares the modulation of OS by rooibos, Chinese green tea and commercial rooibos and green tea supplements in rat sperm. Male Wistar rats (n = 60) were supplemented with fermented rooibos, ‘green’ rooibos, Chinese green tea, rooibos supplement, green tea supplement or water for 10 weeks while OS was induced during the last 2 weeks. Sperm count and motility were significantly higher for rats consuming fermented rooibos and ‘green’ rooibos when compared with the other groups. Catalase activity was significantly higher in the sperm of rats consuming fermented rooibos, ‘green’ rooibos and both the rooibos and green tea supplements. Superoxide dismutase concentration in the sperm of rats supplemented with fermented rooibos, ‘green’ rooibos and green tea was higher. Sperm glutathione levels of rats consuming the fermented and ‘green’ rooibos were also significantly higher. Rooibos fermented and ‘green’ rooibos showed a tendency to lower the levels of ROS and lipid peroxidation when compared with the control group. In conclusion, both rooibos extracts could offer a measure of protection against induced oxidative damage by increasing the antioxidant defence mechanisms and thereby improving the sperm quality and function. Copyright © 2012 John Wiley & Sons, Ltd.

A total of 43 individuals were included in a study of genetic and environmental factors associated with cardiovascular disease; seven subjects (16%) were diagnosed with the metabolic syndrome. A statistically significant association was observed between the E2 allele of the apolipoprotein E (Apo E) polymorphism and an increasing number of metabolic syndrome features (p = 0.03). Clinical and biochemical abnormalities identified could be ascribed to the combined effects of unfavorable genotypes and environmental factors known to interact with the Apo E gene. Excessive alcohol intake, high-calorie diets and smoking should be restricted in individuals with the Apo E2 and/or E4 alleles, which are associated with a significantly increased risk of cardiovascular disease.

This study investigated whether rooibos herbal tea Aspalathus linearis has an ergogenic effect during a fatiguing arm strength test to exhaustion. Thirty-two male participants were randomised in a single blinded, cross-over placebo controlled study in which they ingested standardised rooibos or placebo capsules for four weeks prior to a fatiguing elbow flexion/extension exercise test entailing five sets/bouts of 15 repetitions of maximum voluntary contractions separated by 10-second rest intervals on a Biodex System 3 at a speed of 60° per second. Peak torque flexion (Nm) was consistently higher in the rooibos experimental (Re) compared to the placebo control (Pc) across the five exercise bouts, and this performance trend during flexion was also seen in the total work (joules) completed, although not significant (P > 0.05). It appears that the antioxidant properties of rooibos, may have contributed to an improvement in physical performance during a maximal isokinetic arm exercise protocol to induce fatigue.

The chemoprotective properties of unfermented and fermented rooibos (Aspalathus linearis) and honeybush (Cyclopia intermedia) herbal teas, and green and black teas (Camellia sinensis) were investigated against fumonisin B1 (FB1) promotion in rat liver utilizing diethylnitrosamine (DEN) as cancer initiator. The various teas differently affected the clinical chemical parameters associated with liver and kidney damage associated with FB1 suggesting specific FB1/iron/polyphenolic interactions. Green tea enhanced (P0.05) the FB1-induced reduction of the oxygen radical absorbance capacity, while fermented herbal teas and unfermented honeybush significantly (P0.05) decreased FB1-induced lipid peroxidation in the liver. The teas exhibited varying effects on FB1-induced changes in the activities of catalase, glutathione peroxidase (GPx) glutathione reductase (GR) as well as the glutathione (GSH) status. Unfermented rooibos and honeybush significantly (P0.05) to marginally (P0.1) reduced the total number of foci (10microm), respectively, while all the teas reduced the relative amount of the larger foci. Fermentation seems to reduce the protective effect of the herbal teas. Differences in the major polyphenolic components and certain FB1/polyphenolic/tissue interactions may explain the varying effects of the different teas on the oxidative parameters, hepatotoxic effects and cancer promotion in rat liver.

Reactive species are products of normal cellular metabolism and may be deleterious or beneficial. At low/moderate concentrations, reactive species are involved in physiological roles including cell signalling, defense against infectious agents and mitogenic responses. However, unbalanced defense mechanism of antioxidants, overproduction of reactive species or incorporation of free radicals into the living system from the environment may result in oxidative stress, a deleterious process that can lead to damage of important cell structures, including lipids and membranes, proteins and nucleic acids. The role of oxida‐ tive stress as a contributing factor in the pathophysiology of various diseases is increas‐ ingly being recognized, and augmenting the oxidative defense capacity of the cell through the intake of antioxidants as a way of preventing free radical-mediated cellular injuries is becoming a popular strategy. Much attention is being focused on the health beneficial role of phenolic phytochemicals derived from plants. They are considered to play an important role as physiologically functional foods and for the prevention of clini‐ cal conditions related to oxidative stress, even though their modes of action may still not be fully understood. Rooibos (Aspalathus linearis) is a popular South African tisane en‐ joyed for its taste and aroma. Rooibos has been made in the Cederberg mountain region of South Africa for generations and has been used medicinally for alleviation of allergies, asthma, infantile colic and skin problems. The potential antioxidative, immune-modulat‐ ing, chemopreventive and chemotherapeutic actions of rooibos have been reported in several studies. This review provides a comprehensive data on the current knowledge of the biological and chemotherapeutic activity of rooibos and its major flavonoids. Most re‐ cent in vitro and in vivo (animal and human) studies were conducted with special atten‐ tion paid to clinical conditions in which oxidative stress has been implicated. The conclusion described directions for future rooibos research to establish its activity and utility as a human chemopreventive and therapeutic agent.

Background: Cadmium (Cd) is a well known environmental and industrial toxicant causing damaging effects in numerous organs. In this study, we examined the role of heme oxygenase-1 (HO-1) in modulating the Cd-induced apoptosis in human hepatoma (HepG2) cells after 24 h exposure. Methods: HepG2 cells were exposed to 5 and 10 μM Cd as CdCl2 for 24 h while other sets of cells were pre-treated with either 10 μM Cobalt protoporphyrin (CoPPIX) or 10 μM Tin protoporphyrin (SnPPIX) for 24 h, or 50 μM Z-DEVD-FMK for 1 h before exposure to 5 and 10 μM CdCl2 for 24 h. Expressions of caspase 3, cytosolic cytochrome c, mitochondrial Bax and anti-apoptotic BCL-xl proteins were assessed by western blot. Intracellular reactive oxygen species (ROS) production was determined using the dihydrofluorescein diacetate (H2DFA) method. Cell viability was assessed by MTT assay, while a flow cytometry method was used to assess the level of apoptosis in the cell populations. Results: Our results show that there were a significant increase in the expression of cytosolic cytochrome c, mitochondrial Bax protein, and caspase 3 at 5 and 10 μM compared to the control, but these increases were attenuated by the presence of CoPPIX. The presence of SnPPIX significantly enhanced Cd-induced caspase 3 activities. CoPPIX significantly decreased the level of ROS production by 24.6 and 22.2 % in 5 and 10 μM CdCl2, respectively, but SnPPIX caused a significant increase in ROS production in the presence of CdCl2. HepG2 cell viability was also significantly impaired by 13.89 and 32.53 % in the presence of 5 and 10 μM CdCl2, respectively, but the presence of CoPPIX and Z-DEVD-FMK significantly enhanced cell survival, while SnPPIX enhanced Cd-impaired cell viability. The presence of CoPPIX and Z-DEVD-FMK also significantly decreased the population of apoptotic and necrotic cells compared with Cd. Conclusion: In summary, the present study showed that HO-1 attenuates the Cd-induced caspase 3 dependent pathway of apoptosis in HepG2 cells, probably by modulating Cd-induced oxidative stress.

Bioactive polyphenolics are ubiquitously present in plants and may play an important role in the prevention and management of certain human diseases. Three known flavonoids viz Kaemperol-3-O-rutinoside (1), quercetin-3-O-glucoside (2) and kaemperol-3-O-glucoside (3) and inseparable mixture (1:1) of quercetin-3-O-glucose/galactose (4) were isolated, and identified for the first time from Holarrhena floribunda. The antioxidant capacity using the ORAC, FRAP and TEAC assays and inhibition of lipid peroxidation were measured for isolated flavonoids. The result showed that compounds 2 and 4 showed significantly increased ORAC, TEAC, and FRAP activities with low pro-oxidant potential as well as improved lipid peroxidation inhibition levels when compared to compounds 1 and 3. The most active compounds were found to be flavonoids with a quercetin basic structure. These results imply that the isolated flavonoid glycosides are responsible for the antioxidant activity of the plant leaves and it forms the scientific basis for its traditional usage.

Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1–3) and six known (4–10) acylphloroglucinols alongside a known dialcohol triterpene (11). The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate)-phloroglucinol (helinivene A, 1), 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl)-phloroglucinol (helinivene B, 2), 8-(2-methylpropanone)-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3), 1-(2-methylbutanone)-4-O-prenyl-phloroglucinol (4), 1-(2-methylpropanone)-4-O-prennyl-phloroglucinol (5), 1-(butanone)-3-prenyl-phloroglucinol (6), 1-(2-methylbutanone)-3-prenyl-phloroglucinol (7), 1-butanone-3-(3-methylbut-2-enylacetate)-phloroglucinol (8), 1-(2-methylpropanone)-3-prenylphloroglucinol (9), caespitate (10), and 3β-24-dihydroxyterexer-14-ene (11). Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2) when measured as oxygen radicals absorbance capacity (ORAC), ferric-ion reducing antioxidant power (FRAP), trolox equivalent absorbance capacity (TEAC) and including the inhibition of Fe2+-induced lipid peroxidation (IC50 = 5.12 ± 0.90, 3.55 ± 1.92) µg/mL, while anti-tyrosinase activity at IC50 = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors.

Antimutagenic activity of aqueous extracts of the South African herbal teas, Aspalathus linearis (rooibos) and Cyclopia spp. (honeybush) was compared with that of Camellia sinensis (black, oolong and green) teas in the Salmonella mutagenicity assay using aflatoxin B(1) (AFB(1)) and 2-acetylaminofluorene (2-AAF) as mutagens. The present study presents the first investigation on antimutagenic properties of C. subternata, C. genistoides and C. sessiliflora. The herbal teas demonstrated protection against both mutagens in the presence of metabolic activation, with the exception of "unfermented" (green/unoxidised) C. genistoides against 2-AAF, which either protected or enhanced mutagenesis depending on the concentration. Antimutagenic activity of "fermented" (oxidised) rooibos was significantly (P0.05) less than that of Camellia sinensis teas against AFB(1), while for 2-AAF it was less (P0.05) than that of black tea and similar (P0.05) to that of oolong and green teas. Antimutagenic activity of unfermented C. intermedia and C. subternata exhibited a similar protection as fermented rooibos against AFB(1). Against 2-AAF, fermented rooibos exhibited similar protective properties than unfermented C. intermedia and C. sessiliflora. Unfermented rooibos was less effective than the C. sinensis teas and fermented rooibos, but had similar (P0.05) antimutagenicity to that of fermented C. sessiliflora against AFB(1) and fermented C. subternata against 2-AAF. Fermented C. intermedia and C. genistoides exhibited the lowest protective effect against 2-AAF, while fermented C. intermedia exhibited the lowest protection when utilising AFB(1) as mutagen. Aspalathin and mangiferin, major polyphenols in rooibos and Cyclopia spp., respectively, exhibited weak to moderate protective effects when compared to the major green tea catechin, (-)epigallocatechin gallate (EGCG). Antimutagenic activity of selected herbal tea phenolic compounds indicated that they contribute towards (i) observed antimutagenic activity of the aqueous extracts against both mutagens and (ii) enhancement of the mutagenicity of 2-AAF by unfermented C. genistoides. Antimutagenic activity of the South African herbal teas was mutagen-specific, affected by fermentation and plant material, presumably due to changes and variation in phenolic composition.

In accordance with national and international regulatory standards, namely ISO/IEC 17025, the validation of chromatography methods is becoming necessary. This study provides an optimized and fully validated reversephase high performance liquid chromatography (RP-HPLC) assay with ultra-violet (UV) detection for the measurement of L-ascorbic acid (L-AA) in fruit, vegetable and food products. Several commercial fruit juices and teas, fresh fruit and vegetables and food extract products were analyzed using a high performance liquid chromatographic system with UV detection. Chromatographic separation of L-AA was achieved on a reverse phase C18 150 mm×4.6 mm, 0.5 μm column with UV detection of 245 nm at room temperature. Distilled water/acetonitrile/formic acid (99: 0.9: 0.1, v/v/v) at a flow rate of 1 mLmin-1 was used as the mobile phase, in isocratic mode. Samples were extracted in 4.5% metaphosphoric acid solution and filtered through a 0.45 μm membrane. The method was validated for accuracy, precision, linearity, range, limit of detection, limit of quantification, specificity, stability, robustness and system suitability in accordance with ISO 17025 validation requirements. Validation results demonstrated a linear response within a range of 5 to 125 μg/mL with a correlation coefficient of 0.999 was obtained. Mean recoveries ranged from 99 to 103% and 92 to 96% for L-AA standards and samples, respectively. The method was found to be precise (COV’s