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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.

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 .

The green chemistry approach has continuously been applied for the synthesis of functional nanomaterials to reduce waste, environmental hazards, and the use of toxic chemicals among other reasons. Bioactive natural compounds have been found great potential in this regard and are used to improve the stability, activity, and biodistribution of metal nanoparticles (MNPs). Aspalathin (ASP) from Aspalathus linearis (rooibos) has a well-defined pharmacological profile and functional groups capable of both reducing and capping agents in the synthesis of metallic nanoparticles (NP). This study provides the first report of the phytomediated synthesis of gold and silver nanoparticles (AuNPs/AgNPs) via ASP and the green rooibos (GR) extract. The study demonstrated a green chemistry approach to the biosynthesis of nanoparticles of GR-AuNPs, ASP-AuNPs, GR-AgNPs, and ASP-AgNPs. The results showed that GR and ASP could act both as reducing and stabilising agents in the formation of crystalline, with different shapes and dispersity of NPs in the ranges of 1.6–6.7 nm for AgNPs and 7.5–12.5 nm for the AuNPs. However, the ASP NPs were less stable in selected biogenic media compared to GR NPs and were later stabilised with polyethene glycol. The cytotoxicity studies showed that GR-AgNPs were the most cytotoxic against SH-SY5Y and HepG2 with IC50 108.8 and 183.4 μg/mL, respectively. The cellular uptake analysis showed a high uptake of AuNPs and indicated that AgNPs of rooibos at a lower dose (1.3–1.5 μg/mL) is favourable for its anticancer potential. This study is a contribution to plant-mediated metallic nanoparticles using a pure single compound that can be further developed for targeted drug delivery for cancer cells treatments in the coming years.

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.

Diabetes mellitus (DM) is one of the most dangerous metabolic diseases with a high rate of mortality worldwide. It is well known that insulin resistance and deficiency in insulin production from pancreatic &beta, cells are the main characteristics of DM. Due to the detrimental side effects of the current treatment, there is a considerable need to develop new effective antidiabetic drugs, especially alpha-glucosidase and alpha-amylase inhibitors with lesser adverse effects. These inhibitors are known to be directly involved in the delay of carbohydrate digestion, resulting in a reduction of glucose absorption rate and, consequently, reducing the postprandial rise of plasma glucose, which can reduce the risk of long-term diabetes complications. Furthermore, natural products are well-known sources for the discovery of new bioactive compounds that can serve as scaffolds for drug discovery, including that of new antidiabetic drugs. The phytochemical investigation of Salvia aurita collected from Hogobach Pass, Eastern Cape Province, South Africa (SA), yielded four known abietane diterpenes namely carnosol (1), rosmanol (2), 7-methoxyrosmanol (3), 12-methoxycarnosic acid (4), and one flavonoid named 4,7-dimethylapigenin (5). Structural characterization of these isolated compounds was conducted using 1 and 2D NMR, in comparison with reported spectroscopic data. These compounds are reported for the first time from S. aurita. The biological evaluation of the isolated compound against alpha-glucosidase exhibited strong inhibitory activities for 3 and 2 with the half maximal inhibitory concentration (IC50) values of 4.2 &plusmn, 0.7 and 16.4 &plusmn, 1.1 &micro, g/mL respectively, while 4 and 1 demonstrated strong alpha-amylase inhibitory activity amongst the isolated compounds with IC50 values of 16.2 &plusmn, 0.3 and 19.8 &plusmn, 1.4 &micro, g/mL. Molecular docking analysis confirms the strong inhibitory activity of 3 against alpha-glucosidase. Additionally, excellent antioxidant capacities were displayed by 2, 1, and 3, respectively, with oxygen radical absorbance capacity (ORAC) (25.79 &plusmn, 0.01, 23.96 &plusmn, 23.94 &plusmn, 0.02) mM Trolox equivalent (TE)/g, 1 and 2 as ferric-ion reducing antioxidant power (FRAP) (3.92 &plusmn, 0.002, 1.52 &plusmn, 0.002) mM ascorbic acid equivalent (AAE)/g, 5 and 2 as Trolox equivalent absorbance capacity (TEAC) (3.19 &plusmn, 0.003, 2.06 &plusmn, 0.003) mM TE/g. The methanolic extract of S. aurita is a rich source of abietane diterpenes with excellent antioxidant and antidiabetic activities that can be useful to modulate oxidative stress and might possibly be excellent candidates for the management of diabetes. This is the first scientific report on the phytochemical isolation and biological evaluation of the alpha-glucosidase and alpha-amylase inhibitory activities of Salvia aurita.

In this study, procyanidin dimers and Leucosidea sericea total extract (LSTE) were employed in the synthesis of silver nanoparticles (AgNPs) and characterized by ultraviolet-visible (UV-Visible) spectroscopy, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and dynamic light scattering (DLS) techniques. AgNPs of about 2&ndash, 7 nm were obtained. DLS and stability evaluations confirmed that the AgNPs/procyanidins conjugates were stable. The formed nanoparticles exhibited good inhibitory activities against the two enzymes studied. The IC50 values against the amylase enzyme were 14.92 &plusmn, 1.0, 13.24 &plusmn, 0.2, and 19.13 &plusmn, 0.8 &micro, g/mL for AgNPs coordinated with LSTE, F1, and F2, respectively. The corresponding values for the glucosidase enzyme were 21.48 &plusmn, 0.9, 18.76 &plusmn, 1.0, and 8.75 &plusmn, 0.7 &micro, g/mL. The antioxidant activities were comparable to those of the intact fractions. The AgNPs also demonstrated bacterial inhibitory activities against six bacterial species. While the minimum inhibitory concentrations (MIC) of F1-AgNPs against Pseudomonas aeruginosa and Staphylococcus aureus were 31.25 and 15.63 &micro, g/mL respectively, those of LSTE-AgNPs and F2-AgNPs against these organisms were both 62.50 &micro, g/mL. The F1-AgNPs demonstrated a better bactericidal effect and may be useful in food packaging. This research also showed the involvement of the procyanidins as reducing and capping agents in the formation of stable AgNPs with potential biological applications.

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.

The re-investigation of a methanolic extract of Salvia africana-lutea collected from the Cape Floristic Region, South Africa (SA), afforded four new abietane diterpenes, namely 19-acetoxy-12-methoxycarnosic acid (1), 3&beta, acetoxy-7&alpha, methoxyrosmanol (2), 19-acetoxy-7&alpha, methoxyrosmanol (3), 19-acetoxy-12-methoxy carnosol (4), and two known named clinopodiolides A (5), and B (6), in addition to four known triterpenes, oleanolic, and ursolic acids (7, 8), 11,12-dehydroursolic acid lactone (9) and &beta, amyrin (10). The chemical structural elucidation of the isolated compounds was determined on the basis of one and two dimensional nuclear magnetic resonance (1D and 2D NMR), high-resolution mass spectrometry (HRMS), ultra violet (UV), fourier transform infrared (IR), in comparison with literature data. The in vitro bio-evaluation against alpha-glucosidase showed strong inhibitory activities of 8, 10, and 7, with the half inhibitory concentration (IC50) values of 11.3 &plusmn, 1.0, 17.1 &plusmn, 1.0 and 22.9 &plusmn, 2.0 &micro, g/mL, respectively, while 7 demonstrated the strongest in vitro alpha-amylase inhibitory activity among the tested compounds with IC50 of 12.5 &plusmn, 0.7 &micro, g/mL. Additionally, some of the compounds showed significant antioxidant capacities. In conclusion, the methanolic extract of S. africana-lutea is a rich source of terpenoids, especially abietane diterpenes, with strong antioxidant and anti-diabetic activities that can be helpful to modulate the redox status of the body and could therefore be an excellent candidate for the prevention of the development of diabetes, a disease where oxidase stress plays an important role.

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.

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.

Aspalathin, the main polyphenol of rooibos (Aspalathus linearis), is associated with diverse health promoting properties of the tea. During fermentation, aspalathin is oxidized and concentrations are significantly reduced. Standardized methods for quality control of rooibos products do not investigate aspalathin, since current techniques of aspalathin detection require expensive equipment and expertise. Here, we describe a simple and fast thin-layer chromatography (TLC) method that can reproducibly visualize aspalathin in rooibos herbal tea and plant extracts at a limit of detection (LOD) equal to 178.7 ng and a limit of quantification (LOQ) equal to 541.6 ng. Aspalathin is a rare compound, so far only found in A. linearis and its (rare) sister species A. pendula. Therefore, aspalathin could serve as a marker compound for authentication and quality control of rooibos products, and the described TLC method represents a cost-effective approach for high-throughput screening of plant and herbal tea extracts.

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.

Ten flavonoid-related structures viz. heliteretifolin (1), isoxanthohumol (2), 2',4',6'-trihydroxy-3'-prenylchalcone (3), isoglabranin (4), glabranin (5), 7-methoxy-isoglabranin (6), quercetin (7), 4'-methoxyquercetin (8), 4'-methoxykaempferol (9) and mosloflavone (10) were isolated from a H. teretifolium methanolic extract and identified. One of them (compound 1) is reported for the first time from a natural source, while compounds 6, 8–10 were isolated for the first time from the genus Helichrysum. The total extract of H. teretifolium showed potent antioxidant activity. When tested for total antioxidant capacity compound 3 possesses moderate biological activity compared to 2, which displayed some of the highest TEAC values (4529.01 ± 2.44, 4170.66 ± 6.72) µM TE/g, respectively. Compounds 7 and 8 demonstrated the highest inhibitory activities on Fe2+-induced lipid peroxidation (IC50 = 2.931, 6.449 µg/mL), tyrosinase (8.092, 27.573) and elastase (43.342, 86.548). Additionally, the total antioxidant capacities measured as FRAP (4816.31 ± 7.42, 3584.17 ± 0.54) µM AAE/g, and ORAC for hydroxyl radical (7.265 ± 0.71, 6.779 ± 3.40) × 106 and peroxyl radical (17.836 ± 2.90, 12.545 ± 5.07) × 103 µM TE/g were also observed for compounds 7 and 8, respectively. In conclusion, H. teretifolium total extract represents a rich source of bioactive constituents with potent antioxidant and moderate anti-tyrosinase and anti-elastase activities that can help to avert accumulation of free radicals in the body, and could therefore be good candidates for the prevention and/or treatment of skin-related conditions, such as aging. This is the first scientific report on the chemical and biological profile of H. teretifolium.

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.

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.

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.

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

This study compares the modulation of oxidative stress by an indigenous herbal tea, rooibos, Chinese green tea and commercial rooibos and green tea supplements in rat testicular tissue. Male Wistar rats (n = 60) were fed with either fermented rooibos, “green” rooibos, Chinese green tea, commercial rooibos or green tea supplements for ten weeks. Oxidative stress (OS) was induced in all animals by an intraperitoneal t-butyl hydroperoxide injection in the last two weeks of the study. The superoxide dismutase (SOD) activity increased significantly (P < 0.05) in the testicular tissue of rats that consumed fermented rooibos, green tea and rooibos supplement as compared to the control. The glutathione levels of rats that consumed the green tea supplement was also significantly (P < 0.05) increased when compared with the control. Reactive oxygen species (ROS) levels were significantly (P < 0.05) decreased in rats that consumed the rooibos supplement, while lipid peroxidation measured as thiobarbituric acid reactive substances (TBARS) was significantly (P < 0.05) decreased in rats that consumed fermented rooibos and green tea. In conclusion, both extracts of fermented rooibos and green tea could be effective in the protection of testicular tissue against oxidative damage by possibly increasing the antioxidant defense mechanisms in rats, while reducing lipid peroxidation.Key words: Antioxidants, epididymal sperm, catalase, glutathione, green tea (Camellia sinensis), lipid peroxidation, oxidative stress, reactive oxygen species, rooibos (Aspalathus linearis), superoxide dismutase.

Aim & background Phlorotannins are a family of polyphloroglucinols with numerous biological activities including anticancer, antimalarial and antioxidant. They are highly sought for utilization in food ingredients, animal feeds, fertilizers and medicines. This work reports the isolation, from brown algae, of four phlorotannin derivatives namely phloroglucinol (1), eckol (2), 7-phloroeckol (3) and 2-phloroeckol (4). Their radical scavenging activity was assayed to elucidate their capacity to scavenge free radical species. Their structural and electronic features were then compared across structures to provide an explanation for the differences in their radical scavenging properties. Moreover, the two main radical scavenging mechanisms, namely hydrogen atom transfer (HAT) and electron transfer (ET), were checked to determine the preferred mode of radical scavenging. Methods Polyphenols were determined spectrophotometrically according to the Folin–Ciocalteu colorimetric methods and the antioxidant assays were determined by means of ORAC assay and the Trolox equivalent antioxidant capacity (TEAC) assay. Theoretical studies were performed by means of the Density Functional Theory (DFT) method. Results Theoretical predictions indicate that the radical scavenging activities follow the order 1 Conclusion Overall, the results suggest that the position of substitution of phloroglucinol unit on eckol (2) plays a significant role in determining the radical scavenging ability of the resulting eckol derivatives.

Persistent immune activation characterises HIV infection and is associated with depletion of CD4+ T-cells and increased risk of disease progression. Early loss of gut mucosal integrity results in the translocation of microbial products such as lipopolysaccharide (LPS) into the systemic circulation. This is an important source of on-going immune stimulation. The purpose of this study was to determine levels of CD4+ T-cell activation (%CD25 expression) and apoptosis (% annexin V/7-AAD) in asymptomatic, untreated HIV infection at baseline and after stimulation with LPS and incubation with or without vitamin C and N-acetylcysteine. LPS induced a significant (P<0.03) increase in %CD25 expression, annexin V, and 7-AAD in HIV positive individuals. NAC in combination with vitamin C, significantly (P=0.0018) reduced activation and early apoptosis of CD4+ T-cells to a greater degree than with either antioxidant alone. Certain combinations of antioxidants could be important in reducing the harmful effects of chronic immune activation and thereby limit CD4+ T-cell depletion. Importantly, we showed that CD4+ T-cells of the HIV positive group responded better to a combination of the antioxidants at this stage than those of the controls. Therefore, appropriate intervention at this asymptomatic stage could rescue the cells before repetitive activation results in the death of CD4+ T-cells.

Rooibos, a unique South African herbal tea, is known to be an important source of unique polyphenolic compounds. In the present study we have quantified the main polyphenolic compounds in both fermented/traditional and unfermented/"green" rooibos (Aspalathus linearis) and evaluated its cardioprotective effects against ischaemia/reperfusion injury. Male Wistar rats consumed aqueous rooibos and green tea (Camellia sinensis) extracts (2%, w/v) for 7 weeks before their hearts were rapidly excised and perfused in a working heart perfusion apparatus. The results showed that the rooibos supplemented hearts significantly improved aortic output recovery after reperfusion when compared to the green tea supplemented hearts. Additionally, we showed that the rooibos extracts, containing the highest amount of flavonols, significantly decreased the level of cleaved caspase-3 and PARP, both pro-apoptotic proteins, during reperfusion when compared to green tea. Green tea supplementation increased phosphorylation of total PKB/Akt, Akt (threonine 308) and Akt (serine 473). The rooibos extracts did not cause significant change in the levels of the pro-survival PKB/Akt (threonine 308 and serinet 473). The GSH/GSSG ratio in the hearts of the green tea supplemented group was significantly (p

The possible mechanism of photoprotection by polyphenolic extracts of honeybush and the two most abundant polyphenols found in honeybush, hesperidin and mangiferin were determined using a mouse model. Ethanol: acetone soluble extracts and pure honeybush compounds were applied topically to the skin of SKH-1 mice before daily exposures to ultraviolet B (UVB) (180 mJ/cm²) for 10 days. The honeybush extracts reduced signs of sunburn, such as erythema, peeling and hardening of the skin and also significantly (P < 0.05) reduced edema, epidermal hyperplasia and the induction of cyclooxygenase-2 (COX-2), ornithine decarboxylase (ODC), GADD45 and OGG1/2 expression. The fermented honeybush extract significantly (P < 0.05) reduced lipid peroxidation and depletion of the antioxidant enzymes catalase and superoxide dismutase. Hesperidin and mangiferin were less effective. These results show that extracts of honeybush and to some extent, hesperidin and mangiferin, renders protection against UVB-induced skin damage. The mechanisms investigated suggest that honeybush extracts protected the skin via modulation of induced-oxidative damage, inflammation and cell proliferation. Other specific biological properties such as modulation of signaling pathways could also be involved.

In South Africa, the plant Aspalathus linearis (Brum.f) Dahlg. (Fabaceae) is traditionally used as a "tea" referred to as rooibos or redbush. This plant has been listed as a medicinal plant based mostly on anecdotal evidence.Despite a long history of traditional use in South Africa, very little scientific data are available from controlled clinical trials confirming its popular use. The aim of the present study was to investigate the effect of rooibos on biochemical and oxidative stress parameters in adults at risk for cardiovascular disease.After a washout period of 2 weeks, 40 volunteers consumed six cups of fermented/traditional rooibos daily for 6 weeks, followed by a control period. Blood biochemical parameters indicative of antioxidant activity and content (total polyphenols), lipid peroxidation (conjugated dienes - CDs, thiobarbituric acid reactive substances - TBARS), redox status (total glutathione - tGSH, ratio of reduced to oxidized glutathione - GSH:GSSG), lipid profile (total cholesterol, low density lipoprotein - LDL and high density lipoprotein - HDL cholesterol and triacylglycerol levels) and liver and kidney function were measured at the end of each study period.Plasma antioxidant capacity was not altered, but plasma total polyphenol levels increased significantly after rooibos consumption compared with the control levels (from 79.8±16.9 mg/L to 89.8±14.1 mg/L). Significant decreases in plasma markers of lipid peroxidation were found after rooibos consumption, as reported by levels of CDs (167.3±29.5 nmol/mL vs. 108.8±20.1 nmol/mL) and TBARS (1.9±0.6 μmol/L vs. 0.9±0.3 μmol/L). Reduced glutathione (797±238 μmol/L vs. 1082±140 μmol/L) and the GSH:GSSG ratio (41±14 vs. 76±17) were both significantly increased after consumption of rooibos. The lipid profiles showed that rooibos consumption, compared with the control values, significantly decreased serum LDL-cholesterol (4.6±1.3 mmol/L vs. 3.9±0.7 mmol/L) and triacylglycerols (1.7±0.8 mmol/L vs. 1.2±0.7 mmol/L), while HDL-cholesterol (0.9±0.1 mmol/L vs. 1.2±0.2 mmol/L) was significantly increased.Confirming its popular use, consumption of fermented, traditional rooibos significantly improved the lipid profile as well as redox status, both relevant to heart disease, in adults at risk for developing cardiovascular disease.

The antioxidant properties of the fruit of the Rosa roxburghii (RR) plant have been associated with several putative health promoting effects. The possible cytotoxic, mutagenic/antimutagenic and genotoxic effects of RR fruit extract were investigated. The effect on antioxidant status and protection against induced oxidative stress were also investigated using primary rat hepatocytes. A RR fruit extract containing 45 g/L total ascorbic acid and 65 g/L total polyphenols was used in this study. Dilutions up to 0.08% (v/v) increased significantly the antioxidant status in primary rat hepatocytes. The glutathione redox state was decreased with RR treatment but was increased in Chang liver cells and MT-2 lymphoblast. No cyto- or genotoxicity were observed at levels of up to 5% (v/v) of the fruit extract. In addition, a significant protection against t-BHP induced oxidative stress was observed in primary rat hepatocytes. The Ames test revealed no mutagenic activity using the Salmonella typhimurium strains TA98, TA100 and TA102. A significant antimutagenic effect of the extract was observed against the metabolic activated mutagens 2-acetylaminofluorene and aflatoxin B1 and to a lesser extent against methyl methanesulfonate. It is concluded that these results support the associated health promoting potential of Rosa Roxburghii fruit and in particular against oxidative stress. Copyright © 2007 John Wiley & Sons, Ltd.

Background: This study investigated the hepatic, renal and endogenous antioxidant status modulatory effects of chronic cosupplementation of rooibos and red palm oil (RPO) in male Wistar rats. Materials and Methods: Rats were randomized into four groups (n=10/group) and fed daily either standard rat chow (SRC) and water ( Group I ), SRC and the aqueous rooibos extract (2% w/v; ( Group II ), SRC and RPO (200 μL/day) with water ( Group III ), or SRC and RPO (200 μL/day) with rooibos (2% w/v; Group IV ) for 22 weeks. Results: Chronic feeding of rooibos, RPO or their combination did not induce any adverse hepatic or renal effects, as shown by serum levels of alkaline phosphatase, alanine- and aspartate aminotransferase, lactate dehydrogenase, albumin, creatinine, blood urea nitrogen and uric acid. Histopathology analyses showed that liver from the three supplementation groups displayed normal hepatic histoarchitecture. Chronic feeding of RPO did not influence the redox status in the blood and liver significantly. Supplementation of rooibos alone for 22 weeks significantly (P

The modulating effect of ethanol/acetone (E/A) soluble fractions, prepared from methanolic extracts of processed and unprocessed rooibos (Aspalathus linearis) and honeybush (Cyclopia intermedia) as well as green (Camellia sinensis) teas was established in a two-stage mouse skin carcinogenesis assay. Topical application of the tea fractions prior to the tumour promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), on ICR mouse skin initiated with 7,12-dimethylbenz[a]anthracene (DMBA) suppressed skin tumorigenesis significantly (P

Rooibos and honeybush teas significantly (P < 0.05) enhanced the activity of cytosolic glutathione S-transferase alpha. A significant (P < 0.05) to marginal (P < 0.1) increase in the activity of the microsomal UDP-glucuronosyl transferase was obtained with unprocessed rooibos and honeybush teas, respectively. Oxidized glutathione (GSSG) levels were significantly (P < 0.05) reduced in the liver of all tea treated rats while reduced glutathione (GSH) was markedly increased in the liver of the herbal tea treated rats. These changes resulted in a significant (P < 0.05) increase in the GSH/ GSSG ratio by the unprocessed, processed rooibos and unprocessed honeybush teas. Green and black teas markedly to significantly decreased the oxygen radical absorbance capacity in liver homogenates, respectively. Modulation of phase II drug metabolizing enzymes and oxidative status in the liver may be important events in the protection against adverse effects related to mutagenesis and oxidative damage.

Background Acute liver injury occur after intraperitoneal administration of lipopolysaccharide (LPS). Oxidative stress and release of pro-inflammatory cytokines are both implicated in the pathogenesis of LPS-induced acute liver injury. This study investigated the ameliorative effect of fermented rooibos (Aspalathus linearis) extract on LPS-induced acute liver injury. Method Major phenolic compounds in the fermented rooibos extract by HPLC-DAD, as well as the in vitro antioxidant capacity were quantified before the start of the experiment. Male Wistar rats were randomized into 4 groups (n = 10 per group) and given either water or fermented rooibos extract for 4 weeks before LPS injection. Hepatic function markers, including aminotransferases and lactate dehydrogenase, lipid peroxidation markers, antioxidant enzymes, glutathione redox status, as well as cytokine levels were monitored in the rats. Results Injection of LPS significantly increased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH). Oxidative stress, evidenced by increased thiobarbituric acid reactive substances (TBARS) measured as malondialdehyde (MDA) in plasma and liver, and decreased glutathione redox status (GSH: GSSG ratio) in whole blood and liver was induced in LPS-challenged rats. Furthermore, hepatic levels of pro-inflammatory response markers TNF-α, IL-1β and IL-6 were increased significantly. Pre-feeding the fermented rooibos extract for 4 weeks decreased LPS-induced elevated levels of serum AST and LDH (significantly, p

We review the hepatocarcinogenic effects of fungal cultures of Fusarium verticillioides(= Fusarium moniliforme) strain MRC 826 in male BD IX rats. Subsequent chemical analyses of the fumonisin B (FB) mycotoxin content in the culture material used and long-term carcinogenesis studies with purified FB1 provide information about dose-response effects, relevance of hepatotoxicity during FB1-induced carcinogenesis, and the existence of a no-effect threshold. Fumonisin intake levels of between 0.08 and 0.16 mg FB/100 g body weight (bw)/day over approximately 2 years produce liver cancer in male BD IX rats. Exposure levels < 0.08 mg FB/100 g bw/day fail to induce cancer, although mild toxic and preneoplastic lesions are induced. The nutritional status of the diets used in the long-term experiments was marginally deficient in lipotropes and vitamins and could have played an important modulating role in fumonisin-induced hepatocarcinogenesis. Short-term studies in a cancer initiation/promotion model in rat liver provided important information about the possible mechanisms involved during the initial stages of cancer development by this apparently nongenotoxic mycotoxin. These studies supported the findings of long-term investigations indicating that a cytotoxic/proliferative response is required for cancer induction and that a no-effect threshold exists for cancer induction. The mechanisms proposed for cancer induction are highlighted and include the possible role of oxidative damage during initiation and the disruption of lipid metabolism, integrity of cellular membranes, and altered growth-regulatory responses as important events during promotion.