Fusarium species are significant phytopathogens responsible for major crop losses and contamination of food products with harmful mycotoxins, posing serious risks to food security and public health. In response to the limitations of conventional agrochemicals, this study explores sustainable antifungal strategies based on plant-derived products and nanotechnology. The aqueous extract of Ocimum basilicum was investigated as a bioresource for both direct antifungal activity and the green synthesis of silver nanoparticles (OB-AgNPs). Liquid chromatography–mass spectrometry (LC-MS) analysis of the O. basilicum aqueous extract revealed the presence of key compounds, including rosmarinic and chicoric acids, which can reduce and stabilize AgNPs. The biosynthesized nanoparticles were characterized using standard analytical techniques, including UV–visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), high-resolution transmission electron microscopy (HRTEM), and powder X-ray diffraction (PXRD). The OB-AgNPs exhibited a surface plasmon resonance (SPR) peak at 437 nm, a zeta potential of ~–16.3 mV, an average size of 28 nm (TEM) while the average hydrodynamic size is ≈57 nm (DLS). The synthesized AgNPs demonstrated stability in potato dextrose broth (PDB) for up to 24 h. The nanoparticles alongside the aqueous extract were evaluated against selected mycotoxigenic Fusarium species including F. verticillioides, F. proliferatum, F. subglutinans, F. graminearum, and F. globosum, following 96 h of exposure. Results showed that the aqueous O. basilicum extract exhibited limited antifungal activity, with significant inhibition observed only against F. globosum MRC 6122 at the highest concentration tested (400 ng/µL). In contrast, the biosynthesized OB-AgNPs demonstrated potent antifungal activity against most of the tested Fusarium strains, except for F. proliferatum MRC 8549 and MRC 8550, indicating substantially greater efficacy than the crude extract. These findings highlight the potential of O. basilicum-mediated AgNPs as effective and eco-friendly antifungal agents. The study underscores the value of integrating plant-based phytochemicals with nanotechnology for controlling Fusarium pathogens, while emphasizing the need for future studies to determine their effects on mycotoxin production, as well as their safety and phytotoxicity for agricultural applications.

Ultraviolet B (UVB) radiation can lead to sunburn, premature skin aging, and skin cancer by promoting the formation of harmful reactive oxygen species (ROS) in skin cells. This study investigated the effects of rooibos and honeybush tea extracts on the expression of oxidative stress and antioxidant response genes in keratinocytes exposed to UVB. Microarray was used to investigate the expression of 84 oxidative stress response genes in response to rooibos and honeybush tea extracts and the effect of pre-exposure to extracts prior to UVB exposure was assessed. The results showed that both rooibos and honeybush tea extracts had antioxidant effects by enhancing the expression of various genes involved in the cellular defence against the damaging effects of UVB. Rooibos and honeybush extracts increased the expression of superoxide dismutases (SODs) and glutathione-related genes in skin cells associated with antioxidant enzymes. The increased expression of these genes indicates the antioxidant properties of the extracts. The tea extracts, especially honeybush, upregulated the expression of glutathione synthesis-related genes (GCLM and GCLC), which play a crucial role in maintaining cellular redox balance. Both tea extracts enhanced the expression of various genes involved in the reduction of hydrogen peroxide and lipid peroxides to prevent cellular damage, such as glutathione peroxidases (GPXs) and peroxiredoxins (PRDXs). The expression of several genes was dependent on the presence of UVB and the time after exposure. Overall, the results suggest that rooibos and honeybush tea extracts have antioxidant properties and can influence various cellular pathways involved in responding to oxidative stress and UVB radiation in skin cells. These findings support the potential benefits of these tea extracts in protecting the skin from UV-induced damage.

Tea is the second most widely consumed non-alcoholic beverage globally. While most teas originate from Camellia sinensis (L.) Kuntze plants, rooibos and honeybush teas are produced from Aspalathus linearis (Burm.f.) R.Dahlgren and Cyclopia species tea plants. Interest in tea and tea-derived components, has increased due to their well-known health benefits. The mechanisms of these health benefits are however poorly understood. Proteomics and metabolomics provide valuable tools to assess the mechanisms of the therapeutic effects of tea in disease treatment. This review summarizes the role played by proteomic and metabolomic studies in investigating the health benefits of C. sinensis, A. linearis, and Cyclopia spp. teas. Surprisingly, no proteomic and metabolomic studies investigating the health benefits of A. linearis and Cyclopia spp. teas and/or their components were identified in a literature search. However, 25 studies using proteomics and 16 studies using metabolomics to investigate the health benefits of C. sinensis teas and/or their components were identified in a literature search. Proteomics and metabolomics have been valuable tools for investigating the health benefits of C. sinensis teas and tea components, and will likely also prove valuable for investigating the effects of A. linearis and Cyclopia spp. teas on human health.

Background: Rooibos is a natural herbal plant containing numerous unique polyphenols which have been associated with certain health benefits. Several of these bioactive constituents have been linked to promoting gut health through its beneficial actions such as anti-inflammatory and anti-spasmodic characteristics. Purpose: The study aims to compare the anti-inflammatory and barrier protective effects of an unfermented and fermented rooibos aqueous extract on intestinal porcine epithelial cells (IPEC-J2). Methods: Aqueous extracts of unfermented and fermented rooibos were prepared, and chemical and antioxidant analysis were performed of each extract. Intestinal porcine epithelial cells (IPEC-J2) were pre-treated with either unfermented or fermented aqueous rooibos extracts (0.1 and 0.05 mg/ml) then exposed to 10 µg/ml of Escherichia coli lipopolysaccharide (LPS). Cell viability, protein and gene expression of pro-inflammatory cytokines were investigated to determine the anti-inflammatory effect of both extracts. Barrier integrity of IPEC-J2 was investigated by measuring the Transepithelial electrical resistance (TEER) and quantifying tight junction gene expression. Results: Both the unfermented and fermented rooibos extracts have significant anti-inflammatory properties by reducing pro-inflammatory cytokine production. Interestingly for certain genes (IL-8, IL-6, IL-1B and CCL20) the fermented extracts, specifically at 0.1 mg/ml, exhibited greater effectiveness by decreasing the expression after LPS-induced inflammation whilst for another gene (TNF-α) the unfermented extract at both concentrations was more efficient in decreasing expression and ultimately protecting the IPEC-J2 cells from inflammation. When evaluating the barrier integrity, 0.1 mg/ml of the unfermented rooibos extract showed the most significant barrier protective effects through upregulation of tight junction proteins, ZO-1, Occludin as well as Claudin-4. Conclusion: Higher concentration of the fermented rooibos extract prevented the inflammatory response significantly whilst the higher concentration of the unfermented rooibos extract enhanced tight junction expression and protected barrier integrity in LPS-induced inflamed intestinal cells. This is attributed to the differences in the polyphenol content of each extract and demonstrating the unique activity mechanisms of different rooibos extracts to reduce onset of early inflammation.

The intestinal epithelium is frequently exposed to environmental contaminants such as fumonisins, mycotoxins implicated in the development of mycotoxicosis across various mammalian species, with fumonisin B1 (FB1) being the most prevalent and toxic congener. Fumonisin B1 (FB1) can be enzymatically hydrolysed to produce hydrolysed fumonisin B1 (HFB1) that displays reduced inhibitory activity toward ceramide synthase. Given the central role of ceramide synthase in sphingolipid metabolism and cellular homeostasis, the reduced inhibitory activity of HFB1 is considered toxicologically favourable, as it is less likely to disrupt membrane integrity and critical signalling pathways. However, the toxicity of HFB1 remains variable across different in vitro and in vivo models. In this study, we evaluated the impact of FB1 and HFB1 on cell viability, apoptosis, and proliferation in the porcine intestinal cell line (IPEC-J2), including inflammatory responses through interleukin 8 (IL-8). Molecular mechanisms and pathways influenced by FB1 and HFB1 exposure were investigated through proteomic and bioinformatic analyses. Differentially abundant proteins (DAPs) were identified and functionally characterised using Gene Ontology analysis based on the Sus scrofa (domestic pig) database, revealing 52 significant DAPs between FB1 and HFB1 treatments compared to the control. Fibronectin 1 (FN1), an adhesive glycoprotein of the intestine, was consistently detected as a DAP in cells exposed to FB1 and HFB1. FB1 upregulates FN1, while HFB1 downregulates it, leading to different oncogenic pathways revealed by STRING enrichment analysis. Proteomic analysis further revealed distinct DAPs following FB1 and HFB1 exposure, implicating alterations in immune modulation (e.g. differential regulation of CD276), iron homeostasis (upregulation of FTL and FTH1), epithelial integrity (downregulation of NTN4, ST14), extracellular matrix remodelling (reduced SPARC), and angiogenesis-related pathways (decreased TINAGL1, FBLN2, SDC4) suggesting early changes in cellular signalling, stress response, and structural regulation that may be relevant to cancer biology and warrant further investigation. These findings also demonstrate that HFB1 activates distinct cancer-related pathways in vitro compared to FB1, with in vivo studies suggesting divergent mechanisms. HFB1 also induces more extensive protein expression changes in IPEC-J2 cells, as reflected by the greater number of DAPs and the complexity of enriched pathways. However, further investigation is needed to determine whether these changes directly contribute to cytotoxicity or represent compensatory cellular responses.

Microbial communities in hybrid linear flow channel reactors and anaerobic sequencing batch reactors operated in series for remediation and beneficiation of tannery wastewater were assessed. Despite concurrent sulfidogenesis, more intensive pre-treatment in hybrid linear flow channel reactors reduced methanogenic inhibition usually associated with anaerobic digestion of tannery effluent and promoted efficiency (max 321 mLCH4/gCODconsumed, 59% biogas CH4). Nitrification and biological sulfate reduction were key metabolic pathways involved in overall and sulfate reducing bacterial community selection, respectively, during pre-treatment. Taxonomic selection could be explained by the proteinaceous and saline character of tannery effluent, with dominant genera being protein and/or amino acid degrading, halotolerant and/or ammonia tolerant. Complete oxidizers dominated the sulfidogenic populations during pre-treatment, while aceticlastic genera dominated the methanogenic populations during anaerobic digestion. With more intensive pre-treatment, the system shows promise for remediation and recovery of biogas and sulfur from tannery wastewater in support of a bio-circular economy.

The anti-cancer potential of Cyclopia species (honeybush) has been demonstrated in several models. The present study investigated the effects of aqueous and polyphenol-enriched (PE) extracts of C. subternata and C. genistoides, as well as mangiferin and hesperidin, on different cell growth parameters in human liver (HepG2) and colon (HT-29) cancer cells. Mangiferin and hesperidin were most abundant in C. genistoides and C. subternata, respectively. Cyclopia subternata extracts had the highest ferric-reducing antioxidant capacity. Following exposure of the cells to the extracts and compounds, cell viability, proliferation, and death (apoptosis and autophagy) were determined. Cyclopia subternata extracts reduced cell viability and inhibited cell proliferation the most, associated with depletion of ATP. In HepG2 cells, the PE extracts were less effective than the aqueous extracts in reducing cell viability but more effective in inhibiting cell proliferation. Despite disrupting cell growth, none of the extracts induced apoptosis. The aqueous extracts affected autophagy in both cancer cells. Disruption of mitochondrial membrane integrity by the different extracts, presumably via polyphenol/iron interactions, is postulated to be involved; however, mangiferin and hesperidin had no effect, suggesting that other polyphenols and/or complex interactions between compounds are likely responsible for the differential cytotoxic and/or cytoprotective effects of the extracts.

Exposure to Ultraviolet B (UVB) radiation can trigger a diverse array of biological responses that have the potential to contribute to the onset of skin cancer. Natural compounds, such as tea polyphenols, have been shown to protect against UVB-induced damage by modulating oxidative stress, inflammatory response, and cell proliferation. The chemopreventive and anti-inflammatory properties of South African rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.) herbal teas have been shown to mainly target the early stages of cancer development through mechanisms that involve intracellular interleukin-1α (IL-1α) inhibition. Thus, the aim was to investigate the preventive effects of unfermented rooibos and honeybush aqueous extracts against UVB-induced oxidative stress and inflammation in HaCaTs. Honeybush was found to reduce the accumulation of UVB-induced IL-1α while maintaining cell viability and without affecting apoptosis. Furthermore, only honeybush extract was able to decrease the secretion of interleukin-6 (IL-6) caused by UVB exposure. Honeybush and rooibos extracts significantly decreased the secretion of UVB-induced interleukin-8 (IL-8). Except for rooibos extract at a concentration of 0.2 mg/mL, both extracts restored the expression of antioxidant genes to levels observed prior to UVB exposure. The anti-inflammatory effects of these herbal tea extracts are likely attributed to the antioxidant properties of their polyphenolic constituents, which modulate the oxidative stress-induced pathways governing inflammatory responses.

Mycological (mycotoxigenic Fusarium and aflatoxigenic Aspergillus spp.) and multiple mycotoxins [aflatoxin B1 (AFB1), fumonisin B (FB), deoxynivalenol and zearalenone] surveillance was conducted on raw whole grain sorghum (Sorghum bicolor) and pearl millet (Pennisetum glaucum) produced on smallholder farms, and processed products sold at open markets in northern Namibia. Fungal contamination was determined with morphological methods as well as with quantitative Real-Time PCR (qPCR). The concentrations of multiple mycotoxins in samples were determined with liquid chromatography tandem mass spectrometry. The incidence of mycotoxigenic Fusarium spp., Aspergillus flavus and A. parasiticus, as well as the concentrations of AFB1 and FB were significantly (P < 0.001) higher in the malts as compared to the raw whole grains, with Aspergillus spp. and AFB1 exhibiting the highest contamination (P < 0.001). None of the analysed mycotoxins were detected in the raw whole grains. Aflatoxin B1 above the regulatory maximum level set by the European Commission was detected in sorghum (2 of 10 samples; 20

In maize subsistence farming areas in South Africa, daily consumption of maize contaminated by high level of mycotoxins contributes to long-term health effects such as immune deficiency and cancer. Biocontrol methods that are safe and cost-effective are critical to addressing this public health problem.

Microbial communities were monitored in terms of structure, function and response to physicochemical variables during anaerobic digestion of tannery and associated slaughterhouse effluent in: (i) 2 L biochemical methane potential batch reactors at different inoculum to substrate ratios (2-5) and initial sulfate concentrations (665-2000 mg/L), and (ii) 20 L anaerobic sequencing batch reactors with different mixing regimes (continuous vs. intermittent). Methanogenic and sulfidogenic community compositions in the 2 L reactors evolved initially, but stabilised after the start of biogas generation, although significant (ANOSIM p<0.05) changes in the physicochemical parameters indicated continued metabolic activity. Both hydrogenotrophic and acetoclastic archaeal genera were present in high relative abundances. Continuous stirring preferentially selected the metabolically versatile genus Methanosarcina, suggesting that higher specific methane generation in the continuously stirred system (168 vs. 19.5 mL methane per gram volatile solids per week) was related to the metabolic activities of members of this genus.

B-series fumonisins (FBs) are a family of carcinogenic mycotoxins that commonly occur in maize. These mycotoxins cause multiple diseases in animals and are epidemiologically associated with several human diseases in populations for which maize is a dietary staple. FBs are produced by multiple genera of the fungiAspergillus,Fusarium andTolypocladium, but the plant pathogenFusarium verticillioides is considered the primary cause of FB contamination in maize. OneF. verticillioides strain, MRC 826, is reported to produce high levels of FBs. However, in the current study, 18 isolates derived from strain MRC 826 exhibited highly variable levels of FB, which negatively correlated (r=-0.333;P<0.008) with fungal growth. Microsatellite analysis confirmed that all MRC 826 derived isolates examined were clonal, and 100% DNA sequence identity was observed across theFUM gene clusters of two high FB producing and two low FB producing isolates. At the gene expression level, qRT-PCR at each time point (7, 14, 21 and 28 days of incubation) showed differential upregulation of selectedFUM genes in the high compared to the low FB isolates. Variation in FB production appears due to differences inFUM gene expression, most likely caused by sequence differences at unexamined loci not part of theFUM cluster or from epigenetic influences. Clarification of the genetic/epigenetic basis for quantitative differences in fumonisin production among strains and isolates ofF. verticillioides has potential to reveal targets for reducing FB contamination in maize.

Modulation of the expression of hepatic and renal genes encoding xenobiotic metabolizing enzymes by an aspalathin-enriched green rooibos (Aspalathus linearis) extract (GRE) was investigated in the liver and kidneys of F344 rats following dietary exposure of 28d, as well as selected xenobiotic metabolizing genes in rat primary hepatocytes. In the liver, GRE upregulated genes (p<0.05) encoding aldehyde dehydrogenase, glucose phosphate isomerase, and cytochrome P450 while 17-hydroxysteroid dehydrogenase 2 (Hsd172) was downregulated. In primary hepatocytes, GRE lacked any effect, while aspalathin downregulatedHsd172, mimicking the effect of GREin vivo,and upregulated catechol- O-methyl transferase and marginally (p<0.1) cytochrome P450 2e1. In the kidneys, GRE upregulated (p<0.05) genes encoding the phase II xenobiotic metabolism enzymes, glutathione-S-transferase m mu and microsomal glutathione-S-transferase, while downregulating genes encoding the ATP binding cassette transporter, cytochrome P450, gamma glutamyltransferase 1, and N-acetyltransferase 1. Differential modulation of the expression of xenobiotic metabolizing genesin vivoand in vitroby GRE is dose-related, duration of exposure, the tissue type, and interactions between specific polyphenol and/or combinations thereof. Aspalathin is likely to be responsible for the downregulation of estradiol and testosterone catabolism by GRE in the liver. The differential gene expression by GRE in the liver and kidneys could, depending on the duration exposure and dose utilized, determine the safe use of such an extract in humans for specific health and/or disease outcomes.

In developing countries the enforcement of compliance to detailed mycotoxin regulations ensures protection of the population from adverse health effects of mycotoxin exposure. In low-income or developing countries mycotoxin regulations are either lacking or poorly enforced which create scenarios where mycotoxin exposures occur above levels set by health regulatory bodies. Population groups that are the worst affected include subsistent maize growing farmer communities where mono-cereal crops are cultivated and locally consumed, and mycotoxin contamination are not monitored. Other factors that aggravate the situation include the consumption of highly mycotoxin contaminated unprocessed maize, the lack of knowledge about the adverse effects as well as traditional uses of maize products not intended for human consumption during periods of food insecurity. These scenarios require ingenious ways to reduce mycotoxin exposure in poor rural communities where access to sophisticated mycotoxins reduction techniques is not available or practically viable. Although community-based and culturally acceptable methods have, to some extent, been adapted the efficacy thereof varies due to the lack of sufficient training. Integration of these methods with more sophisticated technological methods is envisaged, and will be based on a better understanding of mycotoxin biosynthesis and fungus-host interactions on a molecular level. In addition, other methods which include the detoxification of mycotoxins utilising degradation enzymes, clay adsorbents, utilisation of non-toxigenic fungal strains and resistant maize cultivars to fungal infections are just a few approaches under scrutiny. The introduction of good agriculture practices and storage techniques and the identification of critical control points during hazard analyses need to be further explored. Introduction of mycotoxin monitoring programs and validated screening procedures to monitor exposure should be a priority in the future, to facilitate community-based and effective intervention programmes of mycotoxin reduction.

The yeast Saccharomyces cerevisiae was genetically modified to assemble a minicellulosome on its cell surface by heterologous expression of a chimeric scaffoldin protein from Clostridium cellulolyticum under the regulation of the phosphoglycerate kinase 1 (PGK1) promoter and terminator regulatory elements, together with the beta-xylanase 2 secretion signal of Trichoderma reesei and cell wall protein 2 (Cwp2) of S. cerevisiae. Fluorescent microscopy and Far Western blot analysis confirmed that the Scaf3p is targeted to the yeast cell surface and that the Clostridium thermocellum cohesin domain is functional in yeast. Similarly, functionality of the C. thermocellum dockerin domain in yeast is shown by binding to the Scaf3 protein in Far Western blot analysis. Phenotypic evidence for cohesin-dockerin interaction was also established with the detection of a twofold increase in tethered endoglucanase enzyme activity in S. cerevisiae cells expressing the Scaf3 protein compared with the parent strain. This study highlights the feasibility to future design of enhanced cellulolytic strains of S. cerevisiae through emulation of the cellulosome concept. Potentially, Scaf3p-armed yeast could also be developed into an alternative cell surface display strategy with various tailor-made applications.

The yeast Saccharomyces cerevisiae was genetically modified to assemble a minicellulosome on its cell surface by heterologous expression of a chimeric scaffoldin protein from Clostridium cellulolyticum under the regulation of the phosphoglycerate kinase 1 (PGK1) promoter and terminator regulatory elements, together with the beta-xylanase 2 secretion signal of Trichoderma reesei and cell wall protein 2 (Cwp2) of S. cerevisiae. Fluorescent microscopy and Far Western blot analysis confirmed that the Scaf3p is targeted to the yeast cell surface and that the Clostridium thermocellum cohesin domain is functional in yeast. Similarly, functionality of the C. thermocellum dockerin domain in yeast is shown by binding to the Scaf3 protein in Far Western blot analysis. Phenotypic evidence for cohesin-dockerin interaction was also established with the detection of a twofold increase in tethered endoglucanase enzyme activity in S. cerevisiae cells expressing the Scaf3 protein compared with the parent strain. This study highlights the feasibility to future design of enhanced cellulolytic strains of S. cerevisiae through emulation of the cellulosome concept. Potentially, Scaf3p-armed yeast could also be developed into an alternative cell surface display strategy with various tailor-made applications.

The fruity odours of wine are largely derived from the synthesis of esters and higher alcohols during yeast fermentation. The ATF1- and ATF2-encoded alcohol acetyltransferases of S. cerevisiae are responsible for the synthesis of ethyl acetate and isoamyl acetate esters, while the EHT1-encoded ethanol hexanoyl transferase is responsible for synthesizing ethyl caproate. However, esters such as these might be degraded by the IAH1-encoded esterase. The objectives of this study were: (a) to overexpress the genes encoding ester-synthesizing and ester-degrading enzymes in wine yeast; (b) to prepare Colombard table wines and base wines for distillation using these modified strains; and (c) to analyse and compare the ester concentrations and aroma profiles of these wines and distillates. The overexpression of ATF1 significantly increased the concentrations of ethyl acetate, isoamyl acetate, 2-phenylethyl acetate and ethyl caproate, while the overexpression of ATF2 affected the concentrations of ethyl acetate and isoamyl acetate to a lesser degree. The overexpression of IAH1 resulted in a significant decrease in ethyl acetate, isoamyl acetate, hexyl acetate and 2-phenylethyl acetate. The overexpression of EHT1 resulted in a marked increase in ethyl caproate, ethyl caprylate and ethyl caprate. The flavour profile of the wines and distillates prepared using the modified strains were also significantly altered as indicated by formal sensory analysis. This study offers prospects for the development of wine yeast starter strains with optimized ester-producing capability that could assist winemakers in their effort to consistently produce wine and distillates such as brandy to definable flavour specifications and styles.