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Background: Agave angustifolia (AA) and Agave sisalana (AS) are used by local communities for medicinal purposes to treat skin conditions. Small companies add Agave leaf extracts to their cosmetic products, claiming calming and skin-rejuvenating qualities. Aim: The study aimed to assess the phytochemical profiles and antioxidant activities of AA and AS verifying the traditional therapeutic claims about the species and accordingly establishing the assertions of cottage industries. Setting: The AA leaves were collected from the eThekwini Metropolitan Municipality, while AS leaves were sourced from the iLembe district municipality. Methods: The phytochemical extracts were obtained by gradient solvent maceration of the leaves. Qualitative phytochemical screening established the presence of bioactive phytochemicals in the extract. The 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and the ferric reducing and/or antioxidant power (FRAP) methods measured the bioactive phytochemicals’ antioxidant activity. Results: Qualitative phytochemical evaluation confirmed the presence of secondary metabolites in both plants. AS extracts also contained alkaloids. The DPPH antioxidant activity indicated that Agave extracts had 20% to 80% scavenging activity. AS methanol extract had the maximum antioxidant activity among all the extracts. AA methanol and AS hexane extracts had no antioxidant activity. AA ethyl acetate extract had higher antioxidant activity (64%) than AS (52%). AA hexane extract had 70% activity while AS hexane extract had 30%. Conclusion: The detected phytochemicals indicate potential use for emulsifying, antioxidant, anti-ageing, anti-inflammatory, and broad-spectrum antimicrobial activities. Contribution: This study contributes to the existing knowledge of the therapeutic properties of AA and AS plants.

The coastal regions of Africa are endowed with indigenous wild fruit plants rich in nutritional and medicinal phytochemicals and micronutrients. South African wild fruit plants complement the diet and health needs of rural poor households by providing vital dietary nutrients and remedies for various health concerns, and alleviating food insecurity. Milk plum, Natal plum, wild custard apple, and wild medlar medicinal plants are found mainly in the coastal provinces of South Africa. Studies have established that these plants are good sources of vitamins, essential elements, and bioactive phytocompounds such as flavonoids, phenolic acids, and terpenoids, which demonstrate significant antioxidant, antimicrobial and anti-inflammatory activities. The plants studied possess anti-epileptic, antiplasmodial, and snake antivenom qualities. Here we highlight the views of different reports on ethnopharmacological relevance, phytochemistry, and bioactivity of the selected South African indigenous medicinal plants. We found a research gap in the phytochemical composition and phytopharmacological activity evaluation of Carissa macrocarpa and Englerophytum magalismontanum. Significance: • South African indigenous medicinal plants augment the dietary and other health needs of the rural populace. The phytochemistry and phytopharmacological activities of C. macrocarpa and E. magalismontanum have been only partially studied, hence the need for further studies to examine their worth and possible use in cosmetic product enrichment.

Human well-being and ecological reliability continue to face a major threat resulting from heavy metal pollution to soils caused by untreated discharge from metropolitan and industrial wastewater. The potential human health risks of zinc (Zn), copper (Cu) and iron (Fe) contamination to native inhabitants through the food chain were assessed in Pinetown, Durban, where their irrigation processes are from the Umgeni River passing through the highly industrialised Pinetown area. River water, vegetables (cabbage and lettuce) and soil were analysed for Zn, Cu and Fe; transfer factor, health risk index and the daily intake of metals were also calculated. The concentrations of heavy metals indicated the pattern trend as Fe>Zn>Cu for both cabbage and lettuce. The levels of transfer factors for heavy metals ranged from 0.02 mg/kg to 1.89 mg/kg. The health risk index (0.0002–01430) was found to be within the recommended range (

The energy sector is an essential part of a country’s economy – it drives innovation and advances in industrialisation. Coal is the primary source of energy in South Africa. Coal contributes 95% of energy production; coal-fired power also contributes to greenhouse gas emissions, and is thus a hazard to human health and the environment. This calls for an energy mix that is renewable, sustainable, and affordable and that is carbon neutral (climate action). We investigated the potential of anaerobic mono-and co-digestion of goat manure, chicken manure, potato peels, maize pap, and cow manure inoculum for mesophilic recovery of renewable energy using the biomethane potential test. The substrates were characterised through proximate and ultimate analyses to determine the composition preferable for mono- and co-digestion. The key considerations in the determination of both the yield and production rate of methane from digestion of biomass are the substrate composition and characterisation. A high percentage of volatile solids favoured optimum biomethane production as highly volatile components provide microbes with balanced nutrients that enhance metabolic processes to produce biomethane. The mono-digestion process produced lower biomethane than did co-digestion. Higher production of biomethane by co-digestion was due to the balance of the micronutrients and macronutrients that favoured microbial metabolism and regulation of pH. Significance: • The results highlight the need for appropriate techniques in combining energy and waste management. Biogas could provide solutions for some of South Africa’s energy necessities, particularly in rural areas that have abundant biogas.