Usnea barbata is a lichen of the Usneaceae family that grows epiphytically on trunks and branches of trees. It is widespread in Hogsback, South Africa. Extracts of the lichen were investigated for antimicrobial activity against 10 bacterial and 5 fungal strains by dilution method on solid agar medium. The extracts showed significant activity against the Gram-positive bacteria with minimum inhibitory concentration as low as 0.1 mg/ml on Bacillus subtilis, Enterococcus faecalis, Micrococcus viradans and Staphylococcus aureus. The acetone extract was the most active while the water extract showed the least activity against the microbes. Our findings have validated the use of the lichens for the treatment of various infections in man and livestock.

Growing demand for therapeutic products from indigenous medicinal plants has led to increased interest in its cultivation, which presents a viable option for improving smallholder farmers’ livelihoods, as well as sustaining the availability of these resources for future generations. Serious bottlenecks however exist for subsistent farmers in the cultivation of these valuable plants. It was pertinent to probe whether the cultivation of medicinal plants provides feasible solutions to rural poverty, while effectively conserving threatened indigenous biodiversity. The paper employed a comprehensive review of existing literature to explore issues constraining smallholder farmers from involvement in a potentially lucrative plant value chain. Findings indicate challenges such as inadequate domestication of valuable plants species, continued over-harvesting from wild populations, poor knowledge of required agronomic practices, low efficacy perception regarding derivatives from cultivated plants, among others. These constraints occur alongside the conservation-oriented strategy driven by international conservation agencies and wholly adopted by the South African government. Recommendations to improve smallholder involvement in the cultivation of medicinal plants include support to research and extension, targeted inducement to smallholders, contracting and off-take agreements, aimed at promoting an alternative poverty-alleviation-focused economic development strategy. The review adds to the conceptual discourse related to plant diversity, resource conservation, poverty alleviation, and economic development

Medicinal plants play an important role in our African communities for treatment and prevention of various diseases including cancer. This study was aimed on evaluating the cytotoxicity activities of Asparagus laricinus Burch. and Senecio asperulus DC. In vitro cytotoxicity screening was carried out using fluorescent cellular stains on human prostate cancer (PC3), human breast cancer (MCF-7) and the non-cancerous African green monkey kidney (Vero) cell lines. The cells were imaged with the ImageXpress Micro XLS Widefield fluorescent Microscope, and the acquired images were analysed using the MetaXpress software and the Multi-Wavelength cell scoring application module. Melphalan was used as a positive control in all experiments. Asparagus laricinus methanol and Senecio asperulus DC. dichloromethane extracts exhibited cytotoxicity activity against breast cancer cells with IC₅₀ values of 97.6 μg/mL and 69.15 μg/mL, respectively. Cell cycle analysis suggested that Asparagus laricinus methanol extract induced cell death selectively through apoptosis observed from Annexin V-FITC and PI stain. Cell cycle analysis also showed that Senecio asperulus DC. dichloromethane extracts induced breast cancer cells death through cell arrest at the synthesis phase and G2 phase. Senecio asperulus DC. dichloromethane extracts further showed cytotoxicity activity against prostate cancer cells with IC₅₀ values of 69.25 μg/mL due to cell arrest at the G2 and early mitotic (G2/M) phase. We, therefore, propose that the methanol extract of Asparagus laricinus is a suitable aspirant for future breast cancer chemotherapeutic drug, due to its selective cytotoxicity on cancer cells and not on non-cancerous cells.

Medicinal plants are important in the South African traditional healthcare system, the growth in the consumption has led to increase in trade through muthi shops and street vendors. Medicinal plants are prone to contamination with fungi and their mycotoxins. The study investigated multiple mycotoxin contamination using Ultra High Pressure Liquid Chromatography–Tandem Mass Spectrometry (UPLC-ESI-MS/MS) for the simultaneous detection of Aflatoxin B1 (AFB1), Deoxynivalenol (DON), Fumonisins (FB₁, FB₂, FB₃), Nivalenol (NIV), Ochratoxin A (OTA) and Zearalenone (ZEN) in frequently sold medicinal plants. Medicinal plant samples (n = 34) were purchased and analyzed for the presence of eight mycotoxins. DON and NIV were not detected in all samples analyzed. Ten out of thirty-four samples tested positive for mycotoxins —AFB₁ (10.0%); OTA (10.0%); FB1 (30.0%); FB2 (50.0%); FB3 (20.0%); and ZEN (30.0%). Mean concentration levels ranged from AFB₁ (15 µg/kg), OTA (4 µg/kg), FB₁ (7–12 µg/kg), FB₂ (1–18 µg/kg), FB₃ (1–15 µg/kg) and ZEN (7–183 µg/kg). Multiple mycotoxin contamination was observed in 30% of the positive samples with fumonisins. The concentration of AFB₁ reported in this study is above the permissible limit for AFB1 (5 µg/kg). Fumonisin concentration did not exceed the limits set for raw maize grain (4000 µg/kg of FB₁ and FB₂). ZEN and OTA are not regulated in South Africa. The findings indicate the prevalence of mycotoxin contamination in frequently traded medicinal plants that poses a health risk to consumers. There is therefore a need for routine monitoring of multiple mycotoxin contamination, human exposure assessments using biomarker analysis and establishment of regulations and standards.

Background: Microbial infections are one of the major causes of death globally. This is attributed to the rising costs of primary healthcare and its inaccessibility especially in developing countries. Moreover, there has been an increase in microbial strains that have reduced susceptibility to antimicrobial drugs. Research on the antimicrobial properties of medicinal plants, which could address these problems, has become more important as they present fewer side effects when compared to the antibiotics currently in use. This study evaluated the antimicrobial properties of a methanolic extract fromBuxus macowaniiin order to assess its potential in the development of novel antimicrobial drugs.Methods: Antimicrobial activity of the extract was evaluated using the broth microdilution method. The effects ofB. macowaniion the morphology ofB. cereuswere observed using Scanning and Transmission electron microscopy. Chemical profiling of the plant extract was performed using the GCMS.Results: The extract showed antimicrobial activity against all the microbial species used. Microscopic examination of the cells ofB. cereuscells treated withBuxus macowaniishowed some changes in morphology such as damage of the cell wall, swelling of the cells and incomplete cell division that eventually resulted in cell death. Neophytadiene, an antimicrobial compound was detected in the extract using GCMS.Conclusion: The morphological disruptions of the cell wall ofBacillus cereusexplain the antimicrobial properties ofB. macowaniiand indicate its possible application in the development of natural antimicrobial drugs.