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.

The use of green methods for ruthenium oxide nanoparticles (RuONPs) synthesis is gaining attention due to their eco-friendliness, cost-effectiveness, and availability. However, reports on the green synthesis and characterization of RuONPs are limited compared to other metal nanoparticles. The green synthesis and characterization of RuONPs using water extracts of Gunnera perpensa leaves as a reducing agent is reported in this study. The RuONPs were characterized using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Ultraviolet spectroscopy (UV–VIS). MTT assay was used to assess the cytotoxicity of the RuONPs against MCF7 and Vero cell lines. X-ray diffraction analysis results revealed the presence of crystalline and amorphous forms of RuONPs, while IR spectroscopy revealed the presence of functional groups associated with G. perpensa leaves. SEM showed that the RuONPs consisted predominantly of hexagonal and cuboid-like structures with a considerable degree of agglomeration being observed. The cell culture results indicated a low anticancer efficacy of RuONPs against MCF7 and Vero cell lines, suggesting that RuONPs may not be a good lead for anti-cancer drugs. This study highlights the potential of using green synthesis methods to produce RuONPs and their characterization, as well as their cytotoxicity against cancer cells.

Introduction. The use of traditional medicinal plant concoctions to cure or treat different diseases daily in African folk medicine. However, the effects of most medicinal plants on human health or genetic material remain unknown. This study thus aimed to evaluate the mutagenic and antimutagenic potentials of Asparagus laricinus Burch. cladodes, Senecio asperulus DC., and Gunnera perpensa L. roots extract in vitro. Methods. Neutral red uptake assay, alkaline comet assay, and the VITOTOX test was used with plant extract dilutions of 4, 20, 50, and 100 µg/ml, respectively, on hepatic (C3A) cells and Salmonella Typhimurium TA104 strains. Ethyl methane-sulfonate and 4-nitroquinoline oxide were used as positive controls for the comet and VITOTOX assays, respectively. Results. In vitro cytotoxicity and genotoxicity were not observed from all tested extracts, except for the two dichloromethane (DCM) extracts of S. asperulus and G. perpensa, which appeared to be cytotoxic with S9 metabolic activation, but not genotoxic or mutagenic. From the VITOTOX test results, none of the extracts appeared to have antimutagenic properties after treating S. Typhimurium strains with a known mutagen. Conclusions. These results confirm that previously reported anticarcinogenic properties of A. laricinus, S. asperulus, and G. perpensa did not result from the protective mechanism against genotoxicity but from other ones. Moreover, the negative mutagenic and cytotoxic activities of the tested plants highlighted the safe use of these medicinal plants in vitro. Therefore, S. asperulus and G. perpensa DCM extracts require further investigation for their possible in vivo cytotoxic effects on humans.

The first case of coronavirus disease of 2019 (COVID-19) in South Africa (SA) was first reported at the beginning of March 2022, and then further spread from Gauteng, Western Cape, and KwaZulu Natal to the rest of the provinces. It is caused by severe acute respiratory syndrome coronavirus 2. In SA, COVID-19 is less prevalent in children less than 18 years. Only a few studies describe the epidemiology, risk factors, and clinical manifestation of COVID-19 among children in SA in comparison to other countries including China, North America, and Europe. South African children are affected by conditions including poverty, tuberculosis, and human immunodeficiency virus which predispose them to COVID-19. Overcrowding and limited healthcare facilities and resources also complicated the diagnosis and clinical and pharmacological management of COVID-19 in SA. The current review discusses the prevalence, risk factors, and management of COVID-19 in South African children in comparison to other continents in the world.

Background: Cancer mortality rate is still increasing every year despite advanced treatment regimes. Medicinal plants are one of the most important sources of anticancer agents. Aim: This study was conducted to evaluate the cytotoxic effects of the aqueous and methanolic extracts of Hypoxis hemerocallidea, Helichrysum caespititium and Dicoma anomala on prostate cancer cell line (DU145) in vitro. Setting: This is an in vitro study conducted under controlled laboratory settings at the University of Johannesburg, Department of Biomedical Sciences, South Africa. Methods: Corms of the plants were collected and extracted with aqueous and methanolic solvents using the direct maceration method. DU145 cells were treated, respectively, with the aqueous and methanolic extracts of H. hemerocallidea, H. caespititium and D. anomala at various concentrations. Cell viability was quantified using the bisBenzimide H33342 trihydrochloride (Hoechst 33342) and propidium iodide (PI) dual-staining method assay after 48 h. Results: The aqueous extracts of H. hemerocallidea and H. caespititium did not result in significant inhibition of DU145 cell line. However, an antiproliferative effect on the DU145 cell line was seen with D. anomala aqueous extracts at the concentrations of 15 µg/mL and 62.5 µg/mL, respectively. Additionally, methanolic extracts from H. caespititium and D. anomala arrested DU145 cell line at 15 µg/mL and 31 µg/mL concentrations in comparison to the untreated cell line and melphalan treatment control. However, not much termination was noticeable from the methanolic extracts of H. hemerocallidea on the cell line at 48 h. Conclusion: These findings indicate that the methanolic extracts of D. anomala can act as a potential anticancer agent, with further analysis recommended to isolate the active compound and to understand its mechanism of action. Contribution: The potential for D. anomala to be an alternative is supported by these findings, provided that active anticancer constituents are successfully characterised.

The use of green synthesis methods for RuONPs is gaining attention due to their eco-friendliness, cost-effectiveness, and availability. However, reports on the green synthesis and characterization of RuONPs are limited compared to other metal nanoparticles. The green synthesis and characterization of ruthenium oxide nanoparticles (RuONPs) using Gunnera perpensa leaves water extract as a reducing agent is reported in this study. The RuONPs were characterized using X-Ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Ultraviolet spectroscopy (UV-VIS). MTT assay was used to assess the cytotoxicity of the RuONPs against MCF7 and Vero cell lines. The characterization results revealed the presence of crystalline and amorphous forms of RuONPs, functional groups associated with G. perpensa leaves, and both spherical and rod-like structures. The cell culture results indicated a low anticancer efficacy of RuONPs against MCF7 and Vero cell lines, suggesting that RuONPs may not be a good lead for anti-cancer drugs. This study highlights the potential of using green synthesis methods to produce RuONPs and their characterization, as well as their cytotoxicity against cancer cells.