Medicinal plants are used by a large proportion of the global population as complementary and alternative medicines. However, little is known about their toxicity. G. africana has been used to treat wounds, coughs and skin diseases and is used in cosmetic formulations such as lotions and shampoos. The acute oral and dermal toxicity potential of G. africana was analyzed after a single administration of 300 and 2000 mg/kgbw for acute oral toxicity and 2000 mg/kgbw for acute dermal toxicity. Female Sprague-Dawley rats were used for the acute oral toxicity study whereas both male and female Sprague-Dawley rats were used for the acute dermal toxicity study. In the Episkin skin irritation test, the irritation potential of G. africana (concentrate) and G. africana (in-use dilution) extracts were assessed using the Episkin reconstituted human epidermis. In the dermal sensitization study, female CBA/Ca mice were treated with G. africana concentrations of 50, 100 and 200 mg/ml respectively. The vehicle of choice was dimethylformamide which acted as a control. The results of the acute oral and dermal toxicity studies revealed that the median lethal dosage (LD50) for G. africana extract in Sprague-Dawley rats was considered to exceed 2000 mg/kgbw. In the irritation test, the G. africana (concentrate) and G. africana (in-use dilution) extracts were non-irritant on the Episkin reconstituted human epidermis. In the dermal sensitization study, the stimulation index (SI) values for the mice treated with the G. africana extract at concentrations of 50, 100 and 200 mg/ml/kgbw, when compared to the control group, were 1.3, 0.9 and 1.3 respectively. The open application of the extract at the various concentrations did not result in a SI of ≥ 3 in any group. Hence, it did not elicit a hypersensitivity response. These findings demonstrate that the acute toxicity profile for G. africana is acceptable and can subsequently be used for single use in the pharmaceutical and cosmetic industries.

The indiscriminate use of non-regulated skin lighteners among African populations has raised health concerns due to the negative effects associated with skin lightener toxicity. For this reason, there is a growing interest in the cosmetic development of plants and their metabolites as alternatives to available chemical-derived skin lightening formulations. Approximately 90% of Africa’s population depends on traditional medicine, and the continent’s biodiversity holds plant material with various biological activities, thus attracting considerable research interest. This study aimed to review existing evidence and document indigenous African plant species capable of inhibiting the enzyme tyrosinase and melanogenesis for potential incorporation into skin lightening products. Literature search on melanin biosynthesis, skin lightening, and tyrosinase inhibitors resulted in the identification of 35 plant species were distributed among 31 genera and 21 families across 15 African countries and 9 South African provinces. All plants identified in this study showed competent tyrosinase and melanogenesis inhibitory capabilities. These results indicate that African plants have the potential to serve as alternatives to current chemically-derived skin lighteners.

Botrytis cinerea is a fungus that causes gray mold on many fruit crops. Despite the availability of a large number of botryticides, the chemical control of gray mold has been hindered by the emergence of resistant strains. In this paper, tests were done to determine the botryticidal efficacy of selected plant extracts alone or combined with kresoxim-methyl. In total, eight South African medicinal plants viz Artemisia afra, Elyptropappus rhinocerotis, Galenia africana, Hypoxis hemerocallidea, Siphonochilus aetheopicus, Sutherlandia frutescens, Tulbaghia violacea and Tulbaghia alliacea were screened. Allium sativum, a plant species known to have antifungal activity, was included in the in vivo studies. For the in vitro studies, synergistic interactions between the plant extracts and the kresoxim-methyl fungicide were tested with radial growth assays. Data indicated synergistic inhibitory effects between the fungicide and the plant extracts. Next, different doses of plant extracts combined with kresoxim-methyl were used for decay inhibition studies on Granny Smith apples. Synergistic and additive effects were observed for many of the combinations. Even though this study was done using only one strain of B. cinerea, results showed that the tested indigenous South African plant species possess natural compounds that potentiate the activity of kresoxim-methyl.

Many people in developing countries rely primarily on medicinal plants as their main source of healthcare, particularly for the treatment of skin infections. Despite the widespread use of medicinal plants, there is a lack of literature describing the relevance and risks of exposure of the phytochemicals present. Galenia africana has been used traditionally in the form of pastes, decoctions, and lotions to treat wounds and other skin-related ailments. This is a report on the phytochemical composition of G. africana and a review on the pharmacological importance and relevance of these phytochemicals. The major groups of phytochemicals identified in G. africana extracts were aliphatics, aliphatic triterpenoids, fatty acids, flavonoids, and phenolic and tocopherol compounds. These have been found to exhibit medicinal properties, thus highlighting the need to assess the safety of G. africana for topical application. The information related to the safety of the various compounds could indicate the potential risks related to accidental intake of the extract upon topical product applications. This report concludes that the quantities of the phytochemicals present in G. africana should not cause undue risk to human health, which provides comfort to pursue future work on using and developing G. africana as a therapeutic agent.

Malignant melanoma is the major cause of skin cancer-related deaths. Surgery in combination with radiotherapy, immunotherapy or chemotherapy is used to eradicate cancer cells, however, this treatment option is limited by the tolerance of the surrounding healthy tissue. The extracts from Galenia africana have been shown to possess anti-cancer flavonoid compounds and can be a safer and cost-effective alternative treatment. The study aimed to compare the anti-proliferative effects of G. africana on human skin cells (HaCaT) and human malignant melanoma cells (A375). The cells were exposed to various concentrations of the G. africana extract at different times. In vitro assays were employed to determine cell viability and cytotoxicity. Hoechst 33342 staining was performed to observe the nuclear changes, including apoptosis. G. africana significantly reduced the cell viability of the A375 cells in a dose and time-dependent manner, while having no effect on the HaCaT cells. The A375 cells displayed nuclear condensation, brightly stained nuclei and nuclear fragmentation indicative of apoptosis. This suggests a clinical rationale for the use of G. africana as a potential anti-melanoma agent offering efficacy and low toxicity. This study provides new insights for future work on investigating the utilization of G. africana in malignant melanoma treatment.