The in vitro cytotoxicity, genotoxicity and LC-ToF-MS profiling of four South African plants with good antifungal activity

Abstract

• Medicinal plants may cause adverse effects like mutagenic and genotoxic activities • Phenolics, alkaloids, flavonoids, and terpenoids are active against cancer • MTT assay is commonly used for cell proliferation and cytotoxicity studies • Genotoxicity of selected crude extracts was tested against Vero cells • LC-ToF-MS profiling identified secondary metabolites present in tested plants Plants create secondary metabolites which may or may not have biological activities and are not always benign. Therefore, it is essential to assess both their bioactivities and safety. The objective of this research is to assess the in vitro toxicity and phytochemistry of extracts from Bauhinia galpinii, Combretum caffrum , and Maytenus undata extracts. In the past, it has been demonstrated that these plants possess potent antifungal activities against mycotoxigenic fungal strains. The MTT assay was used to evaluate the cytotoxicity of methanolic leaf extracts of selected plants on the viability of the African Green monkey kidney and the human colorectal adenocarcinoma cells. Furthermore, the ability of these plants to cause genotoxicity in Vero cells was investigated using the micronucleus test. The identity and quantity of the phytocompounds present in the plant extracts were analyzed using liquid-chromatography time-of-flight mass spectrometry (LC-ToF-MS) analysis. B. galpinii, C. caffrum , and M. undata extracts were cytotoxic to Vero cells at 500 µg/ml. All the selected medicinal plant extracts demonstrated dose-dependent cytotoxicity against both Caco-2 and Vero cells. B. galpinii, M. obtusifolia , and M. undata extracts were all genotoxic towards the Vero cells at 500 µg/ml, while Combretum caffrum showed genotoxicity at 250 µg/ml. Phenolic glycosides, coumarins, flavonoids, and hydrolysable tannins were identified as major phytochemicals in the secondary metabolite profiling. Given the results, caution in terms of quantities consumed should be exercised when these plants are used in traditional medicine.