Inhibition of nitric oxide production and free radical scavenging activities of four South African medicinal plants

• Published in: Journal of inflammation research 2019-08, Vol.12, p.195-203
• Main Authors: Adebayo, S A, Ondua, M, Shai, L J, Lebelo, S L
• Format: Article
• Language: English
• Subjects: Acetic acid; Acetone; Anti-inflammatory agents; Antioxidants; Antioxidants (Nutrients); Arthritis; Cell culture; Cells (Biology); Chloroform; Chronic pain; Colds; Cytotoxicity; Esters; Ethnomedicine; Ethyl acetate; Flowers & plants; Free radicals; Herbal medicine; Infections; Inflammation; Mammalian cells; Medicinal plants; n-Hexane; Nitric oxide; Nitrogen oxides; Original Research; Pain; Pain management; Phytochemicals; South Africa; Species
• ISSN: 1178-7031; 1178-7031
• DOI: 10.2147/JIR.S199377

Traditional healing is often the preferred form of therapy especially in rural and resource-limited communities. The extracts of plants are used to treat many diseases such as arthritis and chronic pain. Four medicinal plant species, namely, and used in Southern Africa to treat pain and inflammation-related diseases were selected for evaluation in laboratory-based experiments. The selected plant species were evaluated for phytochemical content, antioxidant and anti-inflammatory activities, as well as cytotoxicity effects against mammalian cells in culture. The results indicated that the -hexane and chloroform extracts of had the best antioxidant activities with an IC =0.41 μg/mL. Also, the acetone extracts of had 93.76% nitric oxide (NO) inhibition. However, the chloroform and -hexane extracts of produced NO inhibition of 98.53% and 99.2%, respectively, at 100 μg/mL with IC =17.69 μg/mL. Furthermore, the ethyl acetate extracts also had promising NO inhibitory activity (96.33%), but the cytotoxicity results with cell viabilities of 5.31%, 5.7% and 5.89%, respectively, suggested that the observed activity was due to a cytotoxic effect. Acetone extracts of were also cytotoxic at 30 µg/mL with 6.07-6.67% cell viabilities compared with the acetone extracts of (99.57%). The results partially validate the ethnomedicinal uses of the selected plant species used for inflammation-related conditions. However, because some of the extracts had potential cytotoxic effects, caution is advised in their use, especially those consumed orally.