Bioactivity and Safety of Lyophilised Carrisa edulis

Carissa edulis (C. edulis), from the Apocynaceae family is a widespread plant species prevalent in tropical and subtropical regions of Africa. The plant is extensively utilized in traditional medicine for various ailments, particularly diabetes mellitus (DM), a chronic, non-communicable disease whose complications lead to over 70% of all amputations globally, and considerable deaths across all adult age groups and resource settings. The endpoint biomarkers of the diseased state include inflammation and oxidative degeneration of cells and tissues. The current therapeutic approaches for management of DM are characterized by several limitations such as adverse side effects and prohibitive costs. This, therefore necessitates the need to explore safer, effective, and affordable alternatives that can inhibit, ameliorate, and/or reverse the biological endpoints of DM. Our current study qualitatively and quantitatively determined the phytoconstituents of C. edulis, as well as its activity as an antioxidant and anti-inflammatory agent. The phytoscreening confirmed the presence of numerous biomedically relevant secondary metabolites with high polyphenolic and flavonoid yields. The biosafety studies using Wistar rat models confirmed that C. edulis is nontoxic with an LD50 above 5000mg/kg. The lyopilised hydroethanolic extract demonstrated high anti-oxidant and high anti-inflammatory activities, which were comparable to the standards, ascorbic acid and diclofenac, respectively. It was therefore concluded that the presence of bioactive secondary metabolites in lyophilized extracts of the aerial parts of C. edulis possess satisfactory anti-inflammatory and anti-oxidant profiles. Our results support the continued use of the plant extracts as an adjunct therapy for known biological end points of DM in traditional medical practices in Southern Africa.