PHYTOCHEMICAL, ANTIOXIDANT AND CYTOTOXICITY OF HYDROETHANOLIC EXTRACTS OF CROTALARIA RETUSA L.

For centuries now, plants have served as a great source of compounds with pharmacological properties. Some plants like weeds, however, have not been fully exploited for their medicinal value. In this research, the phytochemical, total phenolic content, antioxidant and antiproliferative effect of Crotalaria retusa, a weed reported to have potential to fight tumours was assessed. The study focused on the leaf, stem, seed, pod and flower of this plant as well as fractions of its stem was assessed. Standard methods such as the MTT, the DPPH and the Folin-Ciocalteau assays were used. The phytochemicals present included saponins, tannins, alkaloids and sterols. The leaf was found to have the highest concentration of phenols (67.35±1.153 mg GAE/g of extract) and the best free radical scavenging activity with an EC50 value of 0.222±0.004 mg/mL. All the extracts induced cytotoxicity in a dose dependent manner. The study revealed that the stem of C. retusa exhibited the highest cytotoxicity against the selected cancer cells. However, extracts of the plant parts were observed to be non-selective towards cancer cells since they were equally toxic to the normal human liver (WRL 68) cells. All the fractions tested against the cancer cells did not exhibit any significant increase in cytotoxicity. The study reveals the antiproliferative nature of C. retusa, with Jurkat being the most sensitive cell line. The antioxidant potential of this plant could be due in part, to its total phenol content. Further study is however needed to determine the active principle of C. retusa.