Phytochemical study and comparative antioxidant activity of the three varieties of Catharanthus roseus (L.) G. Don

Abstract

Catharanthus roseus (L.) G. Don, is a medicinal plant widely used in the treatment of diabetes, hypertension, cancer, and effects of oxidative stress. C. roseus exists in three varieties ("rosea", "alba" and "hybrid") depending on the colour of the flowers. This study focused on phytochemical screening and in vitro antioxidant activity (DPPH and FRAP) of the hydro-ethanol extract of the three varieties. The tests were carried out on leaves, flowers, and roots extracts. The presence of alkaloids, phenols, flavonoids, tannins, saponins, sterols, terpenes, and quinines were noted. However, the absence of reducing sugars, flavonoids, and saponins in the roots and quinines in the leaves was observed. Comparative analysis of DPPH radical scavenging showed that extracts from the flowers and roots of the hybrid were more active, respectively at 130.023±3.2 and 131.189±1.8 mg EqQ/g. FRAP values of the same samples were 175.166± 9.28 and 121.311±7.8 mg EqAA/g dry matter. For the leaves, the best DPPH value of 65.746±2.5 mg EqQ/g was attributed to "rosea" while the FRAP value of 139.935±2.57 mg EqAA/g was for "alba". These interesting antioxidant activities of the "hybrid" variety may be useful against oxidative stress pathologies. The current study might then promote the continuing identification and characterization of new bioactive compounds for a development of Catharanthus roseus.