Canthium parviflorumLeaves: Antioxidant Activity in Food and Biological Systems, pH, and Temperature Stability

Canthium parviflorum leaves were analyzed for their proximate and phytochemical composition. The leaves were extracted with methanol (ME) and analyzed for antioxidant activity by radical scavenging method, reducing power, ferric reducing capacity, and in vitro inhibition of Fenton’s reagent induced oxidation in oil emulsion and microsomes. In addition, the effect of high temperature (100°C, 15 and 30 min) and pH (4.5, 7, and 9) on the antioxidant activity of ME was investigated. The leaves were rich in polyphenols, flavonoids β-carotene, glutathione, α-tocopherol, and ascorbic acid. The ME exhibited varying degree of antioxidant activity in a dose dependent manner. The RSA was 68%–500 μg. Reducing potency was 0.34 and FRAP was 1.377. Canthium exhibited greater inhibition of oxidation in microsomes (73%) than in the oil emulsion (21%). Heat treatment resulted in reduction of radical scavenging activity of extract from 68% to 40%. At pH 4.5 and 7 methanol extract exhibited some percent of antioxidant activity which ranged between 18 and 32%. Data indicates Canthium as a good source of antioxidants and methanol extract exhibited good antioxidant activity