Studies on the chemical constituents, antioxidants and membrane stability activities of <i>Hibiscus rosa sinensis</i>

Abstract

The chemical constituents, antioxidant and membrane stability activities of Hibiscus rosa sinensis Linn. (Malvaceae) flower were determined. The total anthocyanin was 165 mg / kg with about 6 % reduction due to fermentation. Tannin, ascorbic acid, and total polyphenol were 11.8 g / kg; 478 mg / kg; and 14.4 mg / g, respectively. The phytochemical screening revealed the presence of alkaloids and saponins. The antioxidant activity of the extract was significantly lower (EC50 = 43.9 μg / mL) compared to ascorbic acid (E ₅₀ = 3.3 μg / mL). The extract of fermented Hibiscus rosa sinensis exhibited a concentration dependent, biphasic membrane stability of 46.2 % at 1.0 mg / mL and stability of 63.6 % at 2.0 mg / mL. The study indicated that the flower could be a good source of dietary antioxidant and stabilized red blood cells exposed to induced lyses.