Phytochemistry and Biological Activity of Hibiscus rosa-sinensis Extracts

Abstract

This study aimed to assess the phytochemical characteristics, biological activity and antioxidant properties of the leave and flower of Hibiscus rosa sinensis grown in Sudan. It is an ornamental plant that belongs to the Mavales family. Proximate analysis of the targeted parts of the plant revealed that the moisture content in the leaves as well as the flowers was 2.6% (w/w). While the Ash content was 3.05% in the leaves and was 3.55% in the flowers, the protein content was 7.0% in the leaves while it was 12.0% in the flowers, the crude fiber was 15.5% in the leaves and it was only 10.3% in the flowers. Phytochemical screening of the leaves and flowers aqueous and ethanolic extracts showed the presence of flavonoids, saponins, alkaloids, tannins, triterpenes, and cardiac glycosides. The mineral content analysis show the presence of Fe, Al, Cu, Ca, Na, K, Mn, Mg, Cd and Zn. Chloroform extracts of the leaves and flowers were examined for antimicrobial activity against two gram positive bacteria, Staphylococcus aurenus and Bacillus subtilis, two gram negative bacteria, Escherichia coli and Pseudomonas aeruginosa and one type of fungi, Candida albicans. The extracts show no anti-bacterial activities but they possess moderate anti-fungal activity. The leaves and flowers aqueous and ethanolic extracts show appreciable antioxidant activity when tested by DPPH radical.