PHYTOCHEMICAL COMPOSITION AND IN VITRO ANTIOXIDANT ACTIVITY OF Hibiscus sabdariffa.

PHYTOCHEMICAL COMPOSITION AND IN VITRO ANTIOXIDANT ACTIVITY OF Hibiscus sabdariffa calyxes.

Nworah, F. N., *Orji, O. C., Ibegbulam, E. G.

Pharmacology and Pharma-biology Unit, Department of Biochemistry, University of Nigeria, Nsukka, Enugu State, Nigeria.

Corresponding author email: *oyidiya.orji.pg00232@unn.edu.ng

ABSTRACT

Hibiscus sabdariffa calyxes has long been used in traditional food and medicine, including cold or hot drinks, jellies, puddings, and as flavoring agents. This study evaluated the phytochemicals composition and in vitro antioxidant activities of Hibiscus sabdariffa calyxes in aqueous extract form. The analysis qualitatively and quantitatively identified several phytochemicals, revealing 4634.41 ± 10.75 mg of total phenolics, 329.99 ± 4.57 mg of alkaloids, 179.38 ± 0.83 mg of flavonoids, 14.42 ± 0.23 mg of tannins, 1.69 ± 0.00 mg of glycosides, 3.45 ± 0.00 mg of steroids, 173.48 ± 0.13 mg of reducing sugars, and 137.70 ± 2.77 mg of terpenoids per 100 grams of extract. The antioxidant activity was measured through several assays. The DPPH radical scavenging assay resulted in an EC50 of 34.89 µg//ml, compared with the standard at 29.9 µg//ml. Lipid peroxidation inhibition showed an EC50 of 8.53 µg//ml, compared to 2.73 µg//ml for the standard. Nitric oxide scavenging had an EC50 of 3.217 µg//ml, while the standard was shown to have a value of 0.895 µg//ml. The ferric reducing antioxidant power (FRAP) assay demonstrated the extract’s ability to reduce Fe³+ to Fe²+. Additionally, the extract reduced molybdenum (vi) to molybdenum (v). This study on Hibiscus sabdariffa calyxes confirms that the aqueous extract from Hibiscus sabdariffa calyxes is rich in phenolics, contributing to its antioxidant properties and supporting its traditional medicinal uses.

Keywords: Hibiscus sabdariffa, antioxidant, phytochemicals, calyxes