An Assessment of the Nutritional, Phytochemical and Antioxidant Properties of Hook. F. (Malvaceae)
Hibiscus asper is used traditionally as potent sedative, restorative tonic, anti-inflammatory, anti-depressive and anti-anaemic drug, as well as in the management of jaundice. This study evaluated the nutritional, phytochemical and antioxidant properties of the leaf and calyx of the plant with a view to providing more scientific information on its therapeutic potentials. The two plant parts were screened for proximate, mineral and vitamin compositions using standard protocols. The phytochemical analysis of dry samples was done using standard protocols. The antioxidant activity of samples was against 1,1 – diphenyl – 2 picrylhydrazyl (DPPH) radical. All data were subjected to statistical analysis. H. asper calyx had significantly higher nutrients than the leaf except carbohydrate content. The calyx was richer in mineral and vitamin contents than the leaf, especially ascorbic acid (22.17±0.21 mg/100g) and carotenoids (1660.00±15.00 mg/100g). Interestingly, the leaf had higher phytochemical contents compared to the calyx. It had alkaloids (1260.00±18.03 mg/100g), flavoniods (471.67±16.07 mg/100g), and cardiac glycosides (4.10±0.10 mg/100g), whereas the calyx (53.33±0.25 %) showed higher inhibition against DPPH radical than the leaf (36.33±0.45 %). Overall, the calyx was richer in proximate, mineral and vitamin contents. It also showed higher antioxidant activity than the leaf. However the leaf contained significantly higher phytochemicals than the calyx. H. asper is very rich in nutrients and phytochemicals with valuable antioxidant property. The calyx could be an important source of nutrients and the leaf had strong therapeutic potentials in the management of diseases. This study justifies the traditional uses of the plant as food and medicine.
Keywords: Hibiscus asper, secondary metabolites, nutrients, vitamins, natural antioxidant