Chemical constituents and biological activities of different extracts from ginger residues

Ginger, is a herbal plant rich with bioactive chemical compounds which possess high medicinal values, The aim of the present study was to assess in vitro the antioxidant, antiradical, antimicrobial, and anticancer activities of aqueous extracts (cold and hot) of ginger peels and antioxidant, antiradical activities of ethanolic extract of the residual pulp in addition to the semi-purified fractions from hot water extract as a promising. Aqueous extracts of ginger were evaluated against 2,2-diphenyl- 1-picrylhydrazyl (DPPH); 2,2- azinobis (3-ethylbenzothiazoline- 6-sulfonic acid ) (ABTS) as radical methods; potassium permanganate (KMnO4) and methylene blue as non-radical methods; ethanol extract was evaluated against ABTS, methylene blue, and KMnO4; and 6 fractions from column chromatography of hot water extract were evaluated against ABTS. The obtained results were compared with ascorbic acid in addition to analysis of chemical constituents using High-performance liquid chromatography (HPLC). The antimicrobial activity of ginger aqueous extracts was done against gram-negative and positive bacterial strains. Furthermore, the anticancer activity was evaluated against a human hepatocellular cancer cell line (HepG-2). The results revealed that the tested methods go parallel, showing that the extract concentration and incubation time are dependent and proportional with phenols and flavonoids concentration. Hot water extract recorded the highest antioxidant activity when compared with others with 84.15, 74.71, 91.63, and 34.66 % against DPPH, ABTS, KMnO4, and methylene blue respectively, and the highest anticancer and antiradical activity. Thus, the HPLC analysis of hot water extracts showed a profile, containing 9 components. The identified major compounds were p- Hydroxy benzoic acid, and Rosemarinic. From the obtained results it could be concluded that ginger hot water extract 12 of peels and ethanolic extract of the pulp can be used in the production of antioxidant, antiradical, and anticancer for biomedical application on the consumer’s health; with low antimicrobial effect.