Phytochemical analysis and determination of antioxidant, anti-cholesterol, anti-inflammatory and anti-proliferative activities of Gerbera jamesonii flowers

From the flowers of Gerbera jamesonii, eleven compounds have been isolated for the first time and identified as; apigenin (1), kampferol (2), quercetin (3), dihydroquercetin (Taxifolin) (4), quercetin-4`-O-β-d-glucopyranoside (5), rutin (6), 4-β-d-glycopyranosyloxy-5-methylcoumarin (Gerberinside) (7), 5,6-dihydro-4-β-d-glycopyranosyloxy-6-methyl-2 H-pyran-2-one(Gerberin) (8), 3,4-dihydroxybenzoic acid (Protocatechuic acid) (9), stigmasterol (10) and β-sitosteryl-3-O-β-d-glucopyranoside (Daucosterol) (11). The structures have been established by comparison of their NMR and MS data with published ones. Free radical scavenging activity of flower extracts was further investigated, which indicated potent antioxidant activity ranged from 94.4 ± 1.16 to 99.3 ± 0.15 using 16.7 mg/ml of each extract; the IC₅₀ of all extracts was abstemiously low between 3 and 7 mg/ml. All extracts were able to degrade cholesterol with different potencies ranged from 64.96% ± 1.87 to 69.89% ± 4.02 after 96 h of incubation. Compound (6) has a potent anti-inflammatory activity even with low concentration (90.3 ± 0.57, 94.55 ± 0.78, 97.4 ± 1.13, using 0.001, 0.0015 and 0.005 mg, respectively). Concerning anti-proliferative activity, all fractions exerted 100% anti-tumor activity using 1 mg of each sample against HCT-116, MCF-7 human cancer cells and good anti-tumor activity against HepG-2 human cancer cells exceeding Doxorubicin in the case of petroleum ether extract with no cytotoxic activity against BJ-1 human skin healthy cell-line. This could promote the use of G. jamesonii flower extract for pharmacological and health purposes. For author’s knowledge, this is the first report evaluating the biological activities of G. jamesonii flowers extract. Graphical abstract: [Figure not available: see fulltext.]