Ammar M. A. Ali, Mawahib E. M. ElNour
Abstract: The research aimed to study antioxidant activity, total phenolic, flavonoid and tannin contents of methanolic extracts of callus and seeds and petroleum ether extract of seeds of fenugreek (Traigonella foenum-graecum). Callus was induced from hypocotyls and cotyledons explants in MS medium supplemented with combination of 2 mg/l of different auxin (2, 4-D or NAA) + 0.5 mg/l Kinetin. Free radical scavenging activity was evaluated by DPPH method. The highest scavenging activity was obtained from cotyledons derived callus (91.50.16 %) followed by hypocotyls derived callus (85.460.29 %) and methanolic extract of seeds (80.530.01 %). Petroleum ether extract of seeds demonstrated weak antioxidant activity with inhibition percentage 24.560.12 %. Significant differences (phypocotyls derived callus (0.7159mg/g) >cotyledons derived callus (0.4914mg/g) > ascorbic acid (0.1874mg/g). A lower value of IC50 indicates a higher antioxidant activity. Highest phenolic content were observed in callus of cotyledons (412.087 mg/l), compared to callus of hypocotyls (211.1937 mg/l) and methanolic extract of seeds (124.84 mg/l) calculated as mg/l gallic acid equivalent of phenols. Methanolic extract of seeds showed highest level of flavonoid content (424.951 mg/l), compared to callus of cotyledons (217.285 mg/l) and callus of hypocotyls (95.92 mg/l) calculated as mg/l quercetin equivalent of flavonoids. Tannins content were detected only in methanolic extract of seeds (116.259 mg/l calculated as tannic acid equivalent of tannins).
Keywords: Trigonella foenum-graecum L, Flavonoids and phenolic compounds, Antioxidant activity, Callus