Abstract

This research was carried out to evaluate the phenolics and flavonoids content of Medicago sativa leaves extract and to characterize the phenolics and flavonoids profiles using reversed phase-high performance liquid chromatography (RP-HPLC). The antioxidants, anti inflammatory and xanthine oxidase (XO) inhibitory activities of the extract were also determined. The obtained result showed that the total phenolics value was 37.0 ± 0.02 mg gallic acid equivalent (GAE)/g dry matter (DM), and for total flavonoids was 12.6 ± 0.17 mg rutin equivalent/g DM. In addition, the RP-HPLC analyses indicated the presence of gallic acid, pyrogallol, salicylic acid, caffeic acid as phenolics while the detected flavonoids and isoflavonoid were naringenin, apigenin, quercitin, myrcitin and daidezin. The antioxidant activity of Alfalfa by diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) method showed 54.42 and 56.71% inhibition of free radicals at the concentration of 250 μg/ml of leaves crude extract, respectively, but the activities were lower than those of antioxidant standards such as butylated hydroxytoluene (BHT) and α-tocopherol. Nitric oxide (NO) inhibition assay as one of antioxidant potential indicator showed 50.99% inhibitory activity of NO at the concentration of 250 µg/ml, while this value for the vitamins E and C were 91.52 and 94.13%, respectively. Alfalfa exhibited moderate anti-inflammatory activity where the 50% of the NO production by the induced RAW 264.7 cells was inhibited at the concentration of 147.24 μg/ml of Alfalfa crude extract. The cell viability test [3-4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay] showed that Alfalfa extract was not toxic to macrophage RAW 264.7 cells. Meanwhile, leaves crude extract also inhibited the XO 51.63% at the concentration of 250 µg/ml.

Key words: Medicago sativa, Alfalfa, functional properties, antioxidant, anti-inflammatory, xanthine oxidase.