Xanthine Oxidase Inhibition and Antioxidant Effects of Peaganum harmala Seed Extracts

In the present study, seeds of Peaganum harmala were extracted with solvent of varying polarity allowed their separation into four subfractions. Total polyphenols and flavonoids contents of Peaganum harmala seeds extracts (PHSE) were determined as gallic acid equivalent and Quercetin equivalent and were in the following order: chloroform extract (CHE)>ethyl acetate extract (EAE)>crude extract (CE). The superoxide radical scavenging properties of PHSE were determined by either production of uric acid and reduction of Cytochrom c (Cyt c). The inhibition ratios of the Xanthine Oxidase (XO) by CHE and EAE were effective followed by CE. Results for the Cyt c assay were in the same order. The antioxidant potential was confirmed with the non enzymatic methods. The highest DPPH radical scavenging activity was observed with CE followed by EAE and CHE. The β-carotene/linoleic acid bleaching assay revealed that PHSE have a very important antioxidant activity. Results showed that EAE has the highest antioxidant activity (94.21%), followed by CE and CHE respectively. Ferrous ion chelating capacity assay showed that CE, EAE and CE are very active with IC50 of 0.088, 2.256 and 5.286 mg/ml, respectively. Peaganum harmala extracts have strong free radicals scavenging and antioxidant activities and may prove to be of potential health benefit. In addition, the ability of PHSE to inhibit XO can be of great use in some diseases where XO is incriminated.