Fagonia olivieri (DC) being used for the treatment of diabetes, cancer, fever and claimed to be effective in many other stress related disorders. In this study we have evaluated the F. olivieri whole methanol extract and its derived fractions for various in vitro and in vivo antioxidant studies.

Our results showed that F. olivieri is a potential source of natural antioxidants, which justifies its use in folklore medicine.

The crude methanol extract of the whole plant of F. olivieri (FOM) and its derived fractions; n-hexane (FOH), chloroform (FOC), ethyl acetate (FOE), n-butanol (FOB) and aqueous (FOA) were evaluated for the total phenolic and flavonoid content and in vitro antioxidant abilities. The antioxidant effect of FOM was determined by acetaminophen-induced hepatotoxicity in Sprague-Dawley (Rattus novergicus) male rats. The methanol/fractions were also analysed by HPLC analysis for the presence of polyphenolics.

The total phenolic content of the samples ranged from 19.3 ± 0.529 to 106.2 ± 0.892 mg GAE/g extract while total flavonoid content 16.2 ± 0.881 to 50.1 ± 1.764 mg RTE/g extract, respectively. FOA showed highest radical scavenging activity for DPPH (IC50 = 55.2 ± 1.212 μg/ml), ABTS (IC50 = 90.2 ± 1.232 μg/ml) superoxide (IC50 = 37.1 ± 0.643 μg/ml) and for H2O2 (IC50 = 64 ± 1.463 μg/ml). FOE exhibited the highest antioxidant activities for phosphomolybdenum (IC50 = 78.2 ± 0.883 μg/ml) and for hydroxyl radical scavenging (IC50 = 82 ± 2.603 μg/ml). HPLC analysis of FOM and its derived fractions showed the presence of rutin, catechin and gallic acid. Elevated levels of AST, ALT, ALP, LDH and lipid profile in serum and lipid peroxidation and DNA damages in liver; while decreased activity level of CAT, SOD, GSH-Px, GR and reduced glutathione (GSH) concentration induced with acetaminophen in rat were reverted towards the control group with co-administration of FOM.