Antioxidant, antihemolytic, and inhibitory activities of endemic Primula heterochroma against Fe2+-induced lipid peroxidation and oxidative stress in rat brain in vitro.

BACKGROUND

The genus Primula (Primulaceae) has been used in traditional medicine to treat convulsion and microbial or viral infections.

OBJECTIVE

In the present study, we evaluate antioxidant, antihemolytic, and protective effects of flavonoid-rich fractions of endemic Primula heterochroma Stapf. (Primulaceae) against Fe(2+)-induced lipid peroxidation and oxidative stress in rat brain in vitro.

METHODS

Aerial parts of plant were defatted and extracted with 60% acetone. Then, 60% acetone extract was fractionated sequentially with n-hexane, ethyl acetate, and water. Antioxidant activity of fractions was evaluated by employing six different assays, i.e., 1,1-diphenyl-2-picryl hydrazyl (DPPH) and hydrogen peroxide scavenging, metal chelating and reducing power activities and hemoglobin-induced linoleic acid system and Fe(2+)-induced lipid peroxidation and oxidative stress in rat brain. Also, its antihemolytic activity was determined using 2,2'-azobis(2-amidinopropane) dihydrochloride-induced hemolysis in rat erythrocyts.

RESULTS

Among the flavonoid-rich fractions of Primula heterochroma, aqueous fraction demonstrated the most protective effect through decreasing brain thiobarbituric acid reactive substances (TBARS) levels at a dose 200 μg mL(-1) (40%, p < 0.001 versus iron group). Also, the aqueous fraction showed better activity in Fe(2+) chelating (89 ± 3.8 μg mL(-1)) and DPPH radical scavenging (394.4 ± 18.4 μg mL(-1)) models than other fractions. The probable protective mechanism of flavonoid-rich fractions may be attributed to their Fe(2+) chelating, DPPH radical scavenging and reducing power activities. Also, the n-hexane fraction demonstrated a higher protective effect in the hemoglobin-induced linoleic acid system and 2,2'-azobis(2-amidinopropane) dihydrochloride-induced hemolysis (67 ± 2.6 μg mL(-1)).

CONCLUSIONS

Results of this study demonstrate Primula heterochroma is a rich source of natural antioxidant compounds.