In vitro and In vivo Antioxidant Activity of Flavonoid Extracted from Mulberry Fruit (Morus alba L.)

BACKGROUND: Many plants possess antioxidants that exhibit additive or synergistic activities. OBJECTIVE: In this study, an ethanol-extracted flavonoid extracted from mulberry fruit (FEM) was evaluated for the antioxidant activity in vitro and the hemolysis in red blood cell (RBC) and lipid peroxidation in liver in vivo. MATERIALS AND METHODS: Antioxidant activities in vitro were measured by quantifying its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, reducing power, and Fe(2+)-chelating ability. FEM inhibits hemolysis in RBCs and effects of lipid peroxidation in the liver were estimated. RESULTS: The total content of flavonoid compounds was 187.23 mg of quercetin equivalents per grams dried material. In the in vitro assays, FEM demonstrated a strong antioxidant effect, especially in DPPH scavenging activity and reducing power. Mouse RBC hemolysis induced by H(2)O(2) was significantly inhibited by FEM in a dose- and time-dependent manner. The effects of FEM on lipid peroxidation in liver, mitochondria, and microsome were investigated. The percentage of inhibition at high concentration (100 μg/mL) of FEM was 45.51%, 39.36%, and 42.78% for liver, mitochondria, and microsomes, respectively. These results suggest that the FEM possesses a strong antioxidant activity both in vivo and in vitro. SUMMARY: The total content of flavonoid compounds in mulberry fruit was 187.23 mg/g dried material. FEM showed a strong antioxidant effect, especially in 2,2-diphenyl-1-picrylhydrazyl scavenging activity and reducing power. Mouse red blood cell hemolysis induced by H(2)O(2) was significantly inhibited by FEM in a dose- and time-dependent manner. The inhibition percentage at high concentration of FEM was 45.51%, 39.36%, and 42.78% for mouse’s liver, mitochondrial, and microsomes, respectively. Abbreviations used: FEM: Flavonoid Extracted from Mulberry fruit, H(2)O(2): Hydrogen peroxide, DPPH: 2,2-diphenyl-1-picrylhydrazyl, EDTA: Ethylene diamine tetraacetic acid, MDA: malondialdehyde, TBA: 2-thiobarbituric acid, RBC: Red blood cells, DNJ: 1-deoxynojirimycin, LDL: low density lipoprotein, ROS: reactive oxygen species, EDTA2Na: Ethylenediaminetetraacetic acid disodium salt.