The Antioxidant Activity of Total Flavonoids from Paper Mulberry Fruits in Vitro and Its Protective Effect on CCl₄-induced Brain Injury in Mice

Objective: To investigate the antioxidant activity of total flavonoids from paper mulberry fruits in vitro and its effect on brain damage induced by CCl₄ in mice. Method: In order to study the antioxidant activity of total flavonoids from paper mulberry fruits in vitro, a biofilm experiment system with hydrogen peroxide (H₂O₂) inducing erythrocyte hemolysis, lipid peroxidation of liver and brain homogenate, and Fe²⁺-Vc inducing swelling of liver mitochondria were established. Meanwhile, a CCl₄-induced oxidative damage model was established. The in vivo study was performed on 60 KM mice divided into six groups: blank group, model group, positive control group (silymarin, 0.2 g/kg) and total flavonoids groups (0.15, 0.3, 0.6 g/kg). The corresponding dose of drugs was given by intragastric administration every day, and the CCl₄ peanut oil solution (1:1, V:V) was injected intraperitoneally (2 mL/kg) every other day. The blank group was given the same volume of solvent (peanut oil) for 14 days. The contents of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-PX) and catalase (CAT) were determined and the pathological sections of hippocampus were observed to evaluate the antioxidant activity of total flavonoids in vivo. Result: The inhibitory effect of total flavonoids from paper mulberry fruits on erythrocytic hemolysis, lipid peroxidation of liver and brain homogenate and swelling of liver mitochondria increased with the increase of concentration, and its total antioxidant capacity also increased with the increase of concentration in vitro. In the CCl₄ brain injury model, the total flavonoids could significantly increase the SOD, GSH-PX, CAT activity and GSH levels (P<0.05) in the brain tissues of mice, and significantly reduce the MDA level (P<0.05) in a dose-dependent manner, while improving the pathological changed of hippocampal neurons. Conclusion: The total flavonoids from paper mulberry fruits have strong antioxidant activity in vitro, and show a good protective effect on CCl₄ induced oxidative injury in mice brain tissue, have good antioxidant capacity in vivo.