Protective effect of apple polyphenols on chronic ethanol exposure-induced neural injury in rats

Apple polyphenols (AP) have attracted much attention due to their various bioactivities. In this study, the protective effect of AP against chronic ethanol exposure-induced neural injury as well as the possible mechanisms were investigated. Body weight, daily average food intake and daily average fluid intake were measured and daily average ethanol consumption was calculated. The influences of AP on motor behavior and memory were detected by locomotor activity test, rotarod test, beam walking test, and Y maze test and novel object recognition test, respectively. The changes of blood ethanol concentration and the oxidative stress were also measured. AP improved chronic ethanol exposure-induced the inhibition of body weight and the decrease of daily average food intake, but did not influence the daily average fluid intake and the daily average ethanol intake, indicating that the improve effect of AP did not result from the decrease of ethanol intake. Motor activity and motor coordination were not influenced after chronic ethanol exposure though the blood ethanol concentration was higher than that in control group. AP improved significantly chronic ethanol-induced the memory impairment and the hippocampal CA1 neurons damage. Further studies found that AP decreased the contents of NO and MDA and increased the levels of T-AOC and GSH in the hippocampus of rats. These results suggest that AP exerts a protective effect against chronic ethanol-induced memory impairment through improving the oxidative stress in the hippocampus.