Abstract
Sprague-Dawley rats were given freely with 15% ethanol (control) and 15% ethanol containing (1) 0.1% ginseng saponin, (2) 0.02% ginsenoside $Rb_1$, and (3) $Rg_1$ (tests) instead of water for 7 days and aldehyde dehydrogenase (ALDH) and monoamine oxidase (MAO) activity in different regions of brain were examined. In control group, total ALDH activity with indoleacetaldehyde and acetaldehyde as substrate in all different regions was lower than that of normal group except in the hippocampus. The inhibitory effect on the activity was prominent in the corpus striatum and was not in the hippocampus. However, low-$K_m$ ALDH activity in all different regions was much lower than that of normal group. A considerable decrease in mitochondria ALDH activity in cerebellum and striatum was also observed in control group. In test groups total, low-$K_m$, and mitochondria AkDH activities in all different regions were higher than those in control group. Although ALDH activity in the striatum of test group was higher than control group, it was relatively depressed as compared with normal. There was not found a remarkable difference in extent of stimulating effect on the AkDH activity according to the ginseng saponin components. When biogenic aldehydes were used as substrate, ALDH activity with 3,4-dihydroxy-phenylacetaldehyde (DOPAL) in all brain regions of control group was lower than that using 5-hydroxy-indoleacetaldehyde (HIAL) and 3,4-dihydroxyphenylglycolaldehyde (NORAL) as substrate. In control group, ALDH activity with biogenic aldehydes above mentioned was markedly inhibited in the striatum contrary to other regions. The higher ALDH activity with biogenic aldehydes in test group than in control was found in the striatum, cerebrum, and cerebellum. MAO activity in the cerebellum was inhibited in control group and slightly increased in test group. The results of present study suggest that the corpus striatum is significantly affected by ethanol exposure while the hippocampus is not and that ginseng saponin fraction and ginsenosid es might have a preventive effect against depression of brain ALDH activity by chronic administration of ethanol.