Effect of biphenyl dimethyl dicarboxylate on the cellular and nonspecific immunotoxicity by ethanol in mice.

Biphenyl dimethyl dicarboxylate (PMC) has been reported to protect against chronic ethanol toxicity. The present study was conducted to evaluate whether PMC might be accompanied by a reduction of ethanol-induced cellular immunotoxicity. PMC at a dose of 6 mg/kg was orally administered to ICR mice daily for 28 consecutive days, and normal mice were given vehicle. Mice treated with ethanol were given free access to 20% w/v ethanol instead of water. Mice were immunized and challenged with sheep red blood cells (SRBC). Delayed-type hypersensitivity (DTH) reaction to SRBC was increased to normal levels by the combination of PMC and ethanol, compared with the treatment of ethanol alone. Splenic CD4+ cells were also greatly enhanced by PMC treatment as compared with the treatment of ethanol alone. In the case of CD8+ cells, however, a slight reduction was observed by the PMC or ethanol treatment. The natural killer (NK) cell and phagocytic activity used for evaluation of nonspecific immunocompetence were significantly augmented in PMC plus ethanol-treated mice when compared with the treatment of ethanol alone. The number of peripheral leukocytes was significantly decreased by the treatment of ethanol alone, then also restored to normal levels by PMC treatment. These findings indicate that cellular immunotoxicity caused by ethanol consumption is significantly restored or prevented by PMC treatment.