Enhancing effects of diphenyl dimethyl dicarboxylate on serum antibody production in BALB/c mice.

The effects of diphenyl dimethyl dicarboxylate (PMC) on serum antibody production were investigated in BALB/c mice. PMC (3 and 6 mg/kg/d, respectively) was orally administered to the mice for 14 consecutive days. The effects on antibody production were assessed by enzyme-linked immunosorbant assay (ELISA) of immunoglobulin (Ig) subset levels in serum, collected at week 2 from mice with or without immunization by an i.p. injection of 0.1 mg ovalbumin (OVA) in complete Freund's adjuvant (CFA) at week 1 after the first oral administration of PMC. PMC showed a significant enhancement of the levels of total serum IgG, IgG1, IgG2a and IgA without the immunization, while total IgE levels were not affected. When mice were immunized with OVA after the oral administration of PMC, moreover, a marked stimulation of antibody production was observed in mice fed 6 mg/kg/d PMC, hardly accompanied with increase of IgE levels. In these mice, additionally, PMC significantly elevated anti-OVA IgG (including both IgG1 and IgG2a mediated by different T-helper cells) levels. These findings indicate that PMC enhances antibody production in mice with therapeutic concentrations that have shown great promise in the treatment of chronic hepatitis virus of type B.