Immunomodulation of ovalbumin-specific IgG and other classes of antibody response by honey in mice.

It was reported earlier that intraperitoneal administration of honey had immunosuppressive activity on elicitation of allergen-specific murine antibody response as evaluated by passive cutaneous anaphylaxis and double immunodiffusion methods. In this study, the immunomudulatory effect of honey is evaluated by enzyme linked immunosorbent assay (ELISA) using ovalbumin as model allergen. It was found that ovalbumin (OVA)-specific IgG antibody responses elicited with various doses of OVA were significantly suppressed by rock bee honey (p<0.01). Honey was also found to have inhibited the production of OVA-specific IgM, IgA, IgG(1), and IgG(2b) whereas that of IgG(2a) and IgG(3) were not affected. Furthermore, honey also suppressed the OVA-specific total IgG antibody response in various inbred mice with different genetic background. In addition, the suppressive activity of honey was examined in different groups of mice by injecting honey at different time intervals, before and after immunization with OVA. The anti-OVA IgG antibody response was suppressed significantly when honey was injected 12 hours prior/latter to OVA injection. These results confirm the suppressive activity of honey on antibody response and suggest possible clinical application.

Isolation and characterization of allergens from the seeds of Vigna sinensis.

Allergenic components of cowpea vegetable green seeds (Vigna sinensis) were isolated based on solubility, isoelectric precipitation and molecular mass. The allergenicity of the cowpea fractions was monitored by enzyme-linked immunosorbent assay (ELISA) and skin-prick test. The allergenic albumin fraction was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE-specific immunoblotting. The 41 and 55 kDa protein components were found to be major allergens and the allergenicity was resistant to heat and proteolytic enzyme digestion. This study confirms the presence of potent allergens in cowpea seeds.

Immunosuppressive effect of honey on the induction of allergen-specific humoral antibody response in mice.

Our study with honey for its possible immunomodulatory activity reveals the immunosuppressive activity on induction of murine humoral antibody responses against different allergens as determined by passive cutaneous anaphylaxis and Ouchterlony double immunodiffusion techniques. Ovalbumin (OVA)-specific IgE antibody responses elicited with various doses were completely suppressed by different sources of commercial honeys. Honey is also found to have suppressed the induction of OVA-specific humoral antibody responses in different strains of mice. The results obtained in this work confirm the immunosuppressive activity of honey and suggest its possible applicability in conditions requiring immunosuppression.