IMMUNOSTIMULATORY EFFECTS OF WATER-SOLUBLE EXTRACTS OF POPLAR BUDS AND LEAVES AND THEIR POLYPHENOLIC COMPOUNDS

The effects of water-soluble extracts of poplar buds and leaves, and s ome of their polyphenolic compounds, on cellular and humoral responses of the mouse immune system were examined. Both extracts caused signif icant enhancement of the ability of mouse splenic lymphocytes to induc e local graft-versus-host reaction in the LIA test. Pretreatment of th e mice by an extract of poplar buds increased the production of anti-S RBC 19S and 7S antibodies, and an extract of poplar leaves strongly in creased 7S antibody production only. Gentisic, salicylic, gallic, prot ocatechuic, caffeic and chlorogenic acids at a low dose increased 7S a ntibody production, but some of them (chlorogenic and salicylic) at a higher dose decreased this. 19S antibody production was unchanged, exc ept in the group of mice treated by higher doses of gentisic acid, whe re significant stimulation was found.