PG102, a water-soluble extract from an edible fruit, Actinidia arguta, has previously been shown to control various factors involved in allergy pathogenesis. It was investigated whether the original activities of PG102 could be reconstituted by mixing chemical compounds present in PG102. Six compounds present in PG102 were, individually or in the form of mixtures, tested for their effects on the expression of various Th2 cytokines and inflammatory mediators in the cell-based assay. Each chemical inhibited IL-4 expression to varying degrees. The chemical compounds were combined at a ratio present in PG102, resulting in two formulations, CQMIIH and CQM, consisting of all or the first three of the following chemicals, citric, quinic, and malic acids, myo-inositol, isoquercitrin, and 5-hydroxymethyl-2-furaldehyde. The mixtures reconstituted original activities of PG102 to a significant level. In the murine asthma model, CQM ameliorated asthmatic symptoms and significantly decreased the level of IgE and IL-5. The decreased phosphorylation of ERK1/2 was observed in cells and mice treated with PG102 and the mixtures. Our data indicated that the substantial portion of PG102's anti-allergic activities could be reconstituted, in vitro and in vivo, by mixing six chemical compounds, suggesting the possibility of developing a new type of anti-allergic agent. This approach may be useful for developing chemically defined functional products from complex botanical extracts.
Keywords: Actinidia arguta; ERK1/2; IgE; PG102; Th2 cytokine; allergy; asthma; reconstitution.