The calcium-antagonist activity of the material released by olive pollen (PMR), tested on Ca2+-cytosolic of PE/CA-PJ15 cells

Inhalation of olive pollen (Olea europaea L.) is one of the main causes of allergy in Mediterranean countries and some areas of North America. The response to allergens consists in the production of inflammatory cytokines which is mediated by the deregulation of Ca²⁺ signals. In this study, the biological activity of the material released in olive pollen hydration (PMR) was tested on Ca²⁺ cytosolic of PE/CA-PJ15 cells (PJ-15). Ca²⁺ cytosolic was determined by fluorometric assay with the cell line PE/CA-PJ15 (PJ-15) labeled with the fluorescent probe FURA 2 AM. The material released in olive pollen hydration (PMR) was analyzed by HPLC for the determination of phenolic acids. PMR was subjected to fractionation by gel filtration, and the fractions with Ca²⁺-chelating activity were tested with SDS-PAGE and the single bands characterized by proteomic analysis. PMR showed high Ca²⁺-chelating activity and is able of blocking the increase Ca²⁺-cytosolic produced by thapsigargin (TG). PMR then restored Ca²⁺ homeostasis in PJ-15 cells deregulated by the endoplasmic reticulum Ca²⁺-ATPases inhibitor. It is therefore possible that PMR can antagonize the effects of allergens on Ca²⁺ cytosolic. The analytical characterization of the material released by the pollen highlighted in the pollen allergen Ole e 3 and in the p-coumaric acid the possible culprits of the Ca²⁺-antagonist activity of PMR. Furthermore, the sequence of Ole e 3 could provide information for the possible construction of a synthetic peptide to be used in an allergy-targeted Ca²⁺-antagonist therapy.