Modulatory Effect of Phytoestrogens and Curcumin on Induction of Annexin 1 in Human Peripheral Blood Mononuclear Cells and their Inhibitory Effect on Secretory Phospholipase A2

Purpose: To investigate the modulatory effects of phytoestrogens (coumestrol, daidzein and genistein) and curcumin on the induction and secretion of annexin-1 (ANXA-1) in human peripheral blood mononuclear cells (PBMCs) under inflammatory and non-inflammatory conditions, as well as their effect on the activity of phospholipase A₂-V (sPLA₂-V).
Methods: The modulatory effects of phytoestrogens and curcumin on the induction of ANXA1 were investigated via sandwich ELISA method, while their effects on the activity of sPLA₂-V were determined by photometric assays. Besides, the cell viability of these compounds was determined by standard trypan blue exclusion method using PBMCs.
Results: The results indicate a significant increase (p < 0.05) in the total content ofANXA1, particularly by coumestrol (p < 0.01), in both inflammatory and non-inflammatory cells. Besides, the compounds also exhibited a dose-dependent inhibition of sPLA₂-V activity; however, among these compounds, curcumin and genistein were the strongest inhibitors with an IC₅₀ value of 11.1 ± 0.3 μM and13.6 ± 0.6 μM respectively.
Conclusion: The investigated compounds have a potential to induce synthesis and secretion of ANXA1 as well as inhibitory activity of sPLA₂-V, suggesting their inhibitory role in phospholipid metabolism and inflammation.