Vitamin D derivatives: calcitriol and tacalcitol inhibits interleukin-6 and interleukin-8 expression in human nasal polyp fibroblast cultures

ABSTRACTPurposeBiologically active vitamin D3 (VD) derivatives possess modulatory activities on immunological and inflammatory responses which can be reflected by altered levels of pro-inflammatory chemokines. Nasal polyposis (NP), defined as a chronic inflammatory process of upper respiratory system, could be influenced by VD derivatives. The purpose of this study was to investigate the influence of 1α,25-dihydroxyvitamin D3 (calcitriol) and 1α,24(R)-dihydroxyvitamin D3 (tacalcitol) on the secretion of IL-6 and IL-8 by fibroblasts derived from NP.Material and MethodsThe study involved 12 fibroblast cultures derived from NP samples obtained from surgically treated patients. Measurements were performed on the polyp cells after the 6-9 passages. Culture stimulation involved treatment with tacalcitol and calcitriol at a defined strength (from 10−7M to 10−4M). IL-6 and IL-8 concentrations were estimated with ELISA.ResultsTreatment with calcitriol or tacalcitol inhibits the synthesis of both IL-6 and IL-8 compared to the control group. The dose dependence of this effect has been confirmed. VD derivatives influence was marked at higher concentrations. Significant interleukin decrease was observed at 10−5 and 10−4 for calcitriol and 10-4 in the case of tacalcitol.ConclusionsThe present study demonstrates that calcitriol and tacalcitol are capable of affecting pro-inflammatory cytokine (IL-6 and IL-8) levels in NP cultures. Our data imply a potential therapeutical application of topical VD derivates in NP and warrant further investigation.