Immunomodulatory activities of zinc(II)phthalocyanine on the mammalian macrophages through p38 pathway: Potential ex vivo immunomodulatory PDT reagents

A series of zinc phthalocyanine having imidazolyl moieties was synthesized. These compounds' immunostimulatory and immunomodulatory activities were tested on the mammalian macrophages in vitro. In the absence of photo induction neither dmso soluble nor the water soluble imidazole Pc had any immunostimulatory or immunomodulatory effect on the macrophage activity based on the differences in the pro-inflammatory cytokine secretion levels compared to the control groups. Upon photo induction, especially, at 5 min exposure time both derivatives lead to an increased pro-inflammatory cytokine secretion level by LPS activated macrophages. Whereas, this effect was completely reversed after 10 min of light treatment and both derivatives gained stark anti-inflammatory potential. Our molecules were cell penetrating and exerted their effects by regulating the phosphorylation levels of p38. This study is one of its first examples suggesting differential immunomodulatory photo dynamic therapy applications of phthalocyanine derivatives depending on light exposure time as well as their possible route of modulating the intracellular signaling pathways.