Porphyrins are a macrocyclic compound with 18 π electrons and aromaticity, consisting of carbon atoms bridged with four pyrrole units in a highly conjugated, planar conformation that finds potential application in all disciplines, including medicine. Porphyrin molecules are derivatized by attaching different substituents from the meso or beta positions, and their electronic properties can be changed. Synthetic porphyrins have become of interest in medicinal chemistry because they can form chelates with some toxic heavy metals or gamma- ray emitting radioisotopes [1], [2], [3], [4].

In this study, the symmetrical meso-aryl substituted porphyrin molecule previously available in the literature was synthesized. After its chemical characterization, it was tested for its photodynamic biological activities on the mammalian macrophages.

Macrophages are one of the pivotal cell types in the immune system that can regulate both the adaptive and innate arms of the immune system cells by antigen presentation as well as cytokine production [5,6]. Murine macrophage cell line has been well characterized for its pro-inflammatory cytokine production potential in vitro by LPS stimulation to mimic inflammatory responses in vitro [7]. We exploited this technique to test the photodynamic anti-inflammatory activity of the meso aryl substituted porphyrin derivative.

Inflammation plays a key role in the chronic diseases as well as autoimmune disorders by damaging the tissues and organs that eventually cause detrimental effect on the well-being of the patients [8]. Current anti-inflammatory drug molecules either steroid or non-steroid based have side effects associated with them due to their constitutive activities [9,10]. Photodynamic agents present opportunities in this regard by its light induced activation at a certain time and location. These properties decrease potential side effects associated with the drug molecules [11,12].

Our group focused on a meso-aryl substituted porphyrin molecule for its photodynamic anti-inflammatory activities on the mammalian macrophages based on the changes in the pro-inflammatory cytokine production levels after LPS stimulation in dark and light activated conditions. Our results suggest a potential photodynamic therapy agent that can be utilized in inflammatory and autoimmune disorders.