Ruthenium (III)–Indigo Complex Loaded on the Salep Hydrogel as an Anti-inflammatory and Antioxidant Nanocomposite

Inflammation is the main complicating factor of chronic autoimmune diseases. Therefore, attenuating inflammation has a vital role in the treatment of these diseases. Biocompatibility and effective functions of ruthenium(III) complexes were previously confirmed, especially for cancer treatment. In the current study, a ruthenium(III) complex with deprotonated indigo ligands, Ru(HIndig) 3, was synthesized and then loaded on the salep hydrogel (SAH) to obtain a natural anti-inflammatory nanocomposite (SAH-Ru(HIndig) 3 ). The SAH-Ru(HIndig) 3 nanocomposite was entirely characterized by spectroscopy methods, electron microscopy, elemental analysis, and thermogravimetry. The mean size of semispherical particles of SAH-Ru(HIndig) 3 was found to be about 184 ± 65 nm. The in vitro behaviors, including swelling capacity, degradation rate, free radical scavenging capability, and release profile of SAH-Ru(HIndig) 3, were also evaluated. In addition, the biocompatibility and the effect of the nanocomposite on cell migration were examined in RAW264.7 cells. Furthermore, the anti-inflammatory effect of the nanocomposite against the cellular model of inflammation was investigated by determining inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-10 mRNA levels. Consequently, the results revealed that SAH-Ru(HIndig) 3 effectively ameliorates inflammation and potentially affects cell migration. Hence, SAH-Ru(HIndig) 3 could be used to treat inflammatory autoimmune diseases.