Review: Schiff base metal complexes as anti-inflammatory agents

Schiff bases (SB) have unique potential to bind metal ions for widespread applications, especially in the pharmacological industry. The condensation of primary imine and carbonyl compounds produces SB where azomethine functional group appears as a result of replacement of carbonyl group by imine group. A tetradentate salen type SB ligand is a famous unsymmetrical bifunctional ligand that plays a major role in industrial and biological activities. The complexation of SB ligand with copper, zinc, cobalt, nickel, aluminum, ruthenium, vanadium, etc. produce a variety of useful metal complexes. SB and their metal complexes exhibit excellent biological activity for anti-malarial, anti-viral, anti-tumor, anti-fungal and anti-inflammatory properties. This review highlights the current state of knowledge on SB metal complexes with spotlight on synthesis of various SB ligands, metal complexation and their role as anti-inflammatory drugs. Inflammation is generally considered as response of the immune system against burns, allergens and toxic chemicals. Anti-inflammatory and analgesic activity of various SB complexes in different classes of mice and rats have been described by using carrageenan induced edema. The diverse SB metal complexes reported especially in the last two decades are comprehensively reviewed in order to evaluate their suitability as anti-inflammatory and analgesic agents.