INS and type 2 diabetes mellitus: Thiazolidinediones belong to the class of heterocyclic compounds with a five-membered C3NS ring framework which are also referred to as “glitazones” or “insulin enhancers.” Thiazolidinedione (TZD) is a word from early 1923 that describes a class of drugs used to treat type 2 diabetes (Figure 1) [1,2] which are generated from thiazolidine and additionally contain nitrogen and sulfur atoms [3,4,5] and two carbonyl groups at positions 2 and 4.