INS and type 2 diabetes mellitus: The PPARγ activators identified so far include naturally occurring compounds, as some unsaturated fatty acids, some anti-inflammatory molecules—such as a prostaglandin J2 metabolite (15-deoxy-D12,14-PGJ2)—, oxidized low-density lipoprotein (LDL) particles 9-and 13-HODE (hydroxyoctadeca-10E,12Z-dienoic acid) [37, 49], and synthetic compounds, mainly represented by the thiazolidinediones (TZDs) [52], a class of insulin-sensitizing drugs widely used in the treatment of type 2 diabetes mellitus [52, 53].