INS and Insulin resistance: It is noteworthy that the decrease in both serum levels [30,34,35,44,45] and gene expressions [40,45] of proinflammatory cytokines reported in our review, probably due to the modulatory effect of OA on NF-kB [17], could result in an improvement of insulin secretion and beta-cell function because proinflammatory cytokines, whose levels are higher in obese individuals, have an important role in the development of insulin resistance [8,9,10].