IRS1 and obesity due to melanocortin 4 receptor deficiency: In an experimental model of obesity high fat diet-induced, the allicin treatment increased the expression of genes involved in lipolysis [hormone-sensitive lipase (HSL), adipose triglyceride lipase (ATGL), and lipoprotein lipase (LPL)], and insulin signaling pathway [insulin receptor substrate 1 (IRS-1) and IRS-2].