TLR4 and serum lipopolysaccharide activity: The LPS is directly responsible for endotoxemia, so-called, “low grade inflammation”, via Toll-like receptor-4 (TLR-4), by inducing the production of IL-1β, TNF-α and IL-6 from macrophages and, at the same time, some of the adipocytes are also differentiated into “macrophage-like” cells [25].