Anti-inflammatory effects of luteolin on experimental autoimmune thyroiditis in mice

Abstract

Abstract.Hashimoto's thyroiditis (HT) is the most common organ-specific autoimmune disease and is believed to be a predominately T cell-mediated autoimmunity. Signal transducer and activator of transcription (STAT)3 is a crucial transcription factor of T cell-mediated immunity, with key roles in the proliferation and migration of T helper (Th) cells, differentiation of Th cells into Th17 cells, and the balance between Treg cells and Th17 cells. Flavonoid luteolin has been shown to markedly inhibit Tyr705 activation/phosphorylation of STAT3 and exert anti-inflammatory effects in multiple sclerosis. In the present study, the effect of luteolin on experimental autoimmune thyroiditis (EAT) was analyzed in C57BL/6 mice. Hematoxylin and eosin examination showed that luteolin attenuated lymphocytic infiltration and follicle destruction in thyroid glands. Immunohistochemistry results demonstrated that luteolin significantly reduced the phosphorylation of STAT3 within the thyroid. An in vitro study was carried out in a RAW264.7 macrophage cell line. Western blot findings demonstrated that luteolin significantly inhibited interferon-γ-induced increases in cyclooxygenase 2, phosphorylated STAT1 and phosphorylated STAT3 expression levels and the secretion of the proinflammatory cytokine tumor necrosis factor-α in supernatants. The present findings indicated that luteolin may exert potent anti-inflammatory effects on murine EAT, which may provide a novel therapeutic medication strategy for the early intervention of HT.

Formulation, characterization, in vitro and in vivo evaluations of self-nanoemulsifying drug delivery system of luteolin

“…It is a small molecule with a molar mass of 286.24 gmol −1 and a molecular formula of C 15 H 10 O 6 containing a flavone or phenyl chromone ring ( Figure 1). It has been reported to have various pharmacological activities such as anti-oxidative [1][2][3][4][5][6][7], antiallergic [8][9][10][11][12], and anti-inflammatory [13][14][15][16][17][18], anticancer [19][20][21][22][23][24] and anti-diabetic activities [25][26][27]. However, it is reported to have low aqueous solubility [28,29].…”

Dihydroartemisinin attenuates autoimmune thyroiditis by inhibiting the CXCR3/PI3K/AKT/NF-κB signaling pathway

“…A second subcutaneous injection was administered on day 14 using the same amount of Tg in IFA and once every two weeks for a total of six weeks. The blank group received subcutaneous injection of similar amounts of PBS and CFA or IFA at the same days [ 21 , 22 ].…”

Health-Promoting Effects of Thymus Phenolic-Rich Extracts: Antioxidant, Anti-inflammatory and Antitumoral Properties

“…In the same line, flavonoids have also been shown to inhibit the expression of various enzyme systems, inflammatory mediators (e.g., molecules adhesion, cytokines and chemokines) and molecules involved in signal transduction pathways implicated in the inflammatory response [7,24,75]. In particular, luteolin (a common flavone in Thymus plants in general), was reported to inhibit the expression of COX-2 and TNF-α secretion in IFN-γ-stimulated RAW264.7 macrophage cells, and to inhibit the phosphorylation of signal transducer and activator of transcription (STAT)-3, a crucial transcription factor of proliferation and activation of T cells [76].…”