The present study aimed to investigate the therapeutic efficacy of post-inflammatory treatment with luteolin on endotoxin-induced uveitis (EIU) in rats. Intraperitoneal injection of 10 mg/kg luteolin or 1 mg/kg prednisolone (Pred) at 4 hr post-lipopolysaccharide (LPS) injection (200 µg) was associated at 24 hr post-LPS injection with decreased clinical severity scores, number of inflammatory cells, protein levels and levels of tumor necrosis factor (TNF)-α, nitric oxide (NO) and prostaglandin (PG) E2 in the aqueous humor (AqH) and degrees of histological ocular tissue injury. The anti-inflammatory potency of luteolin was comparable to that of Pred. Luteolin exhibited robust efficacy in the treatment of EIU in rats, indicating its potential clinical utility in treating uveitis.

The aim of the present study was to investigate the efficacy of luteolin on endotoxin-induced uveitis (EIU) in rats. EIU was induced in Lewis rats by subcutaneous injections of lipopolysaccharide (LPS). One hr before the LPS injection, 0.1, 1 or 10 mg/kg luteolin or 1 mg/kg prednisolone was intraperitoneally injected. We investigated its effect upon clinical scores, cellular infiltration and protein leakage, as well as on the level of tumor necrosis factor (TNF)-α, nitric oxide (NO) and prostaglandin (PG) E2 in the aqueous humor (AqH). Histologic examination and immunohistochemical analysis in the iris-ciliary body (ICB) were performed to determine the expressions of cyclooxygenase (COX)-2 and inducible NO synthase (iNOS), and then the activated nuclear factor (NF)-κB p65, I kappa B (IκB)-α degradation, phosphorylated (p)-IκB kinase (IKK) α/β and activator protein (AP)-1 c-Jun. Luteolin suppressed, in a dose-dependent manner, the clinical scores, number of inflammatory cells, the protein concentration, and the TNF-α, NO and PGE2 levels in the AqH and improved the histiologic status of the ocular tissue. Luteolin suppressed the expression of iNOS and COX-2 and the activated NF-κB p65, IκB-α degradation, p-IKKα/β and AP-1 p-c-Jun in the ICB. The anti-inflammatory potency of 10 mg/kg luteolin was as strong as that observed with 1 mg/kg prednisolone. These results demonstrate that luteolin attenuates ocular inflammation by inhibiting expression and release of inflammatory markers, along with the inhibition of the activated NF-κB pathway and at least partly AP-1 activity in the ICB.