Inhibiting effect of Radix Hedysari Polysaccharide (HPS) on endotoxin-induced uveitis in rats.
PURPOSE
The aim of this study is to investigate the anti-inflammatory effect of Radix Hedysari Polysaccharide (HPS) on clinical indicators, the expression of Toll-like receptor-4 (TLR4) and its downstream transduction molecules during endotoxin-induced uveitis in rats.


METHODS
EIU was induced through the intraperitoneal injection of male Wistar rats with lipopolysaccharide (LPS 200 μg). HPS (400mg/kg), DXM (1mg/kg) or an equivalent volume of normal saline was injected intraperitoneally 1h before the LPS induction. The clinical manifestation was observed and scored at 2-h intervals using a slit microscope. The degree of inflammatory reaction was determined by routine histological examinations, and the expression of TLR4 and MyD88 in the iris-ciliary body complex was detected through a double-labeled immunofluorescence study. Real-time RT-PCR was used to assess the effects of HPS on the expression of the TLR4 complex, MyD88 and NF-κB p65 mRNA. The protein expression levels of TLR4, MyD88 and NF-κB p65 were examined by western blot.


RESULTS
HPS treatment produced similar therapeutic results with dexamethasone by significantly reducing the clinical severity of EIU as well as fibrin exudations and inflammatory cell infiltration in the eye. Correspondingly, according to the immunofluorescence results, HPS treatment significantly suppressed the expression of TLR4 and MyD88 in the iris-ciliary body complex. HPS treatment could also remarkably reduce the mRNA and protein expression of the TLR4 complex, MyD88 and NF-κB p65.


CONCLUSION
HPS can suppress the intraocular inflammation observed in EIU by inhibiting TLR4 and its downstream signal transduction pathway.
['Yu|Shuo|S|', 'Zhang|Wei|W|', 'Yu|Jinyi|J|', 'Feng|Shilan|S|', 'Guo|Tiankang|T|', 'Lu|Hong|H|']
D000818:Animals D000893:Anti-Inflammatory Agents D004365:Drugs, Chinese Herbal D004731:Endotoxins D005123:Eye D007249:Inflammation D008297:Male D053594:Myeloid Differentiation Factor 88 D011134:Polysaccharides D012333:RNA, Messenger D051381:Rats D017208:Rats, Wistar D051197:Toll-Like Receptor 4 D051996:Transcription Factor RelA D014605:Uveitis
Radix Hedysari Polysaccharide Endotoxin-induced uveitis Anti-inflammatory TLR-4