Gypenosides attenuate lipopolysaccharide-induced optic neuritis in rats.

PURPOSE: To evaluate the effect of gypenosides (GPs) on lipopolysaccharide (LPS)-induced optic neuritis rats.

METHODS

Optic neuritis was induced by a single microinjection of LPS into the optic nerve of Sprague Dawley rats. GPs (400 mg/kg) was administrated by gavage for 21 days. The optic nerve structure changes and demyelination were observed after hematoxylin & eosin and Luxol-fast blue staining. Apoptosis of retinal ganglion cells (RGCs) was evaluated using Brn3a-TUNEL double staining. Expression of CD68 and glial fibrillary acidic protein (GFAP) were detected using immunofluorescence staining. The mRNA levels of inflammatory factors were measured using quantitative real-time PCR. The protein expression levels in the signal transducer and activator of transcription (STAT) and nuclear factor-κB (NF-κB) pathways were detected using Western blot.

RESULTS

GPs treatment prevented the optic nerve structure changes and demyelination in the rats with optic neuritis. GPs treatment downregulated LPS-induced overexpressions of CD68, GFAP and pro-inflammatory factors. GPs treatment inhibited STAT1 and 3 phosphorylation and NF-κB nuclear translocation in the optic nerve and retina of rats with optic neuritis.

CONCLUSION

GPs attenuate LPS-induced inflammation, demyelination and optic nerve damage which may be associated with the inhibition of the NF-κB and STAT pathways.