Cytokine- and chemokine-mediated signalling is involved in the neuroinflammatory process that leads to retinal ganglion cell (RGC) damage in glaucoma. Substances with anti-inflammatory properties could decrease these cytokines and chemokines and thus prevent RGC death. The authors of this study analysed the anti-inflammatory effect of a hydrophilic saffron extract standardized to 3% crocin content, focusing on the regulation of cytokine and chemokine production, in a mouse model of unilateral laser-induced ocular hypertension (OHT). We demonstrated that following saffron treatment, most of the concentration of proinflammatory cytokines (IL-1β, IFN-γ, TNF-α, and IL-17), anti-inflammatory cytokines (IL-4 and IL-10), Brain-derived Neurotrophic Factor (BDNF), Vascular Endothelial Growth Factor (VEGF), and fractalkine were unaffected in response to laser-induced OHT in both the OHT eye and its contralateral eye. Only IL-6 levels were significantly increased in the OHT eye one day after laser induction compared with the control group. These results differed from those observed in animals subjected to unilateral OHT and not treated with saffron, where changes in cytokine levels occurred in both eyes. Therefore, saffron extract regulates the production of proinflammatory cytokines, VEGF, and fractalkine induced by increasing intraocular pressure (IOP), protecting the retina from inflammation. These results indicate that saffron could be beneficial in glaucoma by helping to reduce the inflammatory process.

Purpose: To analyse the anti‐inflammatory effect of saffron extract, by regulating the expression of cytokines and chemokines involved in the neuroinflammatory process leading to retinal ganglion cell (RGC) damage, in a mouse model of unilateral laser‐induced ocular hypertension (OHT). Methods: Three groups of Albino Swiss mice treated with saffron extract were used; saffron naïve group (SNG), saffron laser group 1 day (SLG1d) and saffron laser group 3 days (SLG3d). Both eyes with OHT (treated with laser photocoagulation) and their contralateral were analysed. Retinal samples were processed and multiarray kits (MILLIPLEX MAP Mouse Cytokine/Myokine Magnetic Bead Panel) were used to quantify the expression of: IL‐1β, IL‐4, IL‐6, IL‐10, IL‐17, IFN‐ϒ, TNF‐α, Brain‐derived Neurotrophic Factor (BDNF), Vascular Endothelial Growth Factor (VEGF) and Fractalkine. Immunohistochemical analysis was performed to locate cells expressing the factors and cytokines detected in the multiplex assay. Results: After saffron treatment, no significant differences were found, at 1 and 3 days after laser‐induced OHT, between the concentration of proinflammatory cytokines (IL‐1β, IFN‐γ, TNF‐α and IL‐17), anti‐inflammatory cytokines (IL‐4 and IL‐10), BDNF, VEGF, and fractalkine in both the OHT eye and its contralateral eye, compared to saffron naïve. IL‐6 levels increased significantly in the OHT eye in SLG1d, reaching normal values at SLG3d compared to SNG. These results are contrary to those found in OHT eyes and their contralateral not treated with saffron, in which changes in cytokine levels were observed. Conclusions: Saffron is effective in regulating the production of proinflammatory cytokines, VEGF, and fractalkine induced by increased IOP, thus protecting the retina from its related damage. Saffron could be beneficial as coadjutant therapies in the treatment of glaucoma, thus helping to decrease the inflammatory process that occurs in this pathology.