Topical Curcumin Nanocarriers are Neuroprotective in Rodent Retinal Injury Models

Abstract

Purpose : Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5dione) is a polyphenol extracted from turmeric that has long been advocated for the treatment of a variety of conditions including neurodegenerative and inflammatory disorders. Despite this promise, the clinical use of curcumin has been limited by the poor solubility and low bioavailability of this molecule.

Methods : In this study, we describe the development of a novel and highly stable curcumin nanocarrier formulation that successfully solubilized high concentrations (> 4 mg/mL) of curcumin. Characterisation with x-ray diffraction and in vitro release assays localized curcumin to the nanocarrier interior, with each particle measuring < 20 nm diameter. Resulting nanoparticles were stable for over 60 days when stored at room temperature.

Results : Curcumin-loaded nanocarriers (CN) were found to significantly protect against cobalt chloride induced hypoxia and glutamate-induced toxicity in vitro, with CN treatment significantly increasing R28 cell viability in a dose-dependent manner. Using established glaucoma-related in vivo models of ocular hypertension (OHT) and partial optic nerve transection (pONT), topical application of CN twice-daily for three weeks was found to significantly reduce retinal ganglion cell loss compared to controls as determined histologically using whole-retinal retinal ganglion cell counts.

Conclusions : Collectively, these results suggest that our novel topical CN formulation has potential as an effective neuroprotective therapy in glaucoma and other eye diseases with neuronal pathology.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.