Lycium barbarum polysaccharide solution as a novel therapeutic agent in the prevention of corneal scarring

Abstract

 Lycium barbarum has been used in Traditional Chinese medicine for thousands of years and its use in modern day has been attributed to its anti-aging, anti-oxidizing and anti-fibrotic effects which have been demonstrated in numerous animal models treating a variety of pathologies such as cancer, hepatic fibrosis, glaucoma, ischemic heart disease and many more. Lycium barbarum polysaccharide (LBP) is a essentially a group of sugars including glucose, xylose, galactose, rhamnose, mannose and arabinose. Yet, little has been done to study LBP’s effect on corneal keratocyte differentiation into scar tissue forming myofibroblasts which remodel the extracellular matrix resulting in corneal haze and reduced visual acuity. This study uses an in vitro model to investigate LBP’s potential anti-scarring effects in the cornea and the potential mechanism behind its therapeutic effect if demonstrated. Primary human corneal keratocytes are used for the experiment and pretreated with either LBP solution or dexamethasone solution for 24 hours and then transforming growth factor β1 (TGFβ1) for 48 hours and collected for fibrotic protein and inflammatory, cytokine analysis and cell viability assays. The effectiveness and toxicity of LBP solution was compared to dexamethasone solution to allow a better comparison to what we currently use in clinical practice. This study demonstrated that LBP solution has anti-fibrotic effects comparable to dexamethasone solution while demonstrating selectiveness in affecting the viability of pro-fibrotic myofibroblasts while sparing normal corneal fibroblasts. LBP was found to significantly affect the cell viability of myofibroblasts alone but not the fibroblasts. Moreover, our inflammatory cytokine studies suggest an IL-6/miR-145 mediated pathway behind LBP’s underlying mechanism of action. However, further studies are warranted to further understand LBP’s complicated mechanism of action. In addition, its pharmacological properties regarding its bioavailability and penetrated into the cornea are poorly understood and made complicated by the fact that LBP is a mixture of sugars but is necessary to investigate if we want to study LBP’s function in vivo and even in clinical trials.