Nerve regeneration and corneal wound healing by ophthalmic formulations based on sodium hyaluronate, taurine, vitamin B6 and vitamin B12

Abstract

AbstractPurpose: To evaluate the pharmacological profile of ocular formulations based on cross‐linked sodium hyaluronate (CL‐SH), taurine (Tau), Vit B6 and Vit B12 using in vitro and in vivo paradigms.Methods: Rabbit corneal epithelial cells (SIRC) were used to assess wound healing and ROS formation by scratch assay and oxidative stress (0.3 mM H2O2; 30 min), respectively w/ or w/o ocular formulations exposure. In vivo studies were carried out on albino rabbits to evaluate corneal nerve regeneration and corneal wound healing with or without treatment with six different formulations. Animals were anaesthetised, the corneal epithelium was removed, and formulations were topically administered (30 μl/eye; 3 times/day for 6 days). Slit‐lamp observation was carried out at the following day: T0, T2 and T5. After 6 days the animals were killed, and corneas were collected to evaluate corneal re‐innervation by immunohistochemistry of selective neuronal marker β‐III tubulin.Results: Formulations containing the concentrations 0.16% or 0.32% of CL‐SH, Tau, Vit B6 and B12 accelerated corneal wound healing. Cells exposed to H2O2 led to significant (p < 0.001) increase of ROS concentration that was significantly (p < 0.001) counteract by formulations containing CL‐SH (0.32%) and Tau w/ or w/o Vit B6 and B12. The extent of re‐innervation, in terms of β‐III tubulin staining, was 5‐fold greater (p < 0.01) in the eye of rabbits treated with formulation containing 0.32% CL‐SH, Tau, Vit B6 and Vit B12 (RenerviX®) compared with the control group (no treatment). Furthermore, re‐innervation with RenerviX® group was significantly greater (p < 0.01) also compared with the groups treated with the formulation containing 0.32% CL‐SH and Tau w/o vitamins and with the formulation containing 0.5% linear SH, Tau, and Vit B12.Conclusions: Among all formulations tested, the new ophthalmic gel RenerviX® was able to contrast oxidative stress, to accelerate corneal re‐epithelization and to promote nerve regeneration.