In vivo-wound healing studies of sodium thiosulfate gel in rats

Sodium Thiosulfate (STS) is already reported as an antioxidant, anti-inflammatory agent with antiseptic, antifungal properties. The search for an ideal antiseptic still continues, which is lethal to all types of bacteria and their spores and sustain the activity for a longer time without any harm to the host tissue. The aim of the present study is to evaluate the effect of STS on curing of wounds in rats when compared to Betadine. We developed topical gels having 6% and 12% STS. The effects of STS on wound healing rate of Rats were evaluated against Betadine as positive control. Wounds of control group, selected as Group 1 was treated with normal saline (0.2 ml), twice a day. Reference standard control, designated as Group 2 rats were given with 0.2 ml Betadine twice a day. Rats in Groups 3 and 4 were treated with 0.2 ml of STS gel (6% or 12% respectively) twice a day. In our study, STS formulation has proved to be a safe and efficient wound healing product. It has a neutral pH and longer half life (>12 months). Higher STS dose of 12% proved to have a wound curing rate equivalent to that of Betadine. On 11th Day, 97 ± 0.79% healing was achieved with Betadine and 98 ± 0.67% with 12% STS Gel (^∗P < 0.05). Microscopic images of H&E stained skin tissue from animals treated with Betadine and 12% STS formulation showed a reduction in scar size, lesser amount of inflammatory cells, higher fibroblasts and blood vessels, with considerable collagen accumulation. Furthermore, a significant enhancement in the levels of GPx, CAT and SOD was observed in the tissue at the wound site of the treated group. The IL 10 levels in both groups of STS-treated rats was increased, whereas, TNF-α levels were reduced significantly in tissue homogenate compared with control. Thus, this study shows the wound-healing performance of STS formulation. Further studies are necessary to understand the real mechanism of how STS formulation heals wounds.