Therapeutic Efficacy of an Ethyl Pyruvate-Loaded Emulgel in Accelerating Wound Healing

Background

Ethyl Pyruvate (EP), is an ester of pyruvate with amazing anti-inflammatory, antioxidant, and antimicrobial properties. But EP’s poor aqueous solubility hinders its topical transport. To formulate an EP-loaded emulgel and evaluate its wound-healing efficacy in a rat excisional wound model.

Materials and Methods

An oil-in-water emulsion containing EP was prepared using cotton seed oil, Tween 80/propylene glycol, Span 20, propylene glycol and carbomer as the gelling agent. The emulgel became characterised for droplet size, polydispersity index, pH, viscosity, spread ability, and EP content. Full-thickness 2 cm dorsal excisional wounds were created in male Wistar rats. Animals (n=6 per group) grouped as control, blank gel, silver sulfadiazine and EP emulgel (2% & 4% w/v doses) and them treated daily for 14 days. Wound healing markers such as percentage wound contraction, oxidative stress markers in wound tissue include catalase, reduced glutathione, superoxide dismutase and malondialdehyde and the inflammatory marker myeloperoxidase, were measured. In addition, histopathology of wound tissue was performed.

Results

The optimized EP emulgel exhibited an average globule size of 280±0.21nm with Polydispersity Index (PDI) of 0.3, pH 6.54±0.17, viscosity 9521±0.07 cP and uniform EP content (>98%). EP treated wounds showed dose dependent improvement in wound contraction with p < 0.01 and 0.001 at day 7 (66% vs. 34%) and day 14^th (95% vs. 70%) compared to controls. EP emulgel markedly reduced tissue Malondialdehyde (MDA), Myeloperoxidase (MPO) and the same time as restoring Superoxide Dismutase (SOD), Catalase (CAT) and reduced Glutathione (GSH) activity toward normal. Histology of skin revealed stronger re-epithelialization, denser collagen networks, and reduced inflammatory infiltrate inside the EP group.

Conclusion

EP-loaded emulgel efficiently promotes the wound-healing process, as evident by significant wound contraction, which may be due to its antioxidant and anti-inflammatory effects at wound site.