Effects of antioxidants and hyperbaric oxygen in ameliorating experimental doxorubicin skin toxicity in the rat.

Doxorubicin, an antineoplastic drug, can cause severe ulceration if extravasated when iv injected. In this study, the effects of hyperbaric oxygenation (HBO) and the antioxidants butylated hydroxytoluene (BHT) and beta-carotene were tested on such ulcers using female Sprague-Dawley rats. It was found that HBO and vitamin A did not greatly ameliorate the ulcers produced by doxorubicin, but BHT prefed for 1 week before doxorubicin was injected was able to significantly reduce lesion size (P less than 0.05). Doxorubicin with HBO was a lethal combination, with an 87% mortality among the animals by the fourth week after injection. This was probably due to doxorubicin and HBO both promoting the formation of free radicals which are highly destructive to cells. BHT, when prefed (and to a lesser extent, beta-carotene), demonstrated a protective effect by lowering the death rate (P less than 0.05), probably due to their ability to scavenge free radicals. This experiment also tested more conventionally recommended treatments such as sodium bicarbonate (NaHCO3), hydrocortisone, and ice. NaHCO3 and hydrocortisone decreased lesion size although only at a significance of P less than 0.10. Ice did not aid in the healing of the doxorubicin-induced ulcers and even proved deleterious. Multiple injections of hydrocortisone or NaHCO3 appeared to deepen ulceration. Of all the treatments tested, free radical scavengers appear to most significantly reduce skin toxicity of doxorubicin.