ObjectiveTo study the therapeutic effect of estrogenic equol (Eq) on mustard gas-caused skin wounds and the possible mechanism. MethodsA rabbit skin wound model was established by contaminating the hip skin with mustard gas (0.5 mg/cm2). The contaminated wound was treated externally with different concentrations (10, 50, and 100 μmol/L) of Eq for a week, and the changes of the wound were observed macroscopically. Wound specimens were collected for histopathological evaluation. Cell apoptosis and DNA cycle changes were analyzed by flow cytometry. Levels of IL-6 and TNF-α in the contaminated wound specimens were detected. ResultsThe scores of erythema, edema, erosion and necrosis of the contaminated wounds in the treatment groups were significantly lower than those in the control group 120 h after mustard gas exposure (P<0.05). The scores for changes of histopathological inflammation and necrosis were significantly lower in the 50 μmol/L Eq treatment group than those in the control group 168 h after mustard gas exposure (P<0.05). The results of flow cytometry showed that the proportion of apoptotic cells in the control group was significantly higher than those in the treatment groups 168 h after mustard gas exposure (P<0.05), and the proportion of cells in DNA (S+G2-M) phase in the treatment groups was significantly higher than that in the control group (P<0.05). The levels of IL-6 and TNF-α in the treatment groups were significantly lower than those in the control group 168 h after mustard gas exposure (P<0.05). ConclusionEq can promote healing of mustard gas-caused local skin damaged by inhibiting inflammatory response and cell apoptosis and enhancing cell proliferation.