Objective: To observe the effects of the water extract of Periplaneta americana on the wound healing of experimental scald model mice

and explore its mechanism. Method: Healthy female ICR mice were randomly divided into control group

model group

Kangfuxin group

P. americana water extract low-dose group (0.327 g·kg-1)

middle-dose group (0.490 g·kg-1) and high-dose group (0.653 g·kg-1) group according to body weight

n=13 in each group. The scald mouse models were established by using (82±2)℃ weight burning in hair removal zone on their back. The effect of the topical medicines (0.1 mL/spray) on the scald wound was observed at 5 d and 10 d; the contents of transforming growth factor (TGF)-β1 and interleukin (IL)-6 in serum were detected

and histopathological examination of burn wound skin was conducted. Result: As compared with the normal group

the wound healing rate was significantly reduced at day 5 and day 10 in model group (P<0.01)

the level of IL-6 was significantly increased at day 10 in model group (P<0.05)

with obvious pathological injury in skin. As compared with the model group

he wound healing rate was significantly increased at day 5 and day 10 in P. americana water extract groups (P<0.05

P<0.01); the level of TGF-β1 was significantly increased at day 5 in P. americana water extract middle dose group (P<0.05); the levels of TGF-β1 and IL-6 were reduced at day 10 (P<0.05); TGF-β1 level was also reduced at day 10 in P.americana water extract low-dose group (P<0.05). Pathological test results showed that P.americana water extract can promote proliferation of skin fibroblasts

fibroblast

and capillary vessels in skin of scalded mice

and promote the repair of epidermis

dermis and muscular damages

as well as disorder of dermal collagen fibers

especially in the P.americana water extract middle-dose group. Conclusion: P.americana water extract has obvious promoting effect on would healing in scald mice

promoting repair of epidermal hyperplasia and proliferation of granulation tissue. Its mechanism may be associated with regulating TGF-β1 release (promotion at the early stage

inhibition at the late stage)

inhibiting the release of inflammatory factors

so that P.americana water extract can both promote repair and avoid scarring.