[Effect of human saliva on wound healing]

To observe the effects of saliva on impaired raw surface so as to elucidate the possible mechanism in wound healing by comparing with Yunnan baiyao.

Six wounds (2.5 cm x 2.5 cm in size) were established at both sides on the back of 6 3-month-old adult Japanese rabbits (weighing 2.0-2.5 kg). According to treatment, 36 wounds were randomly divided into 3 groups: wounds were treated with 0.4 mL normal saline (blank control group, n = 12), 0.5 g Yunnan baiyao powder (Yunnan baiyao group, n = 12), and 0.4 mL saliva of health adult (saliva group, n = 12) for 15 days, respectively. And the general observation of raw surface, the scar formation time, wound healing rate, and histopathology were used to evaluate the effectiveness of saliva on wound healing.

The wound healing speeds of saliva group and Yunnan baiyao group were faster than that of blank control group. The wound healing rates of saliva group were significantly higher than those of blank control group and Yunnan baiyao group at 5, 8, and 11 days after injury (P < 0.05). No obvious hemorrhage or necrosis of raw surfaces was observed in saliva group, and the raw surfaces generally were covered with epidermis at 15 days after injury. The inflammatory cells and microvessel density in saliva group were significantly less than those of Yunnan baiyao group and control group (P < 0.05).

Saliva could obviously improve wound healing, which is related to its effects on reducing inflammatory cell infiltration, preventing wound infection, accelerating collagen fibers proliferation, and promoting vessel reconstruction in the process of wound healing.