Effect of medical complex polysaccharides gel liquid in rats wound healing and the mechanism

Objective To investigate the effect of medical complex polysaccharides gel liquid(MCPGL) and its mechanism in process of wound healing by establishing rats model of skin wound. Methods Twenty Wistar rats, a total of 80 wounds were prepared. Four circular wounds of the same size were prepared on both sides of the spine in each rat, and the diameter of each wound was 1.5 cm. The experiment was randomly divided into 4 groups: model group(no treatment after injury), positive drug group (sodium hyaluronate), MCPGL low dose group (MCPGL 200 μL) and MCPGL high dose group (MCPGL 300 μL), each group had 20 wounds. After the operation, the medicine was administered twice a day in the affected area till the 21st d. The rat wound healing time and healing rate were observed after injury. The expression level of cell growth factors [insulin-like growth factor (IGF), vascular endothelial growth factor (VEGF)] were detected by RT-PCR. Pathological changes were observed in the local wound pathology by hematoxylin and eeosin (HE) staining. Single factor analysis of variance and t test were used for the study. Results At the day of injury, the wound deeply affected to fascia layer; 3rd d after injury, wounds of MCPGL low dose group and MCPGL high dose group were contracted, and MCPGL high dose group showed scab; 7th d after injury, wound granulation tissue appeared on several levels, the high dose of MCPGL group was particularly significant; 14th d and 21st d after injury, the 4 groups all appeared wound epithelization. At the 3rd d after injury, the rate of healing was statistically significant difference among the 4 groups (F=8.336, P<0.05). Compared with the model group, MCPGL high dose group significantly accelerated the wound healing rate (P<0.05); the 7th d after injury, the rate of healing was statistically significant difference among the 4 groups (F=33.569, P<0.05). Compared with the model group (48.9±13.5)%, the wound healing rate of sodium hyaluronate group and MCPGL high dose group were (71.4±10.8)%, (75.4±4.8)%, there were significant differences (with P values below 0.05); the 14th d after injury, the healing rate was statistically significant difference among the 4 groups (F=9.885, P<0.05). Compared with the model group, MCPGL high dose group significantly accelerated wound healing rate (P<0.05); the 21st d after injury, the rate of healing was not statistically significant difference among the 4 groups (F=2.45, P=0.07), compared with the model group, the other 3 groups had no statistically significant difference ( with P values above 0.05). The time of healing was not statistically significant difference among the 4 groups (F=1.531, P=0.228). Compared with the model group, sodium hyaluronate group (20.9±2.3) d, (20.5±4.0) d, MCPGL high dose group (18.2±3.2)d, the difference was not statistically significant (with P values above 0.05); compared with the model group, sodium hyaluronate group, MCPGL low dose group (20.7±1.3)d, the differences were not statistically significant (with P values above 0.05). At the 7th d after injury, the expression of IGF was statistically significant difference among the 4 groups (F=130.925, P<0.05). Compared with the model group 0.73±0.04, the expression of IGF mRNA in the MCPGL low dose group 1.04±0.09 and MCPGL high dose group 1.08±0.03 both increased, the differences were statistically significant (with P values below 0.05). Seventh day after injury, the expression of VEGF mRNA was statistically significant difference among the 4 groups (F=84.976, P<0.05). Compared with the model group 0.93±0.06, the expression levels of VEGF mRNA in MCPGL low dose group 1.23±0.03 and MCPGL high dose 1.14±0.08 increased, the differences were statistically significant (with P values below 0.05). The 7th d after injury had pathological observation of wound tissue in rats. In the model group, small number of fibroblasts arranged scattered, containing a large number of inflammatory cells, without complete epidermis covered the wound skin; compared with the model group, MCPGL low dose group of granulation tissue had filled in the wound area, skin had completely covered the surface of the wound. Containing more inflammatory cell infiltration; MCPGL high dose consisted more fiber cells, formed a large number of granulation tissue, and accompanied by newborn capillaries. Epidermis covered the wound surface completely, and there was a small amount of inflammatory cell infiltration. Conclusions The results show that MCPGL can accelerate wound healing within 14 d after injury, and MCPGL has the effect of promoting wound healing. Then the mechanism of action for MCPGL promoting wound healing by promoting the expression of related growth factors can be presumed. Key words: Rats; Wounds and injuries; Wound healing; Medical complex polysaccharides gel liquid; Growth factor