Objective: In recent years, oxidative stress has been implicated in a variety of degenerative process and diseases, including acute and chronic inflammatory conditions such as wound healing. Green tea polyphenols have shown anti-oxidant property. The present study discussed the application of chitosan green tea polyphenol complex on the wound healing.
Methods: The wound healing effect of chitosan green tea polyphenol complex was studied in ten-week-old healthy male Sherman rats weighing 150-180 g by two wound models. The rats were randomly chosen and divided into four groups (n=5), administered with distilled water in Group A as control group, epigallocatechin-3-gallate (EGCG) in Group B, chitosan-EGCG complex in Group C and chitosan-green tea polyphenols complex in Group D, respectively. In rats'incision wound model, two straight paravertebral incisions were made and skin tensile strength was measured using continuous water flow technology on the 10th day. In rats'excision wound model, wound contraction and period of epithelization were measured. The polyphenols release from the complex was continuously monitored by an elution technique in aqueous solution at different pH values (pH=4, 5, 6, 7).
Results: The treatment groups showed significantly enhanced the breaking strength in incision wound (328+/-14.5) g and (421+/-18.5) g compared with control (264+/-16.7) g. In the excision wound model, the wound contraction percentage in treatment groups was relatively increased during the recovery period. Respectively, the percentage of wound contraction ranged from 47.60%+/-2.15% on day 4 to 107.98% +/-1.26% on day 16 compared with control group (8.46%+/-5.42% to 59.80%+/-4.47%). The complex demonstrated a gradual increase in the release rate from the initial stage and slow increase at different pH values. The release rate approximated 0.6-0.7 in the complex and remained stable 6 hours after injury, which may be the end of the release process.
Conclusions: In our study, chitosan polyphenol complex has enhanced the healing of incision wounds by increasing the breaking strength of the wounds. In excision wound model, the complex hastens the period of epithelialization. The study on the optimal release of complex among various pH values could be applied in the wound test, which can lead to a gradually active substance(polyphenols) release and efficient coverage of epithelial layers found in the healing of incision and excision wound.