芦荟提取物对烫伤大鼠创面组织一氧化氮及内皮素含量的影响

The effects of aloe extract on nitric oxide and endothelin levels in deep-partial thickness burn wound tissue in rat

目的观察芦荟凝胶和芦荟粗多糖对烫伤大鼠创面组织含水量及一氧化氮(NO)和内皮素(ET)含量的影响。方法将42只Wistar大鼠背部造成4个直径为3 cm的深Ⅱ度烫伤创面。伤后创面分别外敷质量分数5％芦荟粗多糖膏、质量分数10％芦荟凝胶膏、质量分数1％磺胺嘧啶银(SD-Ag)霜和等渗盐水。根据创面用药的不同分为芦荟粗多糖组、芦荟凝胶组、SD-Ag组、等渗盐水组。伤后4、12、24、48 h及7、14、21 d每时相点处死6只大鼠,取创面全层皮肤测定组织含水量、No和ET含量,计算No／ET值。另取6只大鼠不烫伤,作为正常对照组,检测指标同前。结果伤后12、24、48h,芦荟粗多糖组[(73.4±3．8)％、(76．6±3．0)％、(70．6±3．8)％]和芦荟凝胶组[(74.5±2.6)％、(77．1±3．6)％、(71．2±3．1)%]创面组织含水量显著低于SD-Ag组[(80．1±4．1)％、(80．5±3．9)％、(76．1±3．8)％,P<0．05];伤后7-21 d,除SD-Ag组伤后7 d仍显著高于正常对照组(P<0．05)外,其他各组均基本恢复到正常水平。伤后12 h各烫伤组创面组织NO含量升高达峰值,随后下降,到伤后21d仍显著高于正常对照组(P<0．05);伤后12、24 h,芦荟粗多糖组和芦荟凝胶组创面组织NO含量明显低于SD-Ag组及等渗盐水组(P<0．05)。伤后7 d或14 d各烫伤组创面组织ET含量增加达高峰,随后下降;伤后7、14d均显著高于正常对照组(P<0．05)。伤后12 h各组NO／ET值达峰值,随后下降,伤后14 d基本恢复至正常水平,其中芦荟粗多糖组伤后7 d NO／ET值即恢复至正常水乎,但其他3组仍显著高于正常对照组。结论芦荟粗多糖和芦荟凝胶能有效减少烫伤后早期创面组织NO的释放、优化NO／ET值、减轻血管炎性反应、减少渗出和水肿。

Objective To investigate the effects of polysaccharide extracted from Aloe barbadensis and Aloe barbedensis containing gel on tissue water contents, nitric oxide（NO） and endothelin（ET） levels in wounds of burned rats. Methods Four areas of deep-partial thickness burn wounds with 3 cm in diameter were made on each back of 42 male Wistar rats. Single layer gauze impregnated either with 5% （W/W） aloe raw polysaccharide, 10% （W/W） aloe gel, 1% （ W/W ） sulfadiazine pyridine silver cream （SD-Ag） , or normal saline was respectively applied on different wounds. According to different medications, the wounds were divided into aloe raw polysaccharide group, aloe gel group, SD-Ag group and normal saline group. Six rats in each group were sacrificed at 4,12,24,48 post-scald hour（PSH） and on 7,14,21 post-scald day （PSD） , and the full-thickness skin of wound was harvested for the determination of wound tissues water contents, NO and ET levels, and for calculation of NO/ET ratio. Another 6 normal rats served as normal controls. Results The water content in the wound tissue in aloe raw polysaccharide group at 12, 24 and 48 PSH [（73.4±3.8）%,（76.6±3.0）%,（70.6±3.8）%] and aloe gel group [（74.5±2.6）%,（77.1 ± 3.6）%,（71.2±3. 1）% ] was obviously lower than those in SD-Ag group [（80. 1±4. 1）%,（80.5 ± 3.9）%,（76. 1 ±3.8）%, P 〈0.05]. During 7-21 PSD, all of them returned to the normal level except that in SD-Ag group, as it was still higher than that in normal controls（ P 〈 0.05）. The NO content in wound tissue in each group reached the peak at 12 PSH, decreased thereafter, but it was still obviously higher than that of normal controls on 21 PSD（ P 〈 0. 05）. The ET content in wound tissue of each group reached the peak on 7 or 14 PSD, decreased thereafter, but it was still evidently higher than that in normal controls on 7 or 14 PSD（ P 〈0.05）. The NO content in wound tissue in aloe raw polysaccharide and aloe gel group were markedly lower than those in SD-Ag and normal saline groups at 12 and 24 PSH （ P 〈 0. 05 ）. The NO/ET ratio in each group reached the peak at 12 PSH, decreased thereafter, and it returned to normal value on 14 PSD. On 7 PSD, the NO/ET ratio in aloe gel, SD-Ag and normal saline groups were still significantly higher than that in normal controls, except that returned to normal value in aloe raw polysaccharide group. Conclusion Both aloe raw polysaccharide and aloe gel can decrease wound tissue NO release, optimize NO/ET ratio, lighten vascular inflammatory reaction, and lessen permeability and edema.