穿山龙水提物对四氯化碳致急性肝损伤模型小鼠toll样受体4/髓样分化因子88通路的影响

Protective effect of aqueous extract from dioscorea nipponica Makino against carbon tetrachloride-induced acute liver injury in mice via TLR4/MyD88 signal pathway

目的 观察穿山龙水提物对四氯化碳诱导急性肝损伤模型小鼠的影响,探讨其对toll样受体4（Toll-like receptors 4,TLR4）/髓样分化因子88（Myeloid differentiation factor88,MyD88）信号通路的调控作用.方法 60只小鼠按随机数字表法分为对照组,模型组,穿山龙水提物低、中、高剂量组,每组10只.穿山龙水提物低、中、高剂量组分别灌胃50、100、200 mg/kg穿山龙水提物混悬液,对照组和模型组灌胃等体积溶剂.1次/d,连续给药7 d.末次给药后2 h,除对照组外,其余各组小鼠腹腔注射0.35%四氯化碳橄榄油溶液建立急性肝损伤模型.造模后24 h,采用Western blot检测各组肝组织TLR4、MyD88、NF-κB p65表达;采用PCR法检测各组肝组织IL-1β、TNF-α、IL-6 mRNA表达;采用ELISA法检测各组小鼠血清AST、ALT含量.结果 与模型组比较,穿山龙水提物低、中、高剂量组小鼠血清AST[（98.00±17.75）U/L、（57.49±9.66）U/L、（39.60±9.49）U/L比（113.40±9.71）U/L]、ALT[（76.00±14.73）U/L、（50.70±9.35）U/L、（35.25±9.93）U/L比（95.42±11.64）U/L]水平降低（P〈0.01）;穿山龙水提物高剂量组MyD88[（0.67±0.21）比（1.74±0.42）]、NF-κB p65[（0.51±0.09）比（1.76±0.31）]、TLR4[（0.97±0.25）比（2.99±0.72）]表达降低（P〈0.01）;穿山龙水提物中、高剂量组IL-6 mRNA[（2.22±0.25）、（1.76±0.31）比（5.20±0.60）]、IL-1βmRNA[（1.96±0.35）、（1.47±0.23）比（7.37±0.99）]、TNF-αmRNA[（2.06±0.25）、（1.34±0.33）比（2.98±0.50）]表达降低（P〈0.01）.结论 穿山龙水提物通过抑制TLR4/MyD88信号通路实现对四氯化碳诱导小鼠急性肝损伤的保护作用.

Objective To investigate the effect of the aqueous extracts from Dioscorea nipponica Makino （AEDN） against the carbon tetrachloride （CCl4）-induced mice acute liver injury by regulating TLR4/MyD88 signal pathway.Methods 60 mice were randomly divided into control group, model group, low, medium and high dose AEDN groups according to radom number table with 10 mice in each group. Mice in low, medium and high dose AEDN groups were adiminstrated with 50, 100 and 200 mg/kg AEDN, in control and model groups were adiminstrated with solvent once a day for 7 consecutive days. Two hours after the last administration, mice were intraperitoneal injected with with 0.3% CCl4 olive oil solution to induce acute liver injury model, except for the mice in control group. Twenty-four hours after injection, the expressions of TLR4, MyD88 and NF-κB in liver tissue were evaluated by Western blot, mRNA levels were evaluated by PCR, and the AST and ALT levels in serum were also detected.Results Compared with model group, the serum AST （98.00 ± 17.75 U/L, 57.49 ± 9.66 U/L, 39.60 ± 9.49 U/Lvs. 113.40 ± 9.71 U/L） and ALT levels （76.00 ± 14.73 U/L, 50.70 ± 9.35 U/L, 35.25 ± 9.93 U/Lvs. 95.42 ± 11.64 U/L） were significantly decreased in low, medium and high dose AEDN groups （P〈0.01）; MyD88 （0.67 ± 0.21vs. 1.74 ± 0.42）, NF-κB p65 （0.51 ± 0.09vs. 1.76 ± 0.31） and TLR4 （0.97 ± 0.25vs. 2.99 ± 0.72） levels were down-regulated in high dose AEDN group （P〈0.01）; the mRNA levels of IL-6 （2.22 ± 0.25, 1.76 ± 0.31vs. 5.20 ± 0.60）, IL-1β （1.96 ± 0.35, 1.47 ± 0.23vs. 7.37 ± 0.99）、TNF-α （2.06 ± 0.25, 1.34 ± 0.33vs. 2.98 ± 0.50） in medium and high dose AEDN groups significantly decresed （P〈0.01）.Conclusions The AEDN has protective effect against CCl4-induced acute liver injury in mice via adjusting TLR4/MyD88 signal pathway.