葡甘聚糖对Caco-2细胞中二肽基肽酶Ⅳ抑制作用的研究

Glucomannan inhibit dipeptidyl peptidase 4 (DPP4) activity in the Caco-2 cell

目的:研究不同浓度葡甘聚糖作用长、短不同时间对Caco-2细胞中二肽基肽酶Ⅳ(dipeptidyl peptidase 4,DPP4)的抑制作用。方法:实验分为葡甘聚糖60、240 mg/L两个低浓度梯度组,400、500 mg/L两个中浓度梯度组,700、800、900 mg/L 3个高浓度梯度组,阴性对照组和空白对照组。各实验组分别单独作用于Caco-2细胞12 h和36 h,采用以甘氨酰脯氨酸对硝基苯胺(Gly-Pro-pNA)为底物的发色底物法检测不同浓度葡甘聚糖对体外Caco-2细胞中DPP-Ⅳ活性的影响。结果:(1)低、中、高浓度梯度的葡甘聚糖短时间(12 h)作用于Caco-2细胞后,与阴性对照组相比较得到P值,低浓度梯度组分别为0.579、0.545,中浓度梯度组分别为0.349、0.080,高浓度梯度组分别为0.082、0.097、0.429,差异均无统计学意义(P>0.05)。(2)低、中、高浓度梯度的葡甘聚糖长时间(36 h)作用于Caco-2细胞后,与阴性对照组相比较得到P值,低浓度梯度组分别为0.007、0.002,中浓度梯度组分别为0.621、0.976,高浓度梯度组分别为1.000、0.940、0.994,低浓度梯度组与阴性对照组相比较差异具有统计学意义(P<0.05)。结论:不同浓度葡甘聚糖短时间(12 h)作用于Caco-2细胞后,700 mg/L的高浓度葡甘聚糖对Caco-2细胞中DPP-Ⅳ活性有一定的抑制作用趋势;长时间(36 h)作用于Caco-2细胞后,60、240 mg/L的低浓度葡甘聚糖能够抑制Caco-2细胞中DPP-Ⅳ活性。

AIM： To observe the inhibitory effect of different concentration of Glucomannan on dipeptidyl peptidase 4 activity in the Caco-2 cell at 12 h, 36 h, respectively. METHODS： Seven different concentrations were tested in this experiment, two low concentration groups （60, 240 mg/L）, two middle concentration groups （400, 500 mg/L）, three high concentration groups（700, 800, 900 mg/L） of Glucomannan, negative control group, and blank control group. Each treatment lasted for 12 hours and 36 hours respectively. DPP4 activity was measured with colorimetric determination of product formation （ HGly-Pro-pNA, 0.2 mmol/L, Bachem） in different situations. RESULTS： （1） Compared with the negative control group, the P values of the different concentrations of glucomannan were 0. 579, 0. tion groups）, 0. 349, 0. tration groups）, 0. 082, Concentrations groups） 545 （the low concentration （the middle concen- 0. 097, 0. 429（the high respectively after reacting with Caco-2 cells for a short of time. There were no significant differences detected. （2） At 36 h, the P values were 0.007, 0.002 （the low concentration groups）, 0. 621, 0. 976（the middle concentration groups）, 1.000, 0.940, 0.994 （the high concentrations groups） respectively. The differences between the negative control groups and the low concentration groups have statistical significance （ P 〈 0.05 ）. CONCLUSION： There is a trend indicating that the high concentrations of glucomannan （700 mg/L） may inhibit the DPP4 activity in Caco-2 cells at 12 h. However, under the same circumstance, the low concentration of glucomannan （60, 240 mg/L） can inhibit the DPP4 activity in Caco-2 cells in a long term （36 h）.