Effects of Triptolide on the apoptosis of lymphocytes in sensitized rats
Objective To assess the influence of triptolide (TP) on apoptosis of lymphocyte in sensitized rats in vivo and in vitro . Methods The rat model of allergic airway inflammation was established by first sensitizing followed by challenging the animals with ovalbumin (OVA). The animals were randomly divided into control group, sensitized group, and sensitized and TP treated group. By using the techniques of morphology, terminal deoxynucleotidyl transferase nick and labeling (TUNEL) DNA gel electrophoresis and immunohistochemical staining, the influence of TP on lymphocyte apoptosis was observed. Results In vivo experiments showed that the percentage of eosinophil (20.24±1.63%) and the percentage of lymphocytes (15.61±2.105%) in BALF in sensitized rats were significantly increased when compared with normal control ( P 0.01). In TP treated group, the numbers of both Eos and lymphocytes were significantly decreased, while the apoptosis percentage of lymphocytes in bronchoaloveolus lavage fluids (BALF) in the TP treated group was higher than that in the sensitized group. In vitro experiments showed that TP (10 7 10 5 g/ml) could promote the spleen lymphocyte to undergo apoptosis and expression of Fas/FasL when stimulated with OVA and this induction was does and time dependent to TP. DNA “ladder” formation in gel electrophoresis as well as apoptosis cells were found with typical morphologic characteristics. 10 7 g/ml TP significantly increased the dexamethasone (DXM) promoted apoptosis percentage and expression Fas/FasL. Conclusions TP could induce apoptosis of spleen and lung lymphocytes in sensitized animals, which may be mediated by Fas/FasL system so that it may be one of its anti inflammation mechanisms. Besides, TP could work in coordination with DXM to induce apoptosis of lymphocytes. This study is conducive for the investigation of new therapeutic approaches.