RESUMEN
Objective::This study aims to explore the effect and mechanism of Yuehua capsule serum for autophagy of macrophages infected with multi-drug resistant mycobacterium tuberculosis. Method::The rats were undertaken intragastric gavage with Yuehua capsule by 3.02 g·kg-1 once a day which was produced through low temperature condensation drying method. After 7 days, blood of abdominal aorta of rats was collected to prepare Yuehua capsule serum. RAW264.7 andmultidrug resistant tuberculosis were cultured in vitro.According to cell counting kit-8(CCK-8), 10% drug-containing serum was considered as the effective concentration. The cultured cells were divided into four groups: model groups(10% fetal bovine serum). Yuehua capsule serum(10% Yuehua capsule serum). Autophagy inhibitor group+ 3-MA+ Yuehua capsule medicated serum(3-MA+ 10% Yuehua capsule serum). Rapamycin (Rap) positive control group(200 mg·L-1 Rap+ 10% Yuehua capsule serum). Except for the normal group, the cells of each group were cultured for 24 h and infected for 4 h according to cell-bacteria 1∶10.Testing index: observation of autophagosomes under transmission electron microscope, the test of expression of microtubule-associated protein light chain-3Ⅱ(LC-3Ⅱ), microtubule-associated protein LC 3-Ⅱ/microtubule-associated protein light chain 3-Ⅰ(LC3-Ⅰ) and Beclin-1 with Western blot, indirect immunofluorescence staining for LC3B, and mRNA of Beclin-1 as well as LC3 with real-time fluorescent quantitative polymerase chain reaction(Real-time PCR). Result::Compared with normal group, model group did not see autophagy body cells, cells in the LC-3 Ⅱ, LC-3 Ⅱ/LC-3 Ⅰ, Beclin-1 protein and LC3, Beclin-1 mRNA gene expression level had no significant change, the cells without fluorescent particles, spots, no fluorescence intensity.Compared with model group, Yuehua capsules serum group and Rap positive control group can be observed the formation of phage, mRNA andprotein expression levelof LC-3 Ⅱ, LC-3 Ⅱ/LC-3 Ⅰ, Beclin-1 and LC3, Beclin-1 were significantly increased (P<0.05). Autophagy inhibitor group+ 3-MA+ Yuehua capsule medicated serum did not see autophagy, the mRNA and protein expression level of LC-3 Ⅱ, LC-3Ⅱ/LC-3Ⅰ, Beclin-1 and LC3, Beclin-1 were no significantly increased. Conclusion::Yuehua capsule medicated serum could induce autophagy of macrophages of RAW264.7.The mechanism was probably accomplished through regulating the expression level of autophagy key protein LC3, autophagosome mature protein Beclin-1 and relevant gene, meanwhile the conversion of LC3-I to LC3-Ⅱ was accelerated.