ABSTRACT
ObjectiveTo observe the effects of Aurantii Fructus Immaturus， Atractylodis Macrocephalae Rhizoma， and their combination on slow transit constipation via PTEN-induced putative kinase 1 （PINK1）/Parkin pathway-mediated mitophagy. MethodFifty-six male SD rats were randomly assigned into normal group， model group， natural recovery group， Aurantii Fructus Immaturus group， Atractylodis Macrocephalae Rhizoma group， Aurantii Fructus Immaturus combined with Atractylodis Macrocephalae Rhizoma group， and mosapride group， with 8 rats in each group. Slow transit constipation model was established by gavage with loperamide （3 mg·kg-1·d-1） for 14 days in other groups except the normal group. After successful modeling， except that the model group was continuously induced by loperamide， the normal group and the natural recovery group were administrated with 0.9% normal saline by gavage， and the rats in the Aurantii Fructus Immaturus （1.35 g·kg-1·d-1） group， the Atractylodis Macrocephalae Rhizoma （2.7 g·kg-1·d-1） group， the Aurantii Fructus Immaturus combined with Atractylodis Macrocephalae Rhizoma （4.05 g·kg-1·d-1） group， and the mosapride （1.56 mg·kg-1·d-1） group were administrated with corresponding drugs by gavage for 7 days. The amount of feces， fecal water content， and intestinal propulsion rate of rats were determined. The pathological changes of the colon were evaluated by hematoxylin-eosin （HE） staining and Alcian blue-periodic acid-Schiff （AB-PAS） staining. The activity of respiratory chain complex and the ultrastructure of the colon tissue were determined by ultraviolet spectrophotometry and observed by transmission electron microscopy， respectively. Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） was employed to determine the mRNA levels of PINK1， Parkin， and p62， and Western blot to determine the protein levels of microtubule-associated protein 1 light chain 3 （LC3）， PINK1， and Parkin. ResultCompared with the normal group， the model group and the natural recovery group showed decreases in the amount of feces， fecal water content， intestinal propulsion rate （P<0.05，P<0.01）， and activities of mitochondrial respiratory chain complexes Ⅱ， Ⅲ， and Ⅳ in the colon tissue （P<0.05，P<0.01）. Further， the mRNA levels of PINK1 and Parkin and the protein levels of PINK1， Parkin， and LC3 were up-regulated （P<0.01） and the mRNA level of p62 was down-regulated in the model group （P<0.05） and the natural recovery group. Compared with the model group and the natural recovery group， the Aurantii Fructus Immaturus combined with Atractylodis Macrocephalae Rhizoma group showed increased amount of feces， fecal water content， intestinal propulsion rate， and activities of mitochondrial respiratory chain complexes Ⅱ， Ⅲ， and Ⅳ （P<0.05，P<0.01）. Moreover， the combination meliorated the degree of mitochondrial swelling in the colon tissue， down-regulated the mRNA levels of PINK1 and Parkin and the protein levels of PINK1， Parkin， and LC3 （P<0.05，P<0.01）， and up-regulated the mRNA level of p62 （P<0.05）. ConclusionAurantii Fructus Immaturus and Atractylodis Macrocephalae Rhizoma， and their combination may remedy the colonic motility disorders in rats with slow transit constipation by blocking PINK1/Parkin signaling pathway to inhibit the excessive mitophagy in interstitial cells of Cajal in the colon tissue.