Intervention Mechanism of Xiaoluowan on Experimental Goiter Rats Based on PI3K/Akt/mTORC1 Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveBy observing the effect of Xiaoluowan on phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin complex 1 （mTORC1） pathway in experimental goiter rats， this study aims to explore its therapeutic effect on experimental goiter rats. MethodSixty 5-month-old SD rats of SPF grade were purchased， half males and half females， of which 10 were used as a normal group， and the remaining rats were administrated with propylthiouracil （PTU） solution to induce nodular goiter. After successful modeling， rats were randomly divided into a model group， levothyroxine sodium tablets group， Xiaoluowan low-dose group， medium-dose group， and high-dose group， ten rats each. The levothyroxine sodium tablets group was given 15 μg·kg-1 levothyroxine sodium tablets by gavage. The Xiaoluowan low-， medium-， and high-dose groups were given （ig） Xiaoluowan low-dose （10 g·kg-1）， medium-dose （20 g·kg-1）， and high-dose （30 g·kg-1） Xiaoluowan， and the normal group and model group were administered （ig） with the same volume of 0.9% sodium chloride solution. Four weeks after the intervention， rats were sacrificed by routine intraperitoneal anesthesia using 5% phenobarbital. Subsequently， the histopathology was observed under a microscope， and serum thyroid hormone levels were measured using a Roche electrochemiluminescence immunoassay analyzer. Serum cytokines were detected by enzyme-linked immunosorbent assay （ELISA）， and neurotransmitters were measured using a high-performance liquid chromatograph. The protein level of PI3K/Akt/mTORC1 pathway was determined by Western blot. ResultAs compared with the normal group， the levels of basic fibroblast growth factor （bFGF）， vascular endothelial growth factor （VEGF）， insulin-like growth factor （IGF-1）， 5-hydroxytryptamine （5-HT）， and thyroid stimulating hormone （TSH） were increased， and PI3K， Akt， and mTORC1 protein levels were up-regulated in the model group， while the levels of norepinephrine （NE）， triiodothyronine （T3）， tetraiodothyronine （T4）， free triiodothyronine （FT3）， and free thyroid hormone （FT4） were decreased （P<0.05）. Compared with the model group， the levothyroxine sodium tablets group， and Xiaoluowan low-， medium-， and high-dose groups exhibited reduced levels of bFGF， VEGF， IGF-1， 5-HT， and TSH， and down-regulated PI3K， Akt， and mTORC1 protein levels， and increased NE， T3， T4， FT3， and FT4 levels （P<0.05）. ConclusionXiaoluowan may act on the PI3K/Akt/mTORC1 signaling pathway to play its role in the treatment of nodular goiter， and it is dose-dependent.