ABSTRACT
ObjectiveTo investigate the protective effect of Shentong Zhuyutang-containing serum against oxidative stress and apoptosis in chondrocytes of rats with knee osteoarthritis （KOA）. MethodFifty male rats were orally administered with normal saline， low-， medium-， and high-dose Shentong Zhuyutang （1.73， 3.46， 6.92 g·kg-1）， and glucosamine sulfate （0.3 g·kg-1） for two weeks. Serum samples were collected after the treatment period. The KOA model was established， and chondrocytes were isolated and randomly divided into normal group， model group， low-， medium-， and high-dose Shentong Zhuyutang-containing serum groups， and glucosamine sulfate group. During the chondrocyte culture， adenosine monophosphate （AMP）-activated protein kinase （AMPK） inhibitor Compound C （10 μmol·L-1） was added， and the cells were divided into normal group， model group， Shentong Zhuyutang-containing serum group， and Compound C + Shentong Zhuyutang-containing serum group. Cell proliferation was detected using 5-ethynyl-2'-deoxyuridine （EdU） staining. Apoptosis was determined using terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL）. Reactive oxygen species （ROS） levels were measured using DCFH-DA probe. Glutathione （GSH） and malondialdehyde （MDA） levels were determined using the colorimetric method. Real-time polymerase chain reaction （PCR） was used to measure the mRNA expression levels of matrix metalloproteinase-3 （MMP-3）， MMP-13， type Ⅱ collagen （Col Ⅱ）， and Aggrecan. Western blot was performed to measure the protein expression of phosphorylated （p）-AMPK and silent information regulator factor 1 （Sirt1）. ResultCompared with the normal group， the model group showed a significant decrease in chondrocyte proliferation rate， GSH activity， Col Ⅱ and Aggrecan mRNA expression， p-AMPK and Sirt1 protein levels （P<0.01）， and increased ROS levels， MDA content， TUNEL-positive cell rate， and MMP-3 and MMP-13 mRNA expression （P<0.01）. Compared with the model group， Shentong Zhuyutang-containing serum increased the number of EdU-positive cells， GSH activity， Col Ⅱ and Aggrecan mRNA expression， p-AMPK and Sirt1 protein levels in KOA rat chondrocytes （P<0.05， P<0.01）， and decreased the TUNEL-positive cell rate， ROS levels， MDA content， MMP-3 and MMP-13 mRNA expression （P<0.05， P<0.01）. Compared with the Shentong Zhuyutang-containing serum group， the Compound C + Shentong Zhuyutang-containing serum group showed significantly reduced p-AMPK and Sirt1 protein expression， GSH activity， Col Ⅱ and Aggrecan mRNA levels （P<0.01）， and increased TUNEL-positive cell rate， ROS levels， MDA content， MMP-3 and MMP-13 mRNA levels （P<0.01）. ConclusionShentong Zhuyutang-containing serum attenuates oxidative damage and reduces apoptosis in chondrocytes of rats with KOA， and its protective effect may be associated with the activation of the AMPK/Sirt1 signaling pathway.