Patchouli Alcohol Inhibits D-Gal Induced Oxidative Stress and Ameliorates the Quality of Aging Cartilage via Activating the Nrf2/HO-1 Pathway in Mice

Figure 5

The suppressive effects of patchouli alcohol (PA) on D-gal-induced chondrocyte senescence via upregulating Nrf2/HO-1 signaling pathway. (a–c) Impact of PA on mRNA expression of collagen 2a1 (Col2a1), matrix metalloproteinase 13 (Mmp13), Tp53, Cyclin-Dependent Kinase Inhibitor 1A (Cdkn1a/p21^Cip1/Waf1), catalase (Cat), and superoxide dismutase 1 (Sod1) in D-gal-caused senescent chondrocytes was detected by RT-qPCR. (d) Effect of PA on cell viability and cytotoxicity was determined by CCK-8 assay. (e) PA’s influence upon antioxidant indices (CAT and SOD) generation by D-gal-induced senescent chondrocytes was determined by biochemical kit. (f) Representative images of alcian blue, safranin O, and SA-β-gal staining in aging chondrocytes. The scale bar of alcian blue and safranin O staining, 250 μm. The scale bar of SA-β-gal staining, 100 μm. (g) Representative fluorescent images of ROS levels in D-gal (5 mg/ml) induced senescent chondrocytes. Scale bar, 50 μm. (h and i) The immunofluorescence detection of MMP13 and TP53 in D-gal-caused senescent chondrocytes. Scale bar, 50 μm. (j) The expression and quantitative analysis of COL2A1, MMP13, nuclear factor-erythroid 2-related factor-2 (Nrf2), heme oxygenase-1 (HO-1), TP53, and p21 proteins were assessed through western blotting. The Nrf2 protein expression level is the gray value ratio of the target protein to lamin B, while other proteins were the grayscale ratio of target protein to β-actin. . and vs. corresponding group.

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