Figure 1. Histological scoring of the destabilization of the medial meniscus (DMM), DMM + Metformin joints, and cartilage explants. (A) Representative photographs of the joints of male mice at 2, 5, and 10 weeks after surgery. (B) Osteoarthritis Research Society International (OARSI) scoring of the joints of DMM, DMM + metformin male mice at 2, 5, and 10 weeks after surgery, as well as cartilage explants (D). (C) Representative Safranin O staining of paraffin section of mouse cartilage explants treated with IL-1β + metformin (4 mM and 8 mM) for 5 days. Sections were stained with Safranin O/Fast Green. Two weeks: n = 24; 5 weeks: n = 24; 10 weeks: n = 24. Cartilage explants: (n = 6 per condition). Values are expressed as the mean ± SEM. ***p < 0.001 compared with the control.