Figure 5

Oral NAC administration blocks progression of previously established osteoarthritis in vivo. (a) Schematic showing the protocol used to administer NAC orally starting at two weeks after surgery. (b–e) Osteoarthritis or sham surgery was performed in the left or right knee joints, respectively, in 12-week-old wild-type male Wistar rats, and rats were maintained with or without NAC water (5.0 g/l) from two weeks to six weeks after surgery. Two weeks after surgery (2POW) (and before NAC treatment) or six (6POW) weeks after surgery (when NAC had been administered four weeks), knee joint sections (femur and tibia) were prepared and stained with Safranin O, and the Mankin score was assessed. Bar, 100 μm. (c,e) Data shows the mean Mankin score ± SD (n = 3 each, *P < 0.05).