Suppression effect of N-acetylcysteine on bone loss in ovariectomized mice.

Oxidative stress can trigger DNA damage response and activation of cellular senescence. Accumulating studies have demonstrated that senescent cells can produce senescence-associated secretory phenotype that leads to increased bone resorption and decreased bone formation. And elimination of senescent cells or inhibition of SASP secretion has been shown to prevent bone loss in mice. N-acetylcysteine (NAC) is a strong antioxidant. However, it is unclear whether reversed estrogen deficiency-induced bone loss by antioxidant NAC was associated with the inhibition of oxidative stress, DNA damage, osteocyte senescence and SASP. In this study, OVX mice were supplemented with/without E2 or NAC, and were compared with each other. Our results showed that oxidative stress, DNA damage, osteocyte senescence and the secretion of senescence-associated inflammatory cytokines were increased in OVX mice compared with sham-operated mice. However, these parameters were obviously rescued in OVX mice supplemented with E2 or NAC. Data from this study suggest that NAC can prevent OVX-induced bone loss by inhibiting oxidative stress, DNA damage, cell senescence and the secretion of the senescence-associated secretory phenotype.