Quercetin Derivative Inhibits Oxidative Damage to Osteoblasts

SEOUL, KoreaA glycoside derived from the flavonoid quercetin may protect osteoblast cells from oxidative damage, according to a recent study published Sept. 3, online ahead of print in Experimental and Toxicological Pathology. Eun Mi Choi, department of Food and Nutrition Technology at Kyung Hee University, investigated the effects of quercitrin on osteoblastic MC3T3-E1 cellswidely used as a model of bone building osteblasts.

The MC3T3 cell line was incubated with hydrogen peroxide (H₂O₂) and/or quercetrin, and markers of oxidative damage and osteoblast function were measured. Quercitrin treated cells showed significantly reversed oxidative damage; the protective effect of quercitrin was inhibited by two breast cancer drugs (ICI182780 and LY294002), indicating the glycoside might be affected by the mechanisms of these two drugs, estrogen action and P13k (phosphoinositide 3-kinases) pathway.

Further results showed pre-treatment with quercitrin increased collagen content, alkaline phosphatase (ALP) activity and calcium deposition of osteoblasts, compared with untreated cells incubated with H₂O₂.  These effects were blocked by ERKs and p38 mitogen-activated protein kinases (MAPKs) inhibitors. Pretreatment with quercitrin also reduced the increase in bone-resorbing factor  and oxidative damage markers (malondialdehyde, protein carbonyl, and nitrotyrosine) induced by H₂O₂.