BACKGROUNDGastrodin, as one of the major components extracted from the Chinese herb Gastrodia elata Bl., has many biologic effects, one of which is anti-apoptosis. Apoptosis is considered to be one of the pathogenetic mechanisms in steroid-induced osteonecrosis of the femoral head (ONFH). Therefore, we performed this study to investigate whether gastrodin has the potential to prevent steroid-induced ONFH.

METHODSAll 18 male adult Wistar rats were divided equally into three groups: the steroid group, the gastrodin+steroid group, and the control group. Osteonecrosis was induced by low-dose lipopolysaccharide and subsequent high-dose methylprednisolone. Histomorphometric method was used to determine the incidence of osteonecrosis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay was performed to detect apoptotic index of osteocytes and osteoblasts. Real-time PCR and Western blotting were performed to detect mRNA and protein expression of Bax, Bcl-2, and Caspase-3. Fisher's exact probability test and one-way analysis of variance (ANOVA) with Turkey's post hoc test were used to examine significant differences between groups.

RESULTSThe incidence of osteonecrosis in the gastrodin+steroid group (16.7%) was significantly lower than that in the steroid group (83.3%). According to TUNEL assay, the apoptotic indices in the steroid group, the gastrodin+steroid group, and the control group were 91.1%, 27.1%, and 5.4%, respectively, and the differences were significant between groups. Compared with the control group and the gastrodin+steroid group, the mRNA and protein expression levels of Bax and Caspase-3 were significantly higher in the steroid group, but the Bcl-2 mRNA and protein expression levels were significantly lower.

CONCLUSIONGastrodin could prevent steroid-induced ONFH by anti-apoptosis.