Gamma globulin binding of hinokiflavone with anti-osteoporosis effects: A mechanistic study

Abstract

Oxidative stress can trigger apoptosis and associated reduction of osteoblast activity. Hinokiflavone (HNK) with a biflavonoid-based structure might show potent antioxidant activity. However, before the application of this compound as a promising therapeutic bioactive material, its interaction with blood proteins should be investigated to further reveal its pharmacokinetic and pharmacodynamic properties. Therefore, in this paper, the interaction of HNK with γ-globulin, one of the main blood proteins, was assessed. Then, the antioxidant properties of HNK against H2O2-induced osteoblast cytotoxicity in MC3T3-E1 cells were assessed. It was shown that HNK can potentially bind to γ-globulin mostly with the aid of hydrophilic forces, with a slight effect on the protein structure. It was then determined that HNK significantly recovered cell survival and alkaline phosphatase (ALP) activity and collagen-I content in MC3T3-E1 cells exposed to H2O2. In addition, HNK decreased the production of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) in MC3T3-E1 cells triggered by H2O2. Finally, HNK was shown to control the apoptosis induction in MC3T3-E1 cells triggered by H2O2 mediated by regulation of Bax, Bcl-2 and caspase-3. Taken together, these data demonstrated that HNK with promising blood protein binding properties can show significant protective effects in MC3T3-E1 cells mediated by inhibition of osteoblast dysfunction, oxidative stress, and apoptosis.