Effect of the preadministration of pitaya extract in the gene expression and mineralization of osteoblastic cells exposed to hydrogen peroxide.

Abstract

Osteoporosis is a multifactorial disease of high prevalence in the population, leading to the loss of bone mass and an imbalance in bone remodeling. The association between this imbalance and estrogen deficiency that occurs in menopausal women is still investigated, suggesting that the reduction in estrogen production by the body itself after menopause favors oxidative stress with the consequent change in the functional activity of bone cells. Evidence shows that phytoestrogens can be used as an alternative treatment for postmenopausal osteoporosis due to their ability to bind to estrogen receptors in the body, which would lead to an increase in the rate of deposition and reduction of the rate of bone resorption, in addition to having an antioxidant effect, acting to protect cells against the effects caused by reactive oxygen species (ROS). Therefore, the purpose of the present investigation is to evaluate the effect of pitaya extract (EPY) on gene expression of osteoblastic cells in the presence and absence of oxidative stress. For in vitro analysis, osteoblastic lineage MC3T3-E1 cells will be cultured and divided into control groups and groups with in vitro induction of oxidative stress, receiving or not the addition of XXXEPY. The cell groups will be submitted to RNA extraction to evaluate the expression of alkaline phosphatase (Alp), bone sial-protein (Bsp), osteocalcin (Bglap), Forkhead box protein O1 (Fox01), Histone acetyltransferase 1 (Hat1), Superoxide Dismutase 3 (Sod3) and transcription factor erythroid 2-related factor2 (Nfr2). The data obtained will be statistically analyzed by the Graph Pad Prism 5.0 software with a significance level of 5%.