The effects of diacylglycerol oil on bone metabolism of C57BL/6J mice

Abstract

In epidemiologic and animal studies, high fat diets (HFD) are associated with lower bone mineral density (BMD) and higher risk of osteoporotic fractures. Meanwhile, consuming HFD containing diacylglycerol (DAG) instead of triacylglycerol (TAG) has metabolically beneficial effects such as reduction in body weight and abdominal fat. This study investigated the effects of a HFD containing DAG on oxidative stress and bone metabolism in mice.Four-week-old male C57BL/6J mice (n = 39) were divided into three weight-matched groups based on diet type: a chow diet group, a HFD containing TAG (HFD-TAG) group, and a HFD containing DAG (HFD-DAG) group. After 20 weeks of treatment, body composition and bone microstructure were analyzed using dual energy X-ray absorptiometry and micro-computed tomography. Oxidative stress in bone marrow cells was measured using dihydroethidium staining. RT-PCR and quantitative real-time PCR of bone marrow cells were performed to investigate the expression of transcription factors for osteogenesis or adipogenesis. It was found that the HFD-DAG group had lower body weight, higher BMD, and superior microstructural parameters of bone when compared to the HFD-TAG group. Oxidative stress in bone marrow cells was lower in the HFD-DAG group than in the HFD-TAG group. The HFD-DAG group also showed increased expression of Runx2 and decreased expression of PPARγ in bone marrow cells compared to the HFD-TAG group. Osteocalcin levels measured in plasma were higher in the HFD-DAG group than in the HFD-TAG group.In conclusion, when compared to HFD-TAG, HFD-DAG induces less oxidative stress in bone marrow and has beneficial effects on bone and bone metabolism of C57BL/6J mice.