Detrimental effects of atherogenic and high fat diet on bone and aortic calcification rescued by an isoflavonoid Caviunin β-d-glucopyranoside.

OBJECTIVE: Atherogenic diet (AD) and high fat diet (HFD) cause deleterious effect on bone micro-architecture and this phenomenon prompts aortic calcification. This study aims to show the effects of Caviunin β-d-glucopyranoside (CAFG), against bone loss and its associated aortic calcification in presence of AD and HFD challenged diets.

METHODS: Five groups of C57BL/6 male mice with 8 animals in each group, comprising of chow, AD, HFD, AD+CAFG and HFD+CAFG were fed with respective diets for 16 weeks. At the end of the treatment period, preventive effects of CAFG on bone tissue were analyzed by assessing the osteogenic potential of bone marrow cells, bone micro-architecture, ability of new bone formation and histomorphometry studies. Aortic calcification was assessed by transcription and translation analysis of osteogenic key markers in aortic tissue and assessment of aortic endothelial function. Plasma lipid profiling was done to assess the effects of diets as its role in both bone loss and aortic calcification.

RESULTS: Bone marrow stromal cell (BMSC's) dynamics showed that AD and HFD decreased osteoblast number that led to bone loss, deterioration in bone micro-architecture with up-regulated bone resorptive genes that lead to increase in aortic calcification. CAFG treatment rescued the bone health by modulating BMSC's towards osteogenic lineage. It increased the osteogenic gene expression with simultaneous decrease in osteoclastic genes thus stabilized the receptor activator of nuclear factor-kappa-B ligand/osteoprotegerin ratio that eventually reduced the amount of calcification in aorta. Biochemical studies showed that CAFG reduced the TC, TG and LDL-C content with no marked changes in HDL-C. Moreover, CAFG decreased the osteogenic key markers in the aortic tissue and enhanced endothelial function.

CONCLUSION: Overall, this study indicates that CAFG protected against physiologically challenged diet induced bone loss with associated vascular calcification in mice. Moreover, data revealed that atherogenic diet is more detrimental as compared to the excess fatty acid diet to the bone and aorta.