Aims: This study investigated the effects of β-caryophyllene (BCP) on protecting bone from vitamin D deficiency in mice fed on a diet either lacking (D-) or containing (D+) vitamin D.
Methods: A total of 40 female mice were assigned to four treatment groups (n = 10/group): D+ diet with propylene glycol control, D+ diet with BCP, D-deficient diet with control, and D-deficient diet with BCP. The D+ diet is a commercial basal diet, while the D-deficient diet contains 0.47% calcium, 0.3% phosphorus, and no vitamin D. All the mice were housed in conditions without ultraviolet light. Bone properties were evaluated by X-ray micro-CT. Serum levels of klotho were measured by enzyme-linked immunosorbent assay.
Results: Under these conditions, the D-deficient diet enhanced the length of femur and tibia bones (p < 0.050), and increased bone volume (BV; p < 0.010) and trabecular bone volume fraction (BV/TV; p < 0.010) compared to D+ diet. With a diet containing BCP, the mice exhibited higher BV and bone mineral density (BMD; p < 0.050) than control group. The trabecular and cortical bone were also affected by vitamin D and BCP. In addition, inclusion of dietary BCP improved the serum concentrations of klotho (p < 0.050). In mice, klotho regulates the expression level of cannabinoid type 2 receptor (Cnr2) and fibroblast growth factor 23 (Fgf23) through CD300a. In humans, data suggest that klotho is connected to BMD. The expression of klotho is also associated with bone markers.
Conclusion: These data indicate that BCP enhances the serum level of klotho, leading to improved bone properties and mineralization in an experimental mouse model.Cite this article: Bone Joint Res 2022;11(8):528-540.
Keywords: Bone density; Bone loss; Cortical bone; Vitamin D; Vitamin D deficiency; bone mineral density (BMD); enzyme-linked immunosorbent assay; femora; fibroblast growth factor; serum; tibial bone; trabecular bones; vitamin D+; β-caryophyllene.