Combined effect of insulin and naringin treatments on the histological and biomechanical properties of bone in a rat model of diabetes mellitus.

RODRIGUEZ VALERIA; PICOTTO GABRIELA; RIVOIRA MARÍA ANGÉLICA; RIGALLI ALFREDO; TOLOSA DE TALAMONI NORI

Congreso; International Osteoporosis Foundation (IOF) virtual congress; 2022

Diabetes mellitus (DM) alters the bones increasing the risk of fractures and/or delays the fracture healing. The aim of the present work was to study the histological and biomechanical characteristics of bone in rats with type 1 DM and to evaluate the possible osteoprotective effect of insulin (I) and naringin (NAR), individually or combined. Male Wistar rats were treated for 30 days: 1) controls, 2) DM1, 3) DM1+I, 4) DM1+NAR, 80 mg/Kg, 5) DM1+I+NAR. Bone histomorphometry, bone mineral density (BMD), histology and TRAP staining were evaluated in femur. Biomechanical studies were done in cortical bone (3-point bending test) and trabecular bone (compression test). ANOVA and Bonferroni test were used for statistical analysis. Serum OCN levels and BMD were lower in DM1 rats, but treatments with NAR or I+NAR normalized these values. All groups presented lower bone volume as compared to those from the control group and lower trabecular thickness except that of the I + NAR group. TRAP (+) cells increased in DM1 rats, an effect that decreased with all treatments. DM rats presented lower values of fracture and ultimate loads, which was avoided with I+NAR treatment. Individual and combined exposure to the drugs prevented the decrease in stiffness and absorbed energy induced by DM1. In conclusion, the normalization of serum OCN levels and the decrease in the number of osteoclasts suggest that NAR promotes osteoblastogenesis and inhibits osteoclastogenesis. STZ reduces the resistance to fracture by decreasing the moment of inertia. Only I+NAR restores the resistance to control values. The mechanisms of action of NAR in bone will continue to be studied.