Quercetin-induced Changes in Femoral Bone Microstructure of Adult Male Rabbits

Flavonoids are a group of plant metabolites with antioxidant effects. One of the most abundant flavonoids in the human diet is quercetin. It is found widely in fruits, vegetables and has a lot of beneficial effects on human health. Quercetin has a positive pharmacological effect on bone metabolism and it prevents the organism against bone loss. However, its impact on the size of basic structural units of the compact bone is still unknown. Therefore, the aim of present study was to investigate the impact of the quercetin on femoral bone microstructure in 5-month-old male rabbits. Five rabbits of Californian broiler line were randomly divided into two groups. In the experimental group (E group; n=3), animals were intramuscularly injected with quercetin at dose 1000 μg.kg body weight (bw) for 90 days, 3 times per week. Two rabbits without quercetin administration served as a control group (C group). According to our results, intramuscular application of quercetin had an insignificant effect on cortical bone thickness in male rabbits. In these rabbits, changes in qualitative histological characteristics were present in the middle part of the compacta, where primary vascular longitudinal bone tissue was present and expanded there from the periosteum. Also, a lower number of secondary osteons was found in these animals. From the histomorphometrical point of view, significantly decreased sizes of primary osteons’ vascular canals and secondary osteons (p <0.05) were found in rabbits administered by quercetin. Our findings indicate that subchronic administration of quercetin at the dose used in our study had considerable impact on both qualitative and quantitative histological characteristics of the compact bone in adult male rabbits.