To investigate the effect of naringenin on ovariectomy-induced postmenopausal osteoporosis comprehensively and systemically, thirty-two virgin Sprague-Dawley rats about 3-month-old were used and randomly divided into 4 groups: sham control group (Sham), OVX control group (OVX), naringenin treatment group and 17β-estradiol (E2) treatment group. After 12 weeks treatment with different drugs, 24 h urine were collected, organs were weighed and the organ indies were computed. Uterine pathological changes were observed by making paraffin section. Biochemical parameters and bone turnover markers: serum osteocalcin (BGP) and urine deoxypyridinoline (DPD) were analyzed with automatic biochemical analyzer or ELISA assay. Bone mineral density (BMD) and bone mineral content (BMC) were analyzed by DEXA, bone biomechanical properties was measured by three point bending test and the trabecular bone microarchitecture was evaluated by Micro CT. From the results, we can see that: the gaining of weight and the increasing of bone turnover markers such as serum BGP and urinary DPD could be inhibited by naringenin. The treatment could also enhance the bone strength and prevent the deterioration of trabecular microarchitecture, increase the bone volume, trabecular number and thickness, and decrease the trabecular space. The effects mentioned above were not accompanied with stimulating effects on uterus. Long-term using of naringenin had no obvious influence on other organs and the liver and kidney functions. The study suggests that naringenin had obvious antiosteoporotic effect on ovariectomized rats and it had the potential value for the treatment of postmenopausal osteoporosis.

The bromodomain and extraterminal domain (Bet) family are the regulators of the epigenome and also the pivotal driving factors for the expression of tumor related genes that tumor cells depend on for survival and proliferation. Bromodomain-containing protein 4 (Brd4) is a member of the Bet protein family. Generally, Brd4 identifies acetylated histones and binds to the promoter or enhancer region of target genes to initiate and maintain expression of tumor related genes. Brd4 is closely related to the regulation of multiple transcription factors and chromatin modification and is involved in DNA damage repair and maintenance of telomere function, thus maintaining the survival of tumor cells. This review summarizes the structure and function of Brd4 protein and the application of its inhibitors in tumor research.
Humans ; Transcription Factors/metabolism* ; Nuclear Proteins/metabolism* ; Histones ; Cell Cycle Proteins/metabolism* ; Neoplasms/metabolism* ; Protein Domains