RESUMO
BACKGROUND:Cuscuta chinensis is a mature seed of Cuscutachinensis Lam., can warm kidney. Previous studies demonstrated that kidney compound composed of Cuscuta chinensis could apparently inhibit bone loss and improve bone density. OBJECTIVE:To explore the influence of flavonoids from Cuscuta chinensis on bone mineral density of femur, 1,25(OH)2D3 levels of serum and kidney, the expression of smal intestine CaBp-D9K mRNA in model rats with ovariectomized osteoporosis. METHODS:A total of 72 Sprague-Dawley female rats were equal y and randomly divided into six groups (n=12):sham surgery group, model group, vitamin D3 group and low-, moderate-and high-dose flavonoids groups. The sham surgery group only received sham operation and the other five groups were ovariectomized respectively. One week after ovariectomy, the rats were given flavonoids from low-, moderate-and high-dose Cuscuta chinensis and vitamin D3 (2 mg/kg) by intragastric administration for 3 consecutive months. Blood was obtained from the abdominal aorta. Serum was isolated. The kidney was obtained. Enzyme linked immunosorbent assay was used to determine 1,25(OH)2D3 contents of renal and serum. Rats were sacrificed at the end of experiment. The thighbone was taken out to determine bone mineral density. The second lumbar vertebra was taken out to measure the expression of lumbar vertebra and renal vitamin D receptor mRNA using real-time fluorescent reverse transcription-polymerase chain reaction. The smal intestine was taken out to measure the expression of smal intestine CaBp-D9K mRNA using real-time fluorescent reverse transcription-polymerase chain reaction. RESULTS AND CONCLUSION:Compared with the sham operation group, bone mineral density of femur, and 1,25(OH)2D3 levels of serum and kidney and the expression of lumbar vertebra vitamin D receptor mRNA significantly decreased in model group, and the expression of smal intestine CaBp-D9K mRNA significantly decreased in model group. Compared with the model group, bone mineral density of femur, and 1,25(OH)2D3 levels of serum and kidney, and the expression of the second lumbar vertebra vitamin D receptor mRNA, and the expression of smal intestine CaBp-D9K mRNA were increased in moderate-and high-dose flavonoids groups and vitamin D3 group. Results indicated that flavonoids from Cuscuta chinensis could significantly raise bone mineral density of femur, and 1,25(OH)2D3 levels of serum and kidney and the expression of lumbar vertebra vitamin D receptor mRNA and the expression of smal intestine CaBp-D9K mRNA, accelerate intestinal calcium absorption and osteoblast activity, and reinforce quality of the bone.