| Summary: | 碩士 === 中原大學 === 生物科技研究所 === 97 === The study was to investigate the effect of caffeine on the differentiation of bone progenitor cells, cell activities and bone mineral density (BMD) in rats by in vitro and in vivo studies. In the in vitro trial, cells were obtained from male ICR mice. At the beginning of the study, it was pre-tested to make sure the doses might be used were not toxic to the cells due to osmotic pressure. Then, the effect of caffeine on bone formation, osteoclastogenesis and adipogenesis were investigated. In animal study, fifty male Wister rats were assigned into 5 groups randomly, 10 each, and fed control , 0.1% caffeine, 0.2% caffeine, 0.002% atorvastatin or 0.2% caffeine + 7.0% lard +0.5% cholesterol diet respectively for 20 weeks. The BMD of lumbar vertebra, femur and tibia at 0, 10 and 20 weeks were determined by Dual-energy X-ray absorptiometry (DEXA). The calcium concentration of femur and tibia were also measured after animals were sacrificed.
The results of the in vitro trials showed that 0.005 mM caffeine or 0.01mM caffeine in diet could not affect the mesenchymal stem cells (MSC) to osteoblasts (OB) (p>0.05), but could enhance the differentiation of hematopoietic stem cells (HSC) to osteoclasts (OC) and also their bone resorption (p<0.05). It was observed that 0.01mM caffeine could inhibit the differentiation of MSC to adipocytes (p<0.05). Genistein could increase the differentiation of MSC to OB (p<0.05), and inhibit the differentiation of MSC to adipocytes (p<0.05). The results demonstrated that genistein inhibited the differentiation of HSC to OC and the bone resorption slightly (p<0.10).
Data in the animal trials showed that BMD of lumbar vertebra, femur and tibia were lower in 0.2% caffeine group than in control group (p<0.05). The calcium concentrations of tibia in 0.2% caffeine group was lower than in control group (p<0.05), and in femur was also lower slightly than in control group (p<0.10). It was noticed that BMD of femurs in 0.1% caffeine and 0.2% caffeine + 7.0% lard + 0.5% cholesterol group were lower slightly than in control group respectively (p<0.10). However, 0.002% atorvastatin didn’t affect BMD of lumbar vertebra, femur and tibia comparing with control group (p>0.05).
Conclusion of the study is that caffeine can increase the differentiation of HSC to OC and bone resorption. Therefore, caffeine can decrease BMD of bones in growing rats. Genistein, a phytoestrogen, can increase bone formation and inhibit adipogenesis. It also inhibits osteoclastogenesis and bone resorption. But, atorvastatin which can reduce serum cholesterol doesn’t affect BMD in growing male rats.
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