cryptoxanthins and menaquinone-7

Aging induces a decrease in bone mass, and osteoporosis with its accompanying decrease in bone mass is widely recognized as a major public health problem. Bone loss with increasing age may be due to decreased bone formation and increased bone resorption. Pharmacologic and nutritional factors may prevent bone loss with aging, although chemical compounds in food and plants which act on bone metabolism are poorly understood. We have found that isoflavones (including genistein and daidzein), which are contained in soybeans, have a stimulatory effect on osteoblastic bone formation and an inhibitory effect on osteoclastic bone resorption, thereby increasing bone mass. Menaquinone-7, an analogue of vitamin K(2) which is abundant in fermented soybeans, has been demonstrated to stimulate osteoblastic bone formation and to inhibit osteoclastic bone resorption. Of various carotenoids, beta-cryptoxanthin, which is abundant in Satsuma mandarin (Citrus unchiu MARC), has a stimulatory effect on osteoblastic bone formation and an inhibitory effect on osteoclastic bone resorption. The supplementation of these factors has a preventive effect on bone loss induced by ovariectomy in rats, which are an animal model of osteoporosis, and their intake has been shown to have a stimulatory effect on bone mass in humans. Factors with an anabolic effect on bone metabolism were found in extracts obtained from wasabi leafstalk (Wasabi japonica MATSUM), the marine alga Sargassum horneri, and bee pollen Cistus ladaniferus. Phytocomponent p-hydroxycinnamic acid was also found to have an anabolic effect on bone metabolism. Food chemical factors thus play a role in bone health and may be important in the prevention of bone loss with increasing age.

Topics: Animals; Bone and Bones; Bone Density; Bone Resorption; Citrus sinensis; Coumaric Acids; Cryptoxanthins; Food; Food Analysis; Glycine max; Humans; Isoflavones; Metabolism; Osteogenesis; Osteoporosis; Rats; Stimulation, Chemical; Vitamin K 2; Xanthophylls

Whether the anabolic effect of beta-cryptoxanthin (CRP), a kind of carotenoid, on osteoblastic MC3T3-E1 cells are modulated in the presence of various hormones or nutrient factors were investigated. Cells were cultured for 72 h in a minimum essential medium containing 10% fetal bovine serum (FBS), and the cells with subconfluency were changed to a medium containing either vehicle or CRP (10(-8)-10(-6) M) in the presence or absence of various factors without FBS. Cells were cultured for 72 h. Protein content or alkaline phosphatase activity in osteoblastic cells were significantly increased after culture with CRP (10(-7) or 10(-6) M), 1,25-dihydroxyvitamin D(3) (VD(3); 10(-9) or 10(-8) M), 17beta-estradiol (E(2); 10(-9) M), genistein (10(-7) or 10(-6) M), or menaquinone-7 (MK-7; 10(-7) or 10(-6) M). The effect of CRP (10(-6) M) in increasing protein content in the cells was significantly enhanced in the presence of E(2) (10(-9) M) or genistein (10(-6) M). Gene expression in osteoblastic cells was determined using reverse transcription-polymerase chain reaction (RT-PCR). Culture with CRP (10(-7) or 10(-6) M) caused a significant increase in the expression of Runx2 and alkaline phosphatase mRNAs in the cells. Runx2 mRNA expression was significantly increased after culture with E(2) (10(-9) M) or MK-7 (10(-7) or 10(-6) M), but not VD(3) (10(-9) or 10(-8) M) or genistein (10(-7) or 10(-6) M). Alkaline phosphatase mRNA expression was significantly increased after culture with VD(3) (10(-9) or 10(-8) M), genistein (10(-7) or 10(-6) M), or MK-7 (10(-7) or 10(-6) M), but not E(2) (10(-10) or 10(-9) M). The effect of CRP (10(-7) or 10(-6) M) in increasing Runx2 or alkaline phosphatase mRNA expressions in the cells was not enhanced in the presence of VD(3), E(2), genistein, or MK-7. Culture with zinc sulfate (zinc; 10(-5) M) caused a significant increase in protein content or alkaline phosphatase activity in osteoblastic cells. The effect of CRP (10(-7) M) in increasing protein content or alkaline phosphatase activity in the cells was not significantly enhanced in the presence of zinc (10(-5) M). Culture with zinc (10(-5) M) caused a significant increase in alpha1(I) collagen mRNA expression, while it did not have a significant effect on Runx2 or osteocalcin mRNA expressions in the cells. The effect of CRP (10(-7) M) in increasing Runx2 or alpha1(I) collagen mRNA expressions was significantly enhanced in the presence of zinc (10(-6 )or 10(-5) M). Such an effect was

Topics: Anabolic Agents; Animals; Calcitriol; Cells, Cultured; Collagen Type I; Core Binding Factor Alpha 1 Subunit; Cryptoxanthins; Drug Synergism; Estradiol; Gene Expression Regulation; Genistein; Mice; Osteoblasts; RNA, Messenger; Vitamin K 2; Xanthophylls; Zinc Sulfate