Abstract
A change in circulating biochemical markers of bone metabolism in normal individuals with the intake of juice prepared from Satsuma mandarin (Citrus unshiu MARC.) containing β-crypthoxanthin was investigated. Twenty-one volunteers (ten males and eleven females) were divided into two groups of ten volunteers (five males and five females) and eleven volunteers (five males and six females), and each group was given sequentially juice (192 ml) containing two different contents of β-crypthoxanthin once a day for 28 or 56 days as follows: either regular juice with naturally occurring 802 μg β-cryptoxanthin/100 ml or a reinforced juice containing 1500 μg β-cryptoxanthin/100 ml. As serum bone markers, bone-specific alkaline phosphatase, γ-carboxylated osteocalcin, bone tartrate-resistant acid phosphatase (TRAP), and N-telopeptide of type I collagen were assayed. The intake of regular juice for 28 or 56 days caused a significant increase in γ-carboxylated osteocalcin, a marker of bone formation, and the intake for 56 days produced a significant decrease in serum bone TRAP activity. Moreover, intake of the β-cryptoxanthin reinforced juice for 28 or 56 days caused a significant increase in serum β-carboxylated osteocalcin concentration and a corresponding decrease in serum bone TRAP activity and N-telopeptide of type I collagen, a marker of bone resorption. This study suggests that the intake of β-cryptoxanthin reinforced juice has a stimulatory effect on bone formation and an inhibitory effect on bone resorption in normal individuals.
