Characterization of Stimulatory Effect of Wasabi Leafstalk (Wasabia japonica MATSUM.) Extract on Bone Calcification in Mouse Calvaria Tissue Culture

Abstract

The stimulatory effect of wasabi leafstalk (Wasabia japonica MATSUM.) extract on bone calcification in mouse calvaria tissue culture in vitro was characterized. The extract had an appreciable effect on increasing bone calcium content; the effect was great at 10 and 50 μg/ml, but at higher concentrations (100-300 μg/ml) the effect was weaker. Sinigrin (5-20 μg/ml) had no an effect. Wasabi leafstalk extract (10 μg/ml) did not inhibit the effect of parathyroid hormone (PTH; 10^-6 M), a bone-resorbing hormone, in decreasing bone calcium content, and the effect of the wasabi extract on bone calcification was stable when heated (100°C) and in acid or alkaline. It was subjected to gel filtration chromatography with a superose 12 column connected with a high pressure liquid chromatography system. The presence of fraction IV (retention time of 160-200 min) in the tissue culture caused a remarkable elevation of the bone calcium content; the effect was great at a concentration of 100 μl/ml of medium. The present study suggests that the small molecular components in wasabi leafstalk extract have a stimulatory effect on bone calcification in vitro.