Effect of Marine Algae Extract on Bone Calcification in the Femoral-metaphyseal Tissues of Rats: Anabolic Effect of Sargassum horneri

Abstract

The effect of various algae on bone calcification in the femoral-metaphyseal tissues of rats was investigated. Undaria pinnatifida, Sargassum horneri, Eisenia bicyclis, Cryptonemia scmiziana, Gelidium amansii, and Ulva pertusa Kjellman, which were gathered seasonally, were used. Water suspensions (5%) of marine algae powder were orally administered once daily for 7 days. Bone calcium content was significantly increased by the administration of U. pinnatifida, S. horneri, E. bicyclis, or C. scmitziana. Bone alkaline phosphatase activity, which is an enzyme for calcification, was significantly enhanced by the administration of S. horneri or G. amansii. Femoral-metaphyseal tissues were cultured for 48 hr in Dulbecco’s modified Eagle’s medium containing either vehicle or water-solubilized extract (25 and 50 μg/ml) obtained from U. pinnatifida, S. horneri, E. bicyclis, and C. scmitziana. The bone calcium content was significantly elevated in the presence of S. horneri extract (25 and 50 μg/ml). No effect was seen with other extracts. The effect of S. horneri extract in increasing bone calcium content was completely inhibited in the presence of cycloheximide (10^-6 M), an inhibitor of protein synthesis. The present study demonstrates that S. horneri extract has an anabolic effect on bone calcification in vivo and in vitro. The anabolic effect of S. horneri extract may be based on a newly synthesized protein component.