Histomorphometric alteration of knee articular cartilage and serum alkaline phosphatase in young female mice by chronic supplementation with soybean.

The purpose of the present study was to examine the effect of soybean supplementation on cartilage thickness in the knee joint and serum levels of alkaline phosphatase (ALP) in mice. Forty female mice were fed for 6 months on one of four regimens: low protein, complete protein without soybean, and complete protein containing either 20% or 40% soybean. Body weight differences, histological and histomorphometric analysis, and ALP levels were determined and compared after 6 months. The results showed a significant increase in serum ALP activity and cartilage thickness in both groups fed on soybean-containing diets, compared with the other groups. Additionally, the number of chondrocytes was significantly increased (p < 0.001) in the group taking the 40% soybean regimen, and the proteoglycan content of the intracellular fluid in the tibia was higher in those groups taking soybean. In conclusion, the present study suggests that soybean supplementation is capable of stimulating ALP production and reducing cartilage loss in young female mice. Soybean supplementation during childhood may therefore be potentially useful in protecting joints.