Bone Abstracts

Bone damage is one of the main unfavourable health effects of chronic exposure to cadmium (Cd). This heavy metal stimulates osteoclastic bone resorption and inhibits osteoblastic bone formation resulting in decreased bone mineralization and as a result weakening of the bone biomechanical properties. Recently, using a rat model of chronic human exposure to cadmium, we have revealed that even low exposure to this metal may increase bone vulnerability to fracture. Taking into account that polyphenol compounds have been known to have beneficial impact on bone metabolism and strength we have undertaken the study aimed to investigate whether these compounds are capable of improving the bone strength properties under chronic exposure to cadmium corresponding to low and moderate human exposure. For this purpose, biomechanical properties (yield strength, fracture strength, tension, stiffness, and young modulus) of the femur of the female Wistar rats administered as the only drinking fluid 0.1% water extract of polyphenols from the berries of Aronia melanocarpa or/and cadmium in diet (1 and 5 mg/kg) for 17 months were determined. The bone was subjected to a three-point bending test performed with the use of universal testing machine (Zwick Z2.5TS, Germany). The low (1 mg Cd/kg) and moderate (5 mg Cd/kg) chronic exposure to cadmium to a similar extent weakened the femur biomechanical properties making them more vulnerable to fracture. The administration of polyphenolic compounds under the exposure to 1 and 5 mg Cd/kg importantly improved the bone biomechanical properties. The results of the present study allow for the conclusion that consumption of polyphenolic compounds from the berries of Aronia melanocarpa may decrease the risk of bone fractures under chronic exposure to cadmium.

This study was financially supported by the grant (no. N N405 051140) from the National Science Centre (Poland).