Prevention of bone loss by phloridzin, an apple polyphenol, in ovariectomized rats under inflammation conditions

• Published in: Calcified tissue international 2005-11, Vol.77 (5), p.311-318
• Main Authors: Puel, C, Quintin, A, Mathey, J, Obled, C, Davicco, M J, Lebecque, P, Kati-Coulibaly, S, Horcajada, M N, Coxam, V
• Format: Article
• Language: English
• Subjects: Animals; Body Weight - drug effects; Bone Density - drug effects; Bone Density - physiology; Bone Diseases, Metabolic - complications; Bone Diseases, Metabolic - physiopathology; Bone Diseases, Metabolic - prevention & control; Bone Resorption - drug therapy; Bone Resorption - physiopathology; Bone Resorption - prevention & control; Disease Models, Animal; Female; Femur - drug effects; Femur - metabolism; Femur - physiopathology; Inflammation - complications; Inflammation - drug therapy; Inflammation - physiopathology; Life Sciences; Malus; Malus - chemistry; Organ Size - drug effects; Osteocalcin - blood; Ovariectomy; Phlorhizin - therapeutic use; Plant Extracts - therapeutic use; Rats; Rats, Wistar; Stress, Mechanical; Weight-Bearing
• ISSN: 0171-967X; 1432-0827
• DOI: 10.1007/s00223-005-0060-5

Aging and sex hormones related changes lead to inflammatory and oxidant conditions, which are involved in the pathogenesis of osteoporosis. Recent studies have suggested that polyphenols may exert a protective effect in such conditions. We assessed the effect of phloridzin (Phlo), a flavonoid exclusively found in apple, on bone metabolism in ovariectomized (OVX) or sham-operated (SH) rats with and without inflammation. Six-month-old Wistar rats were allocated to two equal groups that received either a control diet or a diet supplemented with 0.25% Phlo for 80 days. Three weeks before necropsy, inflammation was induced by subcutaneous injection of talc in 10 animals of each group. At necropsy, ovariectomy decreased both total (T-BMD) and metaphyseal (M-BMD) femoral bone mineral density (P < 0.01). Inflammation conditions, checked by an increase in the spleen weight and alpha1-acid glycoprotein concentration in OVX rats, exacerbated the decrease in T-BMD (g/cm2) (as well as M-BMD) observed in castrated animals (P < 0.05). Daily Phlo intake prevented ovariectomy-induced bone loss in conditions of inflammation as shown by T-BMD and M-BMD (P < 0.05). At the diaphyseal site, BMD was improved by Phlo in OVX rats with or without inflammation (P < 0.05). These results could be explained by changes in bone remodeling as the increased urinary deoxypyridinoline excretion in OVX and OVXinf animals was prevented by the polyphenol-rich diet (P < 0.001), while plasma osteocalcin concentration was similar in all experimental groups. In conclusion, Phlo consumption may provide protection against ovariectomy-induced osteopenia under inflammation conditions by improving inflammation markers and bone resorption.