Efficacy of glucosamine alendronate alone & in combination with dihydroquercetin for treatment of osteoporosis in animal model.
ABSTRACT Considerable efforts are being made to develop new, more effective drugs for osteoporosis, including novel forms of bisphosphonates. The present study was carried out to compare the effect of a novel agent glucosamine alendronate (GA) alone and is combination with dihydroquercetin (DHQ) against the effect of a known drug alendronate (ALN) in the senescence-accelerated OXYS rats as model of osteoporosis.
Male OXYS and Wistar (control) rats were randomized across four experimental groups (n=15), which received 1.26 mg GA, 0.84 mg ALN, or 1.26 mg GA + 5.06 mg DHQ per kg of body weight. Untreated rats were used as control groups. At the end of treatment, the bone mineral density (BMD), bone biomechanical properties, and the levels of serum osteocalcin, αC-terminal crosslinked telopeptides of type I collagen (α-CTx) and calcium were measured.
All treatments increased BMD in rats of both strains, but the improvement was more pronounced in OXYS rats: GA+DHQ increased both the strength of the femur by 20 per cent (P<0.01) and BMD by 7.6 per cent (P<0.023). GA+DHQ and ALN reduced serum α-CTx in OXYS rats. Only GA increased the level of osteocalcin in OXYS rats (P<0.05). ALN increased the cross-sectional area of the femur by 9 per cent (P<0.04) in OXYS and by 12 per cent (P<0.05) in Wistar rats.
The combined treatment with GA+DHQ appears to be more effective at maintaining strength of the femur and BMD in OXYS rats, when compared to the individual drugs GA and ALN.
- Medizinische Monatsschrift für Pharmazeuten 05/2009; 32(4):137-40.
- [show abstract] [hide abstract]
ABSTRACT: We studied the effect of flavonoid taxifolin (dihydriquercetin) on the structure and thermal stability of collagen I fibrils. Taxifolin accelerated fibril formation with reconstruction of periodical cross-striation characteristic of these fibrils. Differential scanning calorimetry showed elevation of melting temperature of collagen fibrils formed in neutral or weakly alkaline media, but not of individual tropocollagen molecules in acid medium. Taxifolin capacity to stimulate fibril formation and promote stabilization of fibrillar forms of collagen can be used in medicine.Bulletin of Experimental Biology and Medicine 01/2008; 144(6):791-4. · 0.34 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: We investigated the effects of two flavonoids quercetin and dihydroquercetin (DHQ), which have different solubilities and antioxidant capacities, on hemolysis and platelet aggregation in human blood. Exposure of human red blood cells (RBCs) to free radicals generated by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) for 2h resulted in 63.5+/-3.9% hemolysis (vehicle: 0.3+/-0.4%). Pre-incubation of RBCs with lipid-soluble quercetin and water-soluble DHQ for 30min significantly reduced the AAPH-induced hemolysis to 3.6+/-1.5% and 32.5+/-5.6% respectively. In contrast, quercetin and DHQ were similarly effective in reducing phospholipase C-induced hemolysis (37.2+/-9.1% and 45.4+/-10.0% versus vehicle 75.7+/-5.2%, P<0.001). Pre-incubation with quercetin, but not DHQ, inhibited the aggregation of platelets by adenosine diphosphate. DHQ was more potent than quercetin in inhibiting superoxide produced by xanthine oxidase. These results suggest that the antihemolytic effects of flavonoids may not be directly mediated by removal of free radicals and may likely be due to their interaction with cell membrane.Chemico-biological interactions 06/2009; 182(1):7-12. · 2.46 Impact Factor