Arch Hellen Med, 34(5), September-October 2017, 690-699
Dose-dependent effect of Amphimas pterocarpoides plant extract
A. Patsaki,1 J. Tchoumchoua,2,3 C. Passali,1 P. Lelovas,1 S. Mitakou,2 N. Papaioannou,1
ΟBJECTIVE To assess the phytoestrogenic potential of Amphimas pterocarpoides plant extract on ovariectomy induced bone loss in rats at two different dosages.
METHOD The study used 55 female, 10 month-old Wistar rats. Ovariectomy was performed on 44 rats, while sham operation was performed on the remaining 11 rats (control group). The ovariectomized animals were separated into an untreated group (OVX, n=13) which received drinking water ad libitum right after the surgery and until the end of the experiment, and two treated groups, one of which received Amphimas pterocarpoides extract at 50 mg/kg (ALow group, n=15) and the other at 150 mg/kg (AHigh group, n=16). Measurements of bone mineral density (BMD) were made using dual-energy X-ray absorptiometry (DEXA) at baseline, and 3 and 6 months after ovariectomy. After 6 months treatment, the rats were euthanized, and their femurs were extracted. The femoral biomechanical properties were evaluated using the 3-point bending test (3PB).
RESULTS The percentage changes of the mean values of the proximal tibia BMD from baseline to 3 months for the control, OVX, ALow and AHigh groups were 6.254%, -21.822%, -14.512% and -4.421% whereas, the percentage changes from baseline to 6 months were 8.108%, -32.134%, -23.985% and -8.144, respectively. The 3PB test revealed that the maximal load before fracture (Fmax) demonstrated a significantly higher value in the ALow group compared to the OVX group (112.69 N vs 96.9 N, p<0.001). In addition, the mean value for Stress in the OVX group was significantly lower than in the ALow group (158.48 MPa vs 180.5 MPa, p=0.011). The AHigh group presented higher values in Fmax and Stress than the OVX group, but there was no statistically significant difference between groups.
CONCLUSIONS This study suggests that Amphimas pterocarpoides administered orally for 6 months can prevent the rapid degradation of bone after ovariectomy, and is effective in terms of improving both bone quantity (bone density) and bone quality (biomechanical parameters), which are surrogate markers of fracture risk.
Key words: Biomechanical properties, Bone mineral density, Osteoporosis, Ovariectomy, Phytoestrogens.