Effects of Amomum villosum on longitudinal bone growth in adolescent rats

The fruit of Amomum villosum has been used for an improvement of gastrointestinal motility in traditional Korean medicine. In Dongeuibogam, the traditional book of Korean medicine, there was mentioned that an herbal mixture containing A. villosum used as medicine for malnutrition associated with growth retardation. Many functional studies of A. villosum have been performed, but its effect on the bone growth has not yet reported. This study was aimed to investigate the effect of A. villosum on longitudinal bone growth in adolescent rats. A. villosum was extracted with water for 3h at 100°C in a reflux apparatus. The A. villosum treated group (500mg/kg) and the control group (vehicle) were administered orally twice daily for 4 days. On day 3, tetracycline (20mg/kg) was injected intraperitoneally to form a fluorescent band on the growth plates. On days 2–4, bromodeoxyuridine (BrdU) (50mg/kg) was injected intraperitoneally for labeling proliferating cells. A. villosum caused a significant acceleration of longitudinal bone growth, compared to control group. BrdU-positive cells were increased in the chondrocytes of the A. villosum group. The growth plate width was significantly increased, compared to control group. BMP-2 and IGF-1 were highly expressed in the hypertrophic and proliferative zone, respectively. These results suggest that A. villosum increase the longitudinal bone growth by stimulation of the chondrocyte hypertrophy and chondrogenesis, through regulation of IGF-1 and BMP signaling in the growth plate.