Amomum villosum induces longitudinal bone growth in adolescent female rats

This study was conducted to evaluate the effect of Amomum villosum on longitudinal bone growth.

Adolescent female Sprague-Dawley rats were divided into 3 groups and treated for 4 days: control (distilled water, p.o.), recombinant human growth hormone (rhGH; 100 microg/kg, s.c.), and A. villosum (500 mg/kg, p.o.) groups. On day 3, tetracycline (20 g/kg, i.p.) was injected for growth plate identification. On days 2, and 4, 5-bromo-2'-deoxyuridine (BrdU) (50 mg/kg, i.p.) was injected to label proliferating cells. On day 5, tibias were dissected and fixed in 4% paraformaldehyde, dehydrated, and sectionedfor immunohistochemistry and histomorphometry.

The rate of bone growth in the A. villosum and rhGH groups increased to (410 +/- 44) and (389 +/- 46) microm/day (P<0.01), respectively, as compared with the control (330.7 +/- 34.7) microm/day. The thickness of the growth plates also increased to (591 +/- 37) and (598 +/- 32) microm, respectively, as compared with the control (524 +/- 89) microm (P<0.001). The number of BrdU-positive cells in the chondrocytes of the A. villosum and rhGH groups was also significantly higher (126 +/- 24) and (143 +/- 18) cells/mm2, respectively) than in the control (109 +/- 25) mm2 (P<0.05). Insulin-like growth factor-1 and bone morphogenetic protein-2 in the A. villosum and rhGH groups were highly expressed in the growth plate as compared with the control samples, indicating increased bone formation.

A. villosum could be used to treat growth retardation during adolescence.