Effects of Huang Bai (Phellodendri Cortex) on bone growth and pubertal development in adolescent female rats

Abstract

Background: To evaluate the effects of Huang Bai (Phellodendron amurense) on growth and maturation in adolescent female rats. Methods: Female Sprague-Dawley rats (28â ays old; nâ =â 72) were divided into six daily treatment groups: control (distilled water), Huang Bai (100 and 300â mg/kg), recombinant human GH (rhGH; 20â μg/kg), estradiol (1â μg/kg), and triptorelin (100â μg). Body weight, food intake, and vaginal opening were measured daily from postnatal day (PND) 28 to PND 43. Tetracycline (20â mg/kg) was injected on PND 41. After sacrifice on PND 43, the ovaries and uterus were weighed, and the tibias were fixed in 4% paraformaldehyde. Decalcified and dehydrated tibias were sectioned at a thickness of 40â μm, and sectioned tissues were examined with a fluorescence microscope. Insulin-like growth factor (IGF)-1 and bone morphogenetic protein (BMP)-2 were detected using immunohistochemistry. Results: Relative to controls, body weight was higher in the triptorelin group. Bone growth rate increased in the Huang Bai 100â mg/kg (354.00â ±â 31.1â μm/day), rhGH (367.10â ±â 27.11â μm/day), and triptorelin (374.50â ±â 25.37â μm/day) groups. Expression of IGF-1 and BMP-2 in the hypertrophic zone was higher in all experimental groups. Vaginal opening occurred earlier in the estradiol group (PND 33.58â ±â 1.62) than in controls and later in the triptorelin group (PNDâ >â 43). Ovarian and uterine weights were lower in the oestradiol and triptorelin groups. However, Huang Bai had nonsignificant effects on vaginal opening and the weights of ovaries and the uterus. Conclusions: Huang Bai stimulated bone growth by upregulating IGF-1 and BMP-2 in the growth plate. However, it had no effect on pubertal development.