Effects of Chinese medicine Gukang on the expression of insulin-like growth factor 1 in osteoblasts

Zhao Ke-wei1, Pan Kun-ru2, Yin Ling-fan3, Zhuang Hong1

1Affiliated Orthopedic Hospital of Guangzhou Chinese Traditional Medicine University, Guangzhou   510240, Guangdong Province, China; 2Second Affiliated Hospital of Sun Yat-sen University, Guangzhou   510120, Guangdong Province, China; 3Nan’ao People’s Hospital of Shenzhen, Shenzhen   518121, Guangdong Province, China

Zhao Ke-wei★, Master, Attending physician, Affiliated Orthopedic Hospital of Guangzhou Chinese Traditional Medicine University, Guangzhou   510240, Guangdong Province, China
zkw2004003@ 126.com

Abstract
BACKGROUND: Chinese medicine Gukang has a clear effect of clinical treatment of osteoporosis.
OBJECTIVE: To investigate the effects of Chinese medicine Gukang on the expression of insulin-like growth factor 1 (IGF-1) in osteoblasts at the hypothesis of Chinese medicine Gukang possesses the regulating effect on osteoblasts identical with the estrogen.
DESIGN, TIME AND SETTING: A randomized control experiment of cytokine detection in vitro was performed at Cellular Culture Laboratory, Affiliated Orthopedic Hospital of Guangzhou Chinese Traditional Medicine University between September 2005 and April 2007. 　
MATERIALS: Ten SD neonatal rats were used for the separation and culture of osteoblasts, and ten New Zealand rabbits were used to prepare the drug serum and then were divided into 5 groups randomly: normal control group, high-, middle-, low-concentration groups and estradiol group. Each group contained two rabbits of either gender.
METHODS: Based on the surface area, the rabbits in the high-, middle-, and low-concentration groups were intragastrically administrated with 9.6, 4.8 and 2.4 g/kg serum containing Gukang. Estradiol group was intragastrically administrated with 15% estradiol solution, while the normal control group was given normal saline for 1 week. Two hours after the last administration, blood samples were taken from the heart of each rabbit. Then serum was collected. Osteoblasts at passage 3 were digested with 0.25% pancreatin, and the suspension at the final concentration of 1×107 L-1 was inoculated into 24-well culture plates. Cellular attachment was observed 24 hours later, and meanwhile 10% serum containing corresponding drugs were added to the medium. The supernatant collection was performed 4 days later.
MAIN OUTCOME MEASURES: Enzyme-linked immunosorbent assay techniques were used to detect the expression of IGF-1 in supernatant.
RESULTS: Expression of IGF-1 in osteoblasts in the serum containing the high and middle concentrations of Gukang and estradiol was increased compared with that in the normal control group (P < 0.05). The serum containing low concentration of Gukang was inferior to the high concentration of Gukang and the estradiol (P < 0.05). IGF-1 expression was of insignificant differences between the high concentration group and the estradiol group, and between the low concentration group and the normal control group (P > 0.05).
CONCLUSION: The serum containing certain concentration of Chinese medicine Gukang can increase the secretion of IGF-1 in osteoblasts, and the effect is the same as that of estradiol.

Zhao KW, Pan KR, Yin LF, Zhuang H. Effects of Chinese medicine Gukang on the expression of insulin-like growth factor 1 in osteoblasts.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(28):5414-5417(China)
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