[Astragalus polysaccharides combined with cisplatin decreases the serum levels of CD44 and collagen type IV and hyaluronic acid in mice bearing Lewis lung cancer].

Objective: To observe the effects of Astragalus polysaccharides (APS) combined with cisplatin on growth of Lewis lung cancer (LLC), serum content of collagen type IV (Col4) and hyaluronic acid (HA), and CD44 protein level in LLC-bearing mice.

Methods: C57BL/6J mice (n=90) were randomly divided into 2 groups, 10 mice for blank control group, and 80 mice for tumor-bearing group. The tumor-bearing group was then randomized into 8 subgroups, 10 mice for each subgroup. The tumor-bearing mice were treated by peritoneal injection of normal saline, 6 mg/kg cisplatin, 50, 100, 200 mg/kg APS, and 3 mg/kg cisplatin combined with 50, 100, 200 mg/kg APS, respectively. APS (0.3 mL) was injected once a day from the first to the 20th day after LLC transplantation, and cisplatin of the same volume was injected once a week. On the 21st day, the blood was taken from the eyeballs of all experimental mice. Col4 and HA contents in serum were detected by radioimmunoassay. The expression of CD44 in transplanted tumor cells was determined by immunohistochemistry and image analysis. The inhibition rate of tumor growth was also counted.

Results: The inhibition rates of 6 mg/kg cisplatin, 50, 100, 200 mg/kg APS, and 3 mg/kg cisplatin combined with 50, 100, 200 mg/kg APS on LLC growth in the mice were 49.30%, 17.21%, 39.68%, 42.98%, 51.02%, 57.21% and 65.11%, respectively. Compared with the control subgroup of the tumor-bearing group, cisplatin, APS and cisplatin combined with APS reduced significantly the Col4 and HA content in serum, and down-regulated the expression of CD44.

Conclusion: APS can inhibit the growth of LLC cells, reduce the Col4 and HA content in serum, down-regulate the expression of CD44 protein in LLC-bearing mice, and enhance the therapeutic effect when combined with cisplatin, indicating that it can decrease the toxicity of cisplatin against tumor.