Extracts from Huangqi (Radix Astragali Mongoliciplus) and Ezhu (Rhizoma Curcumae Phaeocaulis) inhibit Lewis lung carcinoma cell growth in a xenograft mouse model by impairing mitogen-activated protein kinase signaling, vascular endothelial growth factor production, and angiogenesis.

OBJECTIVE

To study the anti-tumor effects of the extracts from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) on the growth of Lewis lung carcinoma (LLC) in a xenograft mouse model and to investigate the possible underlying mechanism.

METHODS

LLC tumor-bearing C57BL/6 mice were treated with normal saline, cisplatin (2 mg/kg intraperitoneally every other day), or Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) (1∶1, 2∶1, or 3∶1 ratio; 5 , 8 , or 11 g/kg crude drug intragastrically every day) for 15 d. Body weights and tumor volumes were measured every other day. Tumors were excised on day 15 and analyzed. Tumor microvessel density (MVD) was assessed by immunohistochemical staining of CD34; and expression of vascular endothelial cell growth factor (VEGF), the mitogen-activated protein kinases p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1 and 2 (ERK1/2), and Jun N-terminal kinase (JNK) and their phosphorylated forms were assessed by Western blotting.

RESULTS

Treatment with cisplatin caused a significant loss of body weight compared with controls, whereas Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) extract combinations had no effect. Extracts from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) significantly decreased tumor weight and tumor MVD compared with controls, and at the 3∶1 treatment group had similar efficacy to cisplatin in reducing MVD. Tumors from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) treatments also showed decreased p38 MAPK, p-p38 MAPK, ERK1/2, p-ERK1/2, JNK, and p-JNK expression compared with the control group (all P < 0.01). VEGF protein expression was significantly reduced in the 2∶1 and 3∶1 treatment groups compared with the control group (P < 0.01).

CONCLUSION

Extracts from Huangqi (Radix Astragali Mongolici) and Ezhu (Rhizoma Curcumae Phaeocaulis) hindered LLC growth in the xenograft mouse model, possibly via inhibition of the MAPK signaling pathway, VEGF production, and tumor angiogenesis.