Astragalus membranaceus (Huangqi) and Rhizoma curcumae (Ezhu) decoction suppresses colorectal cancer via downregulation of Wnt5/β-Catenin signal

Background

The decoction of Astragalus membranaceus (Huangqi) and Rhizoma curcumae (Ezhu) has been reported as a potential antitumor agent for colorectal cancer (CRC) in experimental and clinical studies, but its underlying mechanism is still unclear.

Methods

The current research aims to explore the potential of Astragalus membranaceus (Huangqi) and Rhizoma curcumae (Ezhu) decoction (AR decoction) in the treatment of CRC and explore the underlying mechanism. SW620 cells were transient transfection to overexpress or knock down wnt 5 or β-Catenin. Astragalus membranaceus (Huangqi) and Rhizoma curcumae (Ezhu) -containing serum (AR-CS) was used to interfere with SW620 cells. Additional AR-CS, Wnt5 inhibitor (IWP-4), and β-Catenin inhibitor (JW55) were used to intervene in SW620 cells. Furthermore, subcutaneously injection of SW620 cells into the right flank of nude mice replicated xenograft mice, which were treated with AR decoction for 21 days.

Results

AR-CS significantly reduced the mRNA and protein expression levels of Wnt5, β-Catenin, ARF6, and N-Cadherin in SW620 cells, while inhibiting the proliferation and migration of SW620 cells. In cells overexpressing Wnt5 or β-Catenin, these effects of AR-CS were significantly suppressed. On the contrary, the inhibitory effect of AR-CS on the mRNA and protein levels of ARF6 and N-Cadherin and cell proliferation and migration of SW620 was enhanced, when Wnt5 or β-Catenin were knocked down or suppressed by the inhibitors. Moreover, in the mouse model of xenograft tumors, AR decoction not only reduced the tumor volume and inhibited the mRNA levels and protein levels of Wnt5, β-Catenin, ARF6, and N-Cadherin in the tumor, but also inhibit the protein levels of LRP5, LRP6, TCF-4, and LEF1.The histopathology of mice also showed increased apoptosis in tumor tissues, and AR decoction treatment did not cause pathological damage to the kidney and liver.

Conclusions

Our results provide evidence that AR decoction inhibits Wnt5/β-catenin signaling and inhibits the development of CRC, which is a promising traditional medicine in the clinical treatment of CRC.

Regulatory effect of compatibility of Astragalus membranaceus and Rhizoma curcumae on COX-2 expression in gastric cancer MKN-45 cells

AIM: To investigate the effect of Astragalus membranaceus and Rhizoma curcumae′s compatibility on MKN-45 cells and the regulatory action of the compatibility on expression of cyclooxygenase 2 (COX-2), peroxisome proliferators activated receptorγ (PPARγ) and nuclear factor κB (NF-κB).

METHODS: The compatibility of Astragalus membranaceus and Rhizoma curcumae was used on MKN-45 cells and there were five groups including Celecoxib group, Rosiglitazone group, Astragalus membranaceus group, Rhizoma curcumae group and control group. The inhibition ratio in each group was determined using MTT method, and the expressions of COX-2 mRNA, PPARγ mRNA, NF-κB mRNA and COX-2 protein were measured using RT-PCR and Western blot methods.

RESULTS: Both the Chinese drugs and Western medicines had suppression on NF-κB mRNA and COX-2 mRNA. All medicines except Rhizoma curcumae promoted the expression of PPARγ mRNA. The most obvious suppressive effect on COX-2 mRNA expression was detected in celecoxib group and compatibility group. And suppressive effect was significantly stronger in compatibility group than either in Astragalus membranaceus group or Rhizoma curcumae group. Both Rosiglitazone group and compatibility group had the best suppressive effect on NF-κB mRNA and the best promoting effect on PPARγ mRNA.

CONCLUSION: Astragalus membranaceus and Rhizoma curcumae′s compatibility has better effect with marked suppressive effect. The compatibility group showed stronger suppressive effect on COX-2 expression than Astragalus membranaceus and Rhizoma curcumae used alone, closing to Celecoxib. Its suppressive effect on COX-2 may be produced through the signal pathway of PPARγ/NF-κB.