ETHNOPHARMACOLOGICAL RELEVANCE: The medicinal mushroom Antrodia cinnamomea has been used to treat cancer but its anti-angiogenic effects have not been studied in detail.

AIM OF THE STUDY: The main objective of this study was to determine the molecular mechanism of activity underlying the anti-angiogenic effects of A. cinnamomea.

MATERIALS AND METHODS: The effects of an A. cinnamomea ethanol extract (ACEE) on cell migration and microvessel formation were investigated in endothelial cells in vitro and Matrigel plugs implanted into mice in vivo. Activation of intracellular signaling pathways was examined using Western blotting. Protein expression was assessed using immunohistochemistry in a mouse model of lung metastasis.

RESULTS: We show that treatment with ACEE inhibits cell migration and tube formation in human umbilical vein endothelial cells (HUVECs). ACEE suppresses phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) and expression of pro-angiogenic kinases in vascular endothelial growth factor (VEGF)-treated HUVECs, in addition to reducing expression of Janus kinase 2 (JAK2) and phosphorylation of signal transducer and activator of transcription 3 (STAT3). ACEE treatment inhibits VEGF-induced microvessel formation in Matrigel plugs in vivo. In addition, ACEE significantly reduces VEGFR2 expression in Lewis lung carcinoma cells and downregulates the expression of cluster of differentiation 31 (CD31) and VEGFR2 in murine lung metastases.

CONCLUSION: These results indicate that A. cinnamomea produces anti-angiogenic effects by inhibiting the VEGFR2 signaling pathway.