Berberine inhibits angiogenesis in glioblastoma xenografts by targeting the VEGFR2/ERK pathway

Context: Berberine is used in traditional Chinese medicine for thousands of years with recent reports of its anticancer activity. Objective: To test antiangiogenic effects of berberine on human glioblastoma and clarify involvement of the VEGFR2/ERK pathway. Materials and methods: Cell viability, proliferation and migration assays were performed to determine in vitro antiangiogenic effects of berberine (6.25–200 μmol/L, 6–48 h). Ectopic and orthotopic xenograft models in BALB/c nude mice were induced to determine antitumour and antiangiogenic effects of berberine (50 mg/kg by oral gavage for 28 days) or vehicle control (carboxymethylcellulose sodium). Results: Berberine inhibited cell viability (IC(50) of 42 and 32 μmol/L, respectively) and proliferation of U87 and U251 human glioblastoma cell lines. Berberine (50 μmol/L) inhibited cell migration of HUVEC by 67.50 ± 8.14% in the Transwell assay and tube formation of HUVEC by 73.00 ± 11.12% in the Matrigel assay. In the ectopic xenograft model, tumour weight was significantly decreased by 50 mg/kg of berberine (401.2 ± 71.5 mg vs. 860.7 ± 117.1 mg in vehicle group, p ˂ 0.001). Berberine significantly decreased haemoglobin content (28.81 ± 3.64 μg/mg vs. 40.84 ± 5.15 μg/mg in vehicle group, p ˂ 0.001) and CD31 mRNA expression in tumour tissue. In the orthotopic xenograft model, berberine (50 mg/kg) significantly improved the survival rate of mice (p = 0.0078). Berberine inhibited (p ˂ 0.001) the phosphorylation of VEGFR2 and ERK. Discussion and conclusions: Berberine inhibited angiogenesis in glioblastoma xenografts by targeting the VEGFR2/ERK pathway. Our work sheds new light on complementary and alternative therapy for glioblastoma.