Anti-angiogenic activity of water extract from Euphorbia pekinensis Rupr

Ethnopharmacological relevance: Euphorbia pekinensis Rupr. (EP) is a Euphorbia species of Euphorbiaceae, which is widely used in traditional Chinese medicine. It has been reported to exhibit therapeutic effects on solid tumors, leukemias, and malignant ascites although underlying molecular mechanisms are poorly delineated. Anti-angiogenic therapy is a recognized strategy for treating cancer-based solid tumors, and is also associated with malignant ascites treatment.

Study aim: To study the anti-angiogenic properties of the water extract of EP vinegar preparation (WEVEP).

Materials and methods: Following WEVEP treatment, intersegmental blood vessels were assessed during the development of transgenic Tg (flk: mCherry) zebrafish as was the proliferation, migration and network formation of HUVECs in vitro. mRNA expression of specific angiogenic-related genes including VEGF family members, Met, and NRP2 was also measured using quantitative real-time PCR (Q-PCR).

Results: Data demonstrated that angiogenesis was inhibited by the WEVEP in zebrafish (from 100µg/mL to 250µg/mL, p < 0.0001) and in the HUVEC model (from 100µg/mL to 400µg/mL, p < 0.0001). In the zebrafish model, the mean vessel numbers of administered groups were 26.00 ± 1.29 (100µg/mL), 24.54 ± 2.20 (150µg/mL), 22.66 ± 2.68 (200µg/mL), 20.80 ± 1.75 (250µg/mL), compared to 27.67 ± 0.96 of control group. Relative quantitative gene expression in zebrafish treated with WEVEP demonstrated that only VEGFR3 was significantly increased and other 23 genes including Met, VEGFA, Flt-1 were significantly decreased.

Conclusion: WEVEP can positively modulate angiogenesis via multiple targeting mechanisms. Our novel results contribute towards the discovery of a possible mechanism(s) of the traditional use of EP in the treatment of cancer and malignant ascites.