Bioassay-guided isolation of proanthocyanidins with antiangiogenic activities
- J Nat Prod. 2013 Jan 25;76(1):29-35. doi: 10.1021/np300614u.
- 1. Dipartimento di Farmacia, Università degli Studi di Salerno, via Ponte Don Melillo, 84084 Fisciano (SA), Italy.
The proangiogenic members of the vascular endothelial growth factor (VEGF) family and related receptors play a central role in the modulation of pathological angiogenesis. In order to identify plant compounds able to interfere in the VEGFs/VEGFR-1 (Flt-1) recognition by VEGF family members, the extracts of the aerial parts of Campsiandra guayanensis and Feretia apodanthera were screened by a competitive ELISA-based assay. By using this bioassay-oriented approach five proanthocyanindins, including the new natural compounds (2S)-4',5,7-trihydroxyflavan-(4β→8)-afzelechin (1) and (2S)-4',5,7-trihydroxyflavan-(4β→8)-epiafzelechin (2) and the known geranin B (3), proanthocyanidin A2 (4), and proanthocyanidin A1 (5), were isolated. The study of the antiangiogenic activities of compounds 1-5 using ELISA and SPR assays showed compound 1 as being the most active. The antiangiogenic activity of 1 was also confirmed in vivo by the chicken chorioallantoic membrane assay. Our results indicated 1 as a new antiangiogenic compound inhibiting the interaction between VEGF-A or PLGF and their receptor VEGRF-1.