Hydrangenol suppresses VEGF-stimulated angiogenesis by targeting p27KIP1-dependent G1-cell cycle arrest, VEGFR-2-mediated signaling, and MMP-2 expression

Abstract

We previously reported that hydrangenol has potent antitumor activity against human bladder cancer EJ cells. Here, we investigated the antiangiogenic activity of hydrangenol using in vitro and ex vivo models. Treatment with hydrangenol significantly inhibited the proliferation of vascular endothelial growth factor (VEGF)-induced HUVECs in a concentration-dependent manner (EC 50 = 10 μM). Flow cytometry analysis revealed that hydrangenol suppressed the VEGF-induced inhibition of G1-cell cycle phase and also decreased cyclin D1, cyclin E, CDK2, and CDK4 levels. Hydrangenol-mediated arrest in the G1-cell cycle phase was associated with p27KIP1 level, but not p21WAF1 or p53 level. Hydrangenol also significantly inhibited VEGFR-2-mediated signaling pathways including ERK1/2, AKT, and endothelial nitric oxide synthase. Interestingly, immunoprecipitation assay demonstrated that the inhibition of VEGFR-2 activation was independent of VEGF binding, thereby suggesting an allosteric regulation of hydrangenol against VEGFR-2. Additionally, hydrangenol inhibited migration, invasion, and capillary-like tubular formation in VEGF-stimulated HUVECs. Zymography and immunoblot analyses revealed that these inhibitory activities were partially owing to the VEGF-induced inhibition of matrix metalloproteinase-2 activity. Finally, VEGF-mediated microvessel sprouting was inhibited in the presence of hydrangenol in ex vivo aortic ring assay. Taken together, hydrangenol possesses a potent antiangiogenesis potential; thus we believe that hydrangenol may be developed as a therapeutic reagent to treat angiogenesis-mediated diseases.

Coumarins as Modulators of the Keap1/Nrf2/ARE Signaling Pathway

“…Hydrangenol (8-hydroxy-3-(4-hydroxyphenyl)-3,4-dihydroisochromen-1-one) is a natural dihydroisocoumarin mostly obtained from the Hydrangea species (Hydrangeaceae) leaves. Hydrangenol possesses antiinflammatory [250], antidiabetic [251], antioxidant [250,252], anticancer [253], and antiangiogenic activities [254]. It inhibited LPS-induced NO release and iNOS expression via suppression of NF-κB and consequently inhibiting NF-κB-DNA.…”

Hydrangenol Isolated from the Leaves of Hydrangea serrata Attenuates Wrinkle Formation and Repairs Skin Moisture in UVB-Irradiated Hairless Mice

“…Hydrangenol (Figure 1), a natural dihydroisocoumarin, is mostly obtained from the leaves of hydrangea (Hydrangeaceae). Some researchers have reported that hydrangenol possesses antifungal [22], anti-allergic [23], antidiabetic [24], anti-inflammatory, [25] and anti-angiogenic activities [26]. In our previous study, hydrangenol isolated from the leaves of Hydrangea serrata (Thunb.)…”

Hydrangenol, an active constituent of Hydrangea serrata (Thunb.) Ser., ameliorates colitis through suppression of macrophage-mediated inflammation in dextran sulfate sodium-treated mice

“…14 Several studies have reported that both H. serrata extract and hydrangenol show anti-fungal, 17 anti-allergic, 18 anti-diabetic, 19 anti-inflammatory, 20 and anti-angiogenic activities. 21 We also previously reported the potent anti-aging activities of hyrangenol in UVB-induced Hs68 human fibroblasts and HR-1 hairless mice. 21,22 However, little is known about their potential anti-colitic effects.…”