Silymarin Ameliorates Diabetes-Induced Proangiogenic Response in Brain Endothelial Cells through a GSK-3β Inhibition-Induced Reduction of VEGF Release

Abstract EN

Diabetes mellitus (DM) is a major risk factor for cardiovascular disease.

Additionally, it was found to induce a dysfunctional angiogenic response in the brain that was attributed to oxidative stress.

Milk thistle seed extract (silymarin) has potent antioxidant properties, though its potential use in ameliorating diabetes-induced aberrant brain angiogenesis is unknown.

Glycogen synthase kinase-3β is a regulator of angiogenesis that is upregulated by diabetes.

Its involvement in diabetes-induced angiogenesis is unknown.

To evaluate the potential of silymarin to ameliorate diabetes-induced aberrant angiogenesis, human brain endothelial cells (HBEC-5i) were treated with 50 μg/mL advanced glycation end (AGE) products in the presence or absence of silymarin (50, 100 μM).

The angiogenic potential of HBEC-5i was evaluated in terms of migration and in vitro tube formation capacities.

The involvement of GSK-3β was also evaluated.

AGE significantly increased the migration and tube formation rates of HBEC-5i by about onefold (p=0.0001).

Silymarin reduced AGE-induced migration in a dose-dependent manner where 50 μM reduced migration by about 50%, whereas the 100 μM completely inhibited AGE-induced migration.

Similarly, silymarin 50 μg/mL blunted AGE-induced tube formation (p=0.001).

This effect was mediated through a GSK-3β-dependent inhibition of VEGF release.

In conclusion, silymarin inhibits AGE-induced aberrant angiogenesis in a GSK-3β-mediated inhibition of VEGF release.