•Hispidulin down-regulated PKCβII expression in the endothelium.•Hispidulin protected mitochondrial function and the integrity of endothelial cells.•Hispidulin effectively reversed high glucose-impaired vasodilation in rat aorta.•The role of hispidulin action in the amelioration of endothelial dysfunction.Endothelial dysfunction is closely relevant to atherosclerosis complications in diabetic patients. Hispidulin, a flavone derived from the herb Salvia plebeia R. Br., has numerous biological properties including anti-inflammatory and antioxidative effects, but the underlying mechanism of its anti-inflammatory action remains unclear. This study was designed to investigate the effects of hispidulin on endothelial homeostasis and its mechanism. Hispidulin effectively inhibited high glucose-induced oxidative stress by attenuating PKCβII phosphorylation and downstream reactive oxygen species (ROS) production, furthermore reversing the loss of mitochondria membrane potential. Moreover, hispidulin significantly suppressed the expression of NLRP3 inflammasome and IKKβ/NF-κB, and restored high glucose-impaired vasodilation in rat aorta. This study demonstrated that hispidulin ameliorated high glucose-mediated endothelial dysfunction via inhibiting PKCβII-associated NLRP3 inflammasome activation and NF-κB signaling. Besides, these findings indicate the beneficial effects of hispidulin on the improvement of endothelial dysfunction and explain its potential application in the prevention and treatment of diabetic vascular complications.

Seventeen novel ilexgenin A hybrids (IA-aspirin) and (IA-NO), as donor hybrids (IA-NO will release NO in vivo and function as NO donor), were designed and synthesized in order to develop new multi-targeting agents for the treatment of platelet disorders. Their in vitro activities against ADP, AA and thrombin were evaluated. As a result, IA hybrids achieved substantial increases in the three tested pathways compared with IA. Encouragingly, the most potent hybrid compounds 6d and 14d displayed about 8-fold higher potency than aspirin, and 3-fold higher potency than the simultaneous administration of aspirin and IA in inhibiting ADP-induced aggregation with IC50 values of 0.15 mmol/L and 0.14 mmol/L, respectively. The results suggest these IA hybrids are good candidates for multi-target therapies, and especially, may be considered as promising ADP agonists.Ilexgenin A (IA) hybrids achieved substantial increases in three tested pathways compared with IA (1). Encouragingly, the most potent compounds 6d and 14d displayed higher potency than aspirin in inhibiting ADP-induced aggregation with IC50 values of 0.15 mmol/L and 0.14 mmol/L, respectively.

Endothelial dysfunction is a key event in the progression of atherosclerosis with diabetes. Increasing cell apoptosis may lead to endothelial dysfunction. Apigenin and naringenin are two kinds of widely used flavones. In the present study, we investigated whether and how apigenin and naringenin reduced endothelial dysfunction induced by high glucose in endothelial cells. We showed that apigenin and naringenin protected against endothelial dysfunction via inhibiting phosphorylation of protein kinase C βII (PKCβII) expression and downstream reactive oxygen species (ROS) production in endothelial cells exposed to high glucose. Furthermore, we demonstrated that apigenin and naringenin reduced high glucose-increased apoptosis, Bax expression, caspase-3 activity and phosphorylation of NF-κB in endothelial cells. Moreover, apigenin and naringenin effectively restored high glucose-reduced Bcl-2 expression and Akt phosphorylation. Importantly, apigenin and naringenin significantly increased NO production in endothelial cells subjected to high glucose challenge. Consistently, high glucose stimulation impaired acetylcholine (ACh)-mediated vasodilation in the rat aorta, apigenin and naringenin treatment restored the impaired endothelium-dependent vasodilation via dramatically increasing eNOS activity and nitric oxide (NO) level. Taken together, our results manifest that apigenin and naringenin can ameliorate endothelial dysfunction via regulating ROS/caspase-3 and NO pathway.Download high-res image (116KB)Download full-size image