γ-Oryzanol ameliorates fine dust-induced premature endothelial senescence and dysfunction via attenuating oxidative stress

Various cardiovascular diseases are associated with endothelial senescence, and a recent study showed that fine dust (FD)-induced premature endothelial senescence and dysfunction is associated with increased oxidative stress. The aim of the present study was to investigate protective effect of rice bran extract (RBE) and its major component of γ-Oryzanol (γ-Ory) against FD-induced premature endothelial senescence. Porcine coronary artery endothelial cells (PCAECs) were treated with FD alone or with RBE or γ-Ory. Senescence-associated β-galactosidase (SA-β-gal) activity, expression of cell cycle regulatory proteins, and oxidative stress levels were evaluated. The results indicated that SA-β-gal activity in the FD-treated PCAECs was attenuated by RBE and γ-Ory. Additionally, γ-Ory inhibited FD-induced cell cycle arrest, restored cell proliferation, and reduced the expression of cell cycle regulatory proteins. γ-Ory also inhibited oxidative stress and prevented senescence-associated NADPH oxidase and LAS activity in FD-exposed ECs suggesting that γ-Ory could protect against FD-induced ECs senescence and dysfunction.

Niclosamide Inhibits Aortic Valve Interstitial Cell Calcification by Interfering with the GSK-3β/β-Catenin Signaling Pathway

The most common heart valve disorder is calcific aortic valve stenosis (CAVS), which is characterized by a narrowing of the aortic valve. Treatment with the drug molecule, in addition to surgical and transcatheter valve replacement, is the primary focus of researchers in this field. The purpose of this study is to determine whether niclosamide can reduce calcification in aortic valve interstitial cells (VICs). To induce calcification, cells were treated with a pro-calcifying medium (PCM). Different concentrations of niclosamide were added to the PCM-treated cells, and the level of calcification, mRNA, and protein expression of calcification markers was measured. Niclosamide inhibited aortic valve calcification as observed from reduced alizarin red s staining in niclosamide treated VICs and also decreased the mRNA and protein expressions of calcification-specific markers: runt-related transcription factor 2 and osteopontin. Niclosamide also reduced the formation of reactive oxygen species, NADPH oxidase activity and the expression of Nox2 and p22phox. Furthermore, in calcified VICs, niclosamide inhibited the expression of β-catenin and phosphorylated glycogen synthase kinase (GSK-3β), as well as the phosphorylation of AKT and ERK. Taken together, our findings suggest that niclosamide may alleviate PCM-induced calcification, at least in part, by targeting oxidative stress mediated GSK-3β/β-catenin signaling pathway via inhibiting activation of AKT and ERK, and may be a potential treatment for CAVS.

SGLT2 inhibition ameliorates nano plastics-induced premature endothelial senescence and dysfunction

Nano plastics (NPs) have been a significant threat to human health and are known to cause premature endothelial senescence. Endothelial senescence is considered one of the primary risk factors contributing to numerous cardiovascular disorders. Recent studies have suggested that inhibition of sodium glucose co-transporter (SGLT2) ameliorates endothelial senescence and dysfunction. Therefore, our study intends to explore the role of SGLT2 in NPs-induced endothelial senescence and dysfunction. Porcine coronary artery and its endothelial cells were treated with NPs in the presence or absence of Enavogliflozin (ENA), a SGLT2 inhibitor and then SGLTs expression, senescence markers and vascular function were evaluated. NPs significantly up-regulated SGLT2 and ENA significantly decreased NPs-induced senescence-associated-β-gal activity, cell-cycle arrest, and senescence markers p53 and p21 suggesting that inhibition of SGLT2 prevents NPs-induced endothelial senescence. In addition, ENA decreased the formation of reactive oxygen species with the downregulation of Nox2, and p22^phox. Furthermore, SGLT2 inhibition also up regulated the endothelial nitric oxide synthase expression along with improving vascular function. In conclusion, premature endothelial senescence by NPs is, at least in part, associated with SGLT2 and it could be a potential therapeutic target for preventing and/or treating environmental pollutants-induced cardiovascular disorders mediated by endothelial senescence and dysfunction.

Capsaicin inhibits aortic valvular interstitial cell calcification via the redox-sensitive NFκB/AKT/ERK1/2 pathway

Calcific aortic valve stenosis (CAVS), the third most prevalent cardiovascular disorder is known to impose a huge social and economic burden on patients. However, no pharmacotherapy has yet been established. Aortic valve replacement is the only treatment option, although its lifelong efficacy is not guaranteed and involves inevitable complications. So, there is a crucial need to find novel pharmacological targets to delay or prevent CAVS progression. Capsaicin is well known for its anti-inflammatory and antioxidant properties and has recently been revealed to inhibit arterial calcification. We thus investigated the effect of capsaicin in attenuating aortic valve interstitial cells (VICs) calcification induced by pro-calcifying medium (PCM). Capsaicin reduced the level of calcium deposition in calcified VICs, along with reductions in gene and protein expression of the calcification markers Runx2, osteopontin, and BMP2. Based on Gene Ontology biological process and Kyoto Encyclopedia of Genes and Genomes pathway analysis oxidative stress, AKT and AGE-RAGE signaling pathways were selected. The AGE-RAGE signaling pathway activates oxidative stress and inflammation-mediated pathways including ERK and NFκB signaling pathways. Capsaicin successfully inhibited oxidative stress- and reactive oxygen species-related markers NOX2 and p22^phox. The markers of the AKT, ERK1/2, and NFκB signaling pathways, namely, phosphorylated AKT, ERK1/2, NFκB, and IκBα were upregulated in calcified cells, while being significantly downregulated upon capsaicin treatment. Capsaicin attenuates VICs calcification in vitro by inhibition of redox-sensitive NFκB/AKT/ERK1/2 signaling pathway, indicating its potential as a candidate to alleviate CAVS.

Effects of polystyrene nanoplastics on endothelium senescence and its underlying mechanism

Global plastic use has increased rapidly, and environmental pollution associated with nanoplastics (NPs) has been a growing concern recently. However, the impact and biological mechanism of NPs on the cardiovascular system are not well characterized. This study aimed to assess the possibility that NPs exposure promotes premature endothelial cell (EC) senescence in porcine coronary artery ECs and, if so, to elucidate the underlying mechanism. Treatment of ECs with NPs promoted the acquisition of senescence markers, senescence-associated β-galactosidase activity, and p53, p21, and p16 protein expression, resulting in the inhibition of proliferation. In addition, NPs impaired endothelium-dependent vasorelaxation associated with decreased endothelial nitric oxide synthase (eNOS) expression. NPs enhanced reactive oxygen species formation in ECs, and increased oxidative stress levels were associated with the induction of NADPH oxidases expression, followed by the subsequent downregulation of Sirt1 expression. The characteristics of EC senescence and dysfunction caused by NPs are prevented by an antioxidant (N-acetylcysteine), an NADPH oxidase inhibitor (apocynin), and a Sirt1 activator (resveratrol). These findings indicate that NPs induced premature EC senescence, at least in part, through the redox-sensitive eNOS/Sirt1 signaling pathway. This study suggested the effects and underlying mechanism of NPs on the cardiovascular system, which may provide pharmacological targets to prevent NPs-associated cardiovascular diseases.

Taxifolin as a Major Bioactive Compound in the Vasorelaxant Effect of Different Pigmented Rice Bran Extracts

Cardiovascular disease is one of the leading causes of morbidity and mortality in recent years. The intake of polyphenol rich diets has been associated with improved cardiovascular function and reduced cardiovascular risks. Oryza sativa L. is one of the most common cereals worldwide. Rice bran, a byproduct of the rice milling process, contains many bioactive ingredients, including polyphenols, polysaccharides, proteins, and micronutrients. It is also consumed as a healthy diet in the form of rice bran oil and powder in many Asian countries like Japan, South Korea, and India for its several health benefits as a natural antioxidant. Thus, this study evaluated the vasorelaxant effect of ethanolic extracts of brown, green, red, and black rice bran and investigated its underlying vasorelaxant mechanism. Among the four rice bran extracts (RBEs) examined, the red rice bran extract (RRBE) had a strong endothelium-dependent vasorelaxant effect, which was markedly prevented by N-ω-nitro-L-arginine [endothelial nitric oxide synthase (eNOS) inhibitor], wortmannin [phosphoinositide-3 kinase (PI3K) inhibitor], and 1H-[1,2,4]oxadiazole[4,3-alpha]quinoxalin-1-one (inhibitor of guanylate cyclase). Likewise, RRBE induced the phosphorylation of eNOS and Src in cultured endothelial cells, thereby stimulating NO formation. Altogether, these findings propose that RRBE induces endothelium-dependent relaxation, involving at least in part, NO-mediated signaling through the PI3K/eNOS pathway. Further, LC-PDA analysis conducted on the four RBEs also revealed that RRBE highly contained taxifolin, which is an active flavanonol that induces endothelium-dependent vasorelaxation, compared to other RBEs. Subsequently, the underlying mechanism of taxifolin was assessed through vascular reactivity studies with pharmacological inhibitors similar to that of RRBE. These findings deciphered a distinct difference in vasorelaxant effects between RRBE and the other RBEs. We also observed that RRBE induced a potent endothelium-dependent NO-mediated relaxation in coronary artery rings, which involved the Src/PI3K pathway that activates eNOS. Additionally, taxifolin exhibited, at least in part, similar vasoprotective effects of RRBE. Therefore, we propose that RRBE may serve as natural sources of functional phytochemicals that improve cardiovascular diseases associated with disturbed NO production and endothelial dysfunction.

Prevention of Fine Dust-Induced Vascular Senescence by Humulus lupulus Extract and Its Major Bioactive Compounds

Both short- and long-term exposure to fine dust (FD) from air pollution has been linked to various cardiovascular diseases (CVDs). Endothelial cell (EC) senescence is an important risk factor for CVDs, and recent evidence suggests that FD-induced premature EC senescence increases oxidative stress levels. Hop plant (Humulus lupulus) is a very rich source of polyphenols known to have nutritional and therapeutic properties, including antioxidant behavior. The aims of this study were to evaluate whether Humulus lupulus extract prevents FD-induced vascular senescence and dysfunction and, if so, to characterize the underlying mechanisms and active components. Porcine coronary arteries and endothelial cells were treated with FD in the presence or absence of hop extract (HOP), and the senescence-associated-beta galactosidase (SA-β-gal) activity, cell-cycle progression, expression of senescence markers, oxidative stress level, and vascular function were evaluated. Results indicated that HOP inhibited FD-induced SA-β-gal activity, cell-cycle arrest, and oxidative stress, suggesting that HOP prevents premature induction of senescence by FD. HOP also ameliorated FD-induced vascular dysfunction. Additionally, xanthohumol (XN) and isoxanthohumol (IX) were found to produce the protective effects of HOP. Treatment with HOP and its primary active components XN and IX downregulated the expression of p22phox, p53, and angiotensin type 1 receptor, which all are known FD-induced redox-sensitive EC senescence inducers. Taken together, HOP and its active components protect against FD-induced endothelial senescence most likely via antioxidant activity and may be a potential therapeutic agent for preventing and/or treating air-pollution-associated CVDs.