Endothelial dysfunction is one of the main age‐related arterial phenotypes responsible for cardiovascular disease (CVD) in older adults. This endothelial dysfunction results from decreased bioavailability of nitric oxide (NO) arising downstream of endothelial oxidative stress. In this study, we investigated the protective effect of anthocyanins and the underlying mechanism in rat thoracic aorta and human vascular endothelial cells in aging models. In vitro, cyanidin‐3‐rutinoside (C‐3‐R) and cyanidin‐3‐glucoside (C‐3‐G) inhibited the d‐galactose (d‐gal)‐induced senescence in human endothelial cells, as indicated by reduced senescence‐associated‐β‐galactosidase activity, p21, and p16INK4a. Anthocyanins blocked d‐gal‐induced reactive oxygen species (ROS) formation and NADPH oxidase activity. Anthocyanins reversed d‐gal‐mediated inhibition of endothelial nitric oxide synthase (eNOS) serine phosphorylation and SIRT1 expression, recovering NO level in endothelial cells. Also, SIRT1‐mediated eNOS deacetylation was shown to be involved in anthocyanin‐enhanced eNOS activity. In vivo, anthocyanin‐rich mulberry extract was administered to aging rats for 8 weeks. In vivo, mulberry extract alleviated endothelial senescence and oxidative stress in the aorta of aging rats. Consistently, mulberry extract also raised serum NO levels, increased phosphorylation of eNOS, increased SIRT1 expression, and reduced nitrotyrosine in aortas. The eNOS acetylation was higher in the aging group and was restored by mulberry extract treatment. Similarly, SIRT1 level associated with eNOS decreased in the aging group and was restored in aging plus mulberry group. These findings indicate that anthocyanins protect against endothelial senescence through enhanced NO bioavailability by regulating ROS formation and reducing eNOS uncoupling.
Non-alcoholic fatty liver disease (NAFLD) is prevalent in the elderly population, and has symptoms ranging from liver steatosis to advanced fibrosis. Citrus peel extracts (CPEs) contain compounds that potentially improve dyslipidemia; however, the mechanism of action and effects on hepatic steatosis regulation remains unclear. Current study was aimed to investigate the protective effect of CPEs extracted through hot-air drying (CPEW) and freeze-drying (CPEF) and the underlying mechanism in a rat model of high-fat diet-induced NAFLD. The high-fat diet (HFD)-fed rats showed significant increase in total cholesterol, alanine aminotransferase (ALT), triglycerides, aspartate aminotransferase (AST), and lipid peroxidation compared to the normal chow-diet (NCD) group rats; but CPEW and CPEF limited this effect. CPEW and CPEF supplementation reduced both hepatocyte steatosis and fat accumulation involving the regulatory effect of mTORC1. Collectively, CPEW and CPEF protected deterioration of liver steatosis with AMPK activation and regulating ROS accumulation associated with interstitial disorders, which are also associated with endoplasmic reticulum (ER) redox. Thus, the application of CPEW and CPEF may lead to the development of novel therapeutic or preventive agents against NAFLD.
Oxidative stress attributable to the activation of a Nox4-containing NADPH oxidase is involved in aging-associated vascular dysfunction. However, the Nox4-induced signaling mechanism for the vascular alteration in aging remains unclear. In an aged aorta, the expression of Nox4 mRNA and protein by Nox family of genes was markedly increased compared with a young aorta. Nox4 localization mainly to ER was also established. In the aorta of Nox4 WT mice aged 23–24 months (aged), reactive oxygen species (ROS) and endoplasmic reticulum (ER)/oxidative stress were markedly increased compared with the counter KO mice. Furthermore, endothelial functions including eNOS coupling process and acetylcholine-induced vasodilation were significantly disturbed in the aged WT, slightly affected in the counter KO aorta. Consistently, in d-galactose-induced in vitro aging condition, ER-ROS and its associated ER Nox4 expression and activity were highly increased. Also, in chronic d-galactose-treated condition, IRE1α phosphorylation and XBP-1 splicing and were transiently increased, but IRE1α sulfonation was robustly increased in the aging Nox4 WT condition when compared to the counter KO condition. In vitro D-gal-induced aging study, the phenomenon were abrogated with Nox4 knock-down condition and was significantly decreased in GKT, Nox4 inhibitor and 4-PBA, ER chemical chaperone-treated human umbilical vein endothelial cells. The state of Nox4-based ER redox imbalance/ROS accumulation is suggested to determine the pathway “the UPR; IRE1α phosphorylation and XBP-1 splicing and the UPR failure; IRE1α cysteine-based oxidation, especially sulfonation, finally controlling aging-associated vascular dysfunction.
This study was carried out to elucidate the antidiabetic effects of Gryllus bimaculatus powder using a streptozotocin (STZ)‐induced rat model of type I diabetes. Administration of the insect powder significantly rescued representative diabetes markers (i.e., insulin and C‐peptide) in STZ‐treated rats. Improved glucose tolerance test (GTT) and insulin tolerance test (ITT) results were also observed, indicating that Gryllus bimaculatus powder exerts antidiabetic effects. Gryllus bimaculatus powder administration rescued STZ‐induced alterations in both islet morphology and insulin staining patterns. The extract increased antiapoptotic Bcl2 expression and decreased proapoptotic Bax and active caspase 3 expressions. In addition, the Gryllus bimaculatus powder supplementation enhanced AKT/mTOR pathway, a key marker of the state of anabolic metabolism, and its downstream effector, mTOR. Collectively, our results suggest that Gryllus bimaculatus contributes to the maintenance of pancreatic β‐cell function and morphology against a diabetic state through the regulations against apoptosis and anabolic metabolism.
Dyslipidemia is associated with endothelial dysfunction, which is linked to nitric oxide (NO) biology. The coupling of endothelial NO synthase with cofactors is a major step for NO release. This study is aimed to investigate the vascular pharmacology effects of mulberry in rat thoracic aorta and human vascular endothelial cells. In vitro, we investigated the protective effects of the mulberry extract and its main component cyanidin-3-rutinoside (C-3-R), against oxidized low-density lipoprotein (ox-LDL)-induced endothelial nitric oxide synthase (eNOS) uncoupling. Whereas ox-LDL significantly decreased NO levels in endothelial cells, mulberry extract, and C-3-R significantly recovered NO levels and phospho-eNOS Thr495 and Ser1177 expression. In vivo, mulberry was administered to 60% of high-fat diet (w/w)-fed Sprague Dawley (SD) rats for six weeks, in which endothelium-dependent relaxations were significantly improved in organ bath studies and isometric tension recordings. Consistently, aortic expressions of phospho-eNOS and nitrotyrosine were increased. Mulberry also raised serum NO levels, increased phosphorylation of eNOS, and reduced nitrotyrosine and intracellular reactive oxygen species (ROS) in aortas, showing that mulberry preserves endothelium-dependent relaxation in aortas from high-fat diet rats. We suggest that this effect is mediated through enhanced NO bioavailability, in which the regulation of ROS and its reduced eNOS uncoupling are involved.
Constipation is a common condition that affects individuals of all ages, and prolonged constipation needs to be prevented to avoid potential complications and reduce the additional stress on individuals with pre-medical conditions. This study aimed to evaluate the effects of heat-inactivated Lactobacillus plantarum (HLp-nF1) on loperamide-induced constipation in rats. Constipation-induced male rats were treated orally with low to high doses of HLp-nF1 and an anti-constipation medication Dulcolax for five weeks. Study has 8 groups, control group; loperamide-treated group; Dulcolax-treated group; treatment with 3.2 × 1010, 8 × 1010 and 1.6 × 1011, cells/mL HLp-nF1; Loperamide + Dulcolax treated group. HLp-nF1 treated rats showed improvements in fecal pellet number, weight, water content, intestinal transit length, and contractility compared to the constipation-induced rats. Also, an increase in the intestine mucosal layer thickness and the number of mucin-producing crypt epithelial cells were observed in HLp-nF1-treated groups. Further, the levels of inflammatory cytokines levels were significantly downregulated by treatment with HLp-nF1 and Dulcolax. Notably, the metagenomics sequencing analysis demonstrated a similar genus pattern to the pre-preparation group and control with HLp-nF1 treatment. In conclusion, the administration of >3.2 × 1010 cells/mL HLp-nF1 has a positive impact on the constipated rats overall health.