Search Results (29)

The existence of repeat breeder cows (RBCs) causes low reproductive performance. The causes of RBCs include low-quality oocytes and embryos, hormonal dysregulation, and unsuitable uterine environments. To improve unsuitable uterine conditions for RBCs, we focused on nobiletin (NOB), a natural citrus flavone with various beneficial roles. The role of NOB in bovine endometrial epithelial cells (BEECs) was examined. An analysis of BEECs showed that gene expression and altered pathways differed between the control and NOB treatment, with NOB regulating the pathways of steroid biosynthesis, lysosomal function, and inflammatory responses. NOB treatment significantly increased the number and activation of endosomes and lysosomes in BEECs. Moreover, we performed phagocytosis assays using fluorescence-conjugated lipopolysaccharide (LPS) with lysosomes in NOB-treated BEECs, which resulted in an increase in the co-localization of phagocytosed LPS with lysosomes. NOB treatment stimulated the mRNA expression of various lysosomal hydrolases, including cathepsin B and cathepsin K, and suppressed the gene expression of cytokines in inflammation-associated pathways (rheumatoid arthritis, the IL-17 signaling pathway, etc.). NOB significantly suppressed the LPS-induced mRNA expression of the inflammatory cytokine IL-8 and its secretion in BEECs. In conclusion, NOB activates the endosome–lysosomal system via phagocytosis to eliminate the bacterial component LPS and suppress inflammatory responses to defense mechanisms in BEECs. Full article

With the increase in the age of laying chickens, the aging of follicles is accelerated, and the reproductive ability is decreased. Increased oxidative stress and mitochondrial malfunction are indispensable causes of ovarian aging. In this study, the physiological condition of prehierarchical small white follicles (SWFs) was compared between D280 high-producing chickens and D580 aging chickens, and the effect of a plant-derived flavonoid nobiletin (Nob), a natural antioxidant, on senescence of SWFs granulosa cells (SWF-GCs) was investigated. The results showed that Nob treatment activated cell autophagy by activating the AMP-activated protein kinase (AMPK) and Sirtuin-1 (SIRT1) pathways in D-galactose (D-gal)-generated senescent SWF-GCs, restoring the expression of proliferation-related mRNAs and proteins. In addition, the expression of inflammation-related protein NF-κB was significantly enhanced in aging GCs that were induced by D-gal. Nob supplementation significantly increased the antioxidant capacity and decreased the expression of several genes associated with cell apoptosis. Furthermore, Nob promoted activation of PINK1 and Parkin pathways for mitophagy and alleviated mitochondrial edema. Either the AMPK inhibitor dorsomorphin (Compound C) or SIRT1 inhibitor selisistat (EX-527) attenuated the effect of Nob on mitophagy. The protective effect of Nob on natural aging, GC proliferation, and elimination of the beneficial impact on energy regulation of naturally aging ovaries was diminished by inhibition of Nob-mediated autophagy. These data suggest that Nob treatment increases the expression of mitophagy-related proteins (PINK1 and Parkin) via the AMPK/SIRT1 pathways to prevent ovarian aging in the laying chickens. Full article

Metabolism-associated fatty liver disease (MAFLD), a growing health problem worldwide, is one of the major risks for the development of cirrhosis and liver cancer. Oral administration of nobiletin (NOB), a natural citrus flavonoid, modulates the gut microbes and their metabolites in mice. In the present study, we established a mouse model of MAFLD by subjecting mice to a high-fat diet (HFD) for 12 weeks. Throughout this timeframe, NOB was administered to investigate its potential benefits on gut microbial balance and bile acid (BA) metabolism using various techniques, including 16S rRNA sequencing, targeted metabolomics of BA, and biological assays. NOB effectively slowed the progression of MAFLD by reducing serum lipid levels, blood glucose levels, LPS levels, and hepatic IL-1β and TNF-α levels. Furthermore, NOB reinstated diversity within the gut microbial community, increasing the population of bacteria that produce bile salt hydrolase (BSH) to enhance BA excretion. By exploring further, we found NOB downregulated hepatic expression of the farnesoid X receptor (FXR) and its associated small heterodimer partner (SHP), and it increased the expression of downstream enzymes, including cholesterol 7α-hydroxylase (CYP7A1) and cytochrome P450 27A1 (CYP27A1). This acceleration in cholesterol conversion within the liver contributes to mitigating MAFLD. The present findings underscore the significant role of NOB in regulating gut microbial balance and BA metabolism, revealing that long-term intake of NOB plays beneficial roles in the prevention or intervention of MAFLD. Full article

Obesity is a known risk factor for metabolic diseases and is often associated with chronic inflammation in adipose tissue. We previously identified the polyethoxylated flavonoid Nobiletin (NOB) as a circadian clock modulator that directly binds to and activates the ROR receptors in the core oscillator, markedly improving metabolic fitness in obese mice. Here, we show that NOB enhanced the oscillation of core clock genes in differentiated 3T3-L1 adipocytes, including ROR target genes such as Bmal1, Cry1, Dec1, and Dec2. NOB inhibited lipid accumulation in 3T3-L1 and SVF cells, concomitant with the dysregulated circadian expression of adipogenic differentiation-related genes including Cebpb, Pparg, Lpl, Scd1, and Fas. Importantly, RORα/RORγ double knockdown in 3T3-L1 cells (Ror DKD) significantly attenuated the effects of NOB on circadian gene expression and lipid accumulation. Furthermore, whereas NOB upregulated the expression of IκBα, a target of RORs, to inhibit NF-κB activation and proinflammatory cytokine expression, Ror DKD cells exhibited a heightened activation of the NF-κB pathway, further indicating a requisite role of RORs for NOB efficacy in adipocytes. Together, these results highlight a significant regulatory function of the NOB–ROR axis in the circadian expression of clock and clock-controlled genes in adipocytes, thereby governing adipogenic differentiation, lipogenesis, and inflammation. Full article

We here investigated the anti-inflammatory activity of a polymethoxylated flavone-containing fraction (PMFF) from Citrus sinensis and of a prenylflavonoid-containing one (PFF) from Humulus lupulus, either alone or in combination (MIX). To this end, an in vitro model of inflammatory bowel disease (IBD), consisting of differentiated, interleukin (IL)-1β-stimulated Caco-2 cells, was employed. We demonstrated that non-cytotoxic concentrations of either PMFF or PFF or MIX reduced nitric oxide (NO) production while PFF and MIX, but not PMFF, also inhibited prostaglandin E₂ release. Coherently, MIX suppressed both inducible NO synthase and cyclooxygenase-2 over-expression besides NF-κB activation. Moreover, MIX increased nuclear factor erythroid 2–related factor 2 (Nrf2) activation, heme oxygenase-1 expression, restoring GSH and reactive oxygen and nitrogen species (RONs) levels. Remarkably, these effects with MIX were stronger than those produced by PMFF or PFF alone. Noteworthy, nobiletin (NOB) and xanthohumol (XTM), two of the most represented phytochemicals in PMFF and PFF, respectively, synergistically inhibited RONs production. Overall, our results demonstrate that MIX enhances the anti-inflammatory and anti-oxidative effects of the individual fractions in a model of IBD, via a mechanism involving modulation of NF-κB and Nrf2 signalling. Synergistic interactions between NOB and XTM emerge as a relevant aspect underlying this evidence. Full article

Nobiletin (NOB), a naturally occurring small-molecule compound abundant in citrus peels, has displayed potential lipid-lowering and circadian-enhancing properties in preclinical studies. However, the requirement of specific clock genes for the beneficial effects of NOB is not well understood. In the current study, mice with a liver-specific deletion of the core clock component, Bmal1—Bmal1LKO—were fed a high-fat diet (HFD) ad libitum for eight weeks, while NOB (200 mg/kg) was administered by daily oral gavage from the fifth week and throughout the last four weeks. NOB decreased liver triglyceride (TG) alongside the decreasing mRNA levels of de novo lipogenesis (DNL) genes in both Bmal1^flox/flox and Bmal1LKO mice. NOB increased serum very low-density lipoprotein (VLDL) levels in Bmal1LKO mice, which was consistent with higher liver Shp and lower Mttp mRNA expression levels, the key genes that facilitate VLDL assembly and secretion. NOB decreased liver and serum cholesterol levels in the Bmal1^flox/flox mice, consistent with lower Hmgcr and higher Cyp7a1, Cyp8b1, Gata4 and Abcg5 mRNA levels in the liver. In contrast, in the Bmal1LKO mice, NOB increased Hmgcr mRNA levels and had no effect on the above-mentioned genes related to bile acid synthesis and cholesterol excretion, which might contribute to the elevation of liver and serum cholesterol levels in NOB-treated Bmal1LKO mice. NOB inhibited hepatic DNL and decreased liver TG levels in HFD-fed mice independently of liver Bmal1, whereas liver-specific Bmal1 depletion reversed the beneficial effects of NOB on liver cholesterol homeostasis. The complex interactions between NOB, the circadian clock and lipid metabolism in the liver warrant further research. Full article

Intestinal microflora is correlated with obesity, metabolic diseases and digestive tract dysfunctions that are closely related to human health. Nobiletin (NOB) is a dietary polymethoxylated flavonoid with protective effects and activities against oxidative stress, inflammation and cardiovascular disorders. However, the effect and molecular mechanism of NOB in regulating white fat deposition have not been explored. In this study, we reported that NOB administration attenuates weight gain and glucose tolerance in mice fed a high−fat diet (HFD). Additionally, NOB administration substantially restored lipid metabolic disorder and repressed the level of genes related to lipid metabolism in HFD−induced obese mice. The sequencing of 16S rRNA genes in fecal samples unveiled that NOB administration reversed HFD−induced intestinal microbiota composition, particularly in the relative abundances of Bacteroidetes and Firmicutes at the phylum and genus level. Furthermore, NOB supplementation significantly improved the indexes of Chao1 and Simpson and implied NOB can improve intestinal flora diversity in HFD−fed mice. Next, we used LEfSe analysis to explore biomarkers presented as a taxon in different groups. Compared to the HFD group, NOB treatment significantly diminished the proportion of Ruminococcaceae, Ruminiclostridium, Intesinimonas, Oscillibacter and Desulfovibrio. Enriched metabolic pathways were predicted by Tax4Fun analysis and demonstrated that the lipid metabolic pathway is higher in the HFD + NOB group. More importantly, the correlation analysis demonstrated that Parabacteroides was significantly positive and Lactobacillus was negatively related to both body weight and inguinal adipose tissue weight. Collectively, our data emphasized that NOB has the potential to attenuate obesity and confirmed a mechanism for gut microbiota that mediated the beneficial effect of NOB. Full article

Memory impairment is a characteristic of brain aging, and it is associated with a decrease in neurogenesis. Therefore, enhancing neurogenesis is a potential method for mitigating brain aging. Nobiletin (NOB) is a natural polymethoxylated flavonoid derived from citrus peels. It acts as an antioxidant, enhances anti-inflammation, and displays neuroprotective properties. However, the mechanism of NOB on brain aging has not been elucidated. In this study, D-galactose-induced aging mice were treated with NOB (100 mg/kg/day) for 10 weeks. NOB administration attenuated D-galactose-induced memory impairment and restored hippocampal neurogenesis, including the number of newborn neurons and neural stem cells in mice. Furthermore, it downregulated the pro-inflammatory mediators IL-1 β, IL-6, and pP65 (by 42.2%, 22.9%, and 46.4% of those in the D-galactose treated group, respectively) in the hippocampus and blocked microglia and astrocyte activation. In vitro, NOB inhibited D-galactose-induced inflammatory responses in BV2 cells, and the conditioned medium prepared from NOB- and D-galactose-co-treated BV2 cells elevated the viability (90.3% of control) and differential ability (94.9% of control) of C17.2 cells, compared to the D-galactose-treated group alone. It was concluded that NOB could restore memory impairment via the improvement of neurogenesis by ameliorating neuroinflammation in the hippocampus. Overall, NOB is a potential candidate neurogenesis enhancer for improving brain function. Full article

Sarcopenia, a decrease in skeletal muscle mass and function caused by aging, impairs mobility, raises the risk of fractures, diabetes, and other illnesses, and severely affects a senior’s quality of life. Nobiletin (Nob), polymethoxyl flavonoid, has various biological effects, such as anti-diabetic, anti-atherogenic, anti-inflammatory, anti-oxidative, and anti-tumor properties. In this investigation, we hypothesized that Nob potentially regulates protein homeostasis to prevent and treat sarcopenia. To investigate whether Nob could block skeletal muscle atrophy and elucidate its underlying molecular mechanism, we used the D-galactose-induced (D-gal-induced) C57BL/6J mice for 10 weeks to establish a skeletal muscle atrophy model. The findings demonstrated that Nob increased body weight, hindlimb muscle mass, lean mass and improved the function of skeletal muscle in D-gal-induced aging mice. Nob improved myofiber sizes and increased skeletal muscle main proteins composition in D-gal-induced aging mice. Notably, Nob activated mTOR/Akt signaling to increase protein synthesis and inhibited FOXO3a-MAFbx/MuRF1 pathway and inflammatory cytokines, thereby reducing protein degradation in D-gal-induced aging mice. In conclusion, Nob attenuated D-gal-induced skeletal muscle atrophy. It is a promising candidate for preventing and treating age-associated atrophy of skeletal muscles. Full article

Citrus nobiletin (NOB) and tangeretin (TAN) show protective effects against disease-related bone destruction. We achieved demethylation of NOB and TAN into 4′-demethylnobiletin (4′-DN) and 4′-demethyltangeretin (4′-DT) using enzyme-manufacturing methods. In this study, we examined the effects of 4′-DN and 4′-DT on in vitro osteoclast differentiation, and on in vivo osteoporotic bone loss in ovariectomized (OVX) mice. 4′-DN and 4′-DT clearly suppressed the osteoclast differentiation induced by interleukin IL-1 or RANKL treatment. 4′-DN and 4′-DT treatments resulted in higher inhibitory activity in osteoclasts in comparison to NOB or TAN treatments. RANKL induced the increased expression of its marker genes and the degradation of IκBα in osteoclasts, while these were perfectly attenuated by the treatment with 4′-MIX: a mixture of 4′-DN and 4′-DT. In an in silico docking analysis, 4′-DN and 4′-DT directly bound to the ATP-binding pocket of IKKβ for functional inhibition. Finally, the intraperitoneal administration of 4′-MIX significantly protected against bone loss in OVX mice. In conclusion, 4′-DN, 4′-DT and 4′-MIX inhibited the differentiation and function of bone-resorbing osteoclasts via suppression of the NF-κB pathway. Novel 4′-DN, 4′-DT and 4′-MIX are candidates for maintaining bone health, which may be applied in the prevention of metabolic bone diseases, such as osteoporosis. Full article

Nobiletin (NOB) is a naturally occurring compound, commonly found in citrus peel, that shows hepatoprotective and lipid-reducing effects. However, the lipid biomarkers and the potential improvement mechanisms have not been adequately explored. Therefore, we investigated the ameliorative effect and the molecular mechanism of NOB on NAFLD induced by a high-fat diet in mice. The results showed that supplementation with NOB over 12 weeks markedly improved glucose tolerance, serum lipid profiles, inflammatory factors, hepatic steatosis, and oxidative stress. These beneficial effects were mainly related to reduced levels of potential lipid biomarkers including free fatty acids, diacylglycerols, triacylglycerols, and cholesteryl esters according to hepatic lipidomic analysis. Twenty lipids, including DGs and phosphatidylcholines, were identified as potential lipid biomarkers. Furthermore, RT-qPCR and Western blot analysis indicated that NOB inhibited the expression of lipogenesis-related factors such as SREBP-1c, SCD-1, and FAS, and upregulated the expression of lipid oxidation (PPARα) and cholesterol conversion (LXRα, CYP7A1, and CYP27A1) genes as well as antioxidation-related factors (Nucl-Nrf2, NQO1, HO-1, and GCLC), indicating that NOB intake may reduce lipid biosynthesis and increase lipid consumption to improve hepatic steatosis and oxidative stress. This study is beneficial for understanding the ameliorative effects of NOB on NAFLD. Full article

Arsenic (As) is a toxic contaminant present in organic and inorganic forms in the environment. Nobiletin (NOB) is a polymethoxy flavone that has recently gained substantial consideration due to its curative impacts. The present experiment was conducted to assess the hepatoprotective efficiency of NOB on As-generated hepatotoxicity. Twenty-four adult rats were equally distributed into four groups and designated as control, As (50 mg/kg)-treated, As + NOB (50 mg/kg and 25 mg/kg, respectively), and NOB (25 mg/kg)-treated groups. After 30 days, experimental animals were decapitated, then blood and tissue samples were collected for further analysis. The group treated with As showed a significant decrease in the activity of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione (GSH), glutathione reductase (GSR), and total antioxidant status (TAS), and a substantial increase in the accumulation of As in liver tissues, levels of total oxidant status (TOS), hydrogen peroxide (H₂O₂), and lipid peroxidation (TBARS). Significant increases in alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) levels were observed in As-treated rats. Moreover, nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, interleukin (IL)-6, and cyclo-oxygenase (COX)-2 activity, as well as the levels of pro-apoptotic markers (Bax, Caspase-3, and Caspase-9) were increased on exposure to As. In contrast, the anti-apoptotic marker (Bcl-2) level was significantly decreased. As administration showed a significant disturbance in hepatic tissue histology. However, cotreatment of NOB with As considerably increased the antioxidant enzyme activity, with a noteworthy reduction in the deposition of As in hepatic tissues, TBARS, and H₂O₂ levels. NOB-administrated rats showed considerable recovery in terms of inflammation, apoptosis, and histological damage. Hence, NOB can be considered a useful curative compound due to its medicinal properties against As-prompted hepatotoxicity. Full article

Nobiletin (NOB) has attracted much attention owing to its outstanding bioactivities. This study aimed to investigate its anti-arrhythmic effect through electrophysiological and molecular docking studies. We assessed the anti-arrhythmic effects of NOB using aconitine-induced ventricular arrhythmia in a rat model and the electrophysiological effects of NOB on rat cardiomyocytes utilizing whole-cell patch-clamp techniques. Moreover, we investigated the binding characters of NOB with rNav1.5, rNav1.5/QQQ, and hNa_V1.5 via docking analysis, comparing them with amiodarone and aconitine. NOB pretreatment delayed susceptibility to ventricular premature and ventricular tachycardia and decreased the incidence of fatal ventricular fibrillation. Whole-cell patch-clamp assays demonstrated that the peak current density of the voltage-gated Na⁺ channel current was reversibly reduced by NOB in a concentration-dependent manner. The steady-state activation and recovery curves were shifted in the positive direction along the voltage axis, and the steady-state inactivation curve was shifted in the negative direction along the voltage axis, as shown by gating kinetics. The molecular docking study showed NOB formed a π-π stacking interaction with rNav1.5 and rNav1.5/QQQ upon Phe-1762, which is the homolog to Phe-1760 in hNa_V1.5 and plays an important role in antiarrhythmic action This study reveals that NOB may act as a class I sodium channel anti-arrhythmia agent. Full article

Age-associated loss of skeletal muscle mass and function is one of the main causes of the loss of independence and physical incapacitation in the geriatric population. This study used the D-galactose-induced C2C12 myoblast aging model to explore whether nobiletin (Nob) could delay skeletal muscle aging and determine the associated mechanism. The results showed that Nob intervention improved mitochondrial function, increased ATP production, reduced reactive oxygen species (ROS) production, inhibited inflammation, and prevented apoptosis as well as aging. In addition, Nob improved autophagy function, removed misfolded proteins and damaged organelles, cleared ROS, reduced mitochondrial damage, and improved skeletal muscle atrophy. Moreover, our results illustrated that Nob can not only enhance mitochondrial function, but can also enhance autophagy function and the protein synthesis pathway to inhibit skeletal muscle atrophy. Therefore, Nob may be a potential candidate for the prevention and treatment of age-related muscle decline. Full article

In this study, we aimed to evaluate the effect of Nobiletin (NOB) on the placenta of Sprague–Dawley (SD) rats that had undergone reduced uterine perfusion pressure (RUPP) surgery and to evaluate the safety of NOB intervention during pregnancy. The results showed that NOB alleviated placental hypoxia, attenuated placental cell apoptosis, and inhibited placental damage in RUPP rats. No side effect of NOB intervention during pregnancy was observed. BeWo cell lines with P53 knockdown were then constructed using lentiviral transfection, and the P53 signaling pathway was found to be essential for NOB to reduce hypoxia-induced apoptosis of the BeWo cell lines. In summary, NOB attenuated hypoxia-induced placental damage by regulating the P53 signaling pathway, and those findings may contribute some insights into the role of NOB in placental development and the prevention of placental-related diseases. Full article