ABSTRACT
BACKGROUND: Repeated exposure to ultraviolet A (UVA) irradiation, which can penetrate the epidermis and reach the dermis, is one of the major causes of skin photoaging. Photoaged skin is characterized clinically by generalized wrinkling, a dry and loose appearance, and seborrheic keratoses, along with skin barrier dysfunction. Fucoxanthin, a xanthophyll carotenoid with a specific allenic bond and 5,6-monoepoxide in its structure, has been found to serve various functions as a food supplement. In the present study, the protective effects of orally administered fucoxanthin at relatively low concentrations (0.001% and 0.01%) against UVA induced photoaging were evaluated in vivo using hairless mice. RESULTS: Oral supplementation of 0.001% fucoxanthin was sufficient for its metabolites to accumulate in the skin, thereby inhibiting pathological changes induced by UVA irradiation, including impaired skin barrier function and accelerated wrinkle formation. Analysis of gene expression revealed that dietary fucoxanthin exerted antiphotoaging effects, possibly by modulating natural moisturizing factor (NMF) synthesis, desquamation, and ceramide composition in the epidermis, and by inhibiting the UVA induced degradation of collagen fibers and inflammation in the dermis. CONCLUSION: Taken together, our data indicate the potential application of dietary fucoxanthin as a novel ingredient in nutricosmetics for skin care against photoaging. © 2024 Society of Chemical Industry.
ABSTRACT
Introduction: Renal collecting duct carcinoma is often found in advanced cancers and has a poor prognosis. Here, we present the case of symptomatic metastatic collecting duct carcinoma in which we observed an initial therapeutic effect of immune checkpoint inhibitors plus tyrosine kinase inhibitors. Case presentation: The patient was a 69-year-old male who was referred to our hospital for examination of a right chest tumor and related pain. Contrast-enhanced computed tomography and tumor biopsy were performed, leading to a diagnosis of collecting duct carcinoma. A combination of pembrolizumab plus axitinib was initiated as first-line therapy; right chest pain decreased, and tumor shrinkage was observed. Seven months after treatment initiation, tumor progression was noted. Cabozantinib was initiated as second-line therapy; however, was discontinued due to patient fatigue. The patient died 15 months after the initiation of treatment. Conclusion: For symptomatic metastatic collecting duct carcinoma, pembrolizumab plus axitinib may have initial therapeutic effects.
ABSTRACT
Adipocytes play a key role in energy storage and homeostasis. Although the role of transcription factors in adipocyte differentiation is known, the effect of endogenous metabolites of low molecular weight remains unclear. Here, we analyzed time-dependent changes in the levels of these metabolites throughout adipocyte differentiation, using metabolome analysis, and demonstrated that there is a positive correlation between cyclic adenosine diphosphate ribose (cADPR) and Pparγ mRNA expression used as a marker of differentiation. We also found that the treatment of C3H10T1/2 adipocytes with cADPR increased the mRNA expression of those marker genes and the accumulation of triglycerides. Furthermore, inhibition of ryanodine receptors (RyR), which are activated by cADPR, caused a significant reduction in mRNA expression levels of the marker genes and triglyceride accumulation in adipocytes. Our findings show that cADPR accelerates adipocytic differentiation via RyR pathway.
Subject(s)
Adipocytes , Cyclic ADP-Ribose , Mice , Animals , Cyclic ADP-Ribose/metabolism , Adipocytes/metabolism , Transcription Factors/metabolism , PPAR gamma/metabolism , Metabolome , RNA, Messenger/genetics , Cell Differentiation , Adenosine Diphosphate Ribose/metabolism , Adenosine Diphosphate Ribose/pharmacology , Adipogenesis/genetics , 3T3-L1 CellsABSTRACT
Soy isoflavones have been shown to have anti-inflammatory properties; however, the anti-inflammatory effects of isoflavone metabolites produced during soybean germination remain unclear. We found that the daidzein and genistein derivatives, 8-prenyl daidzein (8-PD) and 8-prenyl genistein (8-PG), demonstrated a more potent effect than daidzein and genistein on repressing inflammatory responses in macrophages. Although IkB protein levels were unaltered, 8-PD and 8-PG repressed nuclear factor kappa B (NF-κB) activation, which was associated with reduced ERK1/2, JNK, and p38 MAPK activation and suppressed mitogen- and stress-activated kinase 1 phosphorylation. Inflammatory responses induced by the medium containing hypertrophic adipocyte secretions were successfully suppressed by 8-PD and 8-PG treatment. In the ex vivo study, 8-PD and 8-PG significantly inhibited proinflammatory C-C motif chemokine ligand 2 (CCL2) secretion from the adipose tissues of mice fed a long-term high-fat diet. The data suggest that 8-PD and 8-PG could regulate macrophage activation under obesity conditions.
Subject(s)
Genistein , Isoflavones , Mice , Animals , Genistein/pharmacology , Genistein/metabolism , Glycine max/metabolism , Isoflavones/pharmacology , Isoflavones/metabolism , Macrophages/metabolism , Anti-Inflammatory Agents/pharmacologyABSTRACT
Siphonein is a C19 acylated siphonaxanthin found in some edible green algae (e.g., Codium fragile and Caulerpa lentillifera). Although the content of siphonein in these green algae is similar to or higher than that of siphonaxanthin, studies of health-related biological activity of siphonein are much less than those of siphonaxanthin. Given the difference in the position of the acyl chain, one cannot infer intestinal absorption of siphonein from other general carotenoid fatty acid esters. In this study, we first investigated the intestinal absorption of siphonein using mouse and cell culture models. A small amount of siphonein was detected in the plasma of treated mice, and its concentration was higher than that of siphonaxanthin (i.e., the hydrolyzed product of ingested siphonein) from 1 to 6 h after administration. Pharmacological inhibition tests with differentiated Caco-2 cells showed that Nieman-Pick C1-like 1-mediated facilitated diffusion was involved in the cellular uptake of siphonein. These results indicate that, unlike general carotenoid fatty acid esters, siphonein can be absorbed without hydrolysis. We also evaluated the anti-inflammatory effect of siphonein in differentiated Caco-2 cells. Siphonein pretreatment modulated lipopolysaccharide-induced cellular lipidome alterations and suppressed mRNA expression of proinflammatory chemokines, CXCL8 protein release, and activation of NF-κB. This study provides new insights into the absorption processes of carotenoids and shows the anti-inflammatory effect of siphonein for the first time.
Subject(s)
Chlorophyta , Intestinal Absorption , Animals , Mice , Humans , Caco-2 Cells , Carotenoids , Fatty Acids , Anti-Inflammatory Agents , EstersABSTRACT
Photoaging is characterized by skin dysfunction and wrinkle formation predominantly caused by chronic exposure to ultraviolet (UV) irradiation. Collagen peptides are well-recognized as nutritional supplements for enhancing skin health. Gly-Pro, a dipeptide found in collagen as a major repetitive sequence, is considered a prospect collagen peptide derivative that displays anti-photoaging potential. Herein, we evaluated the photoprotective effects of Gly-Pro in normal human dermal fibroblasts (NHDFs). Pretreatment by Gly-Pro at a concentration of 0.1 µM inhibited UVA-driven generation of reactive oxygen species (ROS) in NHDFs and attenuated UVA-induced changes in mRNA expression and activation of proteins of the MAPK-NF-κB signaling pathway. Meanwhile, Pro-Gly and cyclo(-Gly-Pro), two dipeptides that are structurally similar to Gly-Pro, depicted less anti-photoaging effects against UVA irradiation. Collectively, our data suggests that Gly-Pro has potential as a novel ingredient in nutricosmetic products for skincare and anti-photoaging.
Subject(s)
Dipeptides , NF-kappa B , Humans , Fibroblasts , Signal TransductionABSTRACT
Adipocyte browning is one of the potential strategies for the prevention of obesity-related metabolic syndromes, but it is a complex process. Although previous studies make it increasingly clear that several transcription factors and enzymes are essential to induce browning, it is unclear what dynamic and metabolic changes occur in induction of browning. Here, we analyzed the effect of a beta-adrenergic receptor agonist (CL316243, accelerator of browning) on metabolic change in mice adipose tissue and plasma using metabolome analysis and speculated that browning is regulated partly by inosine 5'-monophosphate (IMP) metabolism. To test this hypothesis, we investigated whether Ucp-1, a functional marker of browning, mRNA expression is influenced by IMP metabolism using immortalized adipocytes. Our study showed that mycophenolic acid, an IMP dehydrogenase inhibitor, increases the mRNA expression of Ucp-1 in immortalized adipocytes. Furthermore, we performed a single administration of mycophenolate mofetil, a prodrug of mycophenolic acid, to mice and demonstrated that mycophenolate mofetil induces adipocyte browning and miniaturization of adipocyte size, leading to adipose tissue weight loss. These findings showed that IMP metabolism has a significant effect on adipocyte browning, suggesting that the regulator of IMP metabolism has the potential to prevent obesity.
Subject(s)
Adipocytes , Inosine Monophosphate , Mycophenolic Acid , Animals , Mice , Adipocytes/drug effects , Adipocytes/metabolism , Adipose Tissue, Brown/metabolism , Adipose Tissue, White/metabolism , Inosine Monophosphate/metabolism , Metabolomics , Mice, Inbred C57BL , Mycophenolic Acid/pharmacology , Mycophenolic Acid/metabolism , Obesity/metabolism , RNA, Messenger/metabolismABSTRACT
Adiponectin, an adipokine, regulates glucose metabolism and insulin sensitivity through the adiponectin receptor (AdipoR). In this study, we searched for metabolites that activate the adiponectin signaling pathway from tomato (Solanum lycopersicu). Metabolites of mature tomato were separated into 55 fractions by liquid chromatography, and then each fraction was examined using the phosphorylation assay of AMP-protein kinase (AMPK) in C2C12 myotubes and in AdipoR-knockdown cells by small interfering RNA (siRNA). Several fractions showed AMPK phosphorylation in C2C12 myotubes and siRNA-mediated abrogation of the effect. Non-targeted metabolite analysis revealed the presence of 721 diverse metabolites in tomato. By integrating the activity of fractions on AMPK phosphorylation and the 721 metabolites based on their retention times of liquid chromatography, we performed a comprehensive screen for metabolites that possess adiponectin-like activity. As the screening suggested that the active fractions contained four carotenoids, we further analyzed ß-carotene and lycopene, the major carotenoids of food. They induced AMPK phosphorylation via the AdipoR, Ca2+/calmodulin-dependent protein kinase kinase and Ca2+ influx, in addition to activating glucose uptake via AdipoR in C2C12 myotubes. All these events were characteristic adiponectin actions. These results indicated that the food-derived carotenoids, ß-carotene and lycopene, activate the adiponectin signaling pathway, including AMPK phosphorylation.
Subject(s)
Adiponectin , Solanum lycopersicum , AMP-Activated Protein Kinases/metabolism , Adenylate Kinase/metabolism , Adiponectin/metabolism , Biological Assay , Calcium/metabolism , Lycopene/metabolism , Solanum lycopersicum/genetics , Phosphorylation , RNA, Small Interfering/metabolism , Receptors, Adiponectin/metabolism , Signal Transduction , beta Carotene/metabolismABSTRACT
Several isoflavonoids are well known for their ability to act as soybean phytoalexins. However, the overall effects of the soybean-Aspergillus oryzae interaction on metabolism remain largely unknown. The aim of this study is to reveal an overview of nutritive and metabolic changes in germinated and A. oryzae-elicited soybeans. The levels of individual nutrients were measured using the ustulation, ashing, Kjeldahl, and Folch methods. The levels of individual amino acids were measured using high-performance liquid chromatography. Low-molecular-weight compounds were measured through metabolome analysis using liquid chromatography-mass spectrometry. Although the levels of individual nutrients and amino acids were strongly influenced by the germination process, the elicitation process had little effect on the change in the contents of individual nutrients and amino acids. However, after analyzing approximately 700 metabolites using metabolome analysis, we found that the levels of many of the metabolites were strongly influenced by soybean-A. oryzae interactions. In particular, the data indicate that steroid, terpenoid, phenylpropanoid, flavonoid, and fatty acid metabolism were influenced by the elicitation process. Furthermore, we demonstrated that not the germination process but the elicitation process induced daidzein prenylation, suggesting that the soybean-A. oryzae interactions produce various phytoalexins that are valuable for health promotion and/or disease prevention.
Subject(s)
Aspergillus oryzae/metabolism , Glycine max/metabolism , Isoflavones/metabolism , Metabolome/physiology , Prenylation/physiology , Amino Acids/metabolism , Fermentation/physiology , Flavonoids/metabolism , Germination/physiology , Nutrients/metabolism , Plant Extracts/metabolismABSTRACT
PURPOSE: Sodium-glucose co-transporter-2 (SGLT2) inhibitors have various pleiotropic effects, including body weight reduction, and therefore have the potential to be used in various applications. However, such effects have not been fully investigated; thus, non-clinical studies using animal models are needed. In animal experiments, SGLT2 inhibitors are usually administered by oral or dietary methods. However, the detailed characteristics of these dosing methods, especially to induce their pleiotropic effects, have not been reported. Therefore, we compared the preventive effects of canagliflozin, an SGLT2 inhibitor, on body weight gain following oral gavage and dietary administration methods in a mouse model of diet-induced obesity. METHODS: Canagliflozin was dosed by oral gavage or dietary administration for 9 weeks to 6-week-old C57BL/6N mice fed a high-fat diet, and parameters related to obesity were evaluated. RESULTS: The suppression of body weight gain, fat mass, and hepatic lipid content was observed following both dosing methods, whereas the effect on body weight tended to be stronger in the dietary administration group. In adipose tissue, fatty acid synthase expression was significantly decreased in the dietary administration group, and its expression was significantly correlated with fat mass. However, the expression of genes related to fatty acid oxidation was unchanged, indicating that the preventive effect on body weight gain was mediated mainly through the suppression of lipid synthesis rather than the promotion of lipid oxidation. CONCLUSION: Canagliflozin prevented body weight gain through the suppression of lipid synthesis via both dosing methods, although there were some differences in the efficacy. The findings of our study can help to identify new mechanisms of action of SGLT2 inhibitors and potential applications.
ABSTRACT
While ß-cryptoxanthin is hypothesized to have a preventive effect on lifestyle-related diseases, its underlying mechanisms are unknown. We investigated the effect of ß-cryptoxanthin on energy metabolism in adipose tissues and its underlying mechanism. C57BL/6J mice were fed a high-fat diet (60% kcal fat) containing 0 or 0.05% ß-cryptoxanthin for 12 weeks. ß-cryptoxanthin treatment was found to reduce body fat gain and plasma glucose level, while increasing energy expenditure. The expression of uncoupling protein (UCP) 1 was elevated in adipose tissues in the treatment group. Furthermore, the in vivo assays showed that the Ucp1 mRNA expression was higher in the ß-cryptoxanthin treatment group, an effect that disappeared upon cotreatment with a retinoic acid receptor (RAR) antagonist. In conclusion, we report that ß-cryptoxanthin reduces body fat and body weight gain and that ß-cryptoxanthin increases the expression of UCP1 via the RAR pathway.
Subject(s)
Adipose Tissue/drug effects , Adipose Tissue/metabolism , Beta-Cryptoxanthin/administration & dosage , Obesity/drug therapy , Receptors, Retinoic Acid/metabolism , Uncoupling Protein 1/genetics , Animals , Energy Metabolism/drug effects , Gene Expression/drug effects , Humans , Male , Mice , Mice, Inbred C57BL , Obesity/genetics , Obesity/metabolism , Receptors, Retinoic Acid/genetics , Signal Transduction/drug effects , Uncoupling Protein 1/metabolismABSTRACT
Activation of the adipose lipolytic pathway during lipid metabolism is mediated by protein kinase A (PKA), which responds to ß-adrenergic stimulation, leading to increased lipolysis. Soy is well known as a functional food and it is able to affect lipolysis in adipocytes. However, the mechanism by which soy components contribute to the lipolytic pathway remains to be fully elucidated. Here, we show that hydrolyzed soy enhances isoproterenol-stimulated lipolysis and activation of PKA in 3T3-L1 adipocytes. We also found that the expression of ß-adrenergic receptors, which coordinate the activation of PKA, is elevated in adipocytes differentiated in the presence of soy hydrolysate. The activity of the soy hydrolysate towards ß-adrenergic receptor expression was detected in its hydrophilic fraction. Our results suggest that the soy hydrolysate enhances the PKA pathway through the upregulation of ß-adrenergic receptor expression and thereby, increase lipolysis in adipocytes.
Subject(s)
Adipocytes/metabolism , Adrenergic beta-Agonists/pharmacology , Glycine max/metabolism , Isoproterenol/pharmacology , Lipolysis/drug effects , Receptors, Adrenergic, beta/metabolism , 3T3-L1 Cells , Animals , Chromatography, High Pressure Liquid/methods , Cyclic AMP-Dependent Protein Kinases/metabolism , Hydrolysis , MiceABSTRACT
Apo-lycopenals, lycopene metabolites produced by an initial cleavage by ß,ß-carotene-9',10'-oxygenase, exhibit diverse biologically active effects. In this study, we investigated the effect of apo-lycopenals on the activation of nuclear receptors involved in glucose and lipid metabolism. Only apo-12'-lycopenal exhibited selective and dose-dependent transactivation activity for peroxisome proliferator-activated receptor γ (PPARγ), whereas neither apo-6'- nor apo-8'-lycopenals displayed this activity ((7.83 ± 0.66)-, (1.32 ± 0.10)-, and (1.31 ± 0.37)-fold higher activity relative to control, respectively). Additionally, apo-12'-lycopenal promoted adipocyte differentiation of 3T3-L1 cells and subsequently increased the mRNA levels of PPARγ (a (2.36 ± 0.07)-fold increase relative to control; p < 0.01) and its target genes, as well as enhanced adiponectin secretion (a (3.25 ± 0.27)-fold increase relative to control; p < 0.01) and insulin-stimulated glucose uptake (1486 ± 85 pmol/well; p < 0.001) in 3T3-L1 cells. Our results indicated that apo-12'-lycopenal promoted adipocyte differentiation by direct binding and activation of PPARγ.
Subject(s)
Adipocytes/cytology , Adipocytes/metabolism , Aldehydes/metabolism , Cell Differentiation , Lycopene/metabolism , PPAR gamma/metabolism , Terpenes/metabolism , 3T3-L1 Cells , Animals , Glucose/metabolism , Insulin/metabolism , Mice , PPAR gamma/geneticsABSTRACT
The mevalonate pathway is essential for the synthesis of isoprenoids and cholesterol. Adipose tissue is known as a major site for cholesterol storage; however, the role of the local mevalonate pathway and its synthesized isoprenoids remains unclear. In this study, adipose-specific mevalonate pathway-disrupted (aKO) mice were generated through knockout of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (HMGCR). aKO mice showed serious lipodystrophy accompanied with glucose and lipid metabolic disorders and hepatomegaly. These metabolic variations in aKO mice were dramatically reversed after fat transplantation. In addition, HMGCR-disrupted adipocytes exhibited loss of lipid accumulation and an increase of cell death, which were ameliorated by the supplementation of mevalonate and geranylgeranyl pyrophosphate but not farnesyl pyrophosphate and squalene. Finally, we found that apoptosis may be involved in adipocyte death induced by HMGCR down-regulation. Our findings indicate that the mevalonate pathway is essential for adipocytes and further suggest that this pathway is an important regulator of adipocyte turnover.
ABSTRACT
Obesity-induced chronic inflammation is a key factor in type 2 diabetes. A vicious cycle involving pro-inflammatory mediators between adipocytes and macrophages is a common cause of chronic inflammation in the adipose tissue. Tomato is one of the most popular vegetables and is associated with a reduced risk of diabetes. However, the molecular mechanism underlying the effect of tomato on diabetes is unclear. In this study, we focused on anti-inflammatory compounds in tomato. We found that the extract of tomato reduced plasma glucose and inflammatory markers in mice. We screened anti-inflammatory fractions in tomato using lipopolysaccharide-stimulated RAW264.7 macrophages, and active compounds were estimated by liquid chromatography-mass spectrometry over a wide range. Surprisingly, a large number of compounds including oxylipin and coumarin derivatives were estimated as anti-inflammatory compounds. Especially, 9-oxo-octadecadienoic acid and daphnetin suppressed pro-inflammatory cytokines in RAW264.7 macrophages inhibiting mitogen-activated protein kinase phosphorylation and inhibitor of kappa B α protein degradation. These findings suggest that tomato containing diverse anti-inflammatory compounds ameliorates chronic inflammation in obese adipose tissue.
Subject(s)
Anti-Inflammatory Agents/isolation & purification , Anti-Inflammatory Agents/pharmacology , Solanum lycopersicum/chemistry , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Animals , Anti-Inflammatory Agents/chemistry , Blood Glucose/metabolism , Chromatography, High Pressure Liquid , Coumarins/chemistry , Coumarins/isolation & purification , Coumarins/pharmacology , Cytokines/metabolism , Drug Evaluation, Preclinical , MAP Kinase Signaling System/drug effects , Macrophages/drug effects , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Nitric Oxide/biosynthesis , Obesity/drug therapy , Obesity/metabolism , Oxylipins/chemistry , Oxylipins/isolation & purification , Oxylipins/pharmacology , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , RAW 264.7 Cells , Spectrometry, Mass, Electrospray Ionization , Umbelliferones/chemistry , Umbelliferones/isolation & purification , Umbelliferones/pharmacologyABSTRACT
Although the Apiaceae herb family has been traditionally used for the management of type 2 diabetes, its molecular mechanism has not been clarified. Coumarin derivatives, which are abundant in plants of the Apiaceae family, were evaluated for their effects on adipogenesis. We found that suksdorfin significantly promoted adipocyte differentiation and enhanced production of adiponectin, an anti-diabetic adipokine. We also demonstrated that suksdorfin activates peroxisome proliferator-activated receptor gamma (PPARγ), a master regulator of adipogenesis. Furthermore, we showed metabolic disorders in obese diabetic KK-Ay mice were attenuated by suksdorfin feeding. Suksdorfin intake induced adipocyte miniaturization and increased expression levels of PPARγ target genes related to adipocyte differentiation. These results indicated that suksdorfin induces adipogenesis in white adipose tissue (WAT) via the activation of PPARγ, leading to improvement of obesity-induced metabolic disorders. Therefore, suksdorfin-mediated amelioration of WAT dysfunctions might be responsible for the anti-diabetic effects of traditional herbal medicine therapy with Apiaceae.
Subject(s)
Adipocytes/drug effects , Coumarins/administration & dosage , Glucose Metabolism Disorders/drug therapy , PPAR gamma/metabolism , 3T3-L1 Cells , Adipocytes/cytology , Adipocytes/metabolism , Adiponectin/metabolism , Animals , Apiaceae/chemistry , Cell Differentiation/drug effects , Coumarins/pharmacology , Enzyme Activation/drug effects , Gene Expression Regulation, Enzymologic/drug effects , Glucose Metabolism Disorders/enzymology , Mice , Mice, Obese , Signal Transduction/drug effectsABSTRACT
Koji is made from grains fermented with Aspergillus oryzae and is essential for the production of many traditional Japanese foods. Many previous studies have shown that koji contributes to the improvement of dyslipidemia. However, little is known regarding the underlying mechanism of this effect. Furthermore, the compound contributing to the activation of lipid metabolism is unknown. We demonstrated that rice koji extract (RKE) induces the mRNA expression of peroxisome proliferator-activated receptor alpha (PPARα) target genes, which promotes lipid metabolism in murine hepatocytes. This effect was not observed in PPARα-KO hepatocytes. We also demonstrated that RKE contained linolenic acid (LIA), oleic acid (OA), and hydroxyoctadecadienoic acids (HODEs), which activate PPARα, using LC-MS analysis. Our findings suggest that RKE, containing LIA, OA, and HODEs, could be valuable in improving dyslipidemia via PPARα activation.
Subject(s)
Aspergillus oryzae/metabolism , Dyslipidemias/metabolism , Lipid Metabolism/drug effects , Liver/metabolism , Oryza/microbiology , PPAR alpha/metabolism , Plant Extracts/pharmacology , Animals , Dyslipidemias/drug therapy , Dyslipidemias/genetics , Hepatocytes/drug effects , Hepatocytes/metabolism , Humans , Liver/drug effects , Mice , Oryza/chemistry , Oryza/metabolism , PPAR alpha/genetics , Plant Extracts/metabolismABSTRACT
The peroxisome proliferator-activated receptor (PPAR)α is mainly expressed in the liver and plays an important role in the regulation of lipid metabolism. It has been reported that PPARα activation enhances fatty acid oxidation and reduces fat storage. Therefore, PPARα agonists are used to treat dyslipidemia. In the present study, we found that 9-oxo-10(E),12(Z),15(Z)-octadecatrienoic acid (9-oxo-OTA), which is a α-linolenic acid (ALA) derivative, is present in tomato (Solanum lycopersicum) extract. We showed that 9-oxo-OTA activated PPARα and induced the mRNA expression of PPARα target genes in murine primary hepatocytes. These effects promoted fatty acid uptake and the secretion of ß-hydroxybutyrate, which is one of the endogenous ketone bodies. We also demonstrated that these effects of 9-oxo-OTA were not observed in PPARα-knockout (KO) primary hepatocytes. To our knowledge, this is the first study to report that 9-oxo-OTA promotes fatty acid metabolism via PPARα activation and discuss its potential as a valuable food-derived compound for use in the management of dyslipidemia.
Subject(s)
Dyslipidemias/metabolism , Linolenic Acids/metabolism , PPAR alpha/genetics , alpha-Linolenic Acid/metabolism , Animals , Dyslipidemias/pathology , Fatty Acids/metabolism , Hepatocytes/metabolism , Humans , Lipid Metabolism/genetics , Liver/metabolism , Mice , PPAR alpha/biosynthesis , RNA, Messenger/metabolismABSTRACT
Obese adipose tissue is characterized by enhanced macrophage infiltration. A loop involving monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNFα) between adipocytes and macrophages establishes a vicious cycle that augments inflammatory changes and insulin resistance in obese adipose tissue. Tomatoes, one of the most popular crops worldwide, contain many beneficial phytochemicals that improve obesity-related diseases such as diabetes. Some of them have also been reported to have anti-inflammatory properties. In this study, we focused on the potential protective effects of phytochemicals in tomatoes on inflammation. We screened fractions of tomato extract using nitric oxide (NO) assay in lipopolysaccharide (LPS)-stimulated RAW264 macrophages. One fraction, RF52, significantly inhibited NO production in LPS-stimulated RAW264 macrophages. Furthermore, RF52 significantly decreased MCP-1 and TNFα productions. The coculture of 3T3-L1 adipocytes and RAW264 macrophages markedly enhanced MCP-1, TNFα, and NO productions compared with the control cultures; however, the treatment with RF52 inhibited the production of these proinflammatory mediators. These results suggest that RF52 from tomatoes may have the potential to suppress inflammation by inhibiting the production of NO or proinflammatory cytokines during the interaction between adipocytes and macrophages.