Emergence of analgesic tolerance and dependence to morphine is frequently the limiting factor in the use of this agent in the management of pain. Hence, this study aimed to investigate the beneficial effects of the natural compound carveol (CV) against morphine antinociceptive tolerance, dependence and conditioned place preference (CPP) in mice. Behavioural paradigms included hot plate and tail-flick (for tolerance), observation of withdrawal signs (for dependence) while biochemical tests involved the assays for mRNA expression, nitrite levels, antioxidants, and immunohistochemistry studies. Behavioural tests indicated that treatment with CV significantly attenuated the morphine analgesic tolerance, physical dependence and CPP in mice. It was observed during biochemical analysis that CV-treated animals exhibited reduced mRNA expression of inducible nitric oxide synthase (iNOS) and NR2B (an NMDA subtype). In addition, decreased levels of nitrite were observed in mouse hippocampus following CV treatment than morphine administration only. Further, CV enhanced the neuronal innate antioxidants including Glutathione-S-Transferase (GST), glutathione (GSH) and catalase (CAT), while curtailed lipid peroxidase (LPO) levels in mice brain tissues. Moreover, CV exerted significant anti-inflammatory effects as evidenced by reduced expression of TNF-α and p-NF-κB in these animals than with morphine treatment only. Together, anti-inflammatory and antioxidant effects might confer needed neuro-protection following morphine administration. These observations warrant further investigations of the beneficial role of CV as a novel agent in overcoming the development of tolerance and physical dependence following morphine use.
Heterocyclic amines and acetamide derivatives are known for their chemotherapeutic potential. Hence, in the present study, morpholine was taken as a principal product and novel morpholine derivatives were designed, formulated, characterized, and screened for the mechanism of inhibition of carbonic anhydrase and their anticancer potential. In addition, in vitro inhibition of hypoxia-inducible factor-1 (HIF-1) protein was also investigated. Results revealed that compounds 1c, 1d, and 1h possessed significant inhibitory activities against carbonic anhydrase with IC50 of 8.80, 11.13, and 8.12 µM, respectively. Interestingly, the carbonic anhydrase inhibitory activity of compound 1h was comparable with that of standard acetazolamide (IC50 7.51 µM). The compounds 1h and 1i significantly inhibited the proliferation of ovarian cancer cell line ID8 with IC50 of 9.40, and 11.2 µM, respectively while the standard cisplatin exhibited an IC50 8.50 µM. In addition, compounds 1c, 1b, 1h and 1i also exhibited significant inhibitory effects on HIF-1α. In conclusion, we report first time the biological potential of morpholine based compounds against ovarian cancer and HIF-1α that may serve as lead molecules for drug discovery.
Drug addiction is a devastating condition that poses a serious burden on the society. The use of some drugs like morphine for their tremendous analgesic properties is also accompanied with developing tolerance, dependence and the withdrawal symptoms. These symptoms are frequently severe enough to reinforce the person in recovery to start over the use of drug again and hinder the clinical use of drugs like morphine for chronic pain. Research into opioid receptors and related molecular pathways has seen resurgence in the wake of the growing opioid epidemic. The current study provides a comprehensive scientific exploration of the molecular mechanisms and underlying signalling in morphine tolerance and dependence. It also critically evaluates current therapeutic approaches, shedding light on their efficacy and limitations, and future prospects. The graphical abstract depicts an overview of the pathways involved in the emergence of morphine-related tolerance and dependence including NMDA, Nitric oxide, and PPAR, as well as behavioural sensitization along with present and future innovative treatment strategies including stem cell therapy that have been discussed in the current manuscript.
2-Mercaptobenzothiazole and its derivatives are widely known for their diverse biological activities, particularly antimicrobial and anticancer potential. In the present study, a series of new hybrid compounds consisting of 2-mercaptobenzothiazole and different aryl amines 2(a-j) were synthesized and characterized by Fourier transform infrared (FTIR), 1H NMR, and 13C NMR spectral data. The synthesized compounds were screened for in vitro antibacterial activities through agar well diffusion assay. Among the series, 2b, 2c, and 2i exhibited significant antibacterial activity comparable to the standard drug levofloxacin. Based on their antibacterial potential, these compounds were further tested for their antibiofilm activity. All of the three compounds showed promising antibiofilm potential, even better than the standard drug cefadroxil at 100 µg/100 µL concentration. Molecular docking studies were performed to explore the antibacterial mechanism of these compounds. Strikingly, the molecule 2i shared the same hydrophobic pockets as those of levofloxacin in case of bacterial kinases and DNA gyrases. In addition, 2i exhibited satisfactory antibiofilm activity in comparison to the standard. Our study therefore suggested that the synthetic compound 2i possesses remarkable antibacterial activity and may serve as a lead molecule for the discovery of potent antibacterial agents.
BACKGROUND & AIMS: The spontaneous preference for dietary lipids is principally regulated by 2 lingual fat taste receptors, CD36 and GPR120. Obese animals and most of human subjects exhibit low orosensory perception of dietary fat because of malfunctioning of these taste receptors. Our aim was to target the 2 fat taste receptors by newly synthesized high affinity fatty acid agonists to decrease fat-rich food intake and obesity. METHODS: We synthesized 2 fat taste receptor agonists (FTA), NKS-3 (CD36 agonist) and NKS-5 (CD36 and GPR120 agonist). We determined their molecular dynamic interactions with fat taste receptors and the effect on Ca2+ signaling in mouse and human taste bud cells (TBC). In C57Bl/6 male mice, we assessed their gustatory perception and effects of their lingual application on activation of tongue-gut loop. We elucidated their effects on obesity and its related parameters in male mice fed a high-fat diet. RESULTS: The two FTA, NKS-3 and NKS-5, triggered higher Ca2+ signaling than a dietary long-chain fatty acid in human and mouse TBC. Mice exhibited a gustatory attraction for these compounds. In conscious mice, the application of FTA onto the tongue papillae induced activation of tongue-gut loop, marked by the release of pancreato-bile juice into collecting duct and cholecystokinin and peptide YY into blood stream. Daily intake of NKS-3 or NKS-5 via feeding bottles decreased food intake and progressive weight gain in obese mice but not in control mice. CONCLUSIONS: Our results show that targeting fat sensors in the tongue by novel chemical fat taste agonists might represent a new strategy to reduce obesity.
Taste Buds , Humans , Male , Mice , Animals , Taste Buds/physiology , Taste/physiology , Mice, Obese , Food Preferences/physiology , Fatty Acids , Dietary Fats/adverse effects , Weight Gain , Obesity/drug therapy , Obesity/etiology
Based on the vernacular reputation of Coriandrum sativum and Citrus limon to treat hypertension, this study was designed to explore the cardiovascular effects of C. sativum (CS) and C. limon (CL) on arsenic-induced hypertension and endothelial damage. Hypertension was induced by arsenic (100 ppm) in drinking water. The crude methanolic extracts of CS and CL were tested for in vivo and in vitro activities using Power Lab. High performance liquid chromatography analysis of CS and CL showed the presence of phenolic compounds. In anesthetized rats, CS (50 mg) and CL (10 mg) showed a marked decrease in blood pressure of 51% and 35%, respectively. Similarly, ascorbic acid (10 mg) also showed a decreased blood pressure (41%). The CS and CL caused complete relaxation (0.003−5 mg/mL) against phenylephrine (1µM) and high K+ (80 mM)-induced contraction. The CS and CL, independently and in combination, exhibited marked (p < 0.001) attenuation in the blood pressure of the arsenic-induced hypertensive rats when compared with the controls. The beneficial effects of the CS and CL were also observed on lipid peroxidation and eNOS. These data suggest that CS and CL possess significant antihypertensive activity, possibly mediated via endothelium protection, and anti-oxidant effects. Thus, this study provides a rationale for the medicinal use of CS and CL in hypertension and also against arsenic-induced cardiovascular complications.
Ajuga bracteosa has been used in traditional medicine to treat hypertension and other ailments. The present study has been designed to investigate the beneficial effects of A. bracteosa in l-nitro arginine methyl ester (l-NAME)-induced hypertensive rats. Hypertension was induced by intraperitoneal injection of l-NAME (185 µmol kg-1 i.p.). The aqueous methanol extract of A. bracteosa (AMEAB, 250 and 500 mg kg-1) and coumarin (30 and 70 mg kg-1) were administered orally from day 8 to day 35 of the study. In vivo antihypertensive activity was assessed by measuring the blood pressure using a PowerLab data system. The effects of the AMEAB and coumarin on nitric oxide (NO), cyclic guanosine monophosphate (cGMP), interleukin-6 (IL-6), the tumor necrosis factor (TNF-α), and oxidative stress markers were also assessed using kit methods. Phytochemical profiling of the AMEAB was carried out through high-performance liquid chromatography (HPLC) where quercetin, gallic acid, caffeic acid, vanillic acid, benzoic acid, syringic acid, p-coumaric acid, and ferulic acid were labeled as plant constituents including coumarin. The AMEAB and coumarin significantly reduced blood pressure at the tested doses of 500 and 70 mg kg-1, respectively. Serum levels of NO and cGMP were found to be significantly increased in AMEAB- and coumarin-treated groups when compared with only l-NAME-challenged rats. In addition, a marked decrease was noticed in the serum concentrations of proinflammatory cytokines (IL-6 and TNF-α) in AMEAB- and coumarin-treated rats. Moreover, in AMEAB- and coumarin-treated animals, a noticeable improvement was observed in the levels of antioxidant enzymes including catalase, superoxide dismutase, and malonaldehyde, and the total oxidant status when compared with those of only l-NAME-challenged rats. The data of real-time polymerase chain reaction (RT-PCR) experiments supported that the antihypertensive and anti-inflammatory activities of the AMEAB and coumarin are possibly mediated through modulation of endothelial nitric oxide synthase (eNOS), angiotensin-converting enzyme (ACE), nuclear factor (NF)-kB, and COX-2 gene expressions. This study concludes that A. bracteosa possesses an antihypertensive effect mediated through the modulation of the antioxidant, anti-inflammatory, and NO/cGMP pathways, thus providing a rationale to the antihypertensive use of A. bracteosa in traditional medicine.
The metabolic syndrome is a plethora of related disorders that are frequently associated with morbidity and mortality in addition to economic burden. While various treatment options are available, the need to understand the pathology and find new targets still remains. Recent data have suggested GPR75 as one such exciting target that has shown to a highly druggable potential. In this review, we have discussed the recent findings on GPR75 in terms of its expression and signaling and the way it could be a novel target in diseases associated with metabolic syndrome including obesity, dyslipidemia, diabetes, cardiovascular disease, and cerebrovascular disease. In addition, the opportunities and challenges related with the druggable potential of GPR75 have also been highlighted in this review.
Cardiovascular Diseases , Dyslipidemias , Metabolic Syndrome , Humans , Metabolic Syndrome/drug therapy , Obesity , Receptors, G-Protein-Coupled/metabolism , Signal Transduction
Nutrition transition can be defined as shifts in food habits, and it is characterized by high-fat (chiefly saturated animal fat), hypercaloric and salty food consumption at the expense of dietary fibers, minerals and vitamins. Western dietary patterns serve as a model for studying the impact of nutrition transition on civilization diseases, such as obesity, which is commonly associated with oxidative stress and inflammation. In fact, reactive oxygen species (ROS) overproduction can be associated with nuclear factor-κB (NF-κB)-mediated inflammation in obesity. NF-κB regulates gene expression of several oxidant-responsive adipokines including tumor necrosis factor-α (TNF-α). Moreover, AMP-activated protein kinase (AMPK), which plays a pivotal role in energy homeostasis and in modulation of metabolic inflammation, can be downregulated by IκB kinase (IKK)-dependent TNF-α activation. On the other hand, adherence to a Mediterranean-style diet is highly encouraged because of its healthy dietary pattern, which includes antioxidant nutraceuticals such as polyphenols. Indeed, hydroxycinnamic derivatives, quercetin, resveratrol, oleuropein and hydroxytyrosol, which are well known for their antioxidant and anti-inflammatory activities, exert anti-obesity proprieties. In this review, we highlight the impact of the most common polyphenols from Mediterranean foods on molecular mechanisms that mediate obesity-related oxidative stress and inflammation. Hence, we discuss the effects of these polyphenols on a number of signaling pathways. We note that Mediterranean diet (MedDiet) dietary polyphenols can de-regulate nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and NF-κB-mediated oxidative stress, and metabolic inflammation. MedDiet polyphenols are also effective in upregulating downstream effectors of several proteins, chiefly AMPK.
Antioxidants/metabolism , Diet, Mediterranean , Obesity/metabolism , Polyphenols/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Dietary Fiber/therapeutic use , Humans , NF-kappa B/genetics , Obesity/diet therapy , Obesity/genetics , Resveratrol/metabolism
We investigated whether docosahexaenoic acid (DHA), a dietary n-3 fatty acid, modulates calcium (Ca2+) signaling and cell cycle progression in human Jurkat T-cells. Our study demonstrates that DHA inhibited Jurkat T-cell cycle progression by blocking their passage from S phase to G2/M phase. In addition, DHA decreased the plasma membrane expression of TRPC3 and TRPC6 calcium channels during T-cell proliferation. Interestingly, this fatty acid increased plasma membrane expression of TRPC6 after 24 h of mitogenic stimulation by phorbol-13-myristate-12-acetate (PMA) and ionomycin. These variations in the membrane expression of TRPC3 and TRPC6 channels were not directly correlated with the mRNA expression, indicating that it was a post-translational phenomenon. DHA increased free intracellular calcium concentrations, [Ca2+]i, via opening TRPC3 and TRPC6 channels. We conclude that the anti-proliferative effect of DHA might involve the modulation of TRPC3 and TRPC6 channels in human T-cells.
Cell Membrane/metabolism , Docosahexaenoic Acids/pharmacology , G2 Phase Cell Cycle Checkpoints/drug effects , Gene Expression Regulation/drug effects , M Phase Cell Cycle Checkpoints/drug effects , T-Lymphocytes/metabolism , TRPC Cation Channels/biosynthesis , TRPC6 Cation Channel/biosynthesis , Humans , Ionomycin/pharmacology , Jurkat Cells , Tetradecanoylphorbol Acetate/pharmacology
CONTEXT: Zizyphus lotus L., ZL is a Mediterranean plant and widely consumed for its beneficial medicinal properties. Objective: We assessed the effects of ZL fruit on diet-induced obesity. Materials and methods: Male C57BL/6j mice were divided into three groups. Each group received either a standard diet or a high-fat diet, HFD (30% of palm oil, w/v) or a HFD-supplemented with ZL fruit powder (10%, w/w) for six weeks, followed by a six weeks period, in which animals were maintained on the HFD and ZL aqueous extract (1%, w/v). We measured plasma parameters and assessed the expression of key genes involved in energy metabolism and inflammation. Results: ZL fruit improved glycaemia, lipids concentrations and inflammation in obese mice. Discussion and conclusion: Our investigations showed that ZL fruit improved glucose tolerance, dyslipidaemia and fatty liver disease, but not the severity of HFD-induced obesity in mice.
Fruit/chemistry , Inflammation/drug therapy , Insulin Resistance , Obesity/complications , Phytotherapy/methods , Plant Extracts/pharmacology , Ziziphus/chemistry , Animals , Blood Glucose/analysis , Inflammation/etiology , Inflammation/pathology , Lipids/blood , Male , Mice , Mice, Inbred C57BL , Mice, Obese
AIM: The pathogenesis of obesity has been associated with high intake of dietary fat, and some recent studies have explored the cellular mechanisms of oro-sensory detection of dietary fatty acids. We further assessed the role of transient receptor potential canonical (TRPC) channels in oro-sensory perception of dietary lipids. METHODS: We determined by RT-qPCR and western blotting the expression of TRPC3/6/7 channels in mouse fungiform taste bud cells (mTBC). Immunocytochemistry was used to explore whether TRPC3 channels were co-expressed with fatty acid receptors. We employed wild-type (WT) mTBC, and those transfected with small interfering RNAs (siRNAs) against TRPC3 or STIM1. Ca2+ signalling was studied in TBC from TRPC3-/- mice and their WT littermates. RESULTS: We demonstrate that mouse fungiform taste bud cells (mTBC) express TRPC3, but not TRPC6 or TRPC7 channels, and their inactivation by siRNA or experiments on TBC from TRPC3-/- mice brought about a decrease in fatty acid-induced gustatory Ca2+ signalling, coupled with taste bud CD36 lipid sensor. TRPC3 channel activation was found to be under the control of STIM1 in lingual mTBC. Behavioural studies showed that spontaneous preference for a dietary long-chain fatty acid was abolished in TRPC3-/- mice, and in mice wherein lingual TRPC3 expression was silenced by employing siRNA. CONCLUSION: We report that lingual TRPC3 channels are critically involved in fat taste perception.
Food Preferences , Taste Perception , Animals , Dietary Fats , Lipids , Mice , TRPC Cation Channels/genetics
Leptin, an anorectic hormone, regulates food intake, energy expenditure and body weight. We assessed the implication of tongue leptin in the modulation of oro-sensory detection of dietary fatty acids in mice. The RT-PCR analysis showed that mRNA encoding leptin and leptin receptor (Ob-Rb) was expressed in mice taste bud cells (TBC). Confocal microscopic studies showed that the lipid sensor CD36 was co-expressed with leptin in mice TBC. Silencing of leptin or Ob-Rb mRNA in tongue papillae upregulated preference for a long-chain fatty acid (LCFA), i.e., linoleic acid (LA), in a two-bottle paradigm in mice. Furthermore, tongue leptin application decreased the preference for the LCFA. These results suggest that tongue leptin exerts an inhibitory action on fatty acid preference. In isolated mice TBC, leptin decreased LCFA-induced increases in free intracellular calcium concentrations, [Ca2+]i. Leptin and LCFA induced the phosphorylation of ERK1/2 and STAT-3 and there were no additive or opposite effects of the two agents on the degree of phosphorylation. However, leptin, but not the LCFA, induced phosphoinositide-3-kinase (PI-3-K)-dependent Akt phosphorylation in TBC. Furthermore, leptin induced hyperpolarization, whereas LCFA induced depolarization in TBC. Our study demonstrates that tongue leptin exerts an inhibitory action on oro-sensory detection of a dietary fatty acid by interfering with Ca2+ signaling and membrane potential in mice TBC.
Dietary Fats/analysis , Fatty Acids/analysis , Leptin/physiology , Taste Perception/physiology , Tongue/chemistry , Animals , CD36 Antigens/genetics , Calcium Signaling/physiology , Dietary Fats/administration & dosage , Fatty Acids/administration & dosage , Gene Expression , Gene Silencing , Male , Membrane Potentials/physiology , Mice , Mice, Inbred C57BL , RNA, Messenger/analysis , Receptors, Leptin/genetics , Taste Buds/chemistry , Taste Buds/physiology
GPR120 is implicated as a lipid receptor in the oro-sensory detection of dietary fatty acids. However, the effects of GPR120 activation on dietary fat intake or obesity are not clearly understood. We investigated to determine whether the binding of TUG891, a novel GPR120 agonist, to lingual GPR120 modulates fat preference in mice. We explored the effects of TUG891 on obesity-related hormones and conducted behavioral choice tests on mice to better understand the physiologic relevance of the action of TUG891. In cultured mouse and human taste bud cells (TBCs), TUG891 induced a rapid increase in Ca2+ by acting on GPR120. A long-chain dietary fatty acid, linoleic acid (LA), also recruited Ca2+ via GPR120 in human and mouse TBCs. Both TUG891 and LA induced ERK1/2 phosphorylation and enhanced in vitro release of glucagon-like peptide-1 from cultured human and mouse TBCs. In situ application of TUG891 onto the tongue of anesthetized mice triggered the secretion of pancreatobiliary juice, probably via the tongue-brain-gut axis. Furthermore, lingual application of TUG891 altered circulating concentrations of cholecystokinin and adipokines, associated with decreased circulating LDL, in conscious mice. In behavioral tests, mice exhibited a spontaneous preference for solutions containing either TUG891 or LA instead of a control. However, addition of TUG891 to a solution containing LA significantly curtailed fatty acid preference. Our study demonstrates that TUG891 binds to lingual GPR120 receptors, activates the tongue-brain-gut axis, and modulates fat preference. These findings may support the development of new fat taste analogs that can change the approach to obesity prevention and treatment.
Biphenyl Compounds/pharmacology , Brain/drug effects , Gastrointestinal Microbiome/drug effects , Phenylpropionates/pharmacology , Receptors, G-Protein-Coupled/agonists , Taste Perception/drug effects , Tongue/drug effects , Animals , Brain/metabolism , Cells, Cultured , Humans , Male , Mice , Mice, Inbred C57BL , Receptors, G-Protein-Coupled/metabolism , Taste Buds/drug effects , Taste Buds/metabolism , Tongue/metabolism
We investigated the implication of Takeda G protein-coupled receptor 5 (TGR5) in fat preference and fat sensing in taste bud cells (TBC) in C57BL/6 wild-type (WT) and TGR5 knock out (TGR5-/-) male mice maintained for 20 weeks on a high-fat diet (HFD). We also assessed the implication of TGR5 single nucleotide polymorphism (SNP) in young obese humans. The high-fat diet (HFD)-fed TGR5-/- mice were more obese, marked with higher liver weight, lipidemia and steatosis than WT obese mice. The TGR5-/- obese mice exhibited high daily food/energy intake, fat mass and inflammatory status. WT obese mice lost the preference for dietary fat, but the TGR5-/- obese mice exhibited no loss towards the attraction for lipids. In lingual TBC, the fatty acid-triggered Ca2+ signaling was decreased in WT obese mice; however, it was increased in TBC from TGR5-/- obese mice. Fatty acid-induced in vitro release of GLP-1 was higher, but PYY concentrations were lower, in TBC from TGR5-/- obese mice than those in WT obese mice. We noticed an association between obesity and variations in TGR5 rs11554825 SNP. Finally, we can state that TGR5 modulates fat eating behavior and obesity.
Bile Acids and Salts/metabolism , Food Preferences , Lipids/chemistry , Obesity/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Animals , Blood Glucose/metabolism , Calcium/metabolism , Diet, High-Fat , Dietary Fats , Disease Models, Animal , Fatty Liver , Inflammation , Insulin/metabolism , Lipopolysaccharides/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Obesity/genetics , Polymorphism, Single Nucleotide
The choice of food is governed largely by the sense of taste. To date, five basic taste modalities have been described; however, there is an increasing agreement on the existence of a 6th fat taste. The taste modalities might interact with each other and also with other senses. The advancements in cellular and molecular biology have helped the characterization of taste signaling mechanisms, down to the receptor level and beyond. CD36 and GPR120 have been shown to be involved in the detection of fat taste while bitter taste is perceived by a number of receptors that belong to a family of taste-type 2 receptors (T2R or TAS2R). Hence, the most common role is played by TAS2R16 and TAS2R38 in bitter taste perception in humans. Increasing evidences from behavioural studies suggest that fat and bitter taste modalities might interact with each other, and this interaction might be critical in obesity. In the current review, we will discuss the evidence from genetic and behavioural studies and propose the molecular mechanism of a cross-talk between fat and bitter tastes.
CD36 Antigens/metabolism , Dietary Fats , Obesity , Receptors, G-Protein-Coupled/metabolism , Signal Transduction , Taste Perception , Humans , Obesity/metabolism , Obesity/physiopathology
The origin of spontaneous preference for dietary lipids in humans and rodents is debated, though recent compelling evidence has shown the existence of fat taste that might be considered a sixth taste quality. We investigated the implication of gustatory and reward brain circuits, triggered by linoleic acid (LA), a long-chain fatty acid. The LA was applied onto the circumvallate papillae for 30 min in conscious C57BL/6J mice, and neuronal activation was assessed using c-Fos immunohistochemistry. By using real-time reverse transcription polymerase chain reaction (RT-qPCR), we also studied the expression of mRNA encoding brain-derived neurotrophic factor (BDNF), Zif-268, and Glut-1 in some brain areas of these animals. LA induced a significant increase in c-Fos expression in the nucleus of solitary tract (NST), parabrachial nucleus (PBN), and ventroposterior medialis parvocellularis (VPMPC) of the thalamus, which are the regions known to be activated by gustatory signals. LA also triggered c-Fos expression in the central amygdala and ventral tegmental area (VTA), involved in food reward, in conjunction with emotional traits. Interestingly, we noticed a high expression of BDNF, Zif-268, and Glut-1 mRNA in the arcuate nucleus (Arc) and hippocampus (Hipp), where neuronal activation leads to memory formation. Our study demonstrates that oral lipid taste perception might trigger the activation of canonical gustatory and reward pathways.
Behavior, Animal , Brain/physiology , Linoleic Acid/administration & dosage , Reward , Taste Buds/physiology , Taste Perception , Taste , Animals , Brain/metabolism , Brain-Derived Neurotrophic Factor/genetics , Brain-Derived Neurotrophic Factor/metabolism , Early Growth Response Protein 1/genetics , Early Growth Response Protein 1/metabolism , Glucose Transporter Type 1/genetics , Glucose Transporter Type 1/metabolism , Linoleic Acid/metabolism , Male , Mice, Inbred C57BL , Neural Pathways/physiology , Neuronal Plasticity , Proto-Oncogene Proteins c-fos/metabolism , Taste Buds/metabolism
Obesity, triggered by high-fat diet (HFD), is associated to altered gustatory perception of dietary lipids. Oleanolic acid (OLA), a triterpene, has been reported to exert anti-obesity effects in animal models. Hence, we investigated the role of OLA in the modulation of oro-sensory perception of lipids in control and HFD-induced obese mice. As expected, OLA-treated obese mice exhibited a decrease in body, liver, and visceral adipose tissue weights. OLA treatment improved glucose tolerance, insulin level, plasma lipopolysaccharide (LPS), and hepatic cholesterol and triglyceride concentrations. OLA-treated obese mice exhibited higher fat preference compared to untreated obese mice, probably due to the increase in mRNA encoding CD36, a fat taste receptor, in mouse taste bud cells (mTBC). This phenomenon was associated with fatty-acid induced increases in free intracellular calcium concentrations, [Ca2+]i, induced in mTBC from OLA-treated obese mice. OLA also influenced the expression of mRNA encoding pro-inflammatory cytokines (IL-1ß and IL-6) and some lipogenic genes (PPARα, SREBP1, FAS, ChREBP, and G6Pase) in liver and adipose tissue. These findings reveal that OLA improves gustatory perception of lipids and exerts protective effects in obesity.
Diet, High-Fat , Inflammation/prevention & control , Obesity/prevention & control , Oleanolic Acid/pharmacology , Adipose Tissue/drug effects , Animals , CD36 Antigens/genetics , Calcium/metabolism , Diet, Mediterranean , Female , Glucose Tolerance Test , Inflammation Mediators/metabolism , Insulin/blood , Interleukin-1beta/genetics , Interleukin-6/genetics , Lipogenesis/genetics , Lipopolysaccharides/blood , Liver/drug effects , Mice, Inbred C57BL , Obesity/etiology , RNA, Messenger/genetics , Taste Buds/drug effects , Taste Buds/metabolism , Weight Gain/drug effects
In the present study, we have investigated the effects of polyphenol-rich infusions from carob leaves and OFI-cladodes on inflammation associated with obesity and dextran sulfate sodium (DSS)-induced ulcerative colitis in Swiss mice. In vitro studies revealed that aqueous extracts of carob leaves and OFI-cladodes exhibited anti-inflammatory properties marked by the inhibition of IL-6, TNF-α and nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells concomitant with NF-κß nucleus translocation inhibition. For in vivo investigations, Swiss male mice were subjected to control or high fat diet (HFD). At the 8th week after the start of study, animals received or not 1% infusion of either carob leaves or OFI-cladode for 4 weeks and were subjected to 2% DSS administration in drinking water over last 7 days. After sacrifice, pro-inflammatory cytokines levels in plasma and their mRNA expression in different organs were determined. Results showed that carob leaf and OFI-cladode infusions reduced inflammation severity associated with HFD-induced obesity and DSS-induced acute colitis indicated by decrease in pro-inflammatory cytokines expression (as such TNF-α, IL1b and IL-6) in colon, adipose tissue and spleen. In addition, plasma levels of IL-6 and TNF-α were also curtailed in response to infusions treatment. Thus, carob leaf and OFI-cladode infusions prevented intestinal permeability through the restoration of tight junction proteins (Zo1, occludins) and immune homeostasis. Hence, the anti-inflammatory effect of carob leaves and OFI-cladodes could be attributed to their polyphenols which might alleviate inflammation severity associated with obesity and colitis.
Colitis/drug therapy , Galactans/administration & dosage , Inflammation Mediators/antagonists & inhibitors , Mannans/administration & dosage , Obesity/drug therapy , Opuntia , Plant Gums/administration & dosage , Polyphenols/administration & dosage , Animals , Cell Line , Colitis/chemically induced , Colitis/metabolism , Dextran Sulfate/toxicity , Diet, High-Fat/adverse effects , Dose-Response Relationship, Drug , Fabaceae , Galactans/isolation & purification , Inflammation/drug therapy , Inflammation/metabolism , Inflammation Mediators/metabolism , Male , Mannans/isolation & purification , Mice , Obesity/etiology , Obesity/metabolism , Plant Gums/isolation & purification , Plant Leaves , Polyphenols/isolation & purification
[This corrects the article DOI: 10.1371/journal.pone.0170823.].
