Palmitoylethanolamide Promotes White-to-Beige Conversion and Metabolic Reprogramming of Adipocytes: Contribution of PPAR-α

Eco-friendly Synthesis and Molecular Modelling of 2-Phenylimidazo[1,2-b]pyridazine Derivatives: In Vitro and In Vivo Studies for Lead Optimization

7-methyl-2-phenylimidazo[1,2-b]pyridazin-3-carboxylic acid (DM1) and 6-methoxy-2-phenylimidazo[1,2-b]pyridazin-3-carboxylic acid (DM2) have been shown to act as human (h) Cav3.1 voltage-gated calcium channel blockers with promising in vivo anti-absence activity, positioning them as potential antiepileptic drugs. The primary aim of this work was to develop cost-effective and environmentally friendly synthetic procedures for preparing 2-phenylimidazo[1,2-b]pyridazine derivatives. After optimizing the synthesis of this compound class using efficient and green techniques such as microwaves and ultrasound irradiation, we further evaluated the antiepileptic effects of DM1 and DM2 in two animal models: CD-1 ICR mice after pentylenetetrazol administration and DBA/2 mice with seizures induced by audiogenic stimuli. Their neuroprotective effect against oxidative stress were assessed using C6 rat brain glioma cells. DM1 and DM2 exhibited potent anti-seizure effects in both animal models and demonstrated significant in vitro neuroprotective activity by reducing reactive oxygen species release. To lay the groundwork for the future rational optimization of this promising class of compounds, the molecular bases of DM1 and DM2 activity were investigated by modelling their interaction with hCav3.1 channels. The calculated binding modes of DM1 and DM2 to hCav3.1 channels partially mirrored that of the selective Cav3.1 blocker Z944, paving the way for future lead optimization.

The Effects of a Food Supplement, Based on Co-Micronized Palmitoylethanolamide (PEA)-Rutin and Hydroxytyrosol, in Metabolic Syndrome Patients: Preliminary Results

BACKGROUND

Metabolic syndrome (MetS) patients have impaired hypothalamic regulatory functions involved in food intake and energy expenditure and suffer from a state of meta-inflammation. Pre-clinical studies demonstrated that ultramicronized palmitoylethanolamide (PEA) acts both on the adipose tissue and the central nervous system, while hydroxytyrosol (HTyr) counteracts several types of dysmetabolism.

OBJECTIVES

The aim of our randomized crossover double-blind placebo-controlled pilot study was to evaluate the potential effects of a food supplement (FS) containing a co-micronized formulation of PEA and rutin along with HTyr, combined with a tailored calorie-controlled Mediterranean diet, in patients with MetS.

METHODS

Nineteen patients were enrolled and block-randomized to an eight-week MD together with the FS or placebo. After a two-week washout period, the treatments were reversed. Data on laboratory parameters and those detected by capillary sampling, anthropometry, body composition analysis, ultrasound examination, blood pressure monitoring, the 36-Item Short-Form Health Survey questionnaire, handgrip strength test, and physical performance tests were collected at each time point (protocol code R.S. 262.22, registered on 20 December 2022).

RESULTS

At the end of the study, patients supplemented with the FS showed a significant reduction in body weight, body mass index, fat mass, and inflammation biomarkers (CRP and ESR), compared to placebo-supplemented patients. In contrast, the fat-free mass, phase angle, and body cell mass were increased in FS compared to placebo patients.

CONCLUSIONS

Although preliminary, the results of our clinical study suggest that co-micronized PEA-rutin and HTyr may be of help against adiposopathy in patients with MetS.

The Anti-Obesity Effect of Fish Oil in Diet-Induced Obese Mice Occurs via Both Decreased Food Intake and the Induction of Heat Production Genes in Brown but Not White Adipose Tissue

Omega-3 (ω-3) polyunsaturated fatty acids in fish oil have been shown to prevent diet-induced obesity in lean mice and to promote heat production in adipose tissue. However, the effects of fish oil on obese animals remain unclear. This study investigated the effects of fish oil in obese mice. C57BL/6J mice were fed a lard-based high-fat diet (LD) for 8 weeks and then assigned to either a fish oil-based high-fat diet (FOD) or continued the LD for additional 8 weeks. A control group was fed a standard diet for 16 weeks. Mice fed the FOD showed weight loss, reduced adipose tissue mass, and lower plasma insulin and leptin levels compared to those fed the LD. Rectal temperatures were higher in the FOD and LD groups compared to the control group. Energy intake was lower in the FOD group than the LD group but similar to the control group. The FOD and LD groups exhibited increased expression of heat-producing genes such as Ppargc1a, Ucp1, Adrb3, and Ppara in brown adipose tissue but not in white adipose tissue. The FOD reduced food consumption and increased rectal temperature and heat-producing genes in brown adipose tissue. Fish oil may therefore be a potential therapeutic approach to obesity.

Palmitoylethanolamide in Postmenopausal Metabolic Syndrome: Current Evidence and Clinical Perspectives

Menopause leads to a decline in estrogen levels, resulting in significant metabolic alterations that increase the risk of developing metabolic syndrome-a cluster of conditions including central obesity, insulin resistance, dyslipidemia, and hypertension. Traditional interventions such as hormone replacement therapy carry potential adverse effects, and lifestyle modifications alone may not suffice for all women. This review explores the potential role of palmitoylethanolamide (PEA), an endogenous fatty acid amide, in managing metabolic syndrome during the postmenopausal period. PEA primarily acts by activating peroxisome proliferator-activated receptor-alpha (PPAR-α), influencing lipid metabolism, energy homeostasis, and inflammation. Evidence indicates that PEA may promote the browning of white adipocytes, enhancing energy expenditure and reducing adiposity. It also improves lipid profiles by boosting fatty acid oxidation and decreasing lipid synthesis, potentially lowering low-density lipoprotein cholesterol and triglyceride levels while increasing high-density lipoprotein cholesterol. Additionally, the anti-inflammatory properties of PEA enhance insulin sensitivity by reducing pro-inflammatory cytokines that interfere with insulin signaling. PEA may aid in weight management by influencing appetite regulation and improving leptin sensitivity. Furthermore, its neuroprotective effects may address the mood disturbances and cognitive decline associated with menopause. Given these multifaceted biological activities and a favorable safety profile, PEA may represent a promising non-pharmacological supplement for managing metabolic syndrome in postmenopausal women. However, further large-scale clinical studies are necessary to establish its efficacy, optimal dosing, and long-term safety. If validated, PEA could become an integral part of strategies to improve metabolic and neuropsychological health outcomes in this population.

Co-Micronized Palmitoylethanolamide and Rutin Associated With Hydroxytyrosol Recover Diabesity-Induced Hepatic Dysfunction in Mice: In Vitro Insights Into the Synergistic Effect

Metabolic dysfunction-associated fatty liver disease (MAFLD) and diabesity (diabetes related to obesity) are interrelated since glucose and lipid alterations play a vital role in the development of both disorders. Due to their multi-variant metabolic features, more than one drug or natural product may be required to achieve proper therapeutic effects. This study aimed to evaluate the effectiveness of a formulation containing co-micronized palmitoylethanolamide and rutin (PEA-Rut) associated with hydroxytyrosol (HT), namely NORM3, against hepatic damage and metabolic alterations in high-fat diet (HFD)-induced diabesity in mice. NORM3 decreased the body weight and fat mass of obese mice. The formulation improved HFD-altered insulin sensitivity and hepatic glucose production and metabolism, as shown by glucose, insulin, pyruvate tolerance tests, Western blot, and real-time PCR. In the liver, NORM3 limited macro- and micro-vacuolar steatosis, as revealed by morphological analysis, and reduced the associated hepatic inflammation. NORM3 counteracted lipid dysfunctions of HFD animals, activating AMPK, a key cellular energy sensor, and normalizing the expression of carnitine palmitoyl-transferase (CPT)1, a rate-limiting enzyme of fatty acid β-oxidation, and other genes involved in lipid homeostasis. Relevantly, the hepatic antioxidant activity of NORM3 was proved (reduced ROS and increased detoxifying factors and enzymes). Finally, in vitro synergistic protective effects of the components (PEA-Rut and HT) on H2O2-induced oxidative challenge in HepG2 were determined (ROS production, inflammation, and antioxidant defense). Our results show the beneficial effect of NORM3 and its potential as an innovative phytotherapeutic combination in limiting hepatic damage progression and counteracting glucose and lipid dysmetabolism associated with diabesity.

Palmitoylethanolamide, an endogenous fatty acid amide, and its pleiotropic health benefits: A narrative review

The global nutritional transition has led to high frequency and severity of chronic degenerative diseases worldwide, primarily driven by chronic inflammatory stress. At the mealtimes, various pharmaceutical products aim to prevent such an inflammatory stress, they usually cause various systemic side effects. Therefore, supplementation of natural and safe ingredients is a great strategy to reduce the risk and severity of inflammatory stress-related diseases. As a result, palmitoylethanolamide (PEA), an endocannabinoid-like mediator, has been extensively studied for its myriad of actions, including anti-inflammatory, anti-microbial, immunostimulatory, neuroprotective, and pain-reducing effects with high tolerability and safety of PEA in animals and humans. Because of the multiple molecular targets and mechanisms of action, PEA has shown therapeutic benefits in various diseases, including neurological, psychiatric, ophthalmic, metabolic, oncological, renal, hepatic, immunological, rheumatological, and gastrointestinal conditions. The current review highlights the roles and functions of PEA in various physiological and pathological conditions, further supporting the use of PEA as an important dietary agent.

New insights into the role of mitochondrial dynamics in oxidative stress-induced diseases

The accumulation of excess reactive oxygen species (ROS) can lead to oxidative stress (OS), which can induce gene mutations, protein denaturation, and lipid peroxidation directly or indirectly. The expression is reduced ATP level in cells, increased cytoplasmic Ca2+, inflammation, and so on. Consequently, ROS are recognized as significant risk factors for human aging and various diseases, including diabetes, cardiovascular diseases, and neurodegenerative diseases. Mitochondria are involved in the production of ROS through the respiratory chain. Abnormal mitochondrial characteristics, including mitochondrial OS, mitochondrial fission, mitochondrial fusion, and mitophagy, play an important role in various tissues. However, previous excellent reviews focused on OS-induced diseases. In this review, we focus on the latest progress of OS-induced mitochondrial dynamics, discuss OS-induced mitochondrial damage-related diseases, and summarize the OS-induced mitochondrial dynamics-related signaling pathways. Additionally, it elaborates on potential therapeutic methods aimed at preventing oxidative stress from further exacerbating mitochondrial disorders.

The human milk endocannabinoidome and neonatal growth in gestational diabetes

Objective

Endocannabinoids and their N-acyl-ethanolamines (NAEs) and 2monoacyl-glycerols (2-MAGs) congeners are involved in the central and peripheral regulation of energy homeostasis, they are present in human milk and are associated with obesity. Infants exposed in utero to gestational diabetes mellitus (GDM) are more likely to develop obesity. The objective of this cross-sectional study is to compare the profile of eCBome mediators in milk of women with gestational diabetes (GDM+) and without (GDM-) and to assess the association with offspring growth. The hypothesis is that the eCBome of GDM+ human milk is altered and associated with a difference in infant growth.

Methods

Circulating eCBome mediators were measured by LC-MS/MS in human milk obtained at 2 months postpartum from GDM+ (n=24) and GDM- (n=29) women. Infant weight and height at 2 months were obtained from the child health record. Z-scores were calculated.

Results

Circulating Npalmitoylethanolamine (PEA) was higher in human milk of GDM+ women than in GDM- women (4.9 ± 3.2 vs. 3.3 ± 1.7, p=0.04). Higher levels were also found for several 2monoacyl-glycerols (2-MAGs) (p<0.05). The levels of NAEs (β=-4.6, p=0.04) and especially non-omega-3 NAEs (B=-5.6, p=0.004) in human milk were negatively correlated with weight-for-age z-score of GDM+ offspring.

Conclusion

The profile of eCBome mediators in human milk at 2 months postpartum was different in GDM+ compared to GDM- women and was associated with GDM+ offspring growth at 2 months.

Clinical trial registration

ClinicalTrials.gov, identifier (NCT04263675 and NCT02872402).

Targeting liver and adipose tissue in obese mice: Effects of a N-acylethanolamine mixture on insulin resistance and adipocyte reprogramming

N-acylethanolamines (NAEs) are endogenous lipid-signalling molecules involved in inflammation and energy metabolism. The potential pharmacological effect of NAE association in managing inflammation-based metabolic disorders is unexplored. To date, targeting liver-adipose axis can be considered a therapeutic approach for the treatment of obesity and related dysfunctions. Here, we investigated the metabolic effect of OLALIAMID® (OLA), an olive oil-derived NAE mixture, in limiting liver and adipose tissue (AT) dysfunction of high-fat diet (HFD)-fed mice. OLA reduced body weight and fat mass in obese mice, decreasing insulin resistance (IR), as shown by homeostasis model assessment index, and leptin/adiponectin ratio, a marker of adipocyte dysfunction. OLA improved serum lipid and hepatic profile and the immune/inflammatory pattern of metainflammation. In liver of HFD mice, OLA treatment counteracted glucose and lipid dysmetabolism, restoring insulin signalling (phosphorylation of AKT and AMPK), and reducing mRNAs of key markers of fatty acid accumulation. Furthermore, OLA positively affected AT function deeply altered by HFD by reprogramming of genes involved in thermogenesis of interscapular brown AT (iBAT) and subcutaneous white AT (scWAT), and inducing the beigeing of scWAT. Notably, the NAE mixture reduced inflammation in iBAT and promoted M1-to-M2 macrophage shift in scWAT of obese mice. The tissue and systemic anti-inflammatory effects of OLA and the increased expression of glucose transporter 4 in scWAT contributed to the improvement of gluco-lipid toxicity and insulin sensitivity. In conclusion, we demonstrated that this olive oil-derived NAE mixture is a valid nutritional strategy to counteract IR and obesity acting on liver-AT crosstalk, restoring both hepatic and AT function and metabolism.

Palmitoylethanolamide counteracts high-fat diet-induced gut dysfunction by reprogramming microbiota composition and affecting tryptophan metabolism

Obesity is associated with gastrointestinal (GI) tract and central nervous system (CNS) disorders. High-fat diet (HFD) feeding-induced obesity in mice induces dysbiosis, causing a shift toward bacteria-derived metabolites with detrimental effects on metabolism and inflammation: events often contributing to the onset and progression of both GI and CNS disorders. Palmitoylethanolamide (PEA) is an endogenous lipid mediator with beneficial effects in mouse models of GI and CNS disorders. However, the mechanisms underlining its enteroprotective and neuroprotective effects still need to be fully understood. Here, we aimed to study the effects of PEA on intestinal inflammation and microbiota alterations resulting from lipid overnutrition. Ultramicronized PEA (30 mg/kg/die per os) was administered to HFD-fed mice for 7 weeks starting at the 12th week of HFD regimen. At the termination of the study, the effects of PEA on inflammatory factors and cells, gut microbial features and tryptophan (TRP)-kynurenine metabolism were evaluated. PEA regulates the crosstalk between the host immune system and gut microbiota via rebalancing colonic TRP metabolites. PEA treatment reduced intestinal immune cell recruitment, inflammatory response triggered by HFD feeding, and corticotropin-releasing hormone levels. In particular, PEA modulated HFD-altered TRP metabolism in the colon, rebalancing serotonin (5-HT) turnover and reducing kynurenine levels. These effects were associated with a reshaping of gut microbiota composition through increased butyrate-promoting/producing bacteria, such as Bifidobacterium, Oscillospiraceae and Turicibacter sanguinis, with the latter also described as 5-HT sensor. These data indicate that the rebuilding of gut microbiota following PEA supplementation promotes host 5-HT biosynthesis, which is crucial in regulating intestinal function.

Changes in plasma endocannabinoids concentrations correlate with 18F-FDG PET/MR uptake in brown adipocytes in humans

Introduction: Recent data suggest a possible role of endocannabinoids in the regulation of brown adipose tissue (BAT) activity. Those findings indicate potential treatment options for obesity. The aim of this study was to evaluate the relationship between plasma endocannabinoids concentrations and the presence of BAT in humans. Methods: The study group consisted of 25 subjects divided into two groups: BAT positive BAT(+), (n = 17, median age = 25 years) and BAT negative BAT(-), (n = 8, median age = 28 years). BAT was estimated using 18F-FDG PET/MR after 2 h of cold exposure. The level of plasma endocannabinoids was assessed at baseline, 60 min and 120 min of cold exposure. Results: In both groups, BAT(+) and BAT(-), during the cooling, we observed a decrease of the same endocannabinoids: arachidonoylethanolamide (AEA), eicosapentaenoyl ethanolamide (EPEA) and oleoyl ethanolamide (OEA) with a much more profound decline in BAT(+) subjects. Statistically significant fall of PEA (palmitoylethanolamide) and SEA (stearoylethanolamide) concentrations after 60 min (FC = 0.7, p = 0.007 and FC = 0.8, p = 0.03, respectively) and 120 min (FC = 0.81, p = 0.004, and FC = 0.9, p = 0.01, respectively) of cooling was observed only in individuals with BAT. Conclusion: We noticed the profound decline of endocannabinoids concentrations in subjects with increased 18F-FDG PET/MR uptake in BAT. Identification of a new molecules related to BAT activity may create a new target for obesity treatment.

Cytokines and regulation of glucose and lipid metabolism in the obesity

The article presents data of the influence of cytokines of different directions of glucose and lipid metabolism in obesity. A change of the basic paradigm regarding adipose tissue has contributed to a number of recent discoveries. This concerns such basic concepts as healthy and diseased adipocytes, and, as a consequence, changes of their metabolism under the influence of cytokins. Distinguishing the concept of organokines demonstrates that despite the common features of cytokine regulation, each organ has its own specifics features of cytokine regulation, each organ has its own specific an important section of this concept is the idea of the heterogeneity of adipose tissue. Knowledge of the function of adipose tissue localized in different compartments of the body is expanding. There are date about the possibility of transition of one type of adipose tissue to another. A possible mechanism linking adipose tissue inflammation and the formation of insulin resistance (IR) is presented in this paper. The mechanism of IR development is closely connected with to proinflammatory cytokins disordering the insulin signal, accompanied by a decrease of the work of glucose transporters. A decrease of the income of glucose into cells leads to a change of glycolysis level to an increase of the fatty acids oxidation. Cytokins are able to participate in the process of the collaboration of some cells with others, that occurs both during physiological and pathological process.

Sex differences in endocannabinoids during 3 years of Mediterranean diet intervention: Association with insulin resistance and weight loss in a population with metabolic syndrome

BACKGROUND

Excess circulating endocannabinoids (eCBs) and imbalanced N-acylethanolamines (NAEs) related eCBs abundance could influence dietary weight loss success. We aimed to examine sex differences in the impact of a 3-years Mediterranean diet (MedDiet) intervention on circulating eCBs, NAEs and their precursor fatty acids, and to analyze the interplay between changes in eCBs or NAEs ratios, insulin resistance and the achievement of clinically meaningful weight reductions.

METHODS

Prospective cohort study in a subsample of N = 105 participants (54.3% women; 65.6 ± 4.6 years) with overweight or obesity and metabolic syndrome that underwent a 3-years MedDiet intervention (PREDIMED-Plus study). Plasma eCBs and NAEs, including 2-arachidonoylglycerol (2-AG), anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), fatty acids, diet, glycemic homeostasis (including the assessment of insulin resistance-HOMA-IR), and cardiovascular risk markers were monitored (at 0-6-12-36 months).

RESULTS

Mediterranean diet adherence increased in both sexes and remained high during the 3 years of follow-up. Reductions in body weight, glycemic and cardiovascular parameters were larger in men than in women. Women presented higher concentrations of NAEs than men throughout the study. In both sexes, AEA and other NAEs (including OEA, and PEA) decreased after 6 months (for AEA: -4.9%), whereas the ratio OEA/AEA increased after 1 year (+5.8%). Changes in 2-AG (-3.9%) and the ratio OEA/PEA (+8.2%) persisted over the 3 years of follow-up. In women, 6-months changes in AEA (OR = 0.65) and the ratio OEA/AEA (OR = 3.28) were associated with the achievement of 8% weight reductions and correlated with HOMA-IR changes (r = 0.29 and r = -0.34). In men, OEA/PEA changes were associated with 8% weight reductions (OR = 2.62) and correlated with HOMA-IR changes (r = -0.32).

CONCLUSION

A 3-years MedDiet intervention modulated plasma concentrations of eCBs and NAEs. Changes in AEA and in the relative abundance of NAEs were associated with clinically meaningful weight reductions. However, marked sex differences were identified in eCBs and NAEs, as well as in the efficacy of the intervention in terms of glycemic and cardiovascular parameters, which could be related to post-menopause alterations in glucose metabolism. These findings support a sex-balanced research strategy for a better understanding of the mechanisms underlying the regulation of body weight loss.

Integrated omics analysis reveals differences in gut microbiota and gut-host metabolite profiles between obese and lean chickens

Abdominal fat is the major adipose tissue in chickens. In chicken, the deposition of abdominal fat affects meat yield and quality. Previous reports suggest that gut microbiota composition and function are associated with lipid metabolism. In this study, we used comparative metagenomics and metabolomics analysis to determine the gut microbiota and gut-host metabolite profiles in Shouguang (SG; a Chinese chicken breed with low-fat deposition) and Luqin (LQ; a fatty-type chicken breed with a fast growth rate) chickens. The results showed that LQ chickens had higher body weight, eviscerated yield, abdominal fat yield, abdominal fat ratio, and triglyceride (TG) content in the breast muscle than SG chickens. Untargeted metabolomics analyses showed a total of 11 liver metabolites, 19 plasma metabolites, and 30 cecal metabolites differentially enriched in LQ and SG chickens based on variable importance in the projection (VIP) ≥ 1 and P ≤ 0.05. These metabolites are involved in lipid and amino acid metabolism. The relative abundance of bacteria in the microbiota differed significantly between the 2 chicken breeds. The functional prediction of microbiota abundant in LQ chickens was starch and lactose degradation. Erysipelatoclostridium was abundant in LQ chickens and significantly positively correlated to palmitoyl ethanolamide (PEA), a key regulator of lipid metabolism. Our findings revealed differences in liver and plasma metabolites between chicken breeds with different adipose deposition capacities. Long-chain acylcarnitines might be important markers of adipose deposition differences in chickens. The cecum's microbial communities and metabolome profiles significantly differed between LQ and SG chickens. However, the relationship between cecal microbiota and their metabolites and liver and plasma metabolites is not thoroughly understood. Future research will focus on relating tissue metabolite changes to intestinal microbiota and their effects on body fat deposition.

Palmitoylethanolamide and Related ALIAmides for Small Animal Health: State of the Art

ALIAmides are a family of fatty acid amides whose name comes from their mechanism of action, i.e., the Autacoid Local Injury Antagonism (ALIA). Actually, the ALIAmide parent molecule, palmitoylethanolamide (PEA), is locally produced on demand from a cell membrane precursor in order to control immune-inflammatory cell responses, avert chronic non-resolving inflammation, and limit the resulting clinical signs. ALIAmide sister compounds, such as Adelmidrol and palmitoylglucosamine, share mechanisms of action with PEA and may also increase endogenous levels of PEA. Provided that their respective bioavailability is properly addressed (e.g., through decreasing the particle size through micronization), exogenously administered ALIAmides thus mimic or sustain the prohomeostatic functions of endogenous PEA. The aim of the present paper is to review the main findings on the use of ALIAmides in small animals as a tribute to the man of vision who first believed in this “according-to-nature” approach, namely Francesco della Valle. After briefly presenting some key issues on the molecular targets, metabolism, and pharmacokinetics of PEA and related ALIAmides, here we will focus on the preclinical and clinical studies performed in dogs and cats. Although more data are still needed, ALIAmides may represent a novel and promising approach to small animal health.