Pharmacological and therapeutic effects of short-chain fatty acids in gastrointestinal and extra-intestinal disorders: evaluation of metabolic, hormonal and inflammatory parameters

The short chain fatty acid (SCFA) butyrate, a main end product of microbial fermentation of dietary fibers in human intestine, plays an important role in the maintenance of intestinal homeostasis and overall health status. The effects exerted by butyrate are multiple and involve several distinct mechanisms of action including epigenetic modifications owing to its inhibitory effects on histone deacetylases, inhibition of NF-κB signaling, or direct agonism on the free fatty acid receptors. At intestinal level, butyrate is the major energy source for colonocytes and acts regulating epithelial cell proliferation, defense barrier, visceral sensitivity and motility, preventing and inhibiting colonic carcinogenesis. Recent experimental evidence has suggested potential extra-intestinal therapeutic applications of butyrate, including the treatment of systemic diseases, among these not only metabolic and inflammatory disorders but also cystic fibrosis, urea cycle enzyme deficiency, X-linked adrenoleukodystrophy. Data from literature and clinical evidence of several research groups show a wide spectrum of possibilities for potential therapeutic use of butyrate by oral administration without having serious adverse effects. Some butyrate-based products are marketed, but their spread is still very limited and greatly understaffed in view of the wide spectrum of possible indications, especially in chronic diseases, where it is possible to predict a lasting use of the compound. The main problem is the availability of butyrate formulations that could overcome the main limitations to the use of butyrate in the therapeutic field, namely its instability and poor palatability. In fact, the unpleasant taste and odour make oral administration of butyrate extremely difficult, especially in children. On the basis of its characteristics, butyrate can be considered a “postbiotic” being a non-viable bacterial metabolic product obtained from probiotic microorganisms that have biologic activity in the host. The direct use of postbiotics, such as butyrate, may be potential alternatives to the use of live probiotic organisms or to dietary fiber intake as prebiotics exerting several and similar beneficial regulatory effects on host biological functions. Even if a growing number of studies has revealed new mechanisms and effects of butyrate with a wide range of potential clinical applications from the intestinal tract to peripheral tissues, more data are needed to elucidate the efficacy of butyrate in gastrointestinal and extra-intestinal diseases and new solutions for an easier administration. To date, several studies have evaluated butyrate effectiveness in several animal models of colitis. In humans few studies have been performed probably due to low compliance for the oral route (for its rancid taste) or rectal enemas administration (for its cumbersome application to the patient and irritability due to acid property). Here, about its intestinal effects, we examined the efficacy of oral butyrate and its derivative N-(1-carbamoyl-2-phenyl-ethyl) butyramide (FBA), as preventive or therapeutic treatment in a murine model of DSS-induced colitis. Both compounds are able to recover the imbalance between pro-inflammatory and anti-inflammatory mediators, altered in colitis and restore gut permeability, avoiding bacterial translocation and modulating immune cell recruitment. Butyrate anti-inflammatory effects are associated not only to the reduction in neutrophil infiltration and HDAC9 transcription in colonic mucosa, but also the restoration of PPAR-γ expression and inhibition of NF-kB activation, protecting colonocytes from inflammation. Alterations in the microbiota have now been implicated in the pathogenesis of some diseases, including food allergy. Intestinal microbiota influences immune system network and impairs its regulatory functions. Allergic infants exhibit an accelerated evolution of microbiota more typical of the adult one with a significantly reduced abundance of butyrate-producing species, such as Lactobacillales and Bifidobacteriales, and increased abundance of Clostridiales. Animal models of food allergy have emerged as tool for identifying mechanisms involved in the development of sensitization to normally harmless food allergens, as well as delineating the critical immune components of the effect or phase of allergic reactions to food. One of the critical advantages of using mouse models to study food allergy is that allergic sensitization or tolerance can be induced to specific allergens under controlled environmental conditions within defined genetic backgrounds, which is not possible in human subjects. This aspect of mouse models allows extensive and precise investigations into the mechanisms involved in disease etiology and responsible for loss of tolerance in patients, identifying new targets and efficacious therapies. Increasing evidence from several mouse models indicates that alterations in regulatory T (Treg) cell function and environmental factors, such as microbiota, are likely important contributors to allergic sensitization and food allergy. Here, we used a model of cow's milk allergy (CMA) induced in mice. In this experimental model of CMA the preventive and therapeutic effects of oral sodium butyrate administration were evaluated. Butyrate was able to suppress acute skin response to the β-lactoglobulin (BLG) allergen, one of the most important cow’s milk proteins, and to reduce anaphylactic symptoms and immediate immune response. Furthermore, butyrate ability to improve gut permeability was also shown, reducing plasma levels of FITC-Dextran evaluated after oral administration. Butyrate reduced ear swelling, hypersensitivity symptoms and limited the decrease of body temperature after BLG challenge. Moreover, butyrate decreased the innate immune response, reducing IgE and IL-4 levels. About butyrate extra-intestinal effect, our study was focused on osteoarthritis (OA), the most common form of arthritis worldwide, whose development is increased by aging, obesity and biomechanical injury. It is a cartilage degenerative disease where chondrocytes play a central role. In fact, in OA chondrocyte phenotype changes and apoptosis and extracellular matrix degradation occur. Using an in vitro model, we demonstrated the effect of sodium butyrate in reducing inflammatory mediators and pathways in chondrocytes activated by IL-1, and, more interestingly, we showed that its chemoattractant activity is mediated by GPR43. Butyrate, not only reduced pro-inflammatory cytokines and adipokines involved in OA, but also decreased the expression of several adhesion molecules, inhibiting inflammatory and anti-apoptotic pathways. We also show the butyrate capability to reduce MMPs production and the loss of collagen type 2, suggesting an improvement of cartilage disruption. Interestingly, butyrate anti-inflammatory effects were associated to its capability to stimulate neutrophil recruitment, increasing the expression of important chemokines (Ccl3 and Cx3cl1) and anti-inflammatory protein AnxA1, suggesting butyrate pro-resolving activity during inflammatory response. The novelty of our data is the involvement of GPR43 in the chemoattractant activity of butyrate in IL-1-stimulated chondrocytes. In fact, butyrate failed to induce the expression of Cx3cl1 and AnxA1 in GPR43-silenced cells, missing its chemoattractant effect. The pro-resolving effect of butyrate was also analyzed in two models of wound healing induced by doxorubicin or mechanical damage. In tissue repair the immediate goal is to achieve tissue integrity, homeostasis and wound healing. Tissue injury causes the immediate onset of acute inflammation. The healing process involves three phases that overlap in time and space: inflammation, tissue formation, and tissue remodeling. Synthesis, remodeling, and deposition of structural extracellular matrix molecules and soluble mediators, are indispensable for initiating repair and progression into the healing state. In our study, we demonstrated that butyrate and FBA treatments accelerate and promote wound resolution process. In our experimental models, we showed that butyrate and its derivative FBA reduced the repair time when used systemically (by oral administration) or topically (by intradermal injection). This protective effect appeared to be time- and concentration-dependent. In summary, we have demonstrated the multiple protective effect of butyrate in limiting molecular events underlying the onset of several inflammatory-based pathologies, suggesting a potential clinical relevance for this compound. In particular, we have also showed the efficacy of its synthetic derivative N-(1-carbamoyl-2-phenyl-ethyl) butyramide or FBA, demonstrating that it could represent an alternative therapeutic option to sodium butyrate, sharing a comparable efficacy, but better palatability and compliance

Butyrate Modulates Inflammation in Chondrocytes via GPR43 Receptor

Background/Aims: Osteoarthritis (OA) is a joint degenerative biomechanical disorder involving immunity, metabolic alterations, inflammation, and cartilage degradation, where chondrocytes play a pivotal role. OA has not effective pharmacological treatments and new therapeutic targets are needed. Adipokines contribute to the low-grade systemic inflammation in OA. Here, we explored novel molecular mechanisms of sodium butyrate (BuNa) in modulating inflammation and chemotaxis in chondrocytes, demonstrating the direct involvement of its G protein-coupled receptor (GPR)-43. Methods: ATDC5 murine chondrocytes were stimulated with interleukin (IL)-1β, in the presence or not of BuNa, for 24 h. RT-PCR and Western blot analysis was performed to evaluate the expression of inflammatory mediators and structural proteins. Results: Butyrate reduced the expression of canonic pro-inflammatory mediators (Nos2, COX-2, IL-6), pro-inflammatory adipokines (lipocalin-2 and nesfatin-1) and adhesion molecule (VCAM-1 and ICAM-1) in IL-1β-stimulated chondrocytes, inhibiting several inflammatory signalling pathways (NFκB, MAPKinase, AMPK-α, PI3K/Akt). Butyrate also reduced metalloproteinase production and limited the loss of type II collagen in IL-1β-inflamed chondrocytes. The chemoattractant effect of butyrate, after different inflammatory challenges, was revealed by increased annexin (AnxA)1 levels and chemokines expression. The chemoattractant and anti-inflammatory activities of butyrate were completely blunted by GPR43 silencing using RNA interference. Conclusion: Taken together, our data suggest the potential application of sodium butyrate as a novel candidate in a multi-target approach for the treatment of chondrocyte inflammation and cartilage degenerative process

Palmitoylethanolamide modulates high-fat diet-shaped gut function and microbiota composition in obese mice

Introduction/Background & aims: Emerging data indicate a pivotal role for gut microbiota in the progression of obesity. Indeed, in the gut, high-fat diet (HFD) intake induces the loss of barrier integrity, causing the transfer of detrimental factors (i.e. lipopolysaccharide, LPS) into the systemic circulation, leading to metabolic dysfunctions and an overall state of low-grade inflammation, called “met- ainflammation” [1]. The metabolic and anti-inflammatory activities of palmitoylethanolamide (PEA), an endogenous lipid mediator, prompt us to evaluate its capability to improve intestinal homeostasis and shape gut microbiota composition altered in HFD-fed obese mice. Method/Summary of work: Male C57Bl/6 J mice received standard diet (STD) or HFD (n = 10 each group). After 12 weeks, a subgroup of HFD mice was treated with PEA (30 μg/kg/die per os) for 7 weeks. Body weight was monitored during the treatment and fat mass was evaluated at the end of experimental time. Systemic parameters and intestinal function were examined using ELISA assay, and Real-Time PCR analysis, respectively. Faecal microbiota was studied by per- forming 16S rDNA amplicon sequencing and linear discriminant analy- sis in order to obtain the operational taxonomic units (OTUs) defining the bacterial communities

nutraceuticals an integrative approach to starve parkinson s disease

Abstract The therapeutic approach of multifactorial complex diseases is always a challenge; Parkinson's disease (PD) is a heterogeneous neurodegenerative disorder triggered by genetic and environmental factors, contributing to its etiology. Indeed, several pathogenic mechanisms lead to selective dopaminergic neuronal injury, including oxidative stress, mitochondrial dysfunction, alteration of endoplasmic reticulum-to-Golgi protein trafficking, excitotoxicity, and neuroinflammation. Current treatment approaches include mainly dopamine replacement therapy or optimizing dopaminergic transmission; however, these strategies that do not counteract the pathogenic mechanisms underlying PD symptoms and often are less effective over time. Recently, there have been growing interest in the therapeutic use of nutraceuticals, that could represent an integrative approach to the pharmacological standard therapy and specifically affect one or more pathogenic pathways. The intake of nutraceuticals or nutritional modifications are generally safe and can be combined with current common drug therapy in most cases to improve the patient's quality of life and/or mitigate PD symptoms. The current review focuses on several key nutritional compounds and dietary modifications that are effective on several pathogenic pathways involved in PD onset and progression, and further highlights the rationale behind their potential use for the prevention and treatment of PD

Extracorporeal shock waves alone or combined with raloxifene promote bone formation and suppress resorption in ovariectomized rats

Osteoporosis is a metabolic skeletal disease characterized by an imbalance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation. We examined the beneficial effect of shock waves (SW) alone or in combination with raloxifene (RAL) on bone loss in ovariectomized rats (OVX). Sixteen weeks after surgery, OVX were treated for five weeks with SW at the antero-lateral side of the right hind leg, one session weekly, at 3 Hz (EFD of 0.33 mJ/mm2), or with RAL (5 mg/kg/die, per os) or with SW+RAL. Sera, femurs, tibiae and vertebrae were sampled for following biochemical and histological analysis. SW, alone or combined with RAL, prevented femur weight reduction and the deterioration of trabecular microarchitecture both in femur and vertebrae. All treatments increased Speed of Sound (SoS) values, improving bone mineral density, altered by OVX. Serum parameters involved in bone remodeling (alkaline phosphatase, receptor activator of nuclear factor kappa-B ligand, osteoprotegerin) and osteoblast proliferation (PTH), altered by ovariectomy, were restored by SW and RAL alone or in combination. In tibiae, SW+RAL significantly reduced cathepsin k and TNF-α levels, indicating the inhibition of osteoclast activity, while all treatments significantly increased runt-related transcription factor 2 and bone morphogenetic-2 expression, suggesting an increase in osteoblastogenic activity. Finally, in bone marrow from tibiae, SW or RAL reduced PPARγ and adiponectin transcription, indicating a shift of mesenchymal cells toward osteoblastogenesis, without showing a synergistic effect. Our data indicate SW therapy, alone and in combination with raloxifene, as an innovative strategy to limit the hypoestrogenic bone loss, restoring the balance between bone formation and resorption

Social isolation triggers oxidative status and impairs systemic and hepatic insulin sensitivity in normoglycemic rats

Drug-naïve psychotic patients show metabolic and hepatic dysfunctions. The rat social isolation model of psychosis allows to investigate mechanisms leading to these disturbances to which oxidative stress crucially contributes. Here, we investigated isolation-induced central and peripheral dysfunctions in glucose homeostasis and insulin sensitivity, along with redox dysregulation. Social isolation did not affect basal glycemic levels and the response to glucose and insulin loads in the glucose and insulin tolerance tests. However, HOMA-Index value were increased in isolated (ISO) rats. A hypothalamic reduction of AKT phosphorylation and a trend toward an increase in AMPK phosphorylation were observed following social isolation, accompanied by reduced GLUT-4 levels. Social isolation also induced a reduction of phosphorylation of the insulin receptor, of AKT and GLUT-2, and a decreased phosphorylation of AMPK in the liver. Furthermore, a significant reduction in hepatic CPT1 and PPAR-α levels was detected. ISO rats also showed significant elevations in hepatic ROS amount, lipid peroxidation and NOX4 expression, whereas no differences were detected in NOX2 and NOX1 levels. Expression of SOD2 in the mitochondrial fraction and SOD1 in the cytosolic fraction was not altered following social isolation, whereas SOD activity was increased. Furthermore, a decrease of hepatic CAT and GSH amount was observed in ISO rats compared to GRP animals. Our data suggest that the increased oxidant status and antioxidant capacity modifications may trigger hepatic and systemic insulin resistance, by altering signal hormone pathway and sustaining subsequent alteration of glucose homeostasis and metabolic impairment observed in the social isolation model of psychosis

Patient's adherence on pharmacological therapy for benign prostatic hyperplasia (BPH)-associated lower urinary tract symptoms (LUTS) is different: Is combination therapy better than monotherapy

Abstract BACKGROUND: Recent studies showed that the non-adherence to the pharmacological therapy of patients affected by BPH-associated LUTS increased the risk of clinical progression of BPH. We examined the patients adherence to pharmacological therapy and its clinical consequences in men with BPH-associated LUTS looking at the differences between drug classes comparing mono vs combination therapy. METHODS: A retrospective, population-based cohort study, using prescription administrative database and hospital discharge codes from a total of 1.5 million Italian men. Patients ≥ 40 years, administered alpha-blockers (AB) and 5alpha-reductase inhibitors (5ARIs), alone or in combination (CT), for BPH-associated LUTS were analyzed. The 1-year and long term adherence together with the analyses of hospitalization rates for BPH and BPH-related surgery were examined using multivariable Cox proportional hazards regression model and Pearson chi square test. RESULTS: Patients exposed to at least 6 months of therapy had a 1-year overall adherence of 29 % (monotherapy AB 35 %, monotherapy 5ARI 18 %, CT 9 %). Patient adherence progressively declined to 15 %, 8 % and 3 % for AB, 5ARI, and CT, respectively at the fifth year of follow up. Patients on CT had a higher discontinuation rate along all the follow-up compared to those under monotherapy with ABs or 5ARIs (all p < 0.0001). Moreover, CT was associated with a reduced risk of hospitalization for BPH-related surgery (HR 0.94; p < 0.0001) compared to AB monotherapy. CONCLUSIONS: Adherence to pharmacological therapy of BPH-associated LUTS is low and varies depending on drugs class. Patients under CT have a higher likelihood of discontinuing treatment for a number of reasons that should be better investigated. Our study suggests that new strategies aiming to increase patient's adherence to the prescribed treatment are necessary in order to prevent BPH progression

Palmitoylethanolamide counteracts autistic-like behaviours in BTBR T+tf/J mice: Contribution of central and peripheral mechanisms

Abstract Autism spectrum disorders (ASD) are a group of heterogeneous neurodevelopmental conditions characterized by impaired social interaction, and repetitive stereotyped behaviours. Interestingly, functional and inflammatory gastrointestinal diseases are often reported as a comorbidity in ASDs, indicating gut-brain axis as a novel emerging approach. Recently, a central role for peroxisome-proliferator activated receptor (PPAR)-α has been addressed in neurological functions, associated with the behaviour. Among endogenous lipids, palmitoylethanolamide (PEA), a PPAR-α agonist, has been extensively studied for its anti-inflammatory effects both at central and peripheral level. Based on this background, the aim of this study was to investigate the pharmacological effects of PEA on autistic-like behaviour of BTBR T+tf/J mice and to shed light on the contributing mechanisms. Our results showed that PEA reverted the altered behavioural phenotype of BTBR mice, and this effect was contingent to PPAR-α activation. Moreover, PEA was able to restore hippocampal BDNF signalling pathway, and improve mitochondrial dysfunction, both pathological aspects, known to be consistently associated with ASDs. Furthermore, PEA reduced the overall inflammatory state of BTBR mice, reducing the expression of pro-inflammatory cytokines at hippocampal, serum, and colonic level. The analysis of gut permeability and the expression of colonic tight junctions showed a reduction of leaky gut in PEA-treated BTBR mice. This finding together with PEA effect on gut microbiota composition suggests an involvement of microbiota-gut-brain axis. In conclusion, our results demonstrated a therapeutic potential of PEA in limiting ASD symptoms, through its pleiotropic mechanism of action, supporting neuroprotection, anti-inflammatory effects, and the modulation of gut-brain axis

An orally administered butyrate-releasing derivative reduces neutrophil recruitment and inflammation in dextran sulphate sodium-induced murine colitis

BACKGROUND AND PURPOSE: Butyrate has shown benefits in inflammatory bowel diseases. However, it is not often administered orally because of its rancid smell and unpleasant taste. The efficacy of a more palatable butyrate-releasing derivative, N-(1-carbamoyl-2-phenylethyl) butyramide (FBA), was evaluated in a mouse model of colitis induced by dextran sodium sulphate (DSS). EXPERIMENTAL APPROACH: Male 10 week-old BALB/c mice received DSS (2.5%) in drinking water (for 5 days) followed by DSS-free water for 7 days (DSS group). Oral FBA administration (42.5 mg·kg-1 ) was started 7 days before DSS as preventive (P-FBA), or 2 days after DSS as therapeutic (T-FBA); both treatments lasted 19 days. One DSS-untreated group received only tap water (CON). KEY RESULTS: FBA treatments reduced colitis symptoms and colon damage. P-FBA and T-FBA significantly decreased polymorphonuclear cell infiltration score compared with the DSS group. FBA reversed the imbalance between pro- and anti-inflammatory cytokines (reducing inducible NOS protein expression, CCL2 and IL-6 transcripts in colon and increasing TGFβ and IL-10). Morever, P-FBA and T-FBA limited neutrophil recruitment (by expression and localization of the neutrophil granule protease Ly-6G), restored deficiency of the butyrate transporter and improved intestinal epithelial integrity, preventing tight-junction impairment (zonulin-1 and occludin). FBA, similar to its parental compound sodium butyrate, inhibited histone deacetylase-9 and restored H3 histone acetylation, exerting an anti-inflammatory effect through NF-κB inhibition and the up-regulation of PPARγ. CONCLUSIONS AND IMPLICATIONS: FBA reduces inflammatory intestinal damage in mice indicating its potential as a postbiotic derivative without the problems associated with the oral administration of sodium butyrate