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The aim of this study was to determine the anti-hypersensitivity activity of novel non-hallucinogenic compounds derived from iboga alkaloids (i.e., ibogalogs), including tabernanthalog (TBG), ibogainalog (IBG), and ibogaminalog (DM506), using mouse models of neuropathic (Chronic Constriction Injury; CCI) and visceral pain (dextrane sulfate sodium; DSS). Ibogalogs decreased mechanical hyperalgesia and allodynia induced by CCI in a dose- and timeframe-dependent manner, where IBG showed the longest anti-hyperalgesic activity at a comparatively lower dose, whereas DM506 displayed the quickest response. These compounds also decreased hypersensitivity induced by colitis, where DM506 showed the longest activity. To understand the mechanisms involved in these effects, two approaches were utilized: ibogalogs were challenged with the 5-HT2A receptor antagonist ketanserin and the pharmacological activity of these compounds was assessed at the respective 5-HT2A, 5-HT6, and 5-HT7 receptor subtypes. The behavioral results clearly demonstrated that ketanserin abolishes the pain-relieving activity of ibogalogs without inducing any effect per se, supporting the concept that 5-HT2A receptor activation, but not inhibition, is involved in this process. The functional results showed that ibogalogs potently activate the 5-HT2A and 5-HT6 receptor subtypes, whereas they behave as inverse agonists (except TBG) at the 5-HT7 receptor. Considering previous studies showing that 5-HT6 receptor inhibition, but not activation, and 5-HT7 receptor activation, but not inhibition, relieved chronic pain, we can discard these two receptor subtypes as participating in the pain-relieving activity of ibogalogs. The potential involvement of 5-HT2B/2 C receptor subtypes was also ruled out. In conclusion, the anti-hypersensitivity activity of ibogalogs in mice is mediated by a mechanism involving 5-HT2A receptor activation.

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Identifying compounds that are neurotoxic either toward the central or the peripheral nervous systems (CNS or PNS) would greatly benefit early stages of drug development by derisking liabilities and selecting safe compounds. Unfortunately, so far assays mostly rely on histopathology findings often identified after repeated-dose toxicity studies in animals. The European NeuroDeRisk project aimed to provide comprehensive tools to identify compounds likely inducing neurotoxicity. As part of this project, the present work aimed to identify diagnostic non-invasive biomarkers of PNS toxicity in mice. We used two neurotoxic drugs in vivo to correlate functional, histopathological and biological findings. CD1 male mice received repeated injections of oxaliplatin or paclitaxel followed by an assessment of drug exposure in CNS/PNS tissues. Functional signs of PNS toxicity were assessed using electronic von Frey and cold paw immersion tests (oxaliplatin), and functional observational battery, rotarod and cold plate tests (paclitaxel). Plasma concentrations of neurofilament light chain (NF-L) and vascular endothelial growth factor A (VEGF-A) were measured, and histopathological evaluations were performed on a comprehensive list of CNS and PNS tissues. Functional PNS toxicity was observed only in oxaliplatin-treated mice. Histopathological findings were observed dose-dependently only in paclitaxel groups. While no changes of VEGF-A concentrations was recorded, NF-L concentrations were increased only in paclitaxel-treated animals as early as 7 days after the onset of drug administration. These results show that plasma NF-L changes correlated with microscopic changes in the PNS, thus strongly suggesting that NF-L could be a sensitive and specific biomarker of PNS toxicity in mice.

(1) Background: Dry eye disease (DED) is a multifactorial ocular surface disease characterized by an imbalance in ocular surface homeostasis, and tear substitutes constitute the first line of treatment. The present study aimed to evaluate the changes in the signs and symptoms of patients with DED treated with a novel tear substitute containing the GlicoPro® complex. (2) Methods: Patients with DED not successfully responding to other tear substitutes were enrolled and treated with a novel ophthalmic solution (two drops four times daily). Patients were examined before starting the study treatment (T0) and after 30 (T1) and 60 (T2) days of treatment by means of Keratograph for the evaluation of the following: (i) tear meniscus height (TMH); (ii) noninvasive Keratograph break-up time (NIKBUT); (iii) bulbar redness; and (iv) infrared meibography. The SANDE questionnaire was administered to assess ocular discomfort symptoms. Analysis of the tear content of proenkephalin and Met/Leu-enkephalin was also performed. (3) Results: At T2, a significant improvement in NIKBUT first, average, and class, TMH, and SANDE score was found. The tear content of proenkephalins was significantly higher at T1, whereas processed active Met/Leu-enkephalins increased at both T1 and T2. (4) Conclusions: Our novel tear substitute based on GlicoPro® resulted in a significant improvement in ocular discomfort symptoms, tear volume, and stability in the patients treated. The increase in active peptides processed in tears may represent the pathophysiological substrate underlying this finding.

Human (h) carbonic anhydrase (CAs, EC 4.2.1.1) isoforms IX and XII were recently confirmed as anticancer targets against solid hypoxic tumours. The “three-tails approach” has been proposed as an extension of the forerunner “tail” and “dual-tail approach” to fully exploit the amino acid differences at the medium/outer active site rims among different hCAs and to obtain more isoform-selective inhibitors. Many three-tailed inhibitors (TTIs) showed higher selectivity against the tumour-associated isoforms hCA IX and XII with respect to the off-targets hCA I and II. X-ray crystallography studies were performed to investigate the binding mode of four TTIs in complex with a hCA IX mimic. The ability of the most potent and selective TTIs to reduce in vitro the viability of colon cancer (HT29), prostate adenocarcinoma (PC3), and breast cancer (ZR75-1) cell lines was evaluated in normoxic (21% O2) and hypoxic (3% O2) conditions demonstrating relevant anti-proliferative effects.

Modulation of mitochondrial K channels represents a pharmacological strategy to promote cardioprotective effects. Isothiocyanates emerge as molecules capable of releasing hydrogen sulfide (H2S), an endogenous pleiotropic gasotransmitter responsible for anti-ischemic cardioprotective effects also through the involvement of mitoK channels. Erucin (ERU) is a natural isothiocyanate resulting from the enzymatic hydrolysis of glucosinolates (GSLs) present in Eruca sativa Mill. seeds, an edible plant of the Brassicaceae family. In this experimental work, the specific involvement of mitoKATP channels in the cardioprotective effect induced by ERU was evaluated in detail. An in vivo preclinical model of acute myocardial infarction was reproduced in rats to evaluate the cardioprotective effect of ERU. Diazoxide was used as a reference compound for the modulation of potassium fluxes and 5-hydroxydecanoic acid (5HD) as a selective blocker of KATP channels. Specific investigations on isolated cardiac mitochondria were carried out to evaluate the involvement of mitoKATP channels. The results obtained showed ERU cardioprotective effects against ischemia/reperfusion (I/R) damage through the involvement of mitoKATP channels and the consequent depolarizing effect, which in turn reduced calcium entry and preserved mitochondrial integrity.

Hydrogen sulfide (H2S) is a signaling molecule endogenously produced within mammals’ cells that plays an important role in inflammation, exerting anti-inflammatory effects. In this view, the research has shown a growing interest in identifying natural H2S donors. Herein, for the first time, the potential of marine extract as a source of H2S-releasing agents has been explored. Different fractions obtained by the Indonesian ascidian Polycarpa aurata were evaluated for their ability to release H2S in solution. The main components of the most active fraction were then characterized by liquid chromatography–high-resolution mass spectrometry (LC-HRMS) and NMR spectroscopy. The ability of this fraction to release H2S was evaluated in a cell-free assay and J774 macrophages by a fluorimetric method, and its anti-inflammatory activity was evaluated in vitro and in vivo by using carrageenan-induced mouse paw edema. The anti-inflammatory effects were assessed by inhibiting the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX2), and interleukin-6 (IL-6), coupled with a reduction in nitric oxide (NO) and IL-6 levels. Thus, this study defines the first example of a marine source able to inhibit inflammatory responses in vivo through the release of H2S.

The management of abdominal pain in patients affected by inflammatory bowel diseases (IBDs) still represents a problem because of the lack of effective treatments. Acetyl L-carnitine (ALCAR) has proved useful in the treatment of different types of chronic pain with excellent tolerability. The present work aimed at evaluating the anti-hyperalgesic efficacy of ALCAR in a model of persistent visceral pain associated with colitis induced by 2,4-dinitrobenzene sulfonic acid (DNBS) injection. Two different protocols were applied. In the preventive protocol, ALCAR was administered daily starting 14 days to 24 h before the delivery of DNBS. In the interventive protocol, ALCAR was daily administered starting the same day of DNBS injection, and the treatment was continued for 14 days. In both cases, ALCAR significantly reduced the establishment of visceral hyperalgesia in DNBS-treated animals, though the interventive protocol showed a greater efficacy than the preventive one. The interventive protocol partially reduced colon damage in rats, counteracting enteric glia and spinal astrocyte activation resulting from colitis, as analyzed by immunofluorescence. On the other hand, the preventive protocol effectively protected enteric neurons from the inflammatory insult. These findings suggest the putative usefulness of ALCAR as a food supplement for patients suffering from IBDs.

[This corrects the article DOI: 10.1371/journal.pone.0170825.].

Abstract Background Neuropathic pain is a clinically relevant adverse effect of several anticancer drugs that markedly impairs patients’ quality of life and frequently leads to dose reduction or therapy discontinuation. The poor knowledge about the mechanisms involved in neuropathy development and pain chronicization, and the lack of effective therapies, make treatment of chemotherapy-induced neuropathic pain an unmet medical need. In this context, the vascular endothelial growth factor A (VEGF-A) has emerged as a candidate neuropathy hallmark and its decrease has been related to pain relief. In the present study, we have investigated the role of VEGF-A and its receptors, VEGFR-1 and VEGFR-2, in pain signalling and in chemotherapy-induced neuropathy establishment as well as the therapeutic potential of receptor blockade in the management of pain. Methods Behavioural and electrophysiological analyses were performed in an in vivo murine model, by using selective receptor agonists, blocking monoclonal antibodies or siRNA-mediated silencing of VEGF-A and VEGFRs. Expression of VEGF-A and VEGFR-1 in astrocytes and neurons was detected by immunofluorescence staining and confocal microscopy analysis. Results In mice, the intrathecal infusion of VEGF-A (VEGF165 isoforms) induced a dose-dependent noxious hypersensitivity and this effect was mediated by VEGFR-1. Consistently, electrophysiological studies indicated that VEGF-A strongly stimulated the spinal nociceptive neurons activity through VEGFR-1. In the dorsal horn of the spinal cord of animals affected by oxaliplatin-induced neuropathy, VEGF-A expression was increased in astrocytes while VEGFR-1 was mainly detected in neurons, suggesting a VEGF-A/VEGFR-1-mediated astrocyte-neuron cross-talk in neuropathic pain pathophysiology. Accordingly, the selective knockdown of astrocytic VEGF-A by intraspinal injection of shRNAmir blocked the development of oxaliplatin-induced neuropathic hyperalgesia and allodynia. Interestingly, both intrathecal and systemic administration of the novel anti-VEGFR-1 monoclonal antibody D16F7, endowed with anti-angiogenic and antitumor properties, reverted oxaliplatin-induced neuropathic pain. Besides, D16F7 effectively relieved hypersensitivity induced by other neurotoxic chemotherapeutic agents, such as paclitaxel and vincristine. Conclusions These data strongly support the role of the VEGF-A/VEGFR-1 system in mediating chemotherapy-induced neuropathic pain at the central nervous system level. Thus, treatment with the anti-VEGFR-1 mAb D16F7, besides exerting antitumor activity, might result in the additional advantage of attenuating neuropathic pain when combined with neurotoxic anticancer agents.

Obesity is a health concern worldwide, and its onset is multifactorial. In addition to metabolic syndrome, a high-fat diet induces many deleterious downstream effects, such as chronic systemic inflammation, a loss of gut barrier integrity, and gut microbial dysbiosis, with a reduction of many butyrate-producing bacteria. These conditions can be ameliorated by increasing legumes in the daily diet. White and kidney beans (Phaseolus vulgaris L.) and their non-nutritive bioactive component phaseolamin were demonstrated to mitigate several pathological features related to a metabolic syndrome-like condition. The aim of the present study was to investigate the molecular pathways involved in the protective effects on the intestinal and liver environment of a chronic oral treatment with P. vulgaris extract (PHAS) on a murine model of the high-fat diet. Results show that PHAS treatment has an anti-inflammatory effect on the liver, colon, and cecum. This protective effect was mediated by peroxisome proliferator-activated receptor (PPAR)-α and γ. Moreover, we also observed that repeated PHAS treatment was able to restore tight junctions’ expression and protective factors of colon and cecum integrity disrupted in HFD mice. This improvement was correlated with a significant increase of butyrate levels in serum and fecal samples compared to the HFD group. These data underline that prolonged treatment with PHAS significantly reduces some pathological features related to the metabolic syndrome-like condition, such as inflammation and intestinal barrier disruption; therefore, PHAS could be a valid tool to be associated with the therapeutic strategy.

Experimental evidence suggests that neuroinflammation is a key pathological event of many diseases affecting the nervous system. It has been well recognized that these devastating illnesses (e.g., Alzheimer’s, Parkinson’s, depression, and chronic pain) are multifactorial, involving many pathogenic mechanisms, reason why pharmacological treatments are unsatisfactory. The purpose of this study was to evaluate the efficacy of a vegetal mixture capable of offering a multiple approach required to manage the multifactoriality of neuroinflammation. A mixture composed of Zingiber officinale (150 mg kg−1), Echinacea purpurea (20 mg kg−1), and Centella asiatica (200 mg kg−1) was tested in a mouse model of systemic neuroinflammation induced by lipopolysaccharide (LPS, 1 mg kg−1). Repeated treatment with the vegetal mixture was able to completely counteract thermal and mechanical allodynia as reported by the Cold plate and von Frey tests, respectively, and to reduce the motor impairments as demonstrated by the Rota rod test. Moreover, the mixture was capable of neutralizing the memory loss in the Passive avoidance test and reducing depressive-like behavior in the Porsolt test, while no efficacy was shown in decreasing anhedonia as demonstrated by the Sucrose preference test. Finally, LPS stimulation caused a significant increase in the activation of glial cells, of the central complement proteins and of inflammatory cytokines in selected regions of the central nervous system (CNS), which were rebalanced in animals treated with the vegetal mixture. In conclusion, the vegetal mixture tested thwarted the plethora of symptoms evoked by LPS, thus being a potential candidate for future investigations in the context of neuroinflammation.

Rheumatoid arthritis is an autoimmune disorder that causes chronic joint pain, swelling, and movement impairment, resulting from prolonged inflammation-induced cartilage and bone degradation. The pathogenesis of RA, which is still unclear, makes diagnosis and treatment difficult and calls for new therapeutic strategies to cure the disease. Recent research has identified FPRs as a promising druggable target, with AMC3, a novel agonist, showing preclinical efficacy in vitro and in vivo. In vitro, AMC3 (1–30 µM) exhibited significant antioxidant effects in IL-1β (10 ng/mL)-treated chondrocytes for 24 h. AMC3 displayed a protective effect by downregulating the mRNA expression of several pro-inflammatory and pro-algic genes (iNOS, COX-2, and VEGF-A), while upregulating genes essential for structural integrity (MMP-13, ADAMTS-4, and COLIAI). In vivo, AMC3 (10 mg kg−1) prevented hypersensitivity and restored postural balance in CFA-injected rats after 14 days. AMC3 attenuated joint alterations, reduced joint inflammatory infiltrate, pannus formation, and cartilage erosion. Chronic AMC3 administration reduced transcriptional changes of genes causing excitotoxicity and pain (EAATs and CCL2) and prevented morphological changes in astrocytes, including cell body hypertrophy, processes length, and thickness, caused by CFA in the spinal cord. This study demonstrates the usefulness of AMC3 and establishes the groundwork for further research.

Tendinopathies represent about 45% of musculoskeletal lesions and they are a big burden in clinics characterized by activity-related pain, focal tendon tenderness and intra-tendinous imaging changes. Many approaches have been proposed for tendinopathies’ management (e.g., nonsteroidal anti-inflammatory drugs, corticosteroids, eccentric exercises, laser therapy), unfortunately with very little support of efficacy or serious side effects, thus making the identification of new treatments fundamental. The aim of the study was to test the protective and pain reliever effect of thymoquinone (TQ)-loaded formulations in a rat model of tendinopathy induced by carrageenan intra-tendon injection (20 µL of carrageenan 0.8% on day 1). Conventional (LP-TQ) and hyaluronic acid (HA)-coated TQ liposomes (HA-LP-TQ) were characterized and subjected to in vitro release and stability studies at 4 °C. Then, TQ and liposomes were peri-tendon injected (20 µL) on days 1, 3, 5, 7 and 10 to evaluate their antinociceptive profile using mechanical noxious and non-noxious stimuli (paw pressure and von Frey tests), spontaneous pain (incapacitance test) and motor alterations (Rota rod test). Liposomes containing 2 mg/mL of TQ and covered with HA (HA-LP-TQ2) reduced the development of spontaneous nociception and hypersensitivity for a long-lasting effect more than the other formulations. The anti-hypersensitivity effect matched with the histopathological evaluation. In conclusion, the use of TQ encapsulated in HA-LP liposomes is suggested as a new treatment for tendinopathies.

Clozapine (CZP) is the only effective drug in schizophrenia resistant to typical antipsychotics. However, existing dosage forms (oral or orodispersible tablets, suspensions or intramuscular injection) show challenging limitations. After oral administration, CZP has low bioavailability due to a large first-pass effect, while the i.m. route is often painful, with low patient compliance and requiring specialised personnel. Moreover, CZP has a very low aqueous solubility. This study proposes the intranasal route as an alternative route of administration for CZP, through its encapsulation in polymeric nanoparticles (NPs) based on Eudragit® RS100 and RL100 copolymers. Slow-release polymeric NPs with dimensions around 400–500 nm were formulated to reside and release CZP in the nasal cavity, where it can be absorbed through the nasal mucosa and reach the systemic circulation. CZP-EUD-NPs showed a controlled release of CZP for up to 8 h. Furthermore, to reduce mucociliary clearance and increase the residence time of NPs in the nasal cavity to improve drug bioavailability, mucoadhesive NPs were formulated. This study shows that the NPs already exhibited strong electrostatic interactions with mucin at time zero due to the presence of the positive charge of the used copolymers. Furthermore, to improve the solubility, diffusion and adsorption of CZPs and the storage stability of the formulation, it was lyophilised using 5% (w/v) HP-β-CD as a cryoprotectant. It ensured the preservation of the NPs’ size, PDI and charge upon reconstitution. Moreover, physicochemical characterisation studies of solid-state NPs were performed. Finally, toxicity studies were performed in vitro on MDCKII cells and primary human olfactory mucosa cells and in vivo on the nasal mucosa of CD-1 mice. The latter showed non-toxicity of B-EUD-NPs and mild CZP-EUD-NP-induced tissue abnormalities.

The distinction between glial painful and protective pathways is unclear and the possibility to finely modulate the system is lacking. Focusing on painful neuropathies, we studied the role of interleukin 1α (IL-1α), an alarmin belonging to the larger family of damage-associated molecular patterns endogenously secreted to restore homeostasis.The treatment of rat primary neurons with increasing doses of the neurotoxic anticancer drug oxaliplatin (0.3–100μM, 48 h) induced the release of IL-1α. The knockdown of the alarmin in neurons leads to their higher mortality when co-cultured with astrocytes. This toxicity was related to increased extracellular ATP and decreased release of transforming growth factor β1, mostly produced by astrocytes.In a rat model of neuropathy induced by oxaliplatin, the intrathecal treatment with IL-1α was able to reduce mechanical and thermal hypersensitivity both after acute injection (100 ng and 300 ng) and continuous infusion (100 and 300 ng/die−1). Ex vivo analysis on spinal purified astrocyte processes (gliosomes) and nerve terminals (synaptosomes) revealed the property of IL-1α to reduce the endogenous glutamate release induced by oxaliplatin. This protective effect paralleled with an increased number of GFAP-positive cells in the spinal cord, suggesting the ability of IL-1α to evoke a positive, conservative astrocyte phenotype.Endogenous IL-1α induced protective signals in the cross-talk between neurons and astrocytes. Exogenously administered in rats, IL-1α prevented neuropathic pain in the presence of spinal glutamate decrease and astrocyte activation.

The term tendinopathy indicates a wide spectrum of conditions characterized by alterations in tendon tissue homeostatic response and damage to the extracellular matrix. The current pharmacological approach involves the use of nonsteroidal anti-inflammatory drugs and corticosteroids often with unsatisfactory results, making essential the identification of new treatments. In this study, the pro-regenerative and protective effects of an aqueous fibroin solution (0.5–500 μg/mL) against glucose oxidase (GOx)-induced damage in rat tenocytes were investigated. Then, fibroin anti-hyperalgesic and protective actions were evaluated in two models of tendinopathy induced in rats by collagenase or carrageenan injection, respectively. In vitro, 5–10 μg/mL fibroin per se increased cell viability and reverted the morphological alterations caused by GOx (0.1 U/mL). Fibroin 10 μg/mL evoked proliferative signaling upregulating the expression of decorin, scleraxin, tenomodulin (p

Persistent pain can be managed with opioids, but their use is limited by the onset of tolerance. Ultramicronized N-palmitoylethanolamine (PEA) in vivo delays morphine tolerance with mechanisms that are still unclear. Since glial cells are involved in opioid tolerance and mast cells (MCs) are pivotal targets of PEA, we hypothesized that a potential mechanism by which PEA delays opioid tolerance might depend on the control of the crosstalk between these cells. Morphine treatment (30 μM, 30 min) significantly increased MC degranulation of RBL-2H3 cells, which was prevented by pre-treatment with PEA (100 μM, 18 h), as evaluated by β-hexosaminidase assay and histamine quantification. The impact of RBL-2H3 secretome on glial cells was studied. Six-hour incubation of astrocytes with control RBL-2H3-conditioned medium, and even more so co-incubation with morphine, enhanced CCL2, IL-1β, IL-6, Serpina3n, EAAT2 and GFAP mRNA levels. The response was significantly prevented by the secretome from PEA pre-treated RBL-2H3, except for GFAP, which was further upregulated, suggesting a selective modulation of glial signaling. In conclusion, ultramicronized PEA down-modulated both morphine-induced MC degranulation and the expression of inflammatory and pain-related genes from astrocytes challenged with RBL-2H3 medium, suggesting that PEA may delay morphine tolerance, regulating MC-astrocyte crosstalk.

Alzheimer’s disease (AD), one of the most widespread neurodegenerative disorder, is a fatal global burden for the elder population. Although many efforts have been made, the search of a curative therapy is still ongoing. Individuating phenotypic traits that might help in investigating treatment response is of growing interest in AD research. AD is a complex pathology characterized by many comorbidities, such as depression and increased susceptibility to pain perception, leading to postulate that these conditions may rely on common biological substrates yet to be determined. In order to investigate those biological determinants to be associable with phenotypic traits, we used the rat model of amyloid beta-induced toxicity. This established model of early phase of AD is obtained by the intracerebroventricular injection of soluble amyloid beta1-42 (Aβ) peptide 7 days before performing experiments. In this model, we have previously reported increased immobility in the forced swimming test, reduced cortical serotonin levels and subtle alterations in the cognitive domain a depressive-like phenotype associated with subtle alteration in memory processes. In light of evaluating pain perception in this animal model, we performed two different behavioral tests commonly used, such as the paw pressure test and the cold plate test, to analyze mechanical hyperalgesia and thermal allodynia, respectively. Behavioural outcomes confirmed the memory impairment in the social recognition test and, compared to sham, Aβ-injected rats showed an increased selective susceptibility to mechanical but not to thermal stimulus. Behavioural data were then corroborated by neurochemical and biochemical biomarker analyses either at central or peripheral level. Data showed that the peptide injection evoked a significant increase in hypothalamic glutamate, kynurenine and dopamine content, while serotonin levels were reduced. Plasma Cystatin-C, a cysteine protease, was increased while serotonin and melatonin levels were decreased in Aβ-injected rats. Urinary levels paralleled plasma quantifications, indicating that Aβ-induced deficits in pain perception, mood and cognitive domain may also depend on these biomarkers. In conclusion, in the present study, we demonstrated that this animal model can mimic several comorbid conditions typical of the early phase of AD. Therefore, in the perspective of generating novel therapeutic strategies relevant to precision medicine in AD, this animal model and the biomarkers evaluated herein may represent an advantageous approach.

Vascular inflammation (VI) represents a pathological condition that progressively affects the integrity and functionality of the vascular wall, thus leading to endothelial dysfunction and the onset of several cardiovascular diseases. Therefore, the research of novel compounds able to prevent VI represents a compelling need. In this study, we tested erucin, the natural isothiocyanate H2S-donor derived from Eruca sativa Mill. (Brassicaceae), in an in vivo mouse model of lipopolysaccharide (LPS)-induced peritonitis, where it significantly reduced the amount of emigrated CD11b positive neutrophils. We then evaluated the anti-inflammatory effects of erucin in LPS-challenged human umbilical vein endothelial cells (HUVECs). The pre-incubation of erucin, before LPS treatment (1, 6, 24 h), significantly preserved cell viability and prevented the increase of reactive oxygen species (ROS) and tumor necrosis factor alpha (TNF-α) levels. Moreover, erucin downregulated endothelial hyperpermeability and reduced the loss of vascular endothelial (VE)-Cadherin levels. In addition, erucin decreased vascular cell adhesion molecule 1 (VCAM-1), cyclooxygenase-2 (COX-2) and microsomal prostaglandin E-synthase 1 (mPGES-1) expression. Of note, erucin induced eNOS phosphorylation and counteracted LPS-mediated NF-κB nuclear translocation, an effect that was partially abolished in the presence of the eNOS inhibitor L-NAME. Therefore, erucin can control endothelial function through biochemical and genomic positive effects against VI.

Conus regius is a marine venomous mollusk of the Conus genus that captures its prey by injecting a rich cocktail of bioactive disulfide bond rich peptides called conotoxins. These peptides selectively target a broad range of ion channels, membrane receptors, transporters, and enzymes, making them valuable pharmacological tools and potential drug leads. C. regius-derived conotoxins are particularly attractive due to their marked potency and selectivity against specific nicotinic acetylcholine receptor subtypes, whose signalling is involved in pain, cognitive disorders, drug addiction, and cancer. However, the species-specific differences in sensitivity and the low stability and bioavailability of these conotoxins limit their clinical development as novel therapeutic agents for these disorders. Here, we give an overview of the main pharmacological features of the C. regius-derived conotoxins described so far, focusing on the molecular mechanisms underlying their potential therapeutic effects. Additionally, we describe adoptable chemical engineering solutions to improve their pharmacological properties for future potential clinical translation.

The racemic mixture dimiracetam negatively modulates NMDA-induced glutamate release in rat spinal cord synaptosomal preparations and is orally effective in models of neuropathic pain. In this study, we compared the effects of dimiracetam, its R- or S-enantiomers, and the R:S 3:1 non-racemic mixture (MP-101). In vitro, dimiracetam was more potent than its R- or S-enantiomers in reducing the NMDA-induced [3H]D-aspartate release in rat spinal cord synaptosomes. Similarly, acute oral administration of dimiracetam was more effective than a single enantiomer in the sodium monoiodoacetate (MIA) paradigm of painful osteoarthritis. Then, we compared the in vitro effects of a broad range of non-racemic enantiomeric mixtures on the NMDA-induced [3H]D-aspartate release. Dimiracetam was a more potent blocker than each isolated enantiomer but the R:S 3:1 non-racemic mixture (MP-101) was even more potent than dimiracetam, with an IC50 in the picomolar range. In the chronic oxaliplatin-induced neuropathic pain model, MP-101 showed a significantly improved anti-neuropathic profile, and its effect continued one week after treatment suspension. MP-101 also performed better than dimiracetam in animal models of cognition and depression. Based on the benign safety and tolerability profile previously observed with racemic dimiracetam, MP-101 appears to be a novel, promising clinical candidate for the prevention and treatment of several neuropathic and neurological disorders.

Glucoraphanin (GRA) is a natural compound that has shown beneficial effects in chronic diseases and in central nervous system disorders. Moreover, GRA displayed antidepressant activity in preclinical models. We have previously demonstrated that a single intracerebroventricular administration of soluble amyloid-beta 1-42 (sAβ 1-42) in rat evokes a depressive-like phenotype by increasing immobility frequency in the forced swimming test (FST). The aim of this work was to investigate the effect of GRA in naïve and in sAβ-1-42-treated rats by using the FST. Behavioural analyses were accompanied by neurochemical and biochemical measurements in the prefrontal cortex (PFC), such as serotonin (5-HT), noradrenaline (NA), kynurenine (KYN), tryptophan (TRP), reactive oxygen species (ROS) and the transcription nuclear factor kappa B (NF-kB) levels. We reported that GRA administration in naïve rats at the dose of 50 mg/kg reduced the immobility frequency in the FST and increased 5-HT and NA levels in the PFC compared to controls. At the same dose, GRA reverted depressive-like effects of sAβ 1-42 administration, restored the 5-HT levels and reduced NF-kB, KYN and ROS levels in PFC. In conclusion, GRA rapidly reverting depressive-like behaviour, together with biochemical and neurochemical alterations, might represent a safe and natural candidate for the treatment of depression.

Neuroinflammation is a key pathological event shared by different diseases affecting the nervous system. Since the underlying mechanism of neuroinflammation is a complex and multifaceted process, current pharmacological treatments are unsatisfactory—a reason why new therapeutic approaches are mandatory. In this context, the endocannabinoid system has proven to possess neuroprotective and immunomodulatory actions under neuroinflammatory status, and its modulation could represent a valuable approach to address different inflammatory processes. To this aim, we evaluated the efficacy of a repeated treatment with NSD1819, a potent β-lactam-based monoacylglycerol lipase inhibitor in a mouse model of neuroinflammation induced by lipopolysaccharide (LPS) injection. Mice were intraperitoneally injected with LPS 1 mg/kg for five consecutive days to induce systemic inflammation. Concurrently, NSD1819 (3 mg/kg) was daily per os administered from day 1 until the end of the experiment (day 11). Starting from day 8, behavioral measurements were performed to evaluate the effect of the treatment on cognitive impairments, allodynia, motor alterations, anhedonia, and depressive-like behaviors evoked by LPS. Histologically, glial analysis of the spinal cord was also performed. The administration of NSD1819 was able to completely counteract thermal and mechanical allodynia as highlighted by the Cold plate and von Frey tests, respectively, and to reduce motor impairments as demonstrated by the Rota rod test. Moreover, the compound was capable of neutralizing the memory loss in the Passive avoidance test, and reducing depressive-like behavior in the Porsolt test. Finally, LPS stimulation caused a significant glial cells activation in the dorsal horn of the lumbar spinal cord that was significantly recovered by NSD1819 repeated treatment. In conclusion, NSD1819 was able to thwart the plethora of symptoms evoked by LPS, thus representing a promising candidate for future applications in the context of neuroinflammation and related diseases.

Brassicaceae are natural sources of bioactive compounds able to promote gut health. Belonging to this plant family, Camelina sativa is an ancient oil crop rich in glucosinolates, polyunsaturated fatty acids, and antioxidants that is attracting renewed attention for its nutraceutical potential. This work aimed at investigating the therapeutic effects of a defatted seed meal (DSM) of Camelina sativa on the colon damage and the persistent visceral hypersensitivity associated with colitis in rats. Inflammation was induced by the intrarectal injection of 2,4-dinitrobenzenesulfonic acid (DNBS). The acute administration of Camelina sativa DSM (0.1–1 g kg−1) showed a dose-dependent pain-relieving effect in DNBS-treated rats. The efficacy of the meal was slightly enhanced after bioactivation with myrosinase, which increased isothiocyanate availability, and drastically decreased by pre-treating the animals with the selective peroxisome proliferator-activated receptor alpha (PPAR α) receptor antagonist GW6471. Repeated treatments with Camelina sativa DSM (1 g kg−1) meal counteracted the development, as well as the persistence, of visceral hyperalgesia in DNBS-treated animals by reducing the intestinal inflammatory damage and preventing enteric neuron damage. In conclusion, Camelina sativa meal might be employed as a nutraceutical tool to manage persistent abdominal pain in patients and to promote gut healing.

Neuropathy development is a major dose-limiting side effect of anticancer treatments that significantly reduces patient’s quality of life. The inadequate pharmacological approaches for neuropathic pain management warrant the identification of novel therapeutic targets. Mitochondrial dysfunctions that lead to reactive oxygen species (ROS) increase, cytosolic Ca2+ imbalance, and lactate acidosis are implicated in neuropathic pain pathogenesis. It has been observed that in these deregulations, a pivotal role is played by the mitochondrial carbonic anhydrases (CA) VA and VB isoforms. Hence, preclinical studies should be conducted to assess the efficacy of two novel selenides bearing benzenesulfonamide moieties, named 5b and 5d, and able to inhibit CA VA and VB against paclitaxel-induced neurotoxicity in mice. Acute treatment with 5b and 5d (30–100 mg/kg, per os – p.o.) determined a dose-dependent and long-lasting anti-hyperalgesic effect in the Cold plate test. Further, repeated daily treatment for 15 days with 100 mg/kg of both compounds (starting the first day of paclitaxel injection) significantly prevented neuropathic pain development without the onset of tolerance to the anti-hyperalgesic effect. In both experiments, acetazolamide (AAZ, 100 mg/kg, p.o.) used as the reference drug was partially active. Moreover, ex vivo analysis demonstrated the efficacy of 5b and 5d repeated treatments in reducing the maladaptive plasticity that occurs to glia cells in the lumbar portion of the spinal cord and in improving mitochondrial functions in the brain and spinal cord that were strongly impaired by paclitaxel-repeated treatment. In this regard, 5b and 5d ameliorated the metabolic activity, as observed by the increase in citrate synthase activity, and preserved an optimal mitochondrial membrane potential (ΔΨ) value, which appeared depolarized in brains from paclitaxel-treated animals. In conclusion, 5b and 5d have therapeutic and protective effects against paclitaxel-induced neuropathy without tolerance development. Moreover, 5b and 5d reduced glial cell activation and mitochondrial dysfunction in the central nervous system, being a promising candidate for the management of neuropathic pain and neurotoxicity evoked by chemotherapeutic drugs.

Cadmium (Cd) is a well-known occupational and environmental pollutant worldwide, and its toxicity is widely recognised. Cd is reported to increase the permeability of the blood–brain barrier (BBB) and to penetrate and accumulate in the brain. Although many lines of evidence show that Cd toxicity is induced by different mechanisms, one of the best known is the Cd-dependent production of reactive oxygen species (ROS). Zinc is a trace element known as coenzyme and cofactor for many antioxidant proteins, such as metallothioneins and superoxide dismutase enzymes. To date, very little is known about the role of Zn in preventing Cd-induced blood–brain barrier (BBB) alterations. The goal of this study was to test the Zn antioxidant capacity against Cd-dependent alterations in a rat brain endothelial cell line (RBE4), as an in vitro model for BBB. In order to mimic acute Cd poisoning, RBE4 cells were treated with CdCl2 30 µM for 24 h. The protective role of ZnCl2 (50 µM) was revealed by evaluating the cell viability, reactive oxygen species (ROS) quantification, cytochrome C distribution, and the superoxide dismutase (SOD) protein activity. Additionally, the effectiveness of Zn in counteracting the Cd-induced damage was investigated by evaluating the expression levels of proteins already known to be involved in the Cd signalling pathway, such as GRP78 (an endoplasmic reticulum (ER) stress protein), caspase3 pro- and cleaved forms, and BAX. Finally, we evaluated if Zn was able to attenuate the alterations of zonula occludens-1 (ZO-1), one of the tight-junction (TJ) proteins involved in the formation of the BBB. Our data clearly demonstrate that Zn, by protecting from the SOD activity impairment induced by Cd, is able to prevent the triggering of the Cd-dependent signalling pathway that leads to ZO-1 dislocation and downregulation, and BBB damage.

Sarcopenia is a gradual and generalized skeletal muscle (SKM) syndrome, characterized by the impairment of muscle components and functionality. Hydrogen sulfide (H2S), endogenously formed within the body from the activity of cystathionine-γ-lyase (CSE), cystathionine- β-synthase (CBS), and mercaptopyruvate sulfurtransferase, is involved in SKM function. Here, in an in vitro model of sarcopenia based on damage induced by dexamethasone (DEX, 1 μM, 48 h treatment) in C2C12-derived myotubes, we investigated the protective potential of exogenous and endogenous sources of H2S, i.e., glucoraphanin (30 μM), L-cysteine (150 μM), and 3-mercaptopyruvate (150 μM). DEX impaired the H2S signalling in terms of a reduction in CBS and CSE expression and H2S biosynthesis. Glucoraphanin and 3-mercaptopyruvate but not L-cysteine prevented the apoptotic process induced by DEX. In parallel, the H2S-releasing molecules reduced the oxidative unbalance evoked by DEX, reducing catalase activity, O2− levels, and protein carbonylation. Glucoraphanin, 3-mercaptopyruvate, and L-cysteine avoided the changes in myotubes morphology and morphometrics after DEX treatment. In conclusion, in an in vitro model of sarcopenia, an impairment in CBS/CSE/H2S signalling occurs, whereas glucoraphanin, a natural H2S-releasing molecule, appears more effective for preventing the SKM damage. Therefore, glucoraphanin supplementation could be an innovative therapeutic approach in the management of sarcopenia.

The channel protein Panx-1 is involved in some pathologies, such as epilepsy, ischemic stroke, cancer and Parkinson’s disease, as well as in neuropathic pain. These observations make Panx-1 an interesting biological target. We previously published some potent indole derivatives as Panx-1 blockers, and as continuation of the research in this field we report here the studies on additional chemical scaffolds, naphthalene and pyrazole, appropriately substituted with those functions that gave the best results as in our indole series (sulphonamide functions and one/two carboxylic groups) and in Panx-1 blockers reported in the literature (sulphonic acid). Compounds 4 and 13, the latter being an analogue of the drug Probenecid, are the most potent Panx-1 blockers obtained in this study, with I = 97% and I = 93.7% at 50 µM, respectively. Both compounds, tested in a mouse model of oxaliplatin-induced neuropathic pain, showed a similar anti-hypersensitivity profile and are able to significantly increase the mouse pain threshold 45 min after the injection of the doses of 1 nmol and 3 nmol. Finally, the molecular dynamic studies and the PCA analysis have made it possible to identify a discriminating factor able to separate active compounds from inactive ones.

MOMAST® GR25 is a polyphenolic granular complex from olive pressing juice with high total content in polyphenols. In this work, we evaluated the possible anti-inflammatory effects of MOMAST® GR25 in both acute and chronic inflammatory models. MOMAST® GR25 decreased the levels of prostaglandin (PG) E2 and 8-iso-PGF2α in isolated rat colon, liver, and heart specimens stimulated with lipopolysaccharide (LPS). In vivo, compared to controls, rats treated with MOMAST® GR25 (100 mg/kg to 1 g/kg) showed a significant reduction in both licking/biting time in the formalin test. In a rat model of osteoarthritis by monoiodoacetate (MIA) injection, MOMAST® GR25 showed pain-relieving properties when acutely administered, reducing mechanical hyperalgesia and spontaneous pain. Moreover, a repeated daily treatment with MOMAST® GR25 (300 mg/kg) fully counteracted osteoarticular pain without the development of tolerance to the antinociceptive effect. Taken together, our present findings showed that MOMAST® GR25 could represent a potential strategy for the treatment of inflammation and pain.

Ligands of the Gi protein-coupled adenosine A3 receptor (A3R) are receiving increasing interest as attractive therapeutic tools for the treatment of a number of pathological conditions of the central and peripheral nervous systems (CNS and PNS, respectively). Their safe pharmacological profiles emerging from clinical trials on different pathologies (e.g., rheumatoid arthritis, psoriasis and fatty liver diseases) confer a realistic translational potential to these compounds, thus encouraging the investigation of highly selective agonists and antagonists of A3R. The present review summarizes information on the effect of latest-generation A3R ligands, not yet available in commerce, obtained by using different in vitro and in vivo models of various PNS- or CNS-related disorders. This review places particular focus on brain ischemia insults and colitis, where the prototypical A3R agonist, Cl-IB-MECA, and antagonist, MRS1523, have been used in research studies as reference compounds to explore the effects of latest-generation ligands on this receptor. The advantages and weaknesses of these compounds in terms of therapeutic potential are discussed.

Most therapies used in patients affected by inflammatory bowel diseases are ineffective in preventing the development of chronic visceral hypersensitivity, mainly due to inflammation-induced enteric neuroplasticity. Glucosinolates, secondary metabolites mainly of Brassicaceae with anti-inflammatory and neuroprotective properties, are effective in treating both neuropathic and arthritis pain through H2S release and Kv7 potassium channel activation. The aim of this work was to investigate the protective and anti-hyperalgesic efficacy of a defatted seed meal from Eruca sativa Mill. (Brassicaceae), rich in glucosinolates, in a rat model of colitis induced by 2,4-dinitrobenzene sulfonic acid (DNBS). The mechanisms of action were also investigated. Visceral pain was assessed by measuring the abdominal response to colorectal distension. Fifteen days after colitis induction, the acute administration of E. sativa defatted seed meal (0.1–1 g kg−1 p.o.) dose-dependently relieved pain. This effect was hampered by co-administering an H2S scavenger or a selective Kv7 blocker. Administering E. sativa (1 g kg−1) for 14 days, starting after DNBS injection, contributed to counteracting visceral pain persistence in the post-inflammatory phase of colitis by promoting colon healing from the damage and reducing enteric gliosis. E. sativa defatted seed meal might be employed as a nutraceutical tool for supporting abdominal pain relief in patients.

Intranasal administration has assumed in the last years an increasing value as an alternative strategy for the systemic adsorption of drugs, as an alternative to oral and parenteral routes thanks to the high vascularized nasal mucosa. Nevertheless, different drug features may restrict its absorption through the nasal mucosa with an insufficient diffusion to the systemic circulation. Several technological strategies are under investigation to improve drug absorption during nasal formulation design and production. The use of bioadhesive polymers can be considered a valid approach to pursue the aforementioned goal. Based on this consideration, Eudragit® Retard RS100 and RL100 resins were selected as positively charged copolymers to prepare polymeric NPs with potential mucoadhesive properties suitable for intranasal application. NPs were produced by the Quasi-emulsion Solvent Evaporation (QESD) method and loaded with diclofenac acid (DIC) or its epolamine salt (DIEP). Preliminary investigations were performed to obtain the optimized blank formulation and drugs loaded NPs evaluating different parameters that can affect particles size and polydispersity. The optimized formulations unloaded and loaded with DIC and DIEP were further evaluated for their thermotropic behavior by differential scanning calorimetry. Mucoadhesive evaluation was assessed by measuring variation in zeta potential and by turbidimetric assay after incubation of particles with mucin in simulated nasal fluid (SNF) at 37 °C at different time points (0, 1 and 24 h) compared to the pure suspensions. Stability of DIC and DIEP loaded NPs was also evaluated in SNF to predict potential aggregation phenomena after nasal administration. Finally, in vivo experiments showed absence of toxicity on the nasal mucosa of mice.

Andrographolide (AG) is a natural diterpene lactone endowed with considerable therapeutic potential for treating numerous diseases, including neurological disorders, but its low aqueous solubility and scarce bioavailability limit its clinical use. To overcome this problem, AG was encapsulated in escinosomes, special nanovesicles made of escin (ESN), a natural saponin, and phosphatidylcholine. Escinosomes loaded with AG had an average size of 164.7 ± 13.30 nm, optimal polydispersity index (0.190 ± 0.0890) and high ζ-potential (−35.4 ± 0.451 mV), and significantly loaded the active substance—the encapsulation efficiency of AG was about 88%. Escinosomes allowed the prolonged release of AG over time, without burst effects—about 85% AG was released after 24 h. Morphological analysis by cryo-transmission electron microscopy showed nanovesicles with a spherical shape, unilamellar and oligolamellar structures, and dimensions in agreement with those measured by dynamic light scattering. In addition, stability studies were performed on AG-loaded escinosomes stored for one month at 4 °C. The pain-relieving efficacy of these nanovesicles was tested in a rat model of oxaliplatin-induced neuropathy. AG-loaded escinosomes, subcutaneously administered, effectively reduced the thermal allodynia characteristic of chemotherapy-induced neuropathy, enhancing and prolonging the effect of the natural compound. Overall, AG-loaded escinosomes were found to be excellent for loading AG, physically and chemically stable for one-month storage, and with controlled-release properties, making the formulation an ideal pharmacological approach for persistent pain treatment.

Chronic pain management requires increasing doses of opioids, the milestone of painkillers, which may result in the onset of tolerance with exacerbated side effects. Maintaining stable analgesia with low doses of opioids is thus imperative. N-palmitoylethanolamine (PEA) is an endogenous lipid compound endowed with pain-relieving as well as anti-inflammatory properties. The ultramicronized formulation of PEA was recently demonstrated to be able to modulate morphine’s effects, delaying tolerance and improving efficacy. To evaluate the possible application to other opioids, in this study, we analysed the capacity of ultramicronized PEA to regulate analgesia and tolerance induced by oxycodone and tramadol. Pre-emptive and continuative treatment with ultramicronized PEA (30 mg kg−1, daily, per os) delayed the onset of opioid tolerance and enhanced opioid analgesia when it was acutely administered in association with tramadol (20 mg kg−1, daily, subcutaneously) or oxycodone (0.5 mg kg−1, daily, subcutaneously). Moreover, PEA exerted antinociceptive effects on tolerant rats, suggesting the use of PEA together with opioids for stable, long-lasting analgesia. To that purpose, the oxycodone dose needed to be increased from 0.3 mg kg−1 (day 1) up to 1 mg kg−1 (day 31) in the oxycodone + vehicle group; the tramadol dose was progressively enhanced from 15 mg kg−1 to 50 mg kg−1 in 31 days in the tramadol + vehicle group. Acute oral co-treatment with PEA (120 mg kg−1) achieved the same analgesia without increasing the dose of both opioids. The behavioural effects of PEA on opioid chronic treatment paralleled a decrease in astrocyte activation in the dorsal horn of the spinal cord (a marker of the development of opioid tolerance) and with a modulation of mRNA expression of IL-6 and serpin-A3. In conclusion, pre- and co-administration of ultramicronized PEA delayed the development of tramadol tolerance, potentiating either oxycodone or tramadol analgesia and allowing a long-lasting analgesic effect with a low opioid dose regimen. The use of PEA is suggested for clinical purposes to support the opioid-based management of persistent pain.

A new formulation of a pomegranate-peel extract (PEm) obtained by PUAE (Pulsed Ultrasound-Assisted Extraction) and titrated in both ellagic acid (EA) and punicalagin is proposed, characterized and then analyzed for potential health properties in mice suffering from the experimental autoimmune encephalomyelitis (EAE). PEm effects were compared to those elicited by a formulation containing EA (EAm). Control and EAE mice were chronically administered EAm and Pem dissolved in the drinking water, starting from the day 10 post-immunization (d.p.i.), with a “therapeutic” protocol to deliver daily 50 mg/kg of EA. Treated EAE mice did not limit their daily access to the beverage, nor did they show changes in body weight, but they displayed a significant amelioration of “in vivo” clinical symptoms. “Ex vivo” histochemical analysis showed that spinal-cord demyelination and inflammation in PEm and EAm-treated EAE mice at 23 ± 1 d.p.i. were comparable to those in the untreated EAE animals, while microglia activation (measured as Ionized Calcium Binding Adaptor 1, Iba1 staining) and astrocytosis (quantified as glial fibrillar acid protein, GFAP immunopositivity) significantly recovered, particularly in the gray matter. EAm and PEm displayed comparable efficiencies in controlling the spinal pathological cellular hallmarks in EAE mice, and this would support their delivery as dietary supplementation in patients suffering from multiple sclerosis (MS).

Erectile dysfunction affects more than 50% of diabetic male patients, with a higher prevalence compared with the general population. Age, clinical factors, and lifestyle habits have been suggested to contribute to the pathophysiology and worsening of erectile dysfunction in diabetic patients. First- and second-line standard treatments are represented by phosphodiesterase type 5 (PDE5) inhibitors and alprostadil, respectively. However, natural compounds have been suggested to ameliorate this clinical condition. This study aims to preclinically characterize the potential synergism among plant-derived products for the improvement of erectile dysfunction in the diabetic condition. The effects of a nutritional supplement composed of Panax ginseng, Moringa oleifera and rutin, as single agents or as a mixture, were evaluated in a streptozotocin (STZ)-induced diabetic rat model with erectile dysfunction. The treatment efficacy was evaluated by measuring sexual-related parameters (i.e., mount and intromission latencies, the mount and intromission frequencies and the ejaculation latency). Results showed that only the mixture was able to significantly reduce the diabetes-related delay in mount latency (p < 0.01). Substantial similar effects were observed by measuring the intromission latency and the mean number of mounts was very similar between rats treated with the mixture and controls. Single agent treatments showed very low effects in terms of intromission frequency, whereas the mixture was able to increase this parameter. Additionally, a statistically significant reduced ejaculation latency was observed in rats treated with the mixture compared with the STZ control. These results are in agreement with the available literature and suggest that the study mixture may ameliorate sexual behavior compared with the administration of the study natural compounds as single agents in diabetic rats. Further preclinical and clinical studies are needed to perform a more comprehensive evaluation of the efficacy and safety of the study mixture.

Marine pharmacology is an exciting and growing discipline that blends blue biotechnology and natural compound pharmacology together. Several sea-derived compounds that are approved on the pharmaceutical market were discovered in sponges, marine organisms that are particularly rich in bioactive metabolites. This paper was specifically aimed at reviewing the pharmacological activities of extracts or purified compounds from marine sponges that were collected in the Mediterranean Sea, one of the most biodiverse marine habitats, filling the gap in the literature about the research of natural products from this geographical area. Findings regarding different Mediterranean sponge species were individuated, reporting consistent evidence of efficacy mainly against cancer, infections, inflammatory, and neurological disorders. The sustainable exploitation of Mediterranean sponges as pharmaceutical sources is strongly encouraged to discover new compounds.

Ocular discomfort and eye pain are frequently reported by patients with dry eye disease (DED), and their management remains a real therapeutic challenge for the Ophthalmologist. In DED patients, injury at the level of each structure of the ocular surface can determine variable symptoms, ranging from mild ocular discomfort up to an intolerable pain evoked by innocuous stimuli. In refractory cases, the persistence of this harmful signal is able to evoke a mechanism of maladaptive plasticity of the nervous system that leads to increased pain responsiveness. Peripheral and, subsequently, central sensitization cause nociceptor hyperexcitability and persistent pain perception that can culminate in the paradoxical situation of perceiving eye pain even in the absence of ocular surface abnormalities. Effective therapeutic strategies of these cases are challenging, and new options are desirable. Recently, a theoretical novel therapeutic approach concerns enkephalins thanks to the evidence that eye pain sensations are modulated by endogenous opioid peptides (enkephalins, endorphins and dynorphins). In this regard, new topical agents open up a new theoretical scenario in the treatment of ocular discomfort and eye pain in the setting of DED, such as, for example, a multimolecular complex based on proteins and glycosaminoglycans also containing opiorphin that may assist the physiological pain-relieving mechanism of the eye.

Acute inflammation is particularly relevant in the pathogenesis of visceral hypersensitivity associated with inflammatory bowel diseases. Glia within the enteric nervous system, as well as within the central nervous system, contributes to neuroplasticity during inflammation, but whether enteric glia has the potential to modify visceral sensitivity following colitis is still unknown. This work aimed to investigate the occurrence of changes in the neuron–glial networks controlling visceral perception along the gut–brain axis during colitis, and to assess the effects of peripheral glial manipulation. Enteric glia activity was altered by the poison fluorocitrate (FC; 10 µmol kg−1 i.p.) before inducing colitis in animals (2,4-dinitrobenzenesulfonic acid, DNBS; 30 mg in 0.25 mL EtOH 50%), and visceral sensitivity, colon damage, and glia activation along the pain pathway were studied. FC injection significantly reduced the visceral hyperalgesia, the histological damage, and the immune activation caused by DNBS. Intestinal inflammation is associated with a parallel overexpression of TRPV1 and S100β along the gut–brain axis (colonic myenteric plexuses, dorsal root ganglion, and periaqueductal grey area). This effect was prevented by FC. Peripheral glia activity modulation emerges as a promising strategy for counteracting visceral pain induced by colitis.

A3 adenosine receptor (A3AR) agonists have emerged as potent relievers of neuropathic pain by a T cell-mediated production of IL-10. The H4 histamine receptor (H4R), also implicated in pain modulation, is expressed on T cells playing a preeminent role in its activation and release of IL-10. To improve the therapeutic opportunities, this study aimed to verify the hypothesis of a possible cross-talk between A3AR and H4R in the resolution of neuropathic pain. In the mouse model of Chronic Constriction Injury (CCI), the acute intraperitoneal co-administration of the A3AR agonist IB-MECA (0.5 mg/kg) and the H4R agonist VUF 8430 (10 mg/kg), were additive in counteracting mechano-allodynia increasing IL-10 plasma levels. In H4R−/− mice, IB-MECA activity was reduced, lower pain relief and lower modulation of plasma IL-1β, TNF-α, IL-6 and IL-10 were shown. The complete anti-allodynia effect of IB-MECA in H4R−/− mice was restored after intravenous administration of CD4+ T cells obtained from naïve wild type mice. In conclusion, a role of the histaminergic system in the mechanism of A3AR-mediated neuropathic pain relief was suggested highlighting the driving force evoked by CD4+ T cells throughout IL-10 up-regulation.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by joint inflammation, cartilage damage and bone destruction. Although the pharmacological treatment of RA has evolved over the last few years, the new drugs have serious side effects and are very expensive. Thus, the research has been directed in recent years towards new possible targets. Among these targets, N-formyl peptide receptors (FPRs) are of particular interest. Recently, the mixed FPR1/FPR2 agonist Cpd43, the FPR2 agonist AT-01-KG, and the pyridine derivative AMC3 have been shown to be effective in RA animal models. As an extension of this research, we report here a new series of pyridinone derivatives containing the (substituted)phenyl acetamide chain, which was found to be essential for activity, but with different substitutions at position 5 of the scaffold. The biological results were also supported by molecular modeling studies and additional pharmacological tests on AMC3 have been performed in a rat model of RA, by repeating the treatments of the animals with 10 mg/kg/day of compound by 1 week.

Persistent pain affecting patients with inflammatory bowel diseases (IBDs) is still very difficult to treat. Carbonic anhydrase (CA) represents an intriguing pharmacological target considering the anti-hyperalgesic efficacy displayed by CA inhibitors in both inflammatory and neuropathic pain models. The aim of this work was to evaluate the effect of inhibiting CA IV, particularly when expressed in the gut, on visceral pain associated with colitis induced by 2,4-di-nitrobenzene sulfonic acid (DNBS) in rats. Visceral sensitivity was assessed by measuring animals’ abdominal responses to colorectal distension. Repeated treatment with the selective CA IV inhibitors AB-118 and NIK-67 effectively counteracted the development of visceral pain induced by DNBS. In addition to pain relief, AB-118 showed a protective effect against colon damage. By contrast, the anti-hyperalgesic activity of NIK-67 was independent of colon healing, suggesting a direct protective effect of NIK-67 on visceral sensitivity. The enzymatic activity and the expression of CA IV resulted significantly increased after DNBS injection. NIK-67 normalised CA IV activity in DNBS animals, while AB-118 was partially effective. None of these compounds influenced CA IV expression through the colon. Although further investigations are needed to study the underlying mechanisms, CA IV inhibitors are promising candidates in the search for therapies to relieve visceral pain in IBDs.

Psoriasis is a chronic immune-mediated inflammatory cutaneous disease characterized by elevated levels of inflammatory cytokines and adipokine Lipocalin-2 (LCN-2). Recently, natural plant-based products have been studied as new antipsoriatic compounds. We investigate the ability of a leaf extract of the marine plant Posidonia oceanica (POE) to inhibit psoriatic dermatitis in C57BL/6 mice treated with Imiquimod (IMQ). One group of mice was topically treated with IMQ (IMQ mice) for 5 days, and a second group received POE orally before each topical IMQ treatment (IMQ-POE mice). Psoriasis Area Severity Index (PASI) score, thickness, and temperature of the skin area treated with IMQ were measured in both groups. Upon sacrifice, the organs were weighed, and skin biopsies and blood samples were collected. Plasma and lesional skin protein expression of IL-17, IL-23, IFN-γ, IL-2, and TNF-α and plasma LCN-2 concentration were evaluated by ELISA. PASI score, thickness, and temperature of lesional skin were reduced in IMQ-POE mice, as were histological features of psoriatic dermatitis and expression of inflammatory cytokines and LCN-2 levels. This preliminary study aims to propose P. oceanica as a promising naturopathic anti-inflammatory treatment that could be introduced in Complementary Medicine for psoriasis. [ABSTRACT FROM AUTHOR]