Neuron-associated macrophage proliferation in the sensory ganglia is associated with peripheral nerve injury-induced neuropathic pain involving CX3CR1 signaling.

Resident macrophages are distributed across all tissues and are highly heterogeneous due to adaptation to different tissue-specific environments. The resident macrophages of the sensory ganglia (sensory neuron-associated macrophages, sNAMs) are in close contact with the cell body of primary sensory neurons and might play physiological and pathophysiological roles. After peripheral nerve injury, there is an increase in the population of macrophages in the sensory ganglia, which have been implicated in different conditions, including neuropathic pain development. However, it is still under debate whether macrophage accumulation in the sensory ganglia after peripheral nerve injury is due to the local proliferation of resident macrophages or a result of blood monocyte infiltration. Here, we confirmed that the number of macrophages increased in the sensory ganglia after the spared nerve injury (SNI) model in mice. Using different approaches, we found that the increase in the number of macrophages in the sensory ganglia after SNI is a consequence of the proliferation of resident CX3CR1+ macrophages, which participate in the development of neuropathic pain, but not due to infiltration of peripheral blood monocytes. These proliferating macrophages are the source of pro-inflammatory cytokines such as TNF and IL-1b. In addition, we found that CX3CR1 signaling is involved in the sNAMs proliferation and neuropathic pain development after peripheral nerve injury. In summary, these results indicated that peripheral nerve injury leads to sNAMs proliferation in the sensory ganglia in a CX3CR1-dependent manner accounting for neuropathic pain development. In conclusion, sNAMs proliferation could be modulated to change pathophysiological conditions such as chronic neuropathic pain.

Vandetanib Blocks the Cytokine Storm in SARS-CoV-2-Infected Mice.

The portfolio of SARS-CoV-2 small molecule drugs is currently limited to a handful that are either approved (remdesivir), emergency approved (dexamethasone, baricitinib, paxlovid, and molnupiravir), or in advanced clinical trials. Vandetanib is a kinase inhibitor which targets the vascular endothelial growth factor receptor (VEGFR), the epidermal growth factor receptor (EGFR), as well as the RET-tyrosine kinase. In the current study, it was tested in different cell lines and showed promising results on inhibition versus the toxic effect on A549-hACE2 cells (IC50 0.79 µM) while also showing a reduction of >3 log TCID50/mL for HCoV-229E. The in vivo efficacy of vandetanib was assessed in a mouse model of SARS-CoV-2 infection and statistically significantly reduced the levels of IL-6, IL-10, and TNF-α and mitigated inflammatory cell infiltrates in the lungs of infected animals but did not reduce viral load. Vandetanib also decreased CCL2, CCL3, and CCL4 compared to the infected animals. Vandetanib additionally rescued the decreased IFN-1ß caused by SARS-CoV-2 infection in mice to levels similar to that in uninfected animals. Our results indicate that the FDA-approved anticancer drug vandetanib is worthy of further assessment as a potential therapeutic candidate to block the COVID-19 cytokine storm.

Vandetanib Reduces Inflammatory Cytokines and Ameliorates COVID-19 in Infected Mice.

The portfolio of SARS-CoV-2 small molecule drugs is currently limited to a handful that are either approved (remdesivir), emergency approved (dexamethasone, baricitinib) or in advanced clinical trials. We have tested 45 FDA-approved kinase inhibitors in vitro against murine hepatitis virus (MHV) as a model of SARS-CoV-2 replication and identified 12 showing inhibition in the delayed brain tumor (DBT) cell line. Vandetanib, which targets the vascular endothelial growth factor receptor (VEGFR), the epidermal growth factor receptor (EGFR), and the RET-tyrosine kinase showed the most promising results on inhibition versus toxic effect on SARS-CoV-2-infected Caco-2 and A549-hACE2 cells (IC50 0.79 µM) while also showing a reduction of > 3 log TCID50/mL for HCoV-229E. The in vivo efficacy of vandetanib was assessed in a mouse model of SARS-CoV-2 infection and statistically significantly reduced the levels of IL-6, IL-10, TNF-α, and mitigated inflammatory cell infiltrates in the lungs of infected animals but did not reduce viral load. Vandetanib rescued the decreased IFN-1ß caused by SARS-CoV-2 infection in mice to levels similar to that in uninfected animals. Our results indicate that the FDA-approved vandetanib is a potential therapeutic candidate for COVID-19 positioned for follow up in clinical trials either alone or in combination with other drugs to address the cytokine storm associated with this viral infection.

Probiotic mixture containing Lactobacillus spp. and Bifidobacterium spp. attenuates 5-fluorouracil-induced intestinal mucositis in mice.

Lactobacillus spp. and Bifidobacterium spp. was used to protect against gastrointestinal disorders. The present study evaluated the effects of probiotic mixture (PM) containing Lactobacillus spp. and Bifidobacterium spp. on intestinal mucositis induced by 5-fluorouracil (5-FU). Swiss male mice (25-30 g) were treated with 5-FU (450 mg/kg, ip) and were orally administered (PM). Probiotic mixture 1 (PM-1) is a mixture of two probiotics (Lactobacillus acidophilus and Bifidobacterium lactis) and probiotic mixture 2 (PM-2) is a mixture of four probiotics (Lactobacillus acidophilus, Lactobacillus paracasei, Lactobacillus rhamnosus, and Bifidobacterium lactis). PM-1 and PM-2 decreased histopathological scores in the duodenum and jejunum after mucositis. PM-2 attenuated 5-FU-induced weight loss. On the other hand, PM-1 did not exert a significant effect on weight loss. Both probiotics mixture increased the villus/crypt ratio in all intestinal segments, increased GSH levels in the duodenum and jejunum, and reduced the MDA, MPO, TNF-α, and IL-6 levels in the duodenum, jejunum, and ileum. PM-2 attenuated the delay in gastric emptying. PM-1 and PM-2 prevented epithelial injury in intestinal mucositis by 5-FU, demonstrating the potential use of these probiotics as therapeutic agents against intestinal mucositis.

Loss of control over the ethanol consumption: differential transcriptional regulation in prefrontal cortex.

Alcohol use disorder (AUD) is a complex multifactorial disease with heritability of ∼50% and corresponds to the state in which the body triggers a reinforcement or reward compulsive behavior due to ethanol consumption, even when faced with negative consequences. Although several studies have shown the impact of high ethanol intake on the prefrontal cortex (PFC) gene expression, few have addressed the relationship between the patterns of gene expression underlying the compulsive behaviour associated with relapsing. In this study, we used a chronic three-bottle free-choice mouse model to investigate the PFC transcriptome in three different groups of mice drinkers: 'Light drinkers' (preference for water throughout the experiment); 'Heavy drinkers' (preference for ethanol with a non-compulsive intake), and 'Inflexible drinkers' (preference for ethanol with a compulsive drinking component). Our aim was to correlate the intake patterns observed in this model with gene expression changes in the PFC, a brain region critical for the development and maintenance of alcohol addiction. We found that the Camk2a gene showed a downregulated profile only in the Inflexible when compared to the Light drinkers group, the Camk2n1 and Pkp2 genes showed an upregulated profile only in the Inflexible drinkers when compared to the Control group, and the Gja1 gene showed an upregulated profile in the Light and Inflexible drinkers when compared to the Control group. These different transcription patterns have been associated to the presence of alcohol, in the Camk2n1 and Gja1 genes; to the amount of ethanol consumed, in the Camk2a gene; and to the loss of control in the alcohol consumption, in the Pkp2 gene. Here, we provide, for the first time, the potential involvement of the Pkp2 gene in the compulsivity and loss of control over the voluntary ethanol consumption.

Polysaccharide fraction isolated from Passiflora edulis inhibits the inflammatory response and the oxidative stress in mice.

OBJECTIVES: The aim of the study was to investigate the anti-inflammatory, antioxidant and antinociceptive actions of PFPe, a polysaccharide fraction isolated from the dried fruit of the Passiflora edulis. METHODS: Animals were pretreated with PFPe (0.3, 1 or 3 mg/kg, i.p.) 1 h before induction of paw oedema by carrageenan, histamine, serotonin, compound 48/80 or prostaglandin E2 (PGE2). Neutrophil migration and vascular permeability were measured after carrageenan injection into the peritoneum, and the action of the PFPe on the tumour necrosis factor-alpha, interleukin-1 beta (IL-1ß), myeloperoxidase (MPO), glutathione (GSH) and malondialdehyde (MDA) levels was also evaluated. To assay nociception, we examined acetic acid-induced writhing, formalin-induced paw licking and response latency in the hot plate test. KEY FINDINGS: Pretreatment with PFPe significantly inhibited carrageenan-induced paw oedema. PFPe also reduced paw oedema induced by compound 48/80, histamine, serotonin, and PGE2 and compound 48/80-induced vascular permeability. In addition, PFPe significantly reduced the MPO activity, MDA and GSH concentrations, and IL-1ß level. In the nociception tests, PFPe reduced acetic acid-induced writhing and formalin-induced paw licking and did not increase the response latency time. CONCLUSIONS: Our results suggest that PFPe administration reduces the inflammatory response by modulation of the liberation or synthesis of histamine and serotonin, by reduction of neutrophil migration, IL-1ß levels, and oxidative stress and nociception.

Riparin A, a compound from Aniba riparia, attenuate the inflammatory response by modulation of neutrophil migration.

Inflammation is a local tissue response to attacks characterized by vascular and cellular events, including intense oxidative stress. Riparin A, a compound obtained from Aniba riparia, has been shown to have antioxidant activity and cytotoxicity in vitro. This study was aimed at evaluating the anti-inflammatory effect of riparin A against acute inflammation. The results of our evaluations in various experimental models indicated that riparin A reduced paw edema induced by carrageenan, compound 48/80, histamine, and serotonin. Furthermore, it decreased leukocyte and neutrophil counts, myeloperoxidase activity, thiobarbituric acid reactive substance (TBARS) levels, and cytokine (tumor necrosis factor-α and interleukin-1ß) levels increased by carrageenan-induced peritonitis, and reversed glutathione levels. Riparin A also reduced carrageenan-induced adhesion and rolling of leukocytes on epithelial cells and did not produce gastric-damage as compared with indomethacin. In conclusion, the data show that riparin A reduces inflammatory response by inhibiting vascular and cellular events, modulating neutrophil migration, inhibiting proinflammatory cytokine production, and reducing oxidative stress.

Phytol, a diterpene alcohol, inhibits the inflammatory response by reducing cytokine production and oxidative stress.

Studies have shown that diterpenes have anti-inflammatory and redox-protective pharmacological activities. The present study aimed to investigate the anti-inflammatory properties of phytol, a diterpene alcohol, in a mouse model of acute inflammation, and phytol effect on leukocyte recruitment, cytokines levels, and oxidative stress. The anti-inflammatory activities of phytol were assessed by measuring paw edema induced by different inflammatory agents (e.g., λ-carrageenan, compound 48/80, histamine, serotonin, bradykinin, and prostaglandin E2 [PGE2 ]), myeloperoxidase (MPO) activity, peritonitis model and cytokine levels. Further, oxidative stress was evaluated by determining glutathione (GSH) levels and malondialdehyde (MDA) concentration. The results showed that phytol (7.5, 25, 50, and 75 mg/kg) significantly reduced carrageenan-induced paw edema, in a dose-dependent manner. In addition, phytol (75 mg/kg) inhibited compound 48/80-, histamine-, serotonin-, bradykinin- and PGE2 -induced paw edema. It also inhibited the recruitment of total leukocytes and neutrophils; decreased MPO activity, tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) levels, and MDA concentration; and increased GSH levels during carrageenan-induced acute inflammation. These results suggest that phytol attenuates the inflammatory response by inhibiting neutrophil migration that is partly caused by reduction in IL-1ß and TNF-α levels and oxidative stress.

Anti-inflammatory and antinociceptive activity of epiisopiloturine, an imidazole alkaloid isolated from Pilocarpus microphyllus.

The aim of this study was to investigate the antinociceptive and anti-inflammatory activities of epiisopiloturine (1), an imidazole alkaloid found in the leaves of Pilocarpus microphyllus. The anti-inflammatory activity of 1 was evaluated using several agents that induce paw edema and peritonitis in Swiss mice. Paw tissue and peritoneal fluid samples were obtained to determine myeloperoxidase (MPO) activity or tumor necrosis factor (TNF)-α and interleukin (IL)-1ß levels. The antinociceptive activity was evaluated by acetic acid-induced writhing, the hot plate test, and pain induction using formalin. Compared to vehicle treatment, pretreatment with 1 (0.1, 0.3, and 1 mg/kg, ip) of mice significantly reduced carrageenan-induced paw edema (p < 0.05). Furthermore, compound 1 at a dose of 1 mg/kg effectively inhibited edema induced by dextran sulfate, serotonin, and bradykinin, but had no effect on histamine-induced edema. The administration of 1 (1 mg/kg) following carrageenan-induced peritonitis reduced total and differential peritoneal leukocyte counts and also carrageenan-induced paw MPO activity and TNF-α and IL-1ß levels in the peritoneal cavity. Pretreatment with 1 also reduced acetic acid-induced writhing and inhibited the first and second phases of the formalin test, but did not alter response latency in the hot plate test. Pretreatment with naloxone reversed the antinociceptive effect of 1.

Role of the NO/K ATP pathway in the protective effect of a sulfated-polysaccharide fraction from the algae Hypnea musciformis against ethanol-induced gastric damage in mice

Seaweeds are the most abundant source of polysaccharides such as alginates and agar, as well as carrageenans. This study aimed to investigate the gastroprotective activity and the mechanism underlying this activity of a sulfated-polysaccharide fraction extracted from the algae Hypnea musciformis (Wulfen) J.V. Lamour. (Gigartinales-Rhodophyta). Mice were treated with sulfated-polysaccharide fraction (3, 10, 30, and 90 mg/kg, p.o.) and, after 30 min, they were administered 50% ethanol (0.5 mL/25 g, p.o.). After 1 h, gastric damage was measured using a planimeter. In addition, samples of the stomach tissue were obtained for histopathological examination and for assays to determine the glutathione and malondialdehyde levels. Other groups of mice were pretreated with N G-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg, i.p.), aminoguanidine (100 mg/kg, i.p.), or glibenclamide (10 mg/kg, i.p.). After 30 min to the aminoguanidine group and 1 h to the other groups, sulfated-polysaccharide fraction (30 mg/kg, p.o.) was administered and gastric damage was induced as described above. Sulfated-polysaccharide fraction prevented ethanol-induced gastric injury in a dose-dependent manner. However, treatment with L-NAME or glibenclamide reversed this gastroprotective effect. Administration of aminoguanidine did not influence the effect of sulfated-polysaccharide fraction. Our results suggest that sulfated-polysaccharide fraction exerts a protective effect against ethanol-induced gastric damage via activation of the NO/K ATP pathway.

A sulfated-polysaccharide fraction from seaweed Gracilaria birdiae prevents naproxen-induced gastrointestinal damage in rats.

Red seaweeds synthesize a great variety of sulfated galactans. Sulfated polysaccharides (PLSs) from seaweed are comprised of substances with pharmaceutical and biomedical potential. The aim of the present study was to evaluate the protective effect of the PLS fraction extracted from the seaweed Gracilaria birdiae in rats with naproxen-induced gastrointestinal damage. Male Wistar rats were pretreated with 0.5% carboxymethylcellulose (control group-vehicle) or PLS (10, 30, and 90 mg/kg, p.o.) twice daily (at 09:00 and 21:00) for 2 days. After 1 h, naproxen (80 mg/kg, p.o.) was administered. The rats were killed on day two, 4 h after naproxen treatment. The stomachs were promptly excised, opened along the greater curvature, and measured using digital calipers. Furthermore, the guts of the animals were removed, and a 5-cm portion of the small intestine (jejunum and ileum) was used for the evaluation of macroscopic scores. Samples of the stomach and the small intestine were used for histological evaluation, morphometric analysis and in assays for glutathione (GSH) levels, malonyldialdehyde (MDA) concentration, and myeloperoxidase (MPO) activity. PLS treatment reduced the macroscopic and microscopic naproxen-induced gastrointestinal damage in a dose-dependent manner. Our results suggest that the PLS fraction has a protective effect against gastrointestinal damage through mechanisms that involve the inhibition of inflammatory cell infiltration and lipid peroxidation.