SARS-CoV-2 infection causes intestinal cell damage: Role of interferon's imbalance.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of the newly emerging lung disease pandemic COVID-19. This viral infection causes a series of respiratory disorders, and although this virus mainly infects respiratory cells, the small intestine can also be an important site of entry or interaction, as enterocytes highly express in angiotensin-2 converting enzyme (ACE) receptors. There are countless reports pointing to the importance of interferons (IFNs) with regard to the mediation of the immune system in viral infection by SARS-CoV-2. Thus, this review will focus on the main cells that make up the large intestine, their specific immunology, as well as the function of IFNs in the intestinal mucosa after the invasion of coronavirus-2.

Photobiomodulation exerts anti-inflammatory effects on the vascular and cellular phases of experimental inflammatory models.

Photobiomodulation therapy (PBMT) is a non-thermal therapeutic procedure widely used in clinical practice. It is considered an effective modality of treatment for the control of various inflammatory conditions with fewer adverse effects as compared to conventional therapy. However, despite the clinical effects, the mechanisms of action and dosimetric parameters of PBMT are not fully understood. This study was performed to describe the effects of two different doses of PBMT on experimental models of inflammation. Male Swiss mice were administered with 0.9% of saline or phlogistic agents (carrageenan, dextran, serotonin, histamine, or bradykinin) by intra-plantar injection and were treated with PBMT at a dose of 1 or 5 J/cm2; right after, the variation of the paw volume was made, and histopathological analysis and myeloperoxidase assay of the carrageenan-induced edematous paw tissues were performed. The action of PBMT on carrageenan-induced vascular permeability was further evaluated. Our results showed that PBMT (1 J/cm2) led to an improvement in paw edema induced by the phlogistic agents and further reduced the histological scores. Inhibition of neutrophil migration was observed following the administration of 1 and 5 J/cm2 of PBMT. However, only 1 J/cm2 of PBMT showed beneficial effects on carrageenan-induced edema. Laser at a dose of 1 J/cm2 showed cellular and vascular effects since it was able to reverse all the inflammatory parameters, and laser at a dose of 5 J/cm2 probably has only cellular effects in the presence of acute inflammation.

Chemical structure and anti-inflammatory effect of polysaccharide extracted from Morinda citrifolia Linn (Noni).

Polysaccharides extracted from plants are very promising molecules in the field of pharmacotherapy. Knowing this, the aim of this study was to extract, characterize and evaluate the action of the polysaccharide of Morinda citrifolia Linn (Noni-PLS) in biological models of inflammatory processes. The characterization tests shown that sample refers to a heteropolysaccharide composed mainly of homogalacturonan and rhamnogalacturonan. This polysaccharide at dose of 10 mg/kg, when tested in our models of inflammation, showed significant activity in reducing carrageenan-induced paw oedema as well as all mediators edemas. This polysaccharide was able to inhibit the migration of leukocytes to the site of inflammation, and still reduced inflammatory nociception tests. This results, allows us to conclude that the polysaccharide extracted from Morinda citrifolia linn has anti-inflammatory potential since it reversed inflammatory parameters such as edema, leukocyte migration and nociception.

Gabapentin, a synthetic analogue of gamma aminobutyric acid, reverses systemic acute inflammation and oxidative stress in mice.

The aim of this study was to investigate the potential anti-inflammatory and anti-oxidant effects of gabapentin (GBP) in mice. The anti-inflammatory and anti-oxidant effects were evaluated using various mediators that induce paw edema, peritonitis model, myeloperoxidase (MPO) activity, proinflammatory cytokine levels, glutathione (GSH) consumption, and malondialdehyde (MDA) production in mice. Pretreatment of mice with GBP (1 mg/kg) significantly reduced carrageenan or dextran-induced paw edema (P<0.05) when compared to vehicle group. Adding to this, GBP (1 mg/kg) significantly inhibited paw edema induced by histamine, serotonin, bradikinin, 48/80 compound, and prostaglandin E2. In the carrageenan-induced peritonitis model, GBP significantly decreased total and differential leukocyte counts and reduced the levels of MPO activity in the plantar tissue and IL-1ß and TNF-α concentrations in the peritoneal exudate. The same dose of GBP also decreased the MDA concentration and increased the levels of GSH into the peritoneal fluid. In summary, our results demonstrated that GBP exhibited anti-inflammatory activity in mice by reducing the action of inflammatory mediators, neutrophil migration and proinflammatory cytokine levels, and anti-oxidant properties by decreasing the concentration of MDA and increasing the GSH content. These observations raise the possibility that GBP could be used to improve tissue resistance to damage during inflammatory conditions.