Sex hormones play a dual role in regulating allergic lung inflammation in mice.

We have previously shown that the prophylactic treatment with cannabidiol (CBD) reduces inflammation in a model of acute lung injury (ALI). In this work we analyzed the effects of the therapeutic treatment with CBD in mice subjected to the model of lipopolysaccharide (LPS)-induced ALI on pulmonary mechanics and inflammation. CBD (20 and 80 mg/kg) was administered (i.p.) to mice 6 h after LPS-induced lung inflammation. One day (24 h) after the induction of inflammation the assessment of pulmonary mechanics and inflammation were analyzed. The results show that CBD decreased total lung resistance and elastance, leukocyte migration into the lungs, myeloperoxidase activity in the lung tissue, protein concentration and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) in the bronchoalveolar lavage supernatant. Thus, we conclude that CBD administered therapeutically, i.e. during an ongoing inflammatory process, has a potent anti-inflammatory effect and also improves the lung function in mice submitted to LPS-induced ALI. Therefore the present and previous data suggest that in the future cannabidiol might become a useful therapeutic tool for the attenuation and treatment of inflammatory lung diseases.

Innate immune responses against microorganisms may be mediated by Toll-like receptors (TLRs). Intestinal ischemia-reperfusion (i-I/R) leads to the translocation of bacteria and/or bacterial products such as endotoxin, which activate TLRs leading to acute intestinal and lung injury and inflammation observed upon gut trauma. Here, we investigated the role of TLR activation by using mice deficient for the common TLR adaptor protein myeloid differentiation factor 88 (MyD88) on local and remote inflammation following intestinal ischemia. Balb/c and MyD88(-/-) mice were subjected to occlusion of the superior mesenteric artery (45 min) followed by intestinal reperfusion (4 h). Acute neutrophil recruitment into the intestinal wall and the lung was significantly diminished in MyD88(-/-) after i-I/R, which was confirmed microscopically. Diminished neutrophil recruitment was accompanied with reduced concentration of TNF-alpha and IL-1beta level. Furthermore, diminished microvascular leak and bacteremia were associated with enhanced survival of MyD88(-/-) mice. However, neither TNF-alpha nor IL-1beta neutralization prevented neutrophil recruitment into the lung but attenuated intestinal inflammation upon i-I/R. In conclusion, our data demonstrate that disruption of the TLR/MyD88 pathway in mice attenuates acute intestinal and lung injury, inflammation, and endothelial damage allowing enhanced survival.

This work demonstrates that I/R is associated with a significant loss of different subpopulations of neurons in the myenteric plexus accompanied by morphological changes, all of which may underlie conditions related to intestinal motility disorder.

Estradiol treatment is able to reduce lung inflammation due to intestinal I/R, but with the concomitant blockade of NOS activity, this effect is abolished. Nitric oxide probably reduces the vascular deleterious effects of intestinal I/R, and E(2) pretreatment reduces lung inflammation after intestinal I/R and exerts these effects by modulating eNOS protein expression in the lungs.