Propolis reverts cigarette smoke-induced emphysema through macrophage alternative activation

Emphysema is an incurable and progressive disease, and cigarette smoke (CS) is the main risk factor. Natural extracts have shown antioxidant and anti-inflammatory properties that can prevent acute lung inflammation and emphysema, but there are almost no reports in literature about therapeutics approaches to emphysema. We hypothesized if supplementation with propolis would repair lung damage in emphysema caused by CS exposure. C57BL/6 mice were exposed to 60 days of CS and then treated or not with propolis extract orally for more 60 days. Histological analysis revealed significant improvement in lung histoarchiteture, with recover of alveolar spaces, septa and elastic fibers in CS+propolis group. This natural extract also was able to increase MMP-2 and decrease MMP-12 expression, favoring the process of tissue repair. Propolis was also capable of recruiting leukocytes, among them macrophages, without ROS release. It leads us to investigate the profile of these macrophages and we showed that propolis could promote macrophage alternative activation and increase IL-10 levels, developing an anti-inflammatory microenvironment. We further investigated Nrf2 participation in lung repair promoted by propolis, but we showed that propolis did not stimulated Nrf2 translocation to nucleus. Proteins and enzymes related to Nrf2 was not altered, other than NQO1, that can be activate by propolis in a Nrf2-indepent manner. Propolis also acts downregulating IGF1. Beneficial effects of propolis s...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Mechanisms of Lung Injury and Repair Source Type: research