Chronic obstructive pulmonary disease (COPD) is the major cause of morbidity and mortality worldwide, and cigarette smoke is a key factor in the development of COPD. Thus, the development of effective therapies to prevent the advancement of COPD has become increasingly essential. We hypothesized that quercetin protects lungs in mice exposed to long-term cigarette smoke. Thirty-five C57BL/6 mice were exposed to cigarette smoke (12 cigarettes per day) for 60 days and pretreated with 10 mg/kg/day of quercetin via orogastric gavage. After the experimental protocol, the animals were euthanized and samples were collected for histopathological, antioxidant defense, oxidative stress and inflammatory analysis. The animals exposed to cigarette smoke showed an increase in respiratory rate and hematological parameters, cell influx into the airways, oxidative damage and inflammatory mediators, besides presenting with alterations in the pulmonary histoarchitecture. The animals receiving 10 mg/kg/day of quercetin that were exposed to cigarette smoke presented a reduction in cellular influx, less oxidative damage, reduction in cytokine levels, improvement in the histological pattern and improvement in pulmonary emphysema compared to the group that was only exposed to cigarette smoke. These results suggest that quercetin may be an agent in preventing pulmonary emphysema induced by cigarette smoke.

Cigarette smoke is highly toxic, and it can promote increased production of reactive species and inflammatory response and leads to liver diseases. Quercetin is a flavonoid that displays antioxidant and anti‐inflammatory activities in liver diseases. This study aimed at evaluating the protective effects of quercetin on livers from mice exposed to long‐term cigarette smoke exposure. Male C57BL/6 mice were divided into five groups: control (CG), vehicle (VG), quercetin (QG), cigarette smoke (CSG), quercetin, and cigarette smoke (QCSG). CSG and QCSG were exposed to cigarette smoke for sixty consecutive days; at the end of the exposures, all animals were euthanized. Mice that received quercetin daily and were exposed to cigarette smoke showed a reduced influx of inflammatory cells, oxidative stress, inflammatory reaction, and histopathological changes in the liver, compared to CSG. These results suggest that quercetin may be an effective adjuvant for treating damage to the liver due to cigarette smoke exposure.

Cigarette smoke (CS) is the major cause of preventable death worldwide, and it can also cause damage to extrapulmonary organs, such as the liver, mainly due the generation of reactive oxygen species (ROS). The liver is an essential organ for human survival since it is mainly responsible for the body metabolism and among other things and it is the place where many endogenous and exogenous substances undergo biological transformation. Lycopene is a nonprovitamin A carotenoid found in red fruits and vegetables, and its role as a potent antioxidant is well known. In this study, we hypothesized that lycopene could protect mouse liver against long‐term CS exposure. Thirty C57BL/6 mice were exposed to twelve cigarette smoke (12 cigarettes per day) for 60 days and pretreated with 25 mg/kg/day or 50 mg/kg/day of lycopene via orogastric gavage. After euthanasia, the hepatic tissue was collected for histopathological, antioxidant defense, oxidative stress, inflammatory, and collagen deposition analysis. Our analysis demonstrated that lycopene results in a suitable outcome to ameliorate the pathological changes, inflammatory and antioxidant profile in a mouse model of long‐term CS exposure, and collagen accumulation in the hepatic extracellular matrix. This study demonstrates for the first time that supplementation of lycopene can be a possible pharmacological tool for the treatment of hepatic damage caused by exposure to long‐term CS.

Acute lung injury (ALI) is characterized by acute respiratory insufficiency, including tachypnea, cyanosis refractory to oxygen, decreased lung compliance, and diffuse alveolar infiltrates, which is a condition associated with high morbidity and mortality that usually results in the development of multiple organ dysfunction. Acute lung injury in humans is histopathologically characterized by neutrophilic alveolitis, injury of the alveolar epithelium and endothelium, hyaline membrane formation, and microvascular thrombi. Different animal models of experimental lung injury have been used to investigate mechanisms of lung injury, such as LPS-induced ALI, hyperoxia-induced ALI, and ventilator-induced lung injury (VILI). Here we will show selected preclinical mice models used as proof of concept to test new drugs in vivo with anti-inflammatory properties, discussing their particularities and clarifying the context of use.

Paracetamol (APAP) overdose is the leading cause of drug-induced liver injury, leading to acute liver failure. However, the role of concurrent acute or chronic ethanol ingestion in this context requires further clarification. In this study, we investigated the effects of acute and chronic ethanol ingestion on APAP-induced hepatotoxicity. Male C57BL/6 mice were randomly allocated into four groups: control (C; water 2×/day for 7 days); APAP (single dose of APAP, 500 mg/kg); acute ethanol (AE; a single ethanol dose—10 mL/kg, and one hour later an overdose of APAP—500 mg/kg); chronic ethanol (CE; ethanol—10 mL/kg, 2×/day for 7 days; and on the last day, an overdose of APAP—500 mg/kg). The results showed that AE induced heightened liver damage, increased necrotic area, and elevated levels of ALT, AST, TBARS, and oxidized glutathione compared to the control group. The AE group exhibited diminished glutathione availability and elevated CYP2E1 levels compared to the other groups. CE maintained a hepatic profile similar to that of the control group in terms of necrosis index, ALT and AST levels, GSH/GSSG ratio, and CYP2E1 activity, along with the upregulation of gene expression of the glucuronidation enzyme compared to the APAP group. Proteomic analysis revealed that the AE protein profile closely resembled that of the APAP group, whereas the C and CE groups were clustered together. In conclusion, ethanol consumption differentially modulated APAP overdose-induced liver damage. Acute consumption exacerbated hepatotoxicity, similar to an APAP overdose alone, whereas chronic consumption appeared to mitigate this injury, at least within the parameters assessed in this study.