Effects of centipedic acid on acute lung injury: A dose-response study in a murine model.

Centipedic Acid (CPA), a natural diterpene from Egletes viscosa, an endemic species of the Caatinga biome, has shown antioxidant and anti-inflammatory properties. However, no report on the CPA on respiratory system mechanics has been so far advanced. We aimed to investigate the dose-response behavior of CPA on E. coli lipopolysaccharide (LPS)-triggered acute lung injury (ALI). Forty-eight C57BL/6 mice were randomly divided into six groups: control (SS), induced to ALI (LPS), 4 groups induced to ALI pre-treated with 12.5, 25, 50 and 100 mg/kg of CPA (CPA12.5, CPA25, CPA50 and CPA100 groups). CPA 100 mg/kg could prevent inflammatory cell infiltration, alveolar collapse, changes in tissue micromechanics and lung function (airway resistance, tissue elastance, tissue resistance and Static compliance). These results indicate preventive potential of this compound in the installation of ALI.

Effects of Anacardic Acid Monoene on the Respiratory System of Mice Submitted to Acute Respiratory Distress Syndrome.

The acute respiratory distress syndrome caused by viral pathogens is a worldwide public health emergency. It is suggested that patients with this condition should be screened using therapies that address the need to prevent mortality. Anacardic acids found in Anacardium species have biological activities related to the antioxidant capacity of their double bonds in the lateral alkyl chain. The present study seeks to investigate the effects of anacardic acid monoene on acute respiratory distress syndrome caused by lipopolysaccharides. Experiments were carried out on mice divided into three groups: control group, acute respiratory distress-induced group, and anacardic acid monoene pretreated group, subsequently, induced to acute respiratory distress by lipopolysaccharides. Results showed that anacardic acid moeno was able to prevent changes in lung function and preserve its mechanical properties from containing inflammatory cell infiltrate, collapse of alveoli, and decreased airway resistance, suggesting that this compound may be effective in preventing the acute respiratory distress syndrome caused by viral pathogens. Supplementary Information: The online version contains supplementary material available at 10.1007/s43450-021-00151-8.

Effects of fixed oil of Caryocar coriaceum Wittm. Seeds on the respiratory system of rats in a short-term secondhand-smoke exposure model.

ETHNOPHARMACOLOGICAL RELEVANCE: Pequi fruit are obtained from the pequi tree (Caryocar coriaceum), from which the pulp and nut are used in order to extract an oil that is commonly used in popular medicine as an antiinflammatory agent, particularly for the treatment of colds, bronchitis and bronchopulmonary infections. Making use of the fixed oil of Caryocar coriaceum (FOCC), an attractive alternative for the treatment of diseases caused by exposure to environmental tobacco smoke. AIM OF THE STUDY: To evaluate whether oral intake FOCC provides beneficial effects in the respiratory system of rats submitted to a short-term secondhand smoke (SHS) exposure model. MATERIALS AND METHODS: The experiments were performed on Wistar rats divided into 4 groups; in the SHS + O and SHS + T groups, the animals were pretreated orally with 0.5 mL of FOCC (SHS + O) or vehicle (Tween-80 [1%] solution) (SHS + T). Immediately after pretreatment, the animals were submitted to the SHS exposure protocol, for a total period of 14 days. Exposures were performed 6 times per day, with a duration of 40 min per exposure (5 cigarettes per exposure), followed by a 1-h interval between subsequent exposures. In the AA + O and AA + T groups, animals were submitted to daily oral pretreatment with 0.5 mL of FOCC (AA + O) or vehicle (AA + T). These animals were then subjected to the aforementioned exposure protocol, but using ambient air. After the exposure period, we investigated the effects of FOCC in respiratory mechanics in vivo (Newtonian resistance -RN, tissue elastance -H, tissue resistance -G, static compliance -CST, inspiratory capacity -IC, PV loop area) histopathology and lung parenchymal morphometry in vitro (polymorphonuclear cells -PMN, mean alveolar diameter -Lm, bronchoconstriction index -BCI), temporal evolution of subjects' masses, and percent composition of the FOCC. RESULTS: Regarding the body mass of the animals, the results demonstrated an average body mass gain of 10.5 g for the animals in the AA + T group, and 15.5 g for those in the AA + O group. On the other hand, the body mass of animals in the SHS + T and SHS + O suffered an average loss of 14.4 and 4.75 g, respectively. Regarding respiratory system analyzes, our results demonstrated significant changes in all respiratory mechanics variables and lung parenchyma morphometry analyzed for the SHS + T group when compared to the AA + T group (p < 0,05), confirming the establishment of pulmonary injury induced by SHS exposure. We also observed that rats pretreated orally with FOCC (SHS + O) showed improvement in all variables when compared to the SHS + T group (p < 0,05), thus demonstrating the effectiveness of FOCC in preventing lung damage induced by short-term SHS exposure. CONCLUSION: In conclusion, our results demonstrate that FOCC was able to prevent lung injury in rats submitted to short-term SHS exposure.

Lung injury caused by exposure to the gaseous fraction of exhaust from biomass combustion (cashew nut shells): a mice model.

Currently, to reduce the use of nonrenewable energy sources in energy matrices, some industries have already incorporated biomass as a source of energy for their processes. Additionally, filters are used in an attempt to retain the particulate matter present in exhaust gases. In this work, the emission gases of a cashew nut shell (CNS) combustion reactor and the deleterious effects on the respiratory system of mice exposed to gaseous fraction present in CNS emissions (GF-CNS) are analyzed. The system for CNS combustion is composed of a cylindrical stainless steel burner, and exhaust gases generated by CNS combustion were directed through a chimney to a system containing two glass fiber filters to retain all the PM present in the CNS exhaust and, posteriorly, were directed to a mice exposure chamber. The results show changes in the variables of respiratory system mechanics (G, H, CST, IC, and PV loop area) in oxidative stress (SOD, CAT, and NO2-), as well as in the histopathological analysis and lung morphometry (alveolar collapse, PMN cells, mean alveolar diameter, and BCI). Through our results, it has been demonstrated that even with the use of filters by industries for particulate material retention, special attention should still be given to the gaseous fraction that is released into the environment.