Ethyl Acetate Fraction of Bixa orellana and Its Component Ellagic Acid Exert Antibacterial and Anti-Inflammatory Properties against Mycobacterium abscessus subsp. massiliense.

Mycobacterium abscessus subsp. massiliense (Mabs) causes chronic infections, which has led to the need for new antimycobacterial agents. In this study, we investigated the antimycobacterial and anti-inflammatory activities of the ethyl acetate fraction of Bixa orellana leaves (BoEA) and ellagic acid (ElAc). In silico analysis predicted that ElAc had low toxicity, was not mutagenic or carcinogenic, and had antimicrobial and anti-inflammatory activities. Apparently, ElAc can interact with COX2 and Dihydrofolate reductase (DHFR) enzymes, which could explain both activities. In vitro analysis showed that BoEA and ElAc exerted antimicrobial activity against Mabs (minimum inhibitory concentration of 1.56, 1.56 mg/mL and bactericidal concentration of 6.25, 3.12 mg/mL, respectively. Clarithromycin showed MIC and MBC of 1 and 6 µg/mL). Treatment with BoEA or ElAc increased survival of Tenebrio molitor larvae after lethal infection with Mabs and reduced carrageenan-induced paw edema in mice, around 40% of edema volume after the fourth hour, similarly to diclofenac. In conclusion, BoEA and ElAc exert antimicrobial effects against Mabs and have anti-inflammatory effects, making them potential sources of antimycobacterial drugs. The biological activities of ElAc may be due to its high binding affinities predicted for COX2 and DHFR enzymes.

Morphological study of larynx, trachea, and lungs of Didelphis marsupialis (LINNAEUS, 1758).

BACKGROUND AND AIM: From a biomedical point of view, the value of marsupials as a model of primitive mammals is indisputable. Among its species, the possum is a model that allows the study of the ontogeny of different organic systems, as well as their physiological aspects. The relevance of anatomical, functional, evolutionary, and phylogenetic study of marsupials for the development of comparative morphology is extensively documented in the literature. However, there are still many aspects to be further evaluated, as the anatomy and histology of the respiratory tract of this species. The aim of this study was to describe the morphology of the larynx, trachea, and lungs of Didelphis marsupialis. MATERIALS AND METHODS: Five adult male animals were donated to the Comparative Animal Anatomy Laboratory - LAAC/CCAA-UFMA, for morphological studies. Specimens were washed in running water to perform biometrics. Then, they were fixed with 10% formaldehyde solution. After the fixation period, the specimens were positioned in dorsal decubitus position, for dissection of the respiratory system organs, by opening the ventral region of the neck and thoracic cavity, with subsequent removal of the pectoral muscles, ribs, and sternum. For histological analysis, fragments of 1 cm2 of the larynx (epiglottis and thyroid cartilages), trachea, and lungs were collected and fixed in 10% formaldehyde solution. Right after fixation, the fragments were dehydrated in increasing concentrations of ethyl alcohol (70, 80, 95, and 100%), diaphanized in xylene, embedded in paraffin, and sectioned into thin slices of 5 µm using a microtome. Sections were stained using the hematoxylin and eosin technique. RESULTS: Anatomically, the larynx starts right after the pharynx. It consisted of four cartilages: Epiglottis, cricoid, thyroid, and arytenoid. The trachea was made of dorsally incomplete cartilaginous rings. At the entrance of the thoracic cavity, it bifurcated into the left and right main bronchus. The left lung was smaller than the right lung, with two lobes (cranial and caudal). The right lung presents the cranial, middle, caudal, and accessory lobes. Histologically, the epiglottis consisted of elastic cartilage and is covered by a non-keratinized stratified squamous epithelium. Thyroid cartilage is made of hyaline cartilage covered by smooth muscle. The trachea presents hyaline cartilage, with ciliated pseudo-stratified epithelium, serous glands, isogenic groups of chondrocytes, and perichondrium. The lung consisted of bronchi, bronchioles, and alveoli, also presenting blood vessels and arteries. CONCLUSION: Morphologically, the larynx, trachea, and lungs of D. marsupialis were similar to those of the other Didelphids described in the literature.