Hepatic fibropoiesis in dogs naturally infected with Leishmania (Leishmania) infantum treated with liposome-encapsulated meglumine antimoniate and allopurinol

Canine Visceral Leishmaniasis: A Histological and Immunohistochemical Study of Fibropoiesis in Chronic Interstitial Pneumonitis

We studied some fibrotic aspects of chronic interstitial pneumonitis in the lungs of dogs infected with Leishmania infantum. The lungs of eleven naturally infected dogs, twelve experimentally infected with two distinct strains of L. infantum (BH401 and BH46), and six uninfected (controls) dogs, were analyzed by histological, parasitological, and immunohistochemical studies. Conventional histology (HE), collagen deposition (Gomori's silver staining for reticulin collagen fibers), and immunohistochemistry for myofibroblast characterization were carried out based on the cellular expression of alpha-smooth muscle actin, vimentin, cytokeratin, E-cadherin, snail antigen homologue 1 (SNAI1) (Snail), and the cytokine expression of transforming growth factor-beta (TGF-β). Parasitological screening was carried out using conventional polymerase chain reaction (PCR) and the immunohistochemical reaction of streptavidin-peroxidase for visualizing Leishmania amastigotes. Dogs naturally infected with L. infantum and experimentally infected with L. infantum BH401 strains showed intense interstitial pneumonitis characterized by thickening of the alveolar septa as a consequence of an intense diffuse and focal (plaques) chronic exudate of mononuclear cells associated with fibrogenesis. The expression of alpha-actin, vimentin, and TGF-β was higher in the lung interstitium of all infected dogs than in the other two groups (BH46 strain and controls). Moreover, in both the naturally and experimentally infected dog (BH401 strain) groups, the expression of Snail was moderate to intense in contrast to the other groups. Based on these immunohistochemical results, we concluded that mesenchymal cells are active in promoting changes in the extracellular matrix in the lungs of dogs naturally and experimentally infected with L. infantum, but it depends on the virulence of the parasite.

Extra virgin coconut oil (Cocos nucifera L.) intake shows neurobehavioural and intestinal health effects in obesity-induced rats

The present study aimed to evaluate the effect of E-VCO on the neurobehaviour and intestinal health parameters of obesity-induced rats, focusing on food consumption, body composition, bacterial and faecal organic acids and histological analyses in the hippocampus and colon. A total of 32 male Wistar rats were randomized into healthy (HG, n = 16) and obese groups (OG, n = 16), which consumed a control or cafeteria diet for eight weeks, respectively. After this period, they were subdivided into four groups: healthy (HG, n = 8); healthy treated with E-VCO (HGCO, n = 8); obese (OG, n = 8); obese treated with E-VCO (OGCO, n = 8), continuing for another eight weeks with their respective diets. The treated groups received 3000 mg kg^-1 of E-VCO and control groups received water via gavage. Food preference, body weight gain, body composition, anxiety- and depression-like behaviour were evaluated. Bacteria and organic acids were evaluated in faeces, and histological analyses of the hippocampus and M1 and M2 macrophages in the colon were performed. E-VCO reduced energy intake (16.68%) and body weight gain (16%), although it did not reduce the fat mass of obese rats. E-VCO showed an antidepressant effect, increased lactic acid bacteria counts and modulated organic acids in obese rats. Furthermore, E-VCO protected the hippocampus from neuronal degeneration caused by the obesogenic diet, decreased the M1 macrophage and increased the M2 macrophage population in the gut. The results suggest neurobehavioural modulation and improved gut health by E-VCO, with promising effects against obesity-related comorbidities.

Use of liposomal nanoformulations in antileishmania therapy: challenges and perspectives

Leishmaniasis is a parasitic disease treatable and curable, however, the chemotherapeutic agents for their treatment are limited. In South American countries, pentavalent antimonials are still the first line of treatment for cutaneous leishmaniasis with an efficacy of about 75%, but the toxicity of the drug causes serious side effects and remains as the main obstacle for treatment. New knowledge aimed to improve drug delivery into the intracellular environment is essential, especially for drugs currently used in the clinic, to develop new anti-Leishmania formulations. In the present study, we analysed the scientific literature to highlight the progress achieved in the last decade regarding the use of nanotechnology for improving the current leishmaniasis treatments. Results allowed us to conclude that the encapsulated Glucantime liposomal formulation can be improved by means of nanoparticle functionalization processes, resulting in new drug delivery systems that can be potentially proposed as alternative therapies for leishmaniasis treatment.

Advances in Therapeutics and Delayed Drug Release

Reducing the frequency of drug administration in the treatment of exotic pets is advantageous because it may decrease handling frequency and thus potential stress and injury risk for the animal, increase owner compliance with the prescribed treatment, and decrease need for general anesthesia in patients that cannot be handled safely. Increasing efficient drug plasma concentration using sustained-released delivery systems is an appealing solution. Potential candidates that could provide a promising solution have been investigated in exotic pets. In this article, the technologies that are the closest to being integrated in exotic pet medicine are reviewed: osmotic pumps, nanoparticles, and hydrogels.