Involvement of cholinergic and adenosinergic systems on the branchial immune response of experimentally infected silver catfish with Streptococcus agalactiae.

It has been recognized that the cholinergic and adenosinergic systems have an essential role in immune and inflammatory responses during bacterial fish pathogens, such as the enzymes acetylcholinesterase (AChE) and adenosine deaminase (ADA), which are responsible for catalysis of the anti-inflammatory molecules acetylcholine (ACh) and adenosine (Ado) respectively. Thus, the aim of this study was to investigate the involvement of the cholinergic and adenosinergic systems on the immune response and inflammatory process in gills of experimentally infected Rhamdia quelen with Streptococcus agalactiae. Acetylcholinesterase activity decreased, while ACh levels increased in gills of infected animals compared to uninfected animals. On the other hand, a significant increase in ADA activity with a concomitant decrease in Ado levels was observed in infected animals compared to uninfected animals. Based on this evidence, we concluded that infection by S. agalactiae in silver catfish alters the cholinergic and adenosinergic systems, suggesting the involvement of AChE and ADA activities on immune and inflammatory responses, regulating the ACh and Ado levels. In summary, the downregulation of AChE activity exerts an anti-inflammatory profile in an attempt to reduce or prevent the tissue damage, while the upregulation of ADA activity exerts a pro-inflammatory profile, contributing to disease pathophysiology.

Quercetin ameliorates polychlorinated biphenyls-induced testicular DNA damage in rats.

Polychlorinated biphenyls (PCBs) are a group of environmental contaminants widely reported to cause gonadal toxicity in both humans and animals. This study investigated the amelioratory role of quercetin in PCBs-induced DNA damage in male Wistar rats. Polychlorinated biphenyls were administered intraperitoneally at a dose of 2 mg kg(-1) alone or in combination with quercetin (orally) at 50 mg kg(-1) for 25 days. Quercetin modulation of PCBs-induced gonadal toxicity was evaluated using selected oxidative stress indices, comet assay, measurement of DNA concentration and histology of the testes. Administration of PCBs alone caused a significant (P < 0.05) depletion in the total thiol level in testes of treated rats. Conversely, the levels of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) production were markedly elevated in testes of PCBs-treated rats compared with control. Further, PCBs exposure produced statistically significant increases in DNA tail migration, degraded double-stranded DNA (dsDNA) concentration and histological alterations of testes of the treated rats compared to control. Quercetin cotreatment significantly improved the testicular antioxidant status, decreased DNA fragmentation and restored the testicular histology, thus demonstrating the protective effect of quercetin in PCBs-treated rats.

Trypanocidal activity of free and nanoencapsulated curcumin on Trypanosoma evansi.

This study aimed to evaluate in vitro and in vivo trypanocidal activity of free and nanoencapsulated curcumin against Trypanosoma evansi. In vitro efficacy of free curcumin (CURC) and curcumin-loaded in lipid-core nanocapsules (C-LNCs) was evaluated to verify their lethal effect on T. evansi. To perform the in vivo tests, T. evansi-infected animals were treated with CURC (10 and 100 mg kg(-1), intraperitoneally [i.p.]) and C-LNCs (10 mg kg(-1), i.p.) during 6 days, with the results showing that these treatments significantly attenuated the parasitaemia. Infected untreated rats showed protein peroxidation and an increase of nitrites/nitrates, whereas animals treated with curcumin showed a reduction on these variables. As a result, the activity of antioxidant enzymes (superoxide dismutase and catalase) differs between groups (P<0.05). Infected animals and treated with CURC exhibited a reduction in the levels of alanine aminotransferase and creatinine, when compared with the positive control group. The use of curcumin in vitro resulted in a better parasitaemia control, an antioxidant activity and a protective effect on liver and kidney functions of T. evansi-infected adult male Wistar rats.