Trypanosoma cruzi: Does the intake of nanoencapsulated benznidazole control acute infections?

Chagas Disease (CD) affects around eight million people worldwide. It is considered a neglected disease that presents few treatment options with efficacy only in the acute phase. Nanoparticles have many positive qualities for treating parasite infections and may be effectively and widely employed in clinical medicine. This research aimed to evaluate the nanoencapsulated benznidazole treatment in animals experimentally infected with Trypanosoma cruzi. To analyze the treatment efficacy, we evaluated survival during thirty days, parasitemia, genotoxicity, and heart and liver histopathology. Thirty-five female Swiss mice were organized into seven groups characterizing a dose curve: A - Negative control (uninfected animals), B - Positive control (infected animals), C - Benznidazole (BNZ) 100 mg/kg (infected animals), D - 5 mg/kg Benznidazole nanocapsules (NBNZ) (infected animals), E - 10 mg/kg Benznidazole nanocapsules (infected animals), F - 15 mg/kg Benznidazole nanocapsules (infected animals), G - 20 mg/kg Benznidazole nanocapsules (infected animals). The animals were infected with the Y strain of T. cruzi intraperitoneally. The treatment was administered for eight days by oral gavage. It was possible to observe that the treatment with the highest NBNZ dose presented efficacy similar to the standard benznidazole drug. The 20 mg/kg NBNZ dose was able to reduce parasitemia, increase survival, and drastically reduce heart and liver tissue damage compared to the 100 mg/kg BNZ dose. Moreover, it showed a lower DNA damage index than the BNZ treatment. In conclusion, the nanoencapsulation of BNZ promotes an improvement in parasite proliferation control with a five times smaller dose relative to the standard dose of free BNZ, thus demonstrating to be a potential innovative therapy for CD.

Açaí (Euterpe oleracea Mart.) reduces the inflammatory response triggered in vitro by the antipsychotic drug olanzapine in RAW 264.7 macrophage cells

BACKGROUND

Açaí (Euterpe oleracea Mart), a Brazilian fruit, is considered a "superfruit" due its energetic properties and bioactive compounds. The açai's anti-inflammatory effects could attenuate the undesirable metabolic and pro-inflammatory side effects triggered by some antipsychotic drugs, such as Olanzapine (OLZ). It is possible to infer that açai supplement could potentially minimize the adverse effects of OLZ. Aim. This study tested the potential in vitro effects of açai hydroalcoholic extract on the inflammatory activation of the RAW 264.7 macrophage line triggered by OLZ antipsychotic drugs.

METHODS

An in vitro protocol was performed using commercial RAW 264.7 macrophages, cultured under sterile conditions at 37°C with 5% CO2 saturation. Initially, a pharmacological curve was defined to determine the concentration of Olanzapine to be used. After this, the cells were supplemented with different concentrations of hydroalcoholic extract of açaí, which had been previously chemically characterized. After 24 and 72 hours of treatment, oxidative and inflammatory tests were performed. Therefore, the aim of this study was to verify whether the hydroalcoholic extract of açaí can modulate the oxy-inflammatory response of olanzapine in vitro.

RESULTS

From a preliminary analysis, the açai extract at 5 mg/mL presented higher activity against inflammation triggered by OLZ (0.03 μg/mL). At this concentration, açai was able to reduce several oxidative and inflammatory markers triggered by OLZ (0.03 μg/mL) exposure, such as nitric oxide (NO), reactive oxygen species (ROS), and pro-inflammatory cytokine levels (IL-1b, IL-6, TNF-a, IFN-g) caused by OLZ (0.03 μg/mL). Moreover, açaí reverted the levels of anti-inflammatory cytokine IL-10 that had been dropped by OLZ exposure to their pre-exposure treatments.

CONCLUSIONS

The results suggest that açai extract could be useful in attenuating the peripheral inflammatory states triggered by OLZ. Additional pre-clinical and clinical investigations could be useful in testing therapeutic açai extract supplements.

Uncaria tomentosa improves cognition, memory and learning in middle-aged rats

Aging accelerates neurodegeneration, while natural and safe neuroprotective agents, such as Uncaria tomentosa, may help to overcome this problem. This study assessed the effects of U. tomentosa extract treatment on the aging process in the brain of Wistar rats. The spatial memory and learning, acetylcholinesterase (AChE) activity, and DNA damage were assessed. Animals of 14 months were tested with different doses of U. tomentosa (5 mg/kg, 15 mg/kg, and 30 mg/kg) and with different durations of treatment (one month and one year). In the Morris Water Maze (MWM), the escape latency was significantly (p < 0.0001) shorter in rats that received 5 mg/kg, 15 mg/kg, and 30 mg/kg of U. tomentosa for both one month and one year of treatment. There was a significant difference in time spent at the platform zone (p < 0.05) of the middle-aged rats treated with U. tomentosa extract for one year when compared to the control rats. The cortex and hippocampus of rats treated with U. tomentosa for one year showed significant (p > 0.05) reduction in AChE activity. DNA damage index on cortex was significantly lower (p < 0.05) in animals treated with 30 mg/kg of U. tomentosa for one month while all the tested doses demonstrated significant (p < 0.001) reductions in DNA damage index in animals treated for one year. In conclusion, U. tomentosa may represent a source of phytochemicals that could enhance memory activity, repair DNA damage, and alter AChE activity, thereby providing neuroprotection during the aging process.

Aluminum-induced alterations of purinergic signalling in embryonic neural progenitor cells

The ubiquitous presence of aluminum in the environment leads to a high likelihood of human exposure. Neurotoxicity of the trivalent cationic form of this metal (Al3+) occurs in the central nervous system via accumulation of Al in cells of neural origin, including neural progenitor cells (NPCs). NPCs play a key role in the development and regeneration of the brain throughout life; therefore, this metal may contribute to neuropathological conditions. Here, we evaluated the effects of different Al³⁺ concentrations (0-50 μM) on the purinergic system of NPCs isolated from embryonic telencephalons, cultured as neurospheres. Al³⁺ adhered to the cell surface of neurospheres reducing extracellular ATP release, as well as ATP, ADP, and AMP hydrolysis by NTPDase and 5'-nucleotidase, respectively. In addition, impaired nucleotide release by Al³⁺ reduced P2Y1 and adenosine A2A receptors expression in differentiated neurospheres. These receptors are crucial for NPC proliferation during brain development and self-repair against external stimuli, such as metal exposure. Thus, Al³⁺ represents an environmental agent linked to neurodegeneration through alterations in the ATP-signalling pathway, proving to be a potential mechanism associated with NPC proliferation and brain degeneration.

Resveratrol-mediated reversal of changes in purinergic signaling and immune response induced by Toxoplasma gondii infection of neural progenitor cells

The effects of Toxoplasma gondii during embryonic development have not been explored despite the predilection of this parasite for neurons and glial cells. Here, we investigated the activation of the purinergic system and proinflammatory responses during congenital infection by T. gondii. Moreover, neuroprotective and neuromodulatory properties of resveratrol (RSV), a polyphenolic natural compound, were studied in infected neuronal progenitor cells (NPCs). For this study, NPCs were isolated from the telencephalon of infected mouse embryos and subjected to neurosphere culture in the presence of EGF and FGF2. ATP hydrolysis and adenosine deamination by adenosine deaminase activity were altered in conditions of T. gondii infection. P2X7 and adenosine A_2A receptor expression rates were augmented in infected NPCs together with an increase of proinflammatory (INF-γ and TNF-α) and anti-inflammatory (IL-10) cytokine gene expression. Our results confirm that RSV counteracted T. gondii-promoted effects on enzymes hydrolyzing extracellular nucleotides and nucleosides and also upregulated P2X7 and A_2A receptor expression and activity, modulating INF-γ, TNF-α, and IL-10 cytokine production, which plays an integral role in the immune response against T. gondii.