No abstract

This study evaluated the knowledge of students in Biological Sciences at the Federal University of Piauí, Campus Senador Helvidio Nunes de Barros about the Human Papillomavirus (HPV).

The N-methyl-(2S,4R)-trans-4-hydroxy-l-proline-enriched fraction (NMP) from Sideroxylon obtusifolium was evaluated as a neuroprotective agent in the intracerebroventricular (icv) pilocarpine (Pilo) model. To this aim, male mice were subdivided into sham (SO, vehicle), Pilo (300 µg/1 µL icv, followed by the vehicle per os, po) and NMP-treated groups (Pilo 300 µg/1 µL icv, followed by 100 or 200 mg/kg po). The treatments started one day after the Pilo injection and continued for 15 days. The effects of NMP were assessed by characterizing the preservation of cognitive function in both the Y-maze and object recognition tests. The hippocampal cell viability was evaluated by Nissl staining. Additional markers of damage were studied—the glial fibrillary acidic protein (GFAP) and the ionized calcium-binding adaptor molecule 1 (Iba-1) expression using, respectively, immunofluorescence and western blot analyses. We also performed molecular docking experiments revealing that NMP binds to the γ-aminobutyric acid (GABA) transporter 1 (GAT1). GAT1 expression in the hippocampus was also characterized. Pilo induced cognitive deficits, cell damage, increased GFAP, Iba-1, and GAT1 expression in the hippocampus. These alterations were prevented, especially by the higher NMP dose. These data highlight NMP as a promising candidate for the protection of the hippocampus, as shown by the icv Pilo model.

Epilepsy is a neurological disorder characterized by recurrent seizures, resulting from excessive neuronal discharges. Sideroxylon obtusifolium is used in Brazil for its anti-inflammatory/antioxidant properties, known to be involved with epilepsy. The anticonvulsant effects of the methanol fraction from S. obtusifolium leaves, rich in N-methyl-(2S,4R)-trans-4-hydroxy-L-proline, were investigated on pilocarpine- and pentylenetetrazole-induced convulsion models. Mice were pretreated with N-methyl-(2S,4R)-trans-4-hydroxy-L-proline (50, 100, 200 mg/kg, p.o.) and, 1 h later, by pilocarpine (400 mg/kg, i.p.) or pentylenetetrazole (80 mg/kg, i.p.). The animals were observed for latency to the first convulsion and latency to death. Immediately after death, brain areas from the pilocarpine groups were harvested for biochemical measurements. The latency to the first convulsion and latency to death increased after N-methyl-(2S,4R)-trans-4-hydroxy-L-proline treatment compared with the pilocarpine- or pentylenetetrazole-only groups. In both convulsion models, sodium valproate (reference drug) was used as a positive control. Additionally, the decreases in striatal dopamine and 3,4-dihydroxyphenylacetic acid contents observed in the pilocarpine-only group were partially prevented in the N-methyl-(2S,4R)-trans-4-hydroxy-L-proline-treated groups. While brain gamma-aminobutyric acid and glutamate contents decreased and increased, respectively, after pilocarpine only, these changes were also prevented by N-methyl-(2S,4R)-trans-4-hydroxy-L-proline. Similarly, N-methyl-(2S,4R)-trans-4-hydroxy-L-proline reduced the brain oxidative stress by decreasing the levels of nitrite and lipid peroxidation and increasing the glutathione content of the pilocarpine-only group. The increases in hippocampal expressions for interleukin 6, interferon-gamma, and glial fibrillary acidic protein, after pilocarpine only, were decreased to normal levels by N-methyl-(2S,4R)-trans-4-hydroxy-L-proline. In conclusion, the study showed significant anticonvulsant effects for N-methyl-(2S,4R)-trans-4-hydroxy-L-proline, probably related to its anti-inflammatory/antioxidant properties. N-Methyl-(2S,4R)-trans-4-hydroxy-L-proline effects were potentiated by VPA (sodium valproate), thus it may also interact with the GABAergic system, as we had recently shown.

Glial cells have been implicated in temporal lobe epilepsy in humans and in its models. Astrocytes are lost in several brain regions after acute seizures induced by pilocarpine and may suffer hyperplasia at subsequent time points. This study investigated the effect of N-methyl-(2S,4R)-trans-4-hydroxy-L-proline (NMP) on astrocytes exposed to cytotoxic concentrations of pilocarpine. Astrocytes were incubated with pilocarpine (half maximal inhibitory concentration (IC 50 )=31.86 mM) for 24 h. Afterwards, they were treated with NMP at concentrations ranging from 3.12 to 100 mg/mL for 24 h. Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cytoplasmic reactive oxygen species (ROS) and mitochondrial transmembrane potential (DCm) were analyzed by flow cytometry using 2',7'-dichlorofluorescein diacetate (DCFH-DA) and rhodamine-123 (Rho123), respectively. Expression of glial fibrillary acidic protein (GFAP) and voltagedependent anion channel-1 (VDAC-1) were measured by western blot. Pilocarpine significantly decreased cell viability and mitochondrial potential and increased ROS concentration significantly by 6.7 times compared to the control. NMP concentrations X25 mg/mL protected astrocytes against pilocarpine-induced injury in a concentration-dependent manner. Concomitantly, NMP reduced cytoplasmic ROS accumulation to 27.3, 24.8, and 12.3% in the groups treated with 25, 50, and 100 mg/mL NMP, respectively. NMP also protected mitochondria from pilocarpine-induced depolarization. These effects were associated with improvement of pilocarpine-induced GFAP and VDAC-1 overexpression, which are important biomarkers of astrocyte dysfunction. In conclusion, the improvement of ROS accumulation, VDAC-1 overexpression, and mitochondrial depolarization are possible mechanisms of the NMP protective action on reactive astrocytes.