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Gentamicin is an aminoglycoside antibiotic used in the treatment of gram-negative bacterial infections. However, its prolonged use is limited due to a high risk of nephrotoxicity. This study aimed to investigate the protective effects of a lipid transfer protein isolated from Morinda citrifolia L., Rubiaceae, seeds against gentamicin-induced nephrotoxicity in rats, and in a proximal tubular epithelial cell line from Rhesus monkey (LLC-MK2). Treatment with 6.25-25 μg/ml of the protein protected cells against cytotoxicity induced by 2 mM gentamicin. In the in vivo study, protein treatment (8 mg/kg, orally administered daily for 7 days 2 h after intraperitoneal injection of 100 mg/kg gentamicin) improved the levels of creatinine, urea, and uric acid. Additionally, it alleviated oxidative stress and inflammation induced by gentamicin, including a reduction in myeloperoxidase activity and cytokine modulation. Data were corroborated with histological analysis showing attenuated alterations by protein treatment. These findings suggest that this protein protects against gentamicin-induced nephrotoxicity. In addition, this natural product may be as an adjunctive tool to reduce kidney toxicity and improve the clinical usage profile of gentamicin.

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.

Background: Envenomation caused by Bothrops alternatus is common in Southern Brazil. Acute Kidney Injury occurs after Bothrops snakebite and more information is necessaryrequired to understand its mechanism. Objective: The objective was to evaluate the effect of Bothrops alternatus venom (BaV) on renal cells and rat isolated kidney function. Methods: Wistar rats (n = 6, weighing 260-320 g) were perfused with a Krebs-Henseleit solution containing 6 g 100 mL-1 of bovine serum albumin. After 30 minutes, the kidneys were perfused with BaV to a final concentration of 1 and 3 μgmL-1; and subsequently were evaluated for Perfusion Pressure (PP), Renal Vascular Resistance (RVR), Urinary Flow (UF), Glomerular Filtration Rate (GFR), and percentage of electrolyte tubular transport. Renal histological analysis, cytokine release, oxidative stress and cytotoxicity in renal proximal tubular cells were assessed. Results: BaV reduced PP, RVR, GFR, UF, total and proximal sodium transport (%TNa+), and chloride (%TCl-) in the isolated kidney perfusion model. Histological analysis of perfused kidneys disclosed the presence of proteinaceous material in the glomeruli and renal tubules, vacuolar tubular epithelial cell degeneration, Bowman's capsule degeneration, swelling of glomerular epithelial cells, glomerular atrophy and degeneration, and the presence of intratubular protein. Cytokine release (TNF-α, IL-1β, IL-10) and oxidative stress were increased in the kidneys. The viability of LLC-MK2 cells (IC50: 221.3 μg/mL) was decreased by BaV and necrosis was involved in cell death. Conclusion: These findings indicate that BaV modifies functional parameters in an isolated perfused kidney model and has cytotoxic effects on renal lineage cells.

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Purpose: Mania is associated with disturbed dopaminergic transmission in frontotemporal regions. D-amphetamine (AMPH) causes increased extracellular DA levels, considered an acknowledged mania model in rodents. Doxycycline (DOXY) is a second-generation tetracycline with promising neuroprotective properties. Here, we tested the hypothesis that DOXY alone or combined with Lithium (Li) could reverse AMPH-induced mania-like behavioral alterations in mice by the modulation of monoamine levels in brain areas related to mood regulation, as well as cytoprotective and antioxidant effects in hippocampal neurons. Methods: Male Swiss mice received AMPH or saline intraperitoneal (IP) injections for 14 days. Between days 8-14, mice receive further IP doses of DOXY, Li, or their combination. For in vitro studies, we exposed hippocampal neurons to DOXY in the presence or absence of AMPH. Results: DOXY alone or combined with Li reversed AMPH-induced risk-taking behavior and hyperlocomotion. DOXY also reversed AMPH-induced hippocampal and striatal hyperdopaminergia. In AMPH-exposed hippocampal neurons, DOXY alone and combined with Li presented cytoprotective and antioxidant effects, while DOXY+Li also increased the expression of phospho-Ser133-CREB. Conclusion: our results add novel evidence for DOXY’s ability the reversal of mania-like features while revealing that antidopaminergic activity in some brain areas, such as the hippocampus and striatum, as well as hippocampal cytoprotective effects may account for this drug’s antimanic action. This study provides additional rationale for designing clinical trials investigating its potential as a mood stabilizer agent.