Therapeutic role of boron on acrylamide-induced nephrotoxicity, cardiotoxicity, neurotoxicity, and testicular toxicity in rats: Effects on Nrf2/Keap-1 signaling pathway and oxidative stress.

BACKGROUND: Acrylamide (ACR) is a heat-related carcinogen used in cooking some foods as well as in other thermal treatments. The present study aims to investigate the possible protective effect of boron (BA) against ACR-induced toxicity of kidney, brain, heart, testis, and bladder tissues in rats. METHODS: Rats have been divided into 5 equal groups: Control (saline), ACR (38.27 mg/kg), BA (20 mg/kg), BA+ ACR (10 mg/kg + ACR), and BA+ ACR (20 mg/kg BA+ACR). Kidney tissue from rats was collected and the levels of malondialdehyde (MDA), glutathione (GSH), and the activity of superoxide dismutase (SOD) were measured. In addition, the kidneys of these animals, as well as the brain, heart, testes, and bladder tissues were examined for possible histological changes. Total Nrf2 and Keap-1 protein expression in kidney, heart, and testis tissues was examined by immunohistochemistry. RESULTS: While significant increases in MDA levels were observed in the kidneys of rats receiving ACR alone, significant decreases in antioxidant markers (SOD and GSH) were observed. Besides, kidney, brain, heart, and testicular tissues were analyzed and damage was observed in the groups receiving ACR. However, no significant histologic changes were noted in the bladder tissue. Both dosages of BA in combination with ACR improved the changes in ACR-induced antioxidant tissue parameters. Despite the fact that MDA levels were decreased with these two dosages, histological structural abnormalities were found to be greatly improved. CONCLUSION: Our results show that BA has a strong protective effect on ACR-induced multi-organ toxicity. The study results show that BA could be a potential element to reduce ACR toxicity to which we are often exposed.

Alternations in interleukin-1ß and nuclear factor kappa beta activity (NF-kB) in rat liver due to the co-exposure of Cadmium and Arsenic: Protective role of curcumin.

Cadmium chloride (Cd) and sodium arsenite (As) are two prominent examples of non-biodegradable substances that accumulate in ecosystems, pose a serious risk to human health and are not biodegradable. Although the toxicity caused by individual use of Cd and As is known, the toxicity of combined use (Cd+As) to mammals is poorly understood. The present study aims to investigate the hepatoprotective effect of curcumin (CUR), a naturally occurring bioactive component isolated from the root stem of Curcuma longa Linn., in preventing liver damage caused by a Cd+As mixture. A group of 30 Sprague-Dawley rats were subjected to intraperitoneal administration of Cd+As (0.44 mg/kg+5.55 mg/kg i.p.) and CUR (100 or 200 mg/kg) for a period of 14 days. The experimental results showed that the animals treated with Cd+As exhibited changes in liver biochemical parameters, inflammation and oxidative stress at the end of the experiment. Administration of CUR significantly reduced inflammation, oxidative stress and lipid peroxidation in the Cd+As plus CUR groups compared to the Cd+As group. Furthermore, histological examination of the liver tissue showed that administration of CUR had led to a significant reduction in the liver damage observed in the Cd+As group. The present study provides scientific evidence for the protective effects of CUR against lipid peroxidation, inflammation, oxidative stress and liver damage induced by Cd+As in the liver of rats. The results of our in vivo experiments were confirmed by those of our molecular modelling studies, which showed that CUR can enhance the diminished antioxidant capacity caused by Cd+As.

Decreased Na+/K+ pump activity in the erythrocyte membrane due to malondialdehyde in rheumatoid arthritis: an in vivo and in silico study.

Apart from demonstrating the interaction behavior of malondialdehyde (MDA) with Na+/K+-ATPase using in silico, the current study aims to investigate the effect of rheumatoid arthritis-related oxidative stress on Na+/K+-ATPase activity that is present in the erythrocyte cell membrane, which is rich in proteins vulnerable to damage from MDA and other free radicals. The target population of this study consists of 28 rheumatoid arthritis patients and 20 healthy volunteers whose MDA levels and Na+/K+-ATPase activity were determined. It was shown that MDA levels of rheumatoid arthritis patients increased (p < 0.001) and their Na+/K+-ATPase activity noticeably decreased when compared to those of healthy individuals. Also, according to this in silico modeling, MDA decreased Na+/K+-ATPase activity in line with the correlation analyses. Consequently, while elevated levels of MDA in the rheumatoid arthritis group were suggestive of oxidative stress, a decreased Na+/K+-ATPase-activity led us to speculate that the cellular membrane had sustained injury. Therefore, our results could be useful in explaining how MDA affects Na+/K+-ATPase activity in the interior of a specific molecular pathway.

The role of Bax/Bcl-2 and Nrf2-Keap-1 signaling pathways in mediating the protective effect of boric acid on acrylamide-induced acute liver injury in rats.

INTRODUCTION: This study aims to investigate whether boric acid (BA) can protect rats from acrylamide (AA)-induced acute liver injury. MATERIALS AND METHODS: AA was used to induce acute liver injury. Thirty rats were divided into five group including Group 1 (saline), Group 2 (AA), Group 3 (20 mg/kg BA), Group 4 (10 mg/kg BA+AA) and Group 5 (20 mg/kg BA+AA). Their blood and liver were harvested to be kept for analysis. Liver function enzyme activities were performed by spectrophotometric method. Catalase (CAT), superoxide dismutase (SOD) activity, and malondialdehyde levels were determined by colorimetric method. The in-silico studies were performed using the "blind docking" method. RESULTS: Administration AA to rats, biochemical parameters, liver histology, and expression levels of apoptotic markers were negatively affected. However, after the administration of BA, the altered biochemical parameters, liver histology, and expression levels of apoptotic markers were reversed. Moreover, the mechanisms of AA-induced deterioration in the levels of SOD, CAT, and Nrf2-Keap-1 and the mechanisms of the protective effect of BA against these deteriorations were explained by in silico studies. CONCLUSION: Thus, the present study could explain the interactions between AA and thiol-containing amino acid residues of Keap-1, the effect of BA on these interactions, and the biochemical toxicity caused by the AA. In this sense, this work is the first of its kind in the literature. Based on the biochemical, histopathological, and in silico results, it can be suggested that BA has the potential to be used as a protective agent against AA-induced liver injury.

A novel method for explaining the product inhibition mechanisms via molecular docking: inhibition studies for tyrosinase from Agaricus bisporus.

The present study aims to investigate the substrate (4-methyl catechol and catechol) specificity and inhibition mechanisms (l-ascorbic acid, citric acid, and l-cysteine) of the tyrosinase enzyme (TYR), which is held responsible for browning in foods and hyperpigmentation in the human skin, through kinetic and molecular docking studies. During the experimental studies, the diphenolase activities of TYR were determined, following which the inhibitory effects of the inhibitors upon the diphenolase activities of TYR. The inhibition types were determined as competitively for l-ascorbic acid and citric acid and noncompetitive for l-cysteine. The kinetic results showed that the substrate specificity was better for catechol while l-cysteine showed the best inhibition profile. As for the in silico studies, they also showed that catechol had a better affinity in line with the experimental results of this study, considering the interactions of the substrates with TYR's active site residues and their distance to CuB metal ion, which is an indicator of diphenolase activity. Besides, the inhibitory mechanisms of the inhibitor molecules were explained by the molecular modeling studies, considering the binding number of the inhibitors with the active site amino acid residues of TYR, the number and length of H bonds, negative binding energy values, and their distance to CuB metal ion. Based on our results, we suggest that the novel method used in this study to explain the inhibitory mechanism of l-cysteine may provide an affordable alternative to the expensive methods available for explaining the inhibitory mechanism of TYR and those of other enzymes. HighlightsThe best affinity for the tyrosinase enzyme occurred with catechol.l-Ascorbic acid, citric acid, l-cysteine inhibited the diphenolic activity of tyrosinase.In silico studies confirmed the best affinity shown by catechol.Product inhibition mechanism of l-cysteine explained by in silico for the first time.Communicated by Ramaswamy H. Sarma.

Evaluation of oxidant and intracellular anti-oxidant activity in rheumatoid arthritis patients: In vivo and in silico studies.

Rheumatoid Arthritis (RA) is the most prevalent cause of the systematic inflammatory arthritis that destroys the joints. While the pathogenesis of RA remains to be clarified, the imbalance in the oxidant and anti-oxidant defense system plays a crucial role. This study aims to evaluate oxidant and anti-oxidant levels of RA patients and their impacts on the activity of the disease via in silico studies. 28 patients who had not previously received any treatment for RA and 20 healthy controls were included. Their oxidative stress markers, antioxidant markers, and inflammatory factors were investigated via in silico studies. Compared to the Control Group, serum CRP levels, MDA levels, and XO activities were higher in RA Group. Cu/ZnSOD and GPx activities decreased while CAT activities remained unchanged. Besides, there was a positive correlation between MDA-serum CRP levels but a negative correlation between MDA levels-Cu/ZnSOD activities. Furthermore, we observed a negative correlation between CRP levels and Cu/ZnSOD activities. Based on these results, it was concluded that oxidative stress had increased, the defense system had weakened, and ROS production had increased. Finally, our study results with SOD and CAT activity were confirmed by molecular docking studies.

New bone cements with Pluronic®F127 for prophylaxis and treatment of periprosthetic joint infections.

In line with the increase in orthopedic prosthetic surgeries, there has been a significant rise in periprosthetic joint infections (PJI) due to Methicillin-Resistant Staphylococcus Aureus (MRSA) bacteria. In case of infection, antibiotic-added spacers are temporarily placed into the periprosthetic region. With the release of antibiotics usually failing to work in fighting off infection, recent studies have centered around developing more effective approaches. New polymethylmethacrylate (PMMA) cement mixtures were prepared for this study with Pluronic®F127, bicarbonate, and citric acid addition. Optimal solutions were searched by monitoring vancomycin release on consecutive days with HPLC in in-vitro. The strengths of the samples were measured via four-point bending tests. Compared to conventional PMMA, strength values were observed to have improved by about 20% with 1.0 g of Pluronic®F127. According to HPLC studies, the highest increase for the area under the curve value was obtained for Pluronic®F127 doped mixture with a value of about 20%. It is understood from SEM and BET studies that addition of Pluronic®F127 helps increase porosity. The present study concludes that the optimum concentration of Pluronic®F127 could improve the strength and drug-releasing capacity of the spacer by increasing its porosity.

Alternations in nuclear factor kappa beta activity (NF-kB) in the rat brain due to long-term use of atomoxetine for treating ADHD: In vivo and in silico studies.

Attention Deficit Hyperactivity Disorder (ADHD) is the most common psychiatric disorder reported particularly in children. Long-term use of antipsychotic drugs used in the treatment of ADHD has been shown to exert toxic effects on the brain. However, not enough research has been carried out on the neurotoxic effects of these drugs on the brain tissue. Atomoxetine (ATX) is the most widely used antipsychotic drug that has gained approval for ADHD treatment. The present study aims to determine the damage induced by long-term use of three different doses of ATX in the brain tissue of experimental rats. 24 rats were divided into Control group (0.5 mL saline), Group 2 (0.5 mg/mL ATX), Group 3 (1.0 mg/mL ATX), and Group 4 (2.0 mg/mL ATX), each group having 6 members. Their brain tissues were taken for stereological, histological, and nuclear factor kappa-B (NF-kB) protein expression analysis. ATX was determined to have caused a few alterations in the brain tissue, such as disruption in the endothelial epithelium of capillaries, a couple of large astrocyte nuclei, and mitotic astrocytes. Moreover, a significant difference was observed in Group 4 compared to Control Group in terms of astrocyte counts in the brain sections. As for Groups 3 and 4, there were differences in terms of oligodendrocyte counts in the incisions cultivated from the brain tissues of the animals. On the other hand, NF-kB positive astrocytes of Groups 3 and 4 differed significantly from those of Control and Group 2. The results of molecular dockings of the present study are in line with the in-vivo results. Therefore, it was concluded that the higher the dose of ATX was, the more damage the brain tissue sustained.

Investigation of serum and brain superoxide dismutase levels depending on atomoxetine used in attention-deficit/hyperactivity disorder treatment: A combination of in vivo and molecular docking studies.

This study aims to determine whether atomoxetine (ATX), used as an alternative to methylphenidate, affects superoxide dismutase (SOD) activity besides glutathione (GSH) and malondialdehyde (MDA) levels, apart from determining possible effects of ATX on SOD activity through molecular docking studies. 24 male Wistar rats were divided into 4 groups, each containing 6 members. After a 6-week application of ATX, blood samples and brain tissues were obtained from the rats for biochemical analyses. Besides, molecular docking studies were conducted using PyRx and Discovery Studio 3.0 programs. No significant difference occurred in GSH and MDA levels after ATX application. A high-dose application of ATX caused a statistically significant change only in the serum-SOD activity compared to that of Control Group. Molecular docking studies revealed that ATX settled in the biggest space rather than the catalytic regions of Cu2Zn2-SOD. Our biochemical and molecular docking data showed that ATX, an alternative drug to stimulant methylphenidate, showed no significant changes in the antioxidant defence system at either low or therapeutic doses after long-term use. Therefore, we suggest ATX could be used as a substitute for methylphenidate in the long-term treatment of ADHD.

The effect of poly(vinyl alcohol) on the photophysical properties of pyronin dyes in aqueous solution: a spectroscopic study.

The photophysical properties of pyronin B (PyB) and pyronin Y (PyY) in water and poly(vinyl alcohol) (PVA) aqueous solutions were studied by using absorption, steady-state fluorescence and time-resolved fluorescence spectroscopy techniques at room temperature. The spectroscopic and photophysical properties of pyronin dyes in the concentrated PVA aqueous solution were different than those found in water. The aggregation of the pyronin dyes in the concentrated PVA aqueous solution was prevented with ease while the dye aggregation was generally formed in water with high dye concentration. The decrease in the aggregation tendency of pyronin dyes in the concentrated PVA aqueous solution caused an increase in radiative transitions. The addition of PVA into the aqueous solution induced the enhancement in the fluorescence intensity of the dyes compared to those in water. As a result, the quantum yields of the dyes were improved by the addition of PVA at high loading. The time-resolved fluorescence study revealed that the fluorescence decay of dyes in all solutions were found to be single-exponential and the fluorescence lifetime of pyronin dyes in the concentrated PVA aqueous solution were also higher than those found in water.