The effects of rotenone-induced toxicity via the NF-κB-iNOS pathway in rat liver

Monoterpenoid Epoxidiol Ameliorates the Pathological Phenotypes of the Rotenone-Induced Parkinson’s Disease Model by Alleviating Mitochondrial Dysfunction

Parkinson’s disease is the second most common neurodegenerative disease. Unfortunately, there is still no definitive disease-modifying therapy. In our work, the antiparkinsonian potential of trans-epoxide (1S,2S,3R,4S,6R)-1-methyl-4-(prop-1-en-2-yl)-7-oxabicyclo [4.1.0]heptan-2,3-diol (E-diol) was analyzed in a rotenone-induced neurotoxicity model using in vitro, in vivo and ex vivo approaches. It was conducted as part of the study of the mitoprotective properties of the compound. E-diol has been shown to have cytoprotective properties in the SH-SY5Y cell line exposed to rotenone, which is associated with its ability to prevent the loss of mitochondrial membrane potential and restore the oxygen consumption rate after inhibition of the complex I function. Under the conditions of rotenone modeling of Parkinson’s disease in vivo, treatment with E-diol led to the leveling of both motor and non-motor disorders. The post-mortem analysis of brain samples from these animals demonstrated the ability of E-diol to prevent the loss of dopaminergic neurons. Moreover, that substance restored functioning of the mitochondrial respiratory chain complexes and significantly reduced the production of reactive oxygen species, preventing oxidative damage. Thus, E-diol can be considered as a new potential agent for the treatment of Parkinson’s disease.

Fate and PPARγ and STATs-driven effects of the mitochondrial complex I inhibitor tebufenpyrad in liver cells revealed with multi-omics

The biological effects of the pesticide and mitochondrial complex I inhibitor tebufenpyrad (TEBU) on liver cells were investigated by combining proteomics and metabolomics. Both cell culture media and cellular lysates were analyzed in dose-response and kinetic experiments on the HepaRG cell line. Responses were compared with those obtained on primary human and rat hepatocytes. A multitude of phase I and II metabolites (>80) mainly common to HepaRG cells and primary hepatocytes and an increase in metabolization enzymes were observed. Synthesis of mitochondrion and oxidative phosphorylation complex constituents, fatty acid oxidation, and cellular uptake of lipids were induced to compensate for complex I inhibition and the decrease in ATP intracellular contents caused by TEBU. Secretion of the 20 S circulating proteasome and overall inhibition of acute inflammation followed by IL-6 secretion in later stages were observed in HepaRG cells. These effects were associated with a decrease in STAT1 and STAT3 transcription factor abundances, but with different kinetics. Based on identified TEBU targets, docking experiments, and nuclear receptor reporter assays, we concluded that liver cell response to TEBU is mediated by its interaction with the PPARγ transcription factor.

1α,25-Dihydroxyvitamin D3 (VD3) Shows a Neuroprotective Action Against Rotenone Toxicity on PC12 Cells: An In Vitro Model of Parkinson's Disease

Parkinson's disease (PD) is characterized by dopaminergic cell loss in the substantia nigra, and PD brains show neuroinflammation, oxidative stress, and mitochondrial dysfunction. The study evaluated the neuroprotective activity of 1α,25-dihydroxy vitamin D3 (VD3), on the rotenone (ROT)-induced cytotoxicity in PC12 cells. The viability parameters were assessed by the MTT and flow cytometry, on cells treated or not with VD3 and/or ROT. Besides, ROS production, cell death, mitochondrial transmembrane potential, reduced GSH, superoxide accumulation, molecular docking (TH and Keap1-Nrf2), and TH, Nrf2, NF-kB, and VD3 receptor protein contents by western blot were evaluated. VD3 was shown to improve the viability of ROT-exposed cells. Cells exposed to ROT showed increased production of ROS and superoxide, which decreased after VD3. ROT decrease in the mitochondrial transmembrane potential was prevented, after VD3 treatment and, VD3 was shown to interact with tyrosine hydroxylase (TH) and Nrf2. While ROT decreased TH, Nrf2, and NF-kB expressions, these effects were reversed by VD3. In addition, VD3 also increased VD3 receptor protein contents and values went back to those of controls after ROT exposure. VD3 protects PC12 cells against ROT damage, by decreasing oxidative stress and improving mitochondrial function. One target seems to be the TH molecule and possibly an indirect Nrf2 activation could also justify its neuroprotective actions on this PC12 cell model of PD.

Aristolochic acid induces mitochondrial apoptosis through oxidative stress in rats, leading to liver damage

Aristolochic acid (AA) are persistent soil pollutants in the agricultural fields of the Balkan Peninsula. Preparations containing aristolochic acid are widely used for anti-inflammatory, diuretic, etc. To study the hepatotoxicity of aristolochic acid, 80 healthy SD rats were selected and divided into 20 mg/kg- AA group, 4 mg/kg-AA group, and 2 mg/kg-AA group and blank group, 20 rats per group. Mainly tested the body weight, liver function, liver tissue oxidative stress and pathological changes of liver tissue in rats. The ALT and AST activities in the serum of the rats in the administration groups were increased compared with the blank group. The activity of MDA in the administration groups was higher than that in the blank group; the activities of SOD, T-AOC and GSH-PX were significantly lower than those in the blank group. HE tissue sections also found that the administration groups showed varying degrees of hepatocyte boundary blur, nuclear fragmentation, and fibrosis tendency. Transmission electron microscopy showed that the mitochondria of the rat liver became more and more severely damaged with the increase of dose. Compared with the blank group, the mRNA expression of Bax, Caspase-9 and Caspase-3 in the administration groups were determined, while the mRNA expression of the Bcl-2 was increased. And compared with the blank control group, the expression levels of apoptotic proteins caspase-9 and caspase-3 increased significantly in the 20 mg/kg-AA group. Aristolochic acid can induce liver injury in rats through oxidative stress pathway and mitochondrial apoptosis pathway.

Functional and Pharmacological Comparison of Human and Mouse Na+/Taurocholate Cotransporting Polypeptide (NTCP)

The Na⁺/taurocholate cotransporting polypeptide (NTCP) is located in the basolateral membrane of hepatocytes, where it transports bile acids from the portal blood back into hepatocytes. Furthermore, NTCP has a role for the hepatic transport of some drugs. Extrapolation of drug transport data from rodents to humans is not always possible, because species differences in the expression level, localization, affinity, and substrate selectivity of relevant transport proteins must be considered. In the present study, a functional comparison of human NTCP (hNTCP) and mouse Ntcp (mNtcp) showed similar K_m values of 67 ± 10 µM and 104 ± 9 µM for the probe substrate estrone-3-sulfate as well as of 258 ± 42 µM and 199 ± 13 µM for the drug rosuvastatin, respectively. IC₅₀ values for the probe inhibitor cyclosporine A were 3.1 ± 0.3 µM for hNTCP and 1.6 ± 0.4 µM for mNtcp. In a drug and pesticide inhibitory screening on both transporters, 4 of the 15 tested drugs (cyclosporine A, benzbromarone, MK571, and fluvastatin) showed high inhibitory potency, but only slight inhibition was observed for the 13 tested pesticides. Among these compounds, only four drugs and three pesticides showed significant differences in their inhibition pattern on hNTCP and mNtcp. Most pronounced was the difference for benzbromarone with a fivefold higher IC₅₀ for mNtcp (27 ± 10 µM) than for hNTCP (5.5 ± 0.6 µM).In conclusion, we found a strong correlation between the transport kinetics and inhibition pattern among hNTCP and mNtcp. However, specific compounds, such as benzbromarone, showed clear species differences. Such species differences have to be considered when pharmacokinetic data are transferred from rodent to humans.

Ameliorative role of inducible nitric oxide synthase inhibitors against sodium arsenite-induced renal and hepatic dysfunction in rats

Arsenic exposure causes immense health distress by increasing risk of cardiovascular abnormalities, diabetes mellitus, neurotoxicity, and nephrotoxicity. The present study explored the role of inducible nitric oxide synthase (iNOS) inhibitors against sodium arsenite-induced renal and hepatic dysfunction in rats. Female Sprague Dawley rats were subjected to arsenic toxicity by administering sodium arsenite (5 mg/kg/day, oral) for 4 weeks. The iNOS inhibitors, S-methylisothiourea (10 mg/kg, i.p.) and aminoguanidine (100 mg/kg, i.p.) were given one hour before sodium arsenite administration in rats for 4 weeks. Sodium arsenite led rise in serum creatinine, urea, uric acid, electrolytes (potassium, fractional excretion of sodium), microproteinuria, and decreased creatinine clearance (p < 0.001) indicated renal dysfunction in rats. Arsenic-intoxication resulted in significant oxidative stress in rat kidneys, which was measured in terms of increase in lipid peroxides, superoxide anion generation and decrease in reduced glutathione (p < 0.001) levels. A threefold increase in renal hydroxyproline level in arsenic intoxicated rats indicated fibrosis. Hematoxylin-eosin staining indicated tubular damage, whereas picrosirius red staining highlighted collagen deposition in rat kidneys. S-methylisothiourea and aminoguanidine improved renal function and attenuated arsenic led renal oxidative stress, fibrosis, and decreased the kidney injury score. Additionally, arsenite-intoxication resulted in significant rise in hepatic parameters (serum aspartate aminotransferase, alanine transferase, alkaline phosphatase, and bilirubin (p < 0.001) along with multi-fold increase in oxidative stress, fibrosis and liver injury score in rats, which was significantly (p < 0.001) attenuated by concurrent administration of iNOS inhibitors). Hence, it is concluded that iNOS inhibitors attenuate sodium arsenite-induced renal and hepatic dysfunction in rats.

The Alleviative Effects of Quercetin on Cadmium-Induced Necroptosis via Inhibition ROS/iNOS/NF-κB Pathway in the Chicken Brain

Cadmium (Cd), a ubiquitous environmental pollutant, has neurotoxicity to humans and animals. Quercetin (QE), the main component of flavonoids, has strong antioxidant and anti-inflammatory effects. However, little is reported about the influence of Cd exposure on necroptosis in the chicken brain and the antagonistic impacts of QE against Cd-induced brain necroptosis. The aim of this study was to ascertain the alleviative mechanism of QE on Cd-induced necroptosis in the chicken brain. Two hundred 3.5-month-old Isa hens were randomly divided into four groups, control group, QE group, Cd group, and Cd + QE co-administration group. The histopathological analysis indicated that necrosis features were observed in the Cd-intoxicated chicken brains. Meanwhile, the expression levels of RIPK1, RIPK3, and MLKL were elevated and the level of Caspase 8 was reduced in the Cd group, which further testified Cd triggered the occurrence of necroptosis in the chicken brain. Cd exposure obviously increased Cd accumulation, ROS generation, and MDA level; weakened the activities of antioxidase (SOD, GPx, and CAT); enhanced iNOS activity and NO production; promoted the expression of inflammatory factors (NF-κB, TNFα, COX-2, iNOS, PTGEs, and IL-1β); and activated HSPs (HSP27, HSP40, HSP60, HSP70, and HSP90). But, these Cd-caused variations were obviously attenuated in the Cd + QE group. This study indicated that QE had an alleviative effect on Cd-induced necroptosis in the chicken brain through inhibition ROS/iNOS/NF-κB pathway.

The Antagonistic Effects of Selenium Yeast (SeY) on Cadmium-Induced Inflammatory Factors and the Heat Shock Protein Expression Levels in Chicken Livers

Cadmium (Cd) is a ubiquitous toxic heavy metal in the natural environment that can cause multiple organ damage to the bodies of animals and humans. Selenium yeast (SeY) is a kind of organic selenium (Se) that has a very strong function against Cd-induced injury to tissues or organs. The aim of the current study was to investigate the roles of inflammatory factors and heat shock proteins (HSPs) in inflammatory injury triggered by Cd and to analyze the protective effects of SeY on Cd-induced damnification in the livers of chickens. Two hundred 120-day-old layers were randomly divided into four groups and raised on a conventional diet, or with Se (0.5 mg/kg SeY), Cd (150 mg/kg CdCl₂), or Se + Cd (0.5 mg/kg SeY and 150 mg/kg CdCl₂) in their basic diets for 120 days. Then, the liver histopathology, production of nitric oxide (NO), activity of inducible NO synthase (iNOS), and mRNA and protein expression levels of inflammatory factors (iNOS, NF-κB, TNF-α, and PTGE) and heat shock proteins (HSPs 27, 40, 60, 70, and 90) were examined. The results showed that exposure to Cd obviously increased Cd accumulation, NO production, iNOS activity, inflammatory factor, and HSP mRNA and protein expression levels and further caused an inflammatory response. Supplementation with SeY had an antagonistic effect on Cd-induced inflammatory injury in chicken livers. Thus, the present study suggests that SeY can be taken as a potential therapeutic for Cd-induced liver inflammatory injury in chickens.

Ameliorative effect of quercetin, catechin, and taxifolin on rotenone-induced testicular and splenic weight gain and oxidative stress in rats

Background The physiological functions of the testis and spleen can be affected through several cellular and molecular mechanisms such as the generation of reactive oxygen species (ROS) that causes oxidative stress. This study aimed at investigating the protective effect of catechin, quercetin, and taxifolin in rotenone-induced testicular and splenetic toxicity. Methods Male Wistar rats were administered with 1.5 mg/kg rotenone (s.c.) for 10 days followed by post-treatment with catechin (5, 10, or 20 mg/kg), quercetin (5, 10, or 20 mg/kg), and taxifolin (0.25, 0.5, or 1.0 mg/kg) for 3 days (s.c.), followed by estimation of biochemical markers of oxidative stress, inflammatory activities, and tissue damage in testes and spleen. Results Exposure of rats to rotenone caused reduced body weight gain, increased organ weight, decreased glutathione level and activities of glutathione transferase and superoxide dismutase, enhanced lipid peroxidation, and increased activities of prooxidant/proinflammatory enzymes and lactate dehydrogenase, which were mitigated by post-treatment with flavonoids. In general, quercetin and taxifolin showed better activity than catechin. Conclusions Catechin, quercetin, and taxifolin ameliorated rotenone-induced weight disturbances and oxidative damage in rats, indicating their potential relevance in toxicant and pesticide-induced tissue injury.