Renal Fibrosis and Oxidative Stress Induced by Silica Nanoparticles in Male Rats and Its Molecular Mechanisms.

Background: The utilization of amorphous silica nanoparticles (SiNPs) is gaining popularity in various applications, but it poses a potential risk to human and environmental health. However, the underlying causes and mechanisms of SiNPs-induced kidney damage are still largely unknown. Objectives: This study aimed to investigate the SiNPs-induced damage in the kidney and further explore the possible mechanisms of SiNPs-induced nephrotoxicity. Methods: Thirty adult male rats were divided into 3 different groups. Rats in groups 2 and 3 were administered SiNPs at 2 dosage levels (25 and 100 mg/kg of body weight), while the rats in the control group received no treatment for 28 days. Reactive oxygen species (ROS), antioxidant enzyme activities (glutathione peroxidase [GPx], superoxide dismutase [SOD], and catalase [CAT]), glutathione (GSH) levels, and oxidation markers (such as lipid peroxidation [malondialdehyde (MDA)] and protein oxidation [protein carbonyl (PCO)]) were analyzed in the kidney tissue. Additionally, renal fibrogenesis was studied through histopathological examination and the expression levels of fibrotic biomarkers. Results: The findings revealed that in vivo treatment with SiNPs significantly triggered oxidative stress in kidney tissues in a dose-dependent manner. This was characterized by increased production of ROS, elevated levels of MDA, PCO, and nitric oxide (NO), along with a significant decline in the activities of SOD, CAT, GPx, and reduced GSH. These changes were consistent with the histopathological analysis, which indicated interstitial fibrosis with mononuclear inflammatory cell aggregation, tubular degeneration, glomerulonephritis, and glomerular atrophy. The fibrosis index was confirmed using Masson's trichrome staining. Additionally, there was a significant upregulation of fibrosis-related genes, including transforming growth factor-beta 1 (TGF-ß1), matrix metalloproteinases 2 and 9 (MMP-2/9), whereas the expression of tissue inhibitor of metalloproteinase 2 (TIMP2) was downregulated. Conclusions: This study provided a new research clue for the role of ROS and deregulated TGF-ß signaling pathway in SiNPs nephrotoxicity.

Silica Nanoparticles Induce Hepatotoxicity by Triggering Oxidative Damage, Apoptosis, and Bax-Bcl2 Signaling Pathway.

The increase in the usage of silica nanoparticles (SiNPs) in the industrial and medical fields has raised concerns about their possible adverse effects on human health. The present study aimed to investigate the potential adverse effects of SiNPs at daily doses of 25 and 100 mg/kg body weight intraperitoneally (i.p.) for 28 consecutive days on markers of liver damage in adult male rats. Results revealed that SiNPs induced a marked increase in serum markers of liver damage, including lactate dehydrogenase (LDH), alanine aminotransferase (ALAT), and aspartate aminotransferase (ASAT). SiNPs also induced an elevation of reactive oxygen species (ROS) production in liver, along with an increase in oxidative stress markers (NO, MDA, PCO, and H2O2), and a decrease in antioxidant enzyme activities (CAT, SOD, and GPx). Quantitative real-time PCR showed that SiNPs also induced upregulation of pro-apoptotic gene expression (including Bax, p53, Caspase-9/3) and downregulation of anti-apoptotic factors Bcl-2. Moreover, histopathological analysis revealed that SiNPs induced hepatocyte alterations, which was accompanied by sinusoidal dilatation, Kupffer cell hyperplasia, and the presence of inflammatory cells in the liver. Taken together, these data showed that SiNPs trigger hepatic damage through ROS-activated caspase signaling pathway, which plays a fundamental role in SiNP-induced apoptosis in the liver.

Subacute silica nanoparticle exposure induced oxidative stress and inflammation in rat hippocampus combined with disruption of cholinergic system and behavioral functions.

Increasing environmental exposure to silica nanoparticles (SiNPs) and limited neurotoxicity studies pose a challenge for safety evaluation and management of these materials. This study aimed to explore the adverse effects and underlying mechanisms of subacute exposure to SiNPs by the intraperitoneal route on hippocampus function in rats. Data showed that SiNPs induced a significant increase in oxidative/nitrosative stress markers including reactive oxygen species (ROS), malondialdehyde (MDA), protein oxidation (PCO) and nitrite (NO) production accompanied by reduced antioxidant enzyme activity (catalase, superoxide dismutase, and glutathione peroxidase) and decreased glutathione (GSH). Phenotypically, SiNPs exhibited spatial learning and memory impairment in the Morris water maze (MWM) test, a decrease of the discrimination index in the novel object recognition test (NORT) and higher anxiety-like behavior. SiNPs affected the cholinergic system as reflected by reduced acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity. In addition, SiNPs significantly increased mRNA expression level of genes related to inflammation (TNF-α, IL-1ß, IL-6, and COX-2) and decreased mRNA expression level of genes related to cholinergic system including choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), AChE, muscarinic acetylcholine receptor M1 (m1AChR) and nicotinic acetylcholine receptors (nAChR). Histopathological results further showed an alteration in the hippocampus of treated animals associated with marked vacuolation in different hippocampus areas. These findings provide new insights into the molecular mechanism of SiNPs-induced hippocampal alterations leading to impairment of cognitive and behavioral functions, and implicating oxidative stress and inflammation in the hippocampus, as well as disruption of cholinergic system.

Lambda-cyhalothrin exposure alters purine nucleotide hydrolysis and nucleotidase gene expression pattern in platelets and liver of rats.

Lambda-cyhalothrin (LCT) is a broad-spectrum pesticide widely used in agriculture throughout the world. This pesticide is considered a potential contaminant of surface and underground water as well as food, posing a risk to ecosystems and humans. In this sense, we decided to evaluate the activity of enzymes belonging to the purinergic system, which is linked with regulation of extracellular nucleotides and nucleosides, such as adenosine triphosphate (ATP) and adenosine (Ado) molecules involved in the regulation of inflammatory response. However, there are no data concerning the effects of LCT exposure on the purinergic system, where extracellular nucleotides act as signaling molecules. The aim of this study was to evaluate nucleotide hydrolysis by E-NTPDase (ecto-nucleoside triphosphate diphosphohydrolase), Ecto-NPP (ecto-nucleotide pyrophosphatase/phosphodiesterase), ecto-5'-nucleotidase and ecto-adenosine deaminase (E-ADA) in platelets and liver of adult rats on days 7, 30, 45 and 60 after daily gavage with 6.2 and 31.1 mg/kg bw of LCT. Gene expression patterns of NTPDases1-3 and 5'-nucleotidase were also determined in those tissues. In parallel, lambda-cyhalothrin metabolites [3-(2-chloro-3,3,3- trifluoroprop-1-enyl)-2,2-dimethyl-cyclopropane carboxylic acid (CFMP), 4-hydroxyphenoxybenzoic acid (4-OH-3-PBA), and 3-phenoxybenzoic acid (3-PBA)] were measured in plasma. Results showed that exposure rats to LCT caused a significant increase in the assessed enzymes activities. Gene expression pattern of ectonucleotidases further revealed a significant increase in E-NTPDase1, E-NTPDase2, and E-NTPDase3 mRNA levels after LCT administration at all times. A dose-dependent increase in LCT metabolite levels was also observed but there no significant variations in levels from weeks to week, suggesting steady-steady equilibrium. Correlation analyses revealed that LCT metabolites in the liver and plasma were positively correlated with the adenine nucleotides hydrolyzing enzyme, E-ADA and E-NPP activities in platelets and liver of rats exposed to lambda-cyhalothin. Our results show that LCT and its metabolites may affect purinergic enzymatic cascade and cause alterations in energy metabolism.

Pyrethroid insecticide lambda-cyhalothrin and its metabolites induce liver injury through the activation of oxidative stress and proinflammatory gene expression in rats following acute and subchronic exposure.

Lambda-cyhalothrin (LTC) [α-cyano-3-phenoxybenzyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethylcyclo-propanecarboxylate] is a synthetic type II pyrethroid insecticide commonly used in residential and agricultural areas. The potential hepatotoxicity of pyrethroids remains unclear and could easily be assessed by measuring common clinical indicators of liver disease. To understand more about the potential risks for humans associated with LTC exposure, male adult rats were orally exposed to 6.2 and 31.1 mg/kg bw of LTC for 7, 30, 45, and 60 days. Histopathological changes and alterations of main parameters related to oxidative stress and inflammatory responses in the liver were evaluated. Further, lambda-cyhalothrin metabolites [3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethyl-cyclopropane carboxylic acid (CFMP), 4-hydroxyphenoxybenzoic acid (4-OH-3-PBA), and 3-phenoxybenzoic acid (3-PBA)] in the liver tissues were identified and quantified by ultra-high-performance liquid chromatography coupled to quadripole time-of-flight mass spectrometry (UHPLC-MS-Q-ToF). Results revealed that LTC exposure significantly increased markers of hepatic oxidative stress in a time-dependent and dose-dependent manner, and this was associated with an accumulation of CFMP and 3-PBA in the liver tissues. In addition, the levels of tumor necrosis factor-α (TNF-α) and interleukin (IL-6 and IL-1ß) gene expressions were significantly increased in the liver of exposed rats compared to controls. Correlation analyses revealed that CFMP and 3-PBA metabolite levels in the liver tissues were significantly correlated with the indexes of oxidative stress, redox status, and inflammatory markers in rats exposed to lambda-cyhalothin. Overall, this study provided novel evidence that hepatic damage is likely due to increased oxidative stress and inflammation under the condition of acute and subchronic exposure to lambda-cyhalothrin and that LTC metabolites (CFMP and 3-PBA) could be used as potential biomarker in human biomonitoring studies.

Anti-oxidant, anti-inflammatory, analgesic and antipyretic activities of grapevine leaf extract (Vitis vinifera) in mice and identification of its active constituents by LC-MS/MS analyses.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Vitis vinifera is used in traditional medicine for diarrhea, hepatitis and stomachaches. The objective of this study was to investigate the anti-oxidant, anti-inflammatory, analgesic and antipyretic properties of the hydroalcoholic leaf extract of Vitis vinifera (EVV) on experimental models to provide scientific basis for its use. MATERIALS AND METHODS: The EVV was chemically characterized by LC-MS/MS analyses. The in vitro antioxidant activities of the EVV extract were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and Ferric reducing antioxidant power assay (FRAP). Analgesic activity using acetic acid induced writhing and formalin test in mice, anti-inflammatory activity using carrageenan induced paw oedema and acetic acid-induced vascular permeability in mice, and antipyretic activity using Brewer's yeast induced pyrexia in rats were evaluated at 100mg/kg, 200mg/kg, and 400mg/kg doses of the extract. RESULTS: The extract (EVV) was found to contain resveratrol, quercetin, catechin, flavone, flavonols, anthocyanin, gallic acid and epicatechin. EVV produced significant dose-response anti-inflammatory activity against carrageenan-induced paw edema. EVV at dosages of 100, 200 and 400mg/kgbw significantly reduced carrageenan-induced paw edema by 34.48% (P<0.05), 36.20% (P<0.05), and 41.37% (P<0.05) at 5h after carrageenan injection, respectively. Also EVV extract reduces significantly acetic acid-induced vascular permeability in mice dose dependently. EVV (100, 200 and 400mg/kgbw) produced significant dose-response analgesic activity in the formalin test. However, the low percentage inhibition (50%) suggests that it is not a centrally acting analgesic. Extract at dosages of 100, 200 and 400mg/kg bw, p.o. significantly reduced acetic acid-induced writhing by 48.15% (p<0.05), 57.97% (p<0.05), and 68.09% (p<0.05), respectively. The extract also caused marked dose-dependent inhibition of formalin-induced pain in the second phase (p<0.05). Statistical significant reduction in rectal temperatures was observed in standard group at 21 and 23h, and in 200mg/kg and 400mg/kg doses of the extract at 23h (p<0.05) compared with the 19h. CONCLUSIONS: The results obtained indicated potential analgesic, anti-inflammatory and antipyretic effects of them hydroalcoholic leaf extract of V. vinifera observed at doses tested which support the claim for the traditional use of the plant in the treatment of various inflammatory and pain diseases.

Naringin suppresses cell metastasis and the expression of matrix metalloproteinases (MMP-2 and MMP-9) via the inhibition of ERK-P38-JNK signaling pathway in human glioblastoma.

Naringin (4',5,7-trihydroxyflavanone 7-rhamnoglucoside), a natural flavonoid, has pharmacological properties. In the present study, we investigated the anti-metastatic activity of naringin and its molecular mechanism(s) of action in human glioblastoma cells. Naringin exhibits inhibitory effects on the invasion and adhesion of U87 cells in a concentration-dependent manner by Matrigel Transwell and cell adhesion assays. Naringin also inhibited the migration of U87 cells in a concentration-dependent manner by wound-healing assay. Additional experiments showed that naringin treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase (MMP)-2 and MMP-9 using a gelatin zymography assay and western blot analyses. Furthermore, naringin was able to reduce the protein phosphorylation of extracellular signal-regulated kinase ERK, p38 mitogen-activated protein kinase and c-Jun N-terminal kinase by western blotting. Collectively, our data showed that naringin attenuated the MAPK signaling pathways including ERK, JNK and p38 and resulted in the downregulation of the expression and enzymatic activities of MMP-2, MMP-9, contributing to the inhibition of metastasis in U87 cells. These findings proved that naringin may offer further application as an antimetastatic agent.

Protective role of naringin against cisplatin induced oxidative stress, inflammatory response and apoptosis in rat striatum via suppressing ROS-mediated NF-κB and P53 signaling pathways.

Cisplatin (Cis) is an effective chemotherapeutic agent successfully used in the treatment of a wide range of malignancies while its usage is limited due to its dose-dependent toxicity. The present study was conducted to investigate the efficacy of naringin, an ubiquitous flavonoid, against Cis-induced striatum injury in Wistar aged rats. Briefly, the experimental procedures were divided in two sets of experiments. In the first, the animals were divided into 4 groups: control, Nar 25mg/kg, Nar 50mg/kg and Nar 100mg/kg. In the second, the animals were divided into 4 groups: Cis (5mg/kg/week for 5 consecutive weeks), Cis+Nar (25mg/kg), Cis+Nar (50mg/kg) and Cis+Nar (100mg/kg). The administration of Cis (5mg/kg/week for 5 consecutive weeks) resulted in a decline in the concentrations of reduced glutathione and ascorbic acid. The activity of membrane bound ATPases and glutathione peroxidase (GPx) were decreased while the activity of catalase (CAT) and superoxide dismutase (SOD) were increased. Further, in striatum tissue, Cis significantly enhance the mRNA gene expression of P53, nuclear factor κB pathway (NFκB) and tumor necrosis factor (TNF-α). Oxidative/nitrosative stress was evident in Cis group by increased malondialdehyde (MDA), protein carbonyls (PCO), reactive oxygen species (ROS) and nitrite concentration (NO). Naringin (25, 50 and 100mg/kg) administration was able to protect against deterioration in striatum tissue, abrogate the change in antioxidant enzyme activities and suppressed the increase in MDA, PCO, NO and TNF-α concentrations. Moreover, Nar inhibited P53, NFkB and TNF-α pathways mediated inflammation and apoptosis, and improved the histological changes induced by Cis. Thus, these findings demonstrated the neuroprotective nature of Nar by attenuating the pro-inflammatory and apoptotic mediators and improving antioxidant competence in striatum tissue. These results imply that Nar has perfect effect against Cis-induced striatum injury in aged rats, which should be developed as an effective food and healthcare product for the treatment of brain injury in the future.