Melatonin attenuates liver injury in arsenic-treated rats: The potential role of the Nrf2/HO-1, apoptosis, and miR-34a/Sirt1/autophagy pathways

Arsenic is a toxic metalloid found in the environment in different organic and inorganic forms. Molecular mechanisms implicated in arsenic hepatotoxicity are complex but include oxidative stress, apoptosis, and autophagy. The current study focused on the potential protective capacity of melatonin against arsenic-induced hepatotoxicity. Thirty-six male Wistar rats were allocated into control, arsenic (15 mg/kg; orally), arsenic (15 mg/kg) plus melatonin (10, 20, and 30 mg/kg; intraperitoneally), and melatonin alone (30 mg/kg) groups for 28 days. After the treatment period, the serum sample was separated to measure liver enzymes (AST and ALT). The liver tissue was removed and then histological alterations, oxidative stress markers, antioxidant capacity, the levels of Nrf2 and HO-1, apoptosis (Bcl-2, survivin, Mcl1, Bax, and caspase-3), and autophagy (Sirt1, Beclin-1, and LC3 II/I ratio) proteins, as well as the expression level of miR-34a, were evaluated on this tissue. Arsenic exposure resulted in the enhancement of serum AST, ALT, and substantial histological damage in the liver. Increased levels of malondialdehyde, a lipid peroxidation marker, and decreased levels of physiological antioxidants including glutathione, superoxide dismutase, and catalase were indicators of arsenic-induced oxidative damage. The levels of Nrf2, HO-1, and antiapoptotic proteins diminished, while proapoptotic and autophagy proteins were elevated in the arsenic group concomitant with a low level of hepatic miR-34a. The co-treatment of melatonin and arsenic reversed the changes caused by arsenic. These findings showed that melatonin reduced the hepatic damage induced by arsenic due to its antioxidant and antiapoptotic properties as well as its regulatory effect on the miR-34a/Sirt1/autophagy pathway.

The protective effects of curcumin against cigarette smoke-induced toxicity: A comprehensive review

Cigarette smoking (CS) is a crucial modifiable risk of developing several human diseases and cancers. It causes lung, bladder, breast, and esophageal cancers, respiratory disorders, as well as cardiovascular and metabolic diseases. Because of these adverse health effects, continual efforts to decrease the prevalence and toxicity of CS are imperative. Until the past decades, the impacts of natural compounds have been under investigation on the harmful effects of CS. Turmeric (Curcuma longa), a rhizomatous herbaceous perennial plant that belongs to the Zingiberaceae family, is the main source of curcumin. This review is an attempt to find out the current knowledge on CS's harmful effects and protective potential of curcumin in the pulmonary, liver, brain, gastrointestinal, and testis organs. According to the present review, simultaneous consumption of curcumin and CS can attenuate CS toxicities including chronic obstructive pulmonary disease, gastrointestinal toxicity, metabolic diseases, testis injury, and neurotoxicity. Moreover, curcumin suppresses carcinogenesis in the skin, liver, lungs, breast, colon, and stomach. Curcumin mediates these protective effects through antioxidant, anti-inflammatory, anti-apoptotic, and anti-carcinogenicity properties.

Attenuation of acrylamide-induced neurotoxicity by supplementation of sitagliptin in Wistar rats

Objectives

Acrylamide (ACR) induces neurotoxicity in humans and animals through different mechanisms. Sitagliptin is a type-2 diabetes medication with neuroprotective properties. The effects of sitagliptin against neurotoxicity stimulated by ACR were examined.

Materials and Methods

Male Wistar rats were classified as follows: 1. Control (normal saline, 11 days, IP), 2. ACR (50 mg/kg, 11 days, IP), 3. ACR (11 days, days 11-20 normal saline), 4-7. ACR+sitagliptin (5, 10, 20, and 40 mg/kg, 11 days, IP), 8. ACR+sitagliptin (10 mg/kg, days 6-11), 9. ACR+sitagliptin (10 mg/kg, days 6-20), 10. Sitagliptin (40 mg/kg, 11 days), 11. ACR+vitamin E (200 mg/kg, IP). Finally, the gait score was evaluated. Reduced glutathione (GSH) and malondialdehyde (MDA) levels were measured in cortex tissue. Also, IL-1β, TNF-α, and caspase-3 levels were assessed in the cortex by western blotting.

Results

ACR caused movement disorders, triggered oxidative stress, and raised TNF-α, IL-1β, and caspase-3 cleaved levels. Supplementation of sitagliptin (10 mg/kg) along with ACR, in 3 protocols, reduced gait disorders compared to the ACR group. Receiving sitagliptin in all doses plus ACR and injection of sitagliptin (10 mg/kg) from days 6 to11 reduced the MDA level of cortex tissue. Sitagliptin (all doses) plus ACR increased the GSH level of the cortex tissue. Sitagliptin (10 mg/kg) with ACR dropped the amounts of TNF-α and caspase-3 cleaved proteins in cortex tissue but did not affect the IL-1β level.

Conclusion

Sitagliptin disclosed preventive and therapeutic effects on ACR neurotoxicity. Sitagliptin possesses antioxidant, anti-inflammatory, and anti-apoptotic properties and inhibits CR neurotoxicity in rats.

Renoprotective effect of thymoquinone against rhabdomyolysis-induced acute kidney injury in the rat model

Objectives

Rhabdomyolysis leads to the release of myoglobin, sarcoplasmic proteins, and electrolytes into the blood circulation causing acute kidney injury (AKI). Thymoquinone, a natural compound found in Nigella sativa seeds, has antioxidant and anti-inflammatory effects. This investigation assessed the renoprotective effect of thymoquinone on rhabdomyolysis-induced AKI in rats.

Materials and Methods

Male Wistar rats were categorized into six groups (n = 6): 1. Control: (normal saline), 2. Glycerol (50 ml/kg, single dose, IM), 3-5: Glycerol + thymoquinone (1, 2.5 and 5 mg/kg, 4 days, IP), 6. Thymoquinone (5 mg/kg). On day 5, serum and kidney tissue were isolated and the amounts of serum creatinine and blood urea nitrogen (BUN), renal malondialdehyde (MDA), glutathione (GSH.), tumor necrosis factor-alpha (TNF-α), neutrophil gelatinase-associated lipocalin (NGAL), and pathological changes were evaluated.

Results

Glycerol increased creatinine, BUN, MDA, TNF-α, and NGAL levels. It decreased GSH amounts and caused renal tubular necrosis, glomerular atrophy, and myoglobin cast in kidney tissue. Co-administration of glycerol and thymoquinone reduced creatinine, BUN, histopathological alterations, and MDA levels, and enhanced GSH amounts. Administration of glycerol and thymoquinone (5 mg/kg) had no significant effect on TNF-α amount but decreased NGAL protein levels. The administration of thymoquinone (5 mg/kg) alone did not display a significant difference from the control group.

Conclusion

Rhabdomyolysis from glycerol injection in rats can cause kidney damage. Thymoquinone may attenuate renal dysfunction and oxidative stress. However, the TNF-α level was not significantly affected. Further studies are needed to explore the potential therapeutic effects of thymoquinone in managing AKI.

Trans-sodium crocetinate suppresses apoptotic and oxidative response following myoglobin-induced cytotoxicity in HEK-293 cells

Objectives

Rhabdomyolysis (RM) is a serious fatal syndrome. The RM leads to acute kidney injury (AKI) as a fatal complication. The belief is that RM-induced AKI is triggered by myoglobin (MB). MB activates oxidative and apoptotic pathways. Trans-sodium crocetinate (TSC) is obtained from saffron. It has anti-oxidant and renoprotective effects. This research was designed to assess the mechanisms of MB-induced cytotoxicity in HEK-293 cells (human embryonic kidney cells) as well as the possible effects of TSC against MB-induced cytotoxicity.

Materials and Methods

HEK-293 cells were exposed to diverse concentrations of TSC (2.5, 5, 10, 20, 40, 80, and 100 µM) for 24 hr. Then, MB (9 mg/ml) was added to the cells. After 24 hr, cell viability was measured through MTT, and the values of ROS generation were calculated using DCFH-DA assay. Also, autophagy and apoptosis markers in cells were assessed by western blot analysis.

Results

MB decreased viability and increased ROS levels in HEK-293 cells. However, pretreatment of HEK-293 cells with TSC for 24 hr reduced the cytotoxicity and ROS production caused by MB. Furthermore, MB enhanced both the apoptosis (cleaved caspase-3 and Bax/Bcl-2 ratio) and autophagy markers (LC3II/I ratio and Beclin-1) in HEK-293 cells. On the other hand, TSC pretreatment condensed the levels of autophagy and apoptosis criteria in response to MB cytotoxicity.

Conclusion

TSC has a positive effect in preventing MB-induced cytotoxicity in HEK-293 cells by increasing anti-oxidant activity and regulation of apoptotic and autophagy signaling pathways.

Melatonin Attenuates Arsenic-Induced Neurotoxicity in Rats Through the Regulation of miR-34a/miR-144 in Sirt1/Nrf2 Pathway

Arsenic (As) exposure is known to cause several neurological disorders through various molecular mechanisms such as oxidative stress, apoptosis, and autophagy. In the current study, we assessed the effect of melatonin (Mel) on As-induced neurotoxicity. Thirty male Wistar rat were treated daily for 28 consecutive days. As (15 mg/kg, gavage) and Mel (10 and 20 mg/kg, i.p.) were administered to rats. Morris water maze test was done to evaluate learning and memory impairment in training days and probe trial. Oxidative stress markers including MDA and GSH levels, SOD activity, and HO-1 levels were measured. Besides, the levels of apoptosis (caspase 3, Bax/Bcl2 ratio) and autophagy markers (Sirt1, Beclin-1, and LC3 II/I ratio) as well as the expression of miR-144 and miR-34a in cortex tissue were determined. As exposure disturbed learning and memory in animals and Mel alleviated these effects. Also, Mel recovered cortex pathological damages and oxidative stress induced by As. Furthermore, As increased the levels of apoptosis and autophagy proteins in cortex, while Mel (20 mg/kg) decreased apoptosis and autophagy. Also, Mel increased the expression of miR-144 and miR-34a which inhibited by As. In conclusion, Mel administration attenuated As-induced neurotoxicity through anti-oxidative, anti-apoptotic, and anti-autophagy mechanisms, which may be recommended as a therapeutic target for neurological disorders.

Minocycline as a Neuroprotective Agent in Arsenic-Induced Neurotoxicity in PC12 Cells

Arsenic is a naturally occurring metalloid that exists in water, soil, food, and air. Humans can be exposed to arsenic through occupational, medical, or nutritional routes. Both acute and chronic forms of toxicity with severe outcomes are likely following arsenic exposure. Neurotoxicity is one of the serious manifestations of arsenic toxicity. In our study, the effect of minocycline, a widely used antimicrobial agent with antioxidant aspects and the ability to cross the blood-brain barrier, was evaluated against arsenic-induced neurotoxicity. PC12 cell line was used as the cellular model of this study. Cells were pre-treated with minocycline (50 nM-1 µM) for 2 h, and then incubated for 24 h after adding sodium arsenite (10 µM). The MTT assay and fluorimetry were performed to study cytotoxicity and reactive oxygen species generation, respectively. Finally, Western blotting was done to determine the levels of caspase-8, Bax, Bcl-2, and caspase-3. Once exposed to arsenic, the cell viability was significantly reduced, the intracellular oxidative balance was significantly disrupted, and the levels of proteins caspase-8, Bax/Bcl-2, and caspase-3 were significantly increased. Minocycline not only attenuated arsenic-induced cytotoxicity and reduced oxidative stress, but also led to lower levels of caspase-8, Bax/Bcl-2, and caspase-3 proteins compared with the arsenic-treated cells. Minocycline can significantly protect cells against arsenic-induced neurotoxicity by antioxidant and anti-apoptosis properties via both intrinsic and extrinsic caspase-dependent apoptotic pathways; therefore, at this point, it's worth considering it as a promising agent for the treatment of arsenic toxicity.

The effect of melatonin on benzo(a)pyrene-induced renal toxicity in mice

Benzo(a)pyrene is a ubiquitous environmental contaminant, which could induce renal injury. It is reported that melatonin has a protective effect against multiple organ injuries by regulating oxidative stress, apoptosis, and autophagy. The aim of this study was to estimate the melatonin effects on benzo(a)pyrene renal toxicity in mice and the possible molecular mechanisms involved in this model. Thirty male mice were allocated to five groups and treated with benzo(a)pyrene (75 mg/kg, oral gavage) and/or melatonin (10 and 20 mg/kg, intraperitoneally). The oxidative stress factors were evaluated in renal tissue. The levels of apoptotic (the Bax/Bcl-2 ratio and caspase-3) and autophagic (the LC3 II/I, Beclin-1, and Sirt1) proteins were examined using Western blot. Following the administration of benzo(a)pyrene, malondialdehyde, caspase-3 and the Bax/Bcl-2 ratio increased in renal tissue, while Sirt1, Beclin-1, and the LC3 II/I ratio diminished. Interestingly, the co-administration of 20 mg/kg melatonin along with benzo(a)pyrene reduced the oxidative stress markers, apoptotic and autophagic proteins. Collectively, melatonin exhibited a protective effect against benzo(a)pyrene-induced renal injury through the suppression of oxidative stress and apoptosis and the inhibition of Sirt1/autophagy pathway.

Minocycline Protects PC12 Cells Against Cadmium-Induced Neurotoxicity by Modulating Apoptosis

Cadmium (Cd) is a well-known heavy metal and a neurotoxic agent. Minocycline (Mino) is an anti-microbial agent with a lipophilic structure that crosses the blood-brain barrier and enters the cerebral tissue. In recent studies, Mino has been introduced as an antioxidant and anti-apoptotic chemical compound, and therefore, it was examined as a protective candidate against Cd-induced neurotoxicity. In this study, PC12 cells were exposed to Cd alone, or after being pre-treated with Mino. Initially, the cell viability and oxidative stress were analyzed using the MTT assay and fluorimetry, respectively. Then, Cd-induced apoptosis and Mino anti-apoptotic effect were evaluated in both intrinsic and extrinsic pathways using western blot analysis. Exposing PC12 cells to Cd for 24 h decreased cell viability and increased production of reactive oxygen species in comparison with the control group. Cd (35 μM) also elevated the level of caspase-8, Bax/Bcl-2, and caspase-3 proteins in the cells. Mino pre-treatment for 2 h (100 nM) increased the number of viable cells and decreased the production of reactive oxygen species, and the level of all apoptotic markers in comparison to Cd-treated cells. Considering all the evidence, it appears that Mino holds promising antioxidant and anti-apoptotic activity and can protect cells against Cd-induced oxidative stress and prevent apoptotic cell death.

Comparison of problems related to 12 and 24-shift shift work in emergency medical technicians of Ardabil province

Introduction: Shift work is one of the factors affecting the performance of employees in the field of health care, which can have important effects on their health. The present study was conducted to compare the problems related to 12 and 24-hour shift work among emergency medical technicians in Ardabil province. Materials and Methods: The present study was descriptive-analytical research that was conducted on 157 technicians from 115 urban emergency centers in Ardabil province who were selected by census method in 2018. The data collection tool was standard shift work (SSW) questionnaire. The data were analyzed through SPSS version 20 software and using descriptive statistics and a chi-square test. Results: The results showed that the physical and mental workload of emergency medical technicians working 12-hour shifts is higher than that of 24-hour shift workers. Also, the willingness of 12-hour shift workers to continue working according to the productivity improvement law was significantly more than urban 24-hour shift workers (P<0.001). 24-hour shift technicians had more time for personal life compared to 12-hour shift workers (P=0.008). Feeling tired during the day, stomachache and heartburn, and back pain were relatively common problems among all emergency medical workers. Conclusion: Considering that the physical and mental workload of 12-hour shift workers is more than 24-hour shifts, it is recommended that managers should prioritize the work schedule of emergency medical technicians, including reducing their working hours.

The protective effect of natural or chemical compounds against arsenic-induced neurotoxicity: Cellular and molecular mechanisms

Arsenic is a notorious metalloid that exists in the earth's crust and is considered toxic for humans and the environment. Both cancerous and non-cancerous complications are possible after arsenic exposure. Target organs include the liver, lungs, kidney, heart, and brain. Arsenic-induced neurotoxicity, the main focus of our study, can occur in central and peripheral nervous systems. Symptoms can develop in a few hours, weeks, or years depending on the quantity of arsenic and the duration of exposure. In this review, we aimed to gather all the compounds, natural and chemical, that have been studied as protective agents in cellular, animal, and human reports. Oxidative stress, apoptosis, and inflammation are frequently described as destructive mechanisms in heavy metal toxicity. Moreover, reduced activity of acetylcholinesterase, the altered release of monoamine neurotransmitters, down-regulation of N-methyl-D-aspartate receptors, and decreased brain-derived neurotrophic factor are important underlying mechanisms of arsenic-induced neurotoxicity. As for neuroprotection, though some compounds have yet limited data, there are others, such as curcumin, resveratrol, taurine, or melatonin which have been studied more deeply and might be closer to a reliable protective agent. We collected the available information on all protective agents and the mechanisms by which they fight against arsenic-induced neurotoxicity.

Melatonin attenuates cardiopulmonary toxicity induced by benzo(a)pyrene in mice focusing on apoptosis and autophagy pathways

Benzo(a)pyrene (BaP) is a polycyclic aromatic hydrocarbon and a serious environmental pollutant. BaP is formed by the incomplete combustion of organic matter at high temperatures. In addition, tobacco smoke and many foods, especially charbroiled food and grilled meats, contain BaP and can cause it to enter human body. Melatonin, a pineal gland hormone, has antioxidant, anti-apoptosis, and autophagy regulatory properties. The possible protective impact of melatonin on cardiopulmonary toxicity induced by BaP was investigated by examining the antioxidant effects and the apoptosis and autophagy properties of melatonin. Thirty male mice were divided into 5 groups and treated for 28 days as follows: (I) control (BaP and melatonin solvent), (II) BaP (75 mg/kg, oral gavage), (III and IV) BaP (75 mg/kg) + melatonin (10 and 20 mg/kg, intraperitoneally), (V) melatonin (20 mg/kg). The oxidative stress factors (MDA and GSH content) were assessed in the heart and lung tissues. The levels of apoptotic (Caspase-3 and the Bax/Bcl-2 ratio) and autophagic (the LC3 ӀӀ/Ӏ, Beclin-1, and Sirt1) proteins were examined by using western blot analysis. Following the administration of BaP, MDA, the Bax/Bcl-2 ratio, and the Caspase-3 proteins increased in the heart and lung tissues, while GSH, Sirt1, Beclin-1, and the LC3 II/I ratio diminished. The coadministration of melatonin along with BaP, MDA, and apoptotic proteins returned to the control values, while GSH and the autophagy proteins were enhanced in both the heart and lungs. Melatonin exhibited a protective effect against BaP-induced heart and lung injury through the suppression of oxidative stress and apoptosis and the induction of the Sirt1/autophagy pathway.

Effect of trans-sodium crocetinate on contrast-induced cytotoxicity in HEK-293 cells

Objectives

Contrast media (CM) are used for diagnostic or therapeutic intervention purposes in medicine. The main adverse reaction after the administration of CM is contrast-induced nephropathy (CIN). This complication is the third cause of renal failure after hospital treatment. The current study is designed to investigate the possible protective effect of trans-sodium crocetinate (TSC), derived from carotenoid crocetin, against sodium amidotrizoate/meglumine amidotrizoate (SAMA) induced cytotoxicity in HEK-293 cells.

Materials and Methods

HEK-293 cells were incubated with different concentrations of TSC (1, 2.5, 5, 10, 25, and 50 µM, for 48 hr) and then SAMA (7 mgI/ml, for 24 hr) was added. The cell viability, intracellular ROS, and phosphatidyl serine exposure were detected by MTT assay, DCFH-DA, and annexin V-FITC/PI method, respectively. The P-ERK/ERK ratio, apoptosis (Bax/Bcl-2 ratio and cleaved caspase-3), and autophagy (LC3 II/I ratio and beclin-1) markers in cells were evaluated by the western blot method.

Results

The exposure of HEK-293 cells to SAMA reduced viability, increased apoptotic cells, enhanced ROS production, and subsequently decreased P-ERK/ERK ratio. Similarly, SAMA enhanced apoptosis (Bax/Bcl-2 ratio and cleaved caspase-3) and autophagy (LC3 II/I ratio and beclin-1) markers in HEK-293 cells. The pretreatment of cells with TSC before exposure to SAMA significantly attenuated contrast-induced cytotoxicity. TSC reduced intracellular ROS production and activated the phosphorylation of ERK. In addition, TSC decreased the levels of apoptosis and autophagy proteins.

Conclusion

The pretreatment of HEK-293 cells with TSC can decrease contrast-induced cytotoxicity through antioxidant effect and modulate ERK, apoptosis, and autophagy pathways.

The blockade of transient receptor potential ankyrin 1 (TRPA1) protects against PTZ-induced seizure

Treatment of epilepsy remains a major problem as some epileptic patients do not respond to the current therapeutics. Transient receptor potential ankyrin 1 (TRPA1) belongs to the TRP channels and has diverse physiological functions in the body. Considering its physiological properties, we aimed to evaluate its role in two experimental models of epilepsy, including pentylenetetrazol (PTZ)-induced acute seizure and PTZ-evoked kindling. Furthermore, the TRPA1 protein levels were assessed in the cerebral cortex, hippocampus, and cerebellum after seizure induction. Three groups of Wistar rats received acute intraperitoneal injection of pentylenetetrazol (PTZ, 85 mg/kg). The groups received intraventricular injections of vehicle (dimethyl sulfoxide, Tween 80, and sterile 0.9% saline), valproate (30 µg/rat), or HC030031 (TRPA1 antagonist, 14 µg/rat) before PTZ injection. In the PTZ-induced kindling model, PTZ was administrated 35 mg/kg every other day for 24 days. PTZ gradually provoked seizure-related behaviors. After experiments, the TRPA1 levels in the brain were assessed using western blot. The results showed that HC030031 reduced the median of seizure scores and S5 duration while increasing S2 and S5 latencies in acute and kindling models. The anticonvulsant effect of HC030031 was comparable with valproate as a standard anticonvulsant drug. Furthermore, induction of seizure, either acute or kindling, enhanced TRPA1 levels in the cerebral cortex, hippocampus, and cerebellum that were prevented by HC030031 or valproate administration. The results of this study showed that HC030031 as a TRPA1 receptor antagonist promoted a significant anticonvulsant effect comparable with valproate. Both drugs prevented TRPA1 upregulation during seizures. These findings imply that TRPA1 is a potential target in treating epilepsy.

Melatonin ameliorates arsenic-induced cardiotoxicity through the regulation of the Sirt1/Nrf2 pathway in rats

Chronic arsenic (As) exposure, mainly as a result of drinking contaminated water, is associated with cardiovascular diseases. Mitochondrial dysfunction, oxidative stress, inflammation, apoptosis, and autophagy have been suggested as the molecular etiology of As cardiotoxicity. Melatonin (Mel) is a powerful antioxidant. Mel improves diabetic cardiomyopathy, cardiac remodeling, and heart failure. Following pre-treatment with Mel (10, 20, or 30 mg/kg/day i.p.), rats were orally gavaged with As (15 mg/kg/day) for 28 days. Electrocardiographic findings showed that Mel decreased the As-mediated QT interval prolongation. The effects of As on cardiac levels of glutathione (GSH) and malondialdehyde (MDA) were reversed by Mel pretreatment. Mel also modulated the Sirt1 and Nrf2 expressions promoted by As. Mel down-regulated autophagy markers such as Beclin-1 expression and the LC3-II/I ratio. Moreover, the cardiac expression of cleaved-caspase-3 and Bax/Bcl-2 ratio was decreased by Mel pretreatment. Reduced expression of miR-34a and miR-144 by As were reversed by Mel. The histopathological changes of cardiac injury associated with As exposure was moderated by Mel. Mel may improve As-induced cardiac dysfunction through anti-oxidative, anti-apoptotic, and anti-autophagic mechanisms.

Osthole attenuated cytotoxicity induced by 6-OHDA in SH-SY5Y cells through inhibition of JAK/STAT and MAPK pathways

Objectives

Natural coumarin called osthole is regarded as a medicinal herb with widespread applications in Traditional Chinese Medicine. It has various pharmacological properties, including antioxidant, anti-inflammatory, and anti-apoptotic effects. In some neurodegenerative diseases, osthole also shows neuroprotective properties. In this study, we explored how osthole protects human neuroblastoma SH-SY5Y cells from the cytotoxicity of 6-hydroxydopamine (6-OHDA).

Materials and Methods

Using the MTT assay and DCFH-DA methods, respectively, the viability of the cells and the quantity of intracellular reactive oxygen species (ROS) were evaluated. Signal Transducers and Activators of Transcription (STAT), Janus Kinase (JAK), extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and caspase-3 activation levels were examined using western blotting.

Results

In SH-SY5Y cells, the results showed that a 24-hour exposure to 6-OHDA (200 µM) lowered cell viability but markedly elevated ROS, p-JAK/JAK, p-STAT/STAT, p-ERK/ERK, p-JNK/JNK ratio, and caspase-3 levels. Interestingly, osthole (100 µM) pretreatment of cells for 24 hr prevented 6-OHDA-induced cytotoxicity by undoing all effects of 6-OHDA.

Conclusion

In summary, our data showed that osthole protects SH-SY5Y cells against 6-OHDA-induced cytotoxicity by inhibiting ROS generation and reducing the activity of the JAK/STAT, MAPK, and apoptotic pathways.

A review of therapeutic potentials of milk thistle (Silybum marianum L.) and its main constituent, silymarin, on cancer, and their related patents

For more than 2000 years, Silybum marianum L. (milk thistle) has been used for treating different complications such as jaundice, hepatitis, and cancers. It has also been shown that silymarin, a flavonolignan extract of the plant, demonstrates chemopreventive effects against cancers. This patent review presents and discusses recent patents concerning the anticancer effects of S. marianum and silymarin. The data were gathered by searching an extensive literature review conducted in Google Scholar, PubMed, Scopus, Google Patent, Patent Scope, and US Patent. Milk thistle and silymarin have been used in a variety of medical, therapeutic, and pharmaceutical fields, according to a large number of documents and patents. Milk thistle and silymarin have been used as complementary treatments for cancers such as skin, prostate, and colorectal cancers, as well as hepatoprotective agents. Silymarin exerts a chemopreventive effect on reactivating cell death pathways by modulation of the antiapoptotic proteins and synergizing with agonists of death domain receptors. Based on the results of these patents, silymarin could be beneficial to oncology patients, especially for the treatment of the side effects of anticancer chemotherapeutics. Following the human propensity to use phytocompounds rather than medicines based on chemical constituents, special attention must be paid to tie the value of milk thistle and silymarin from basic science to clinical applications.

Fasudil attenuates 6-OHDA cytotoxicity in PC12 cells through inhibition of JAK/STAT and apoptosis pathways

Background: 6-Hydroxydopamine (6-OHDA) is widely used to induce neurotoxicity and investigate the mechanisms of Parkinson disease. 6-OHDA causes cell injury through various mechanisms including oxidative stress, inflammation and apoptosis. The selective Rho-kinase inhibitor, fasudil displays neuroprotective effects in several neurodegenerative disorders. The aim of this study was to assess the protective effect of fasudil in PC12 cytotoxicity induced by 6-OHDA. Methods: PC12 cells were exposed to 5, 10, 25, and 50 µM of fasudil concentrations. After 24 h, the IC50 value of 6-OHDA (150 µM) was added. Twenty-four hours later, the viability of cells was evaluated via MTT assay and the formation of reactive oxygen species (ROS) was measured by the fluorimetric method. At the 50 µM concentration of fasudil, with or without 6-OHDA, the changes of protein levels including STAT3, p-STAT3, JAK2, p-JAK2, and caspase-3 were determined via western blotting. Results: Our results showed that 6-OHDA increased the intracellular level of ROS, reduced cell viability, upregulated p-STAT3/STAT3 and p-JAK2/JAK2 ratios and significantly raised cleaved caspase-3 in comparison to control group. Furthermore, pretreatment of cells with fasudil (50 µM) for 24 h could reverse all changes induced by 6-OHDA. Conclusion: 6-OHDA caused cytotoxicity in PC12 cells through inducing of oxidative stress and activating of JAK/STAT and apoptosis pathways, while pretreatment with fasudil exhibited protective effect on 6-OHDA-induced neurotoxicity via the inhibition of oxidative stress and prevention of these pathways.

Quetiapine attenuates the acquisition of morphine-induced conditioned place preference and reduces ERK phosphorylation in the hippocampus and cerebral cortex

Background: Quetiapine is an atypical antipsychotic that antagonizes dopamine and serotonin receptors. It has been suggested that quetiapine can be used to treat substance use disorders, including opioid use disorder. Opioids modulate dopaminergic functions associated with conditioned reinforcement and these effects can be measured via the conditioned place preference (CPP) paradigm. Opioids' unconditioned effects are regulated by several proteins, including extracellular signal-regulated kinase (ERK) and cAMP-responsive element-binding (CREB).Objective: To assess the effect of quetiapine on morphine-induced CPP and motor activity levels, and on the levels of ERK and CREB proteins in the hippocampus and cerebral cortex.Methods: 42 male rats were exposed to a CPP protocol, in which they underwent a conditioning paradigm with saline, quetiapine (40 mg/kg), morphine (10 mg/kg), morphine plus quetiapine (10, 20, or 40 mg/kg), or morphine plus memantine (7.5 mg/kg, a positive control drug) (n = 6 per group). The rats were tested for CPP and exploratory activity. Levels of ERK and CREB proteins in the hippocampus and cerebral cortex were also measured.Results: Quetiapine co-administered with morphine inhibited morphine-induced CPP [F (6, 70) = 11.67, p < .001] and morphine's effects on motor activity (p < .001). Morphine enhanced ERK phosphorylation in the hippocampus (p < .001) and cerebral cortex (p < .001), an effect inhibited by quetiapine.Conclusion: Quetiapine attenuates morphine-induced CPP and locomotion and these effects are associated with a reduction of ERK phosphorylation in the hippocampus and cerebral cortex. These results suggest that quetiapine should be further explored as a potential treatment for opioid use disorder.

Comparison of pharmacokinetic parameters of ranolazine between diabetic and non-diabetic rats

OBJECTIVES

Diabetes mellitus (DM) affects the pharmacokinetics of drugs. Ranolazine is an antianginal drug that is prescribed in DM patients with angina. We decided to evaluate the effect of DM on the pharmacokinetics of ranolazine and its major metabolite CVT-2738 in rats.

MATERIALS AND METHODS

Male rats were divided into two groups: DM (induced by 55 mg/kg Streptozotocin (STZ)) and non-DM. All animals were treated with 80 mg/kg of ranolazine for 7 continuous days. The blood samples were collected immediately at 0 (prior to dosing), 1, 2, 3, 4, 8, and 12 hr after administration of the 7th dose of ranolazine. Serum ranolazine and CVT-2738 concentrations were determined using the high-performance liquid chromatography (HPLC) method. Pharmacokinetic parameters were calculated using a non-compartmental model and compared between the two groups.

RESULTS

The peak serum concentration (Cmax) and area under the curve (AUC) of ranolazine significantly decreased in DM compared with non-DM rats. DM rats showed significantly higher volumes of distribution (Vd) and clearance (CL) of ranolazine than non-DM rats. DM did not affect Ke, Tmax, and T1/2 of ranolazine. The concentration of metabolite was lower than the HPLC limit of detection (LOD).

CONCLUSION

It was found that streptozotocin-induced DM increased Vd and CL of ranolazine, thereby decreasing the AUC of the drug. Therefore, dosage adjustment may be necessary for DM patients, which requires further clinical studies.

The effects of ginger and its constituents in the prevention of metabolic syndrome: A review

Metabolic syndrome is a multifactorial disorder characterized by hyperglycemia, hyperlipidemia, obesity, and hypertension risk factors. Moreover, metabolic syndrome is the most ordinary risk factor for cardiovascular disease (CVD). Numerous chemical drugs are being synthesized to heal metabolic risk factors. Still, due to their abundant side effects, herbal medicines have a vital role in the treatment of these abnormalities. Ginger (Zingiber officinale Roscoe, Zingiberaceae) plant has been traditionally used in medicine to treat disorders, including CVD. The unique ginger properties are attributed to the presence of [6]-gingerol, [8]-gingerol, [10]-gingerol, and [6]-shogaol, which through different mechanisms can be beneficial in metabolic syndrome. Ginger has a beneficial role in metabolic syndrome treatment due to its hypotensive, anti-obesity, hypoglycemic, and hypolipidemic effects. It can significantly reduce atherosclerotic lesion areas, VLDL and LDL cholesterol levels, and elevate adenosine deaminase activity in platelet and lymphocytes. Also, it promotes ATP/ADP hydrolysis. In the current article review, the critical properties of ginger and its constituents' effects on the metabolic syndrome with a special focus on different molecular and cellular mechanisms have been discussed. This article also suggests that ginger may be introduced as a therapeutic or preventive agent against metabolic syndrome after randomized clinical trials.

The protective effect of chemical and natural compounds against vincristine-induced peripheral neuropathy (VIPN)

Vincristine, an alkaloid extracted from Catharanthus rosea, is a class of chemotherapy drugs that act by altering the function of the microtubules and by inhibiting mitosis. Despite its widespread application, a major adverse effect of vincristine that limits treatment duration is the occurrence of peripheral neuropathy (PN). PN presents with several symptoms including numbness, painful sensation, tingling, and muscle weakness. Vincristine-induced PN involves impaired calcium homeostasis, an increase of reactive oxygen species (ROS), and the upregulation of tumor necrosis factor-alpha (TNF-α), and interleukin 1 beta (IL-1β) expression. Several potential approaches to attenuate the vincristine-induced PN including the concomitant administration of chemicals with vincristine have been reported. These chemicals have a variety of pharmaceutical properties including anti-inflammation, antioxidant, and inhibition of calcium channels and calcineurin signaling pathways and increased expression of nerve growth factor (NGF). This review summarized several of these compounds and the mechanisms of action that could lead to effective options in improving vincristine-induced peripheral neuropathy (VIPN).

A review of the effects of Urtica dioica (nettle) in metabolic syndrome

Metabolic syndrome is a serious health condition, yet a common worldwide disorder. It includes several risk factors such as hypertension, dyslipidemia, and high glucose levels which lead the patients to higher risks of cardiovascular diseases, diabetes, and stroke. Phytotherapy plays an important role in treating components of metabolic syndrome. Nettle (Urtica dioica) is considered a valuable plant due to bioactive compounds such as formic acid and rich sources of flavonoids. To acknowledge the role of nettle in metabolic syndrome, several mechanisms have been suggested such as alterations in potassium and calcium channels which improve hypertension. Antihyperlipidemic properties of nettle are mediated by inhibition of HMGCoA reductase and amelioration of lipid peroxidation via antioxidant effects. Also, one of the flavonoids in nettle, quercetin, is responsible for decreasing total cholesterol. Moreover, nettle is responsible for anti-diabetic effects through processes such as increasing insulin secretion and proliferation of pancreatic β-cells. This review aims to gather different studies to confirm the potential efficacy of nettle in metabolic syndrome.

Effects of alpha lipoic acid on metabolic syndrome: A comprehensive review

Metabolic syndrome (MetS) is a multifactorial disease with medical conditions such as hypertension, diabetes, obesity, dyslipidemia, and insulin resistance. Alpha-lipoic acid (α-LA) possesses various pharmacological effects, including antidiabetic, antiobesity, hypotensive, and hypolipidemia actions. It exhibits reactive oxygen species scavenger properties against oxidation and age-related inflammation and refines MetS components. Also, α-LA activates the 5' adenosine monophosphate-activated protein kinase and inhibits the NFκb. It can decrease cholesterol biosynthesis, fatty acid β-oxidation, and vascular stiffness. α-LA decreases lipogenesis, cholesterol biosynthesis, low-density lipoprotein and very low-density lipoprotein levels, and atherosclerosis. Moreover, α-LA increases insulin secretion, glucose transport, and insulin sensitivity. These changes occur via PI3K/Akt activation. On the other hand, α-LA treats central obesity by increasing adiponectin levels and mitochondrial biogenesis and can reduce food intake mainly by SIRT1 stimulation. In this review, the most relevant articles have been discussed to determine the effects of α-LA on different components of MetS with a special focus on different molecular mechanisms behind these effects. This review exhibits the potential properties of α-LA in managing MetS; however, high-quality studies are needed to confirm the clinical efficacy of α-LA.

Protective effect of Toll-like receptor 4 antagonist on inflammation, EEG, and memory changes following febrile seizure in Wistar rats

Neuroinflammation and fever are the main triggers in febrile seizures (FS). Focusing on inflammatory pathways and anti-inflammatory drugs could compensate for the limitations of existing medications. The aim of this study is to evaluate the neuroprotective effect of specific antagonizing Toll-like receptor 4 (TLR4), as a prominent inflammatory axis, on the consequences of FS and adulthood using animal models. Complex FS was induced on 9-11 day old male rat pups using a heated chamber. TAK-242, as a specific TLR4 inhibitor, was injected intraperitoneally before seizure induction. Seizure threshold, duration, and spike number were measured by electrocorticography. The levels of inflammatory cytokines, TLR4 protein expression, and oxidative stress markers were detected by enzyme-linked immunosorbent assay, western blotting, malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) assessments in the cortex and hippocampus. Also, spatial and non-spatial memory were evaluated using the novel object recognition test (NORT) and double Y-maze test during adulthood. The results revealed that provoked inflammatory responses in neonate rats, after FS, were associated with the increase of the tumor necrosis factor alpha, interleukin-1β, and enhanced TLR4 protein expression. Meanwhile, based on performed behavioral tests, the inflammatory process was also involved in adulthood memory deficit. Pretreatment with TAK-242 reduced the inflammatory cytokines and TLR4 protein expression in the cortex and hippocampus of neonate rats and improvement in memory deficit in NORT and double Y-maze tasks. Also, pretreatment with TAK-242 elevated seizure threshold, SOD, and CAT activities, and decreased seizure duration and MDA level with no significant change in spike number. TAK-242 possibly controlled FS via inhibiting inflammation.

Protective Effect of Crocin against Mitochondrial Damage and Memory Deficit Induced by Beta-amyloid in the Hippocampus of Rats

Alzheimer's disease is the most common form of dementia among the elderly. This progressive neurodegenerative disorder affects brain regions that control cognition, memory, language, speech, and awareness. As a potent antioxidant, crocin has been proposed to effectively manage the neurodegenerative disease. In this study, the recovery effects of crocin on the memory deficits caused by the intra-hippocampal injection of amyloid beta1-42 (Aβ1-42) were evaluated in rats. We also considered the protective effects of crocin on the mitochondrial damage caused by Aβ1-42. We examined the memory deficits of rats with the help of the Morris water maze. Then, we determined different mitochondrial toxicity endpoints caused by Aβ1-42, including mitochondrial ROS formation, lipid peroxidation, mitochondrial membrane potential collapse, mitochondrial outer membrane integrity, and cytochrome c release. Our results demonstrated that the behavioral signs of memory deficiency caused by Aβ1-42 significantly (P < 0.01) reduced by both pretreatment and post-treatment with crocin (30 mg/kg). Furthermore, crocin prevented all the Aβ1-42 induced above referenced mitochondrial upstream toxic events leading to neuronal apoptosis. These results demonstrated that crocin is a promising preventive candidate for the potential treatment of Alzheimer's disease. Furthermore, it seems that the antioxidant and neuroprotective effects of crocin are better seen when the compound is pretreated beforehand rather than introduced afterward in Aβ1-42 exposed mitochondria.

The genus Glycyrrhiza (Fabaceae family) and its active constituents as protective agents against natural or chemical toxicities

Licorice is the dried roots and rhizomes of various species of the genus Glycyrrhiza (Fabaceae) that have been used in folk medicine from ancient times. Many important research projects have established several beneficial effects for this medicinal herb, including antiinflammatory, antimicrobial, antiviral, antiprotozoal, antioxidant, antihyperglycemic, antihyperlipidemic, hepatoprotective, and neuroprotective. Licorice contains important bioactive components, such as glycyrrhizin (glycyrrhizic, glycyrrhizinic acid), liquiritigenin, liquiritin, and glycyrrhetinic acid. The protective effects of licorice and its main chemical components against toxins and toxicants in several organs including the brain, heart, liver, kidney, and lung have been shown. In this comprehensive review article, the protective effects of these constituents against natural, industrial, environmental, and chemical toxicities with attention on the cellular and molecular mechanism are introduced. Also, it has been revealed that this plant and its main compounds can inhibit the toxicity of different toxins by the antioxidant, antiinflammatory, and anti-apoptotic properties as well as the modulation of Inhibitor of kappaB kinase (IKK), Extracellular signal-regulated protein kinase1/2 (ERK1/2), p38, inducible nitric oxide synthase, and nuclear factor-κB (NF-κB) signaling pathways. More high-quality investigations in both experimental and clinical studies need to firmly establish the efficacy of licorice and its main constituents against toxic agents.

Protective effects of selenium on acrylamide-induced neurotoxicity and hepatotoxicity in rats

Objective(s):

Acrylamide (ACR), has wide uses in different industries. ACR induced several toxicities including neurotoxicity and hepatotoxicity. The probable protective effects of selenium on ACR-induced neurotoxicity and hepatotoxicity in rats were evaluated.

Materials and Methods:

Male Wistar rats were studied for 11 days in 8 groups: 1. Control, 2. ACR (50 mg/kg, IP), 3-5. ACR+ selenium (0.2, 0.4, 0.6 mg/kg, IP), 6. ACR+ the most effective dose of selenium (0.6 mg/kg, IP) three days after ACR administration, 7. ACR+ vitamin E (200 mg/kg IP, every other day) 8. Selenium (0.6 mg/kg IP). Finally, behavioral tests were done. The levels of malondialdehyde (MDA), glutathione (GSH), Bcl-2, Bax and caspase 3 proteins in liver and cerebral cortex tissues were measured. Also, the amount of albumin, total protein, alanine transaminase (ALT) and aspartate transaminase (AST) enzymes were determined in serum.

Results:

ACR caused the severe motor impairment, increased MDA level and decreased GSH content, enhanced Bax/Bcl-2 ratio and caspase 3 proteins in brain and liver tissues. Besides, the level of AST was elevated while the total serum protein and albumin levels were decreased. Administration of selenium (0.6 mg/kg) (from the first day of the experiment and the third day) significantly recovered locomotor disorders, increased GSH content, and reduced MDA level. Also, selenium decreased Bax/Bcl-2 ratio and caspase 3 levels in brain and liver tissues.

Conclusion:

The oxidative stress and apoptosis pathways have important roles in neurotoxicity and hepatotoxicity of ACR. Selenium significantly reduced ACR-induced toxicity through inhibition of oxidative stress and apoptosis.

Diabetes mellitus aggravates ranolazine-induced ECG changes in rats

PURPOSE

Diabetes mellitus (DM) is known to affect the pharmacokinetics of drugs. In this study, we evaluated the effect of DM on the liver content of CYP 3A2 enzyme. We also explored the ECG changes after administration of ranolazine in non-DM and DM rats.

METHODS

First phase: 24 male Wistar rats were separated into 4 groups. The control group (n = 6) received normal saline and the DM groups (n = 18) were treated with a single dose (55 mg/kg) of streptozocin (STZ; i.p. injection), then were held for 10, 20, and 30 days, respectively. After study duration for each group, the liver CYP 3A2 protein content was determined using western blotting. Second phase: 48 male Wistar rats were classified into two groups of non-DM and DM; and each group was divided into 4 subgroups (n: 6). Experimental groups received oral doses of 20, 40, and 80 mg/kg ranolazine. DM and non-DM control groups received normal saline. Treatment lasted for 28 days, and then the ECG was recorded.

RESULTS

Experimental DM induced by STZ caused a significant decrement in liver CYP3A2 protein content of rats on days 10 and 20 (P < 0.01), and 30 (P < 0.05) compared to the control animals. Significant increases in QT and corrected QT (QTc) intervals (P < 0.01), and bradycardia (P < 0.01) without any significant effect on PR and QRS intervals were observed in DM in comparison with non-DM groups after ranolazine treatment.

CONCLUSIONS

In summary, DM induction in animals resulted in CYP 3A2 inhibition and the prolongation of QT and QTc interval as well as bradycardia after ranolazine treatment.

Retinoprotective Effects of Crocin and Crocetin via Anti-angiogenic Mechanism in High Glucose-Induced Human Retinal Pigment Epithelium Cells

BACKGROUND

Diabetic retinopathy (DR) is one of the most common side effects of diabetes. We aimed to investigate the effects of crocin and crocetin (as a deglycosylated form of crocin in blood stream) in gene expression or protein levels of vascular endothelial growth factor (VEGF), vascular endothelial growth factor-receptor1 (VEGFR-1), matrix metalloproteinases2 (MMP-2), matrix metalloproteinases9 (MMP-9) and thrombospondin-2 (TSP-2) in high glucose cell culture media.

METHODS

The retinal pigment epithelium (RPE) cells were exposed to high glucose (HG, 30 mM glucose concentration) and normal glucose (NG, 24.5 mM mannitol + 5.5 mM glucose) for six days. RPE cells were treated in four treatment groups (crocin, crocetin, Bevacizumab, and crocin + Bevacizumab). Gene expressions were measured using quantitative real-time PCR, and proteins level was evaluated by western blot.

RESULTS

Findings showed that VEGF gene expression and protein level significantly decreased in all treatment groups. In addition, reduction in VEGFR1 gene expression was significantly higher in Bevacizumab and crocin + Bevacizumab groups than other groups. Only, crocin and crocetin could reduce the gene levels of MMP-2 and MMP-9. In addition, TSP-2 protein levels increased when HG cells were exposed crocin or crocin + Bevacizumab groups.

CONCLUSION

Our data showed that crocin and crocetin have anti-VEGF function similar to Bevacizumab, act as an anti-angiogenic agent. Also, crocin and crocetin could decrease MMP-2 and MMP-9 gene levels, as inflammatory and angiogenesis factors. As a result, crocin and crocetin have protective effects against angiogenesis and inflammation in DR.

Protective Effects of Crocin Against Hepatic Damages in D-galactose Aging Model in Rats

Aging is a progressive process which is associated with liver dysfunction and it is due to oxidative stress, inflammation, and cell apoptosis. Long-term D-galactose (D-gal) administration is able to develop an aging model in animals. Crocin as a major active ingredient in saffron has shown anti-inflammatory and hepatoprotective effects via its antioxidant capacity. Thus, the aim of the present study was the assessment of crocin effects on hepatic and metabolic disorders induced by D-gal in rats. Aging model was induced in rats by 56-day administration of D-gal (400 mg/kg/day subcutaneously). Protective effects of different doses of crocin (7.5, 15 and 30 mg/kg/day) in concomitant with D-gal administration were evaluated. Malondialdehyde (MDA) and reduced glutathione (GSH) amounts were measured by means of their reaction, respectively, with thiobarbituric acid and 5,5'-Dithiobis (2-nitrobenzoic acid) (DTNB) under a specific condition. Cyclooxygenase-2 (COX-2), β-galactosidase, induced nitric oxide synthase (iNOS), and carboxymethyllysine (CML) levels were determined by western blotting method. Additionally, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were measured in serum. D-gal administration significantly elevated ALT, AST, ALP levels, which were markedly inhibited by crocin administration. Crocin suppressed the overgeneration of lipid peroxidation products such as MDA. iNOS was elevated by D-gal administration and was returned to the normal extent by crocin. Therefore, Crocin as a powerful antioxidant and radical scavenger, totally exhibited hepatoprotective effects against D-gal-induced toxicity in rats.

Effect of suvorexant on morphine tolerance and dependence in mice: Role of NMDA, AMPA, ERK and CREB proteins

The major problems of morphine use in the clinic are its tolerance and dependence. This study aimed to investigate the effect of suvorexant, a dual orexin receptor antagonist, on morphine-induced dependence and tolerance in mice and evaluate the level of NMDA, AMPA, ERK, p-ERK, CREB and p-CREB proteins in the brain. Tolerance and dependence were induced by repeated injection of morphine in mice (three times a day for 3 days, 50, 50, and 75 mg/kg /day). To evaluate the effects of the drugs on morphine-induced tolerance and dependence, suvorexant (30, 60 and 90 mg/kg), clonidine (positive control, 0.1 mg/kg) and saline were injected intraperitoneally 30 min before each injection of morphine. Tolerance and locomotor activity were assessed by tail-flick and open-field tests, respectively. The effect of suvorexant on the naloxone (5 mg/kg, ip)-induced morphine withdrawal, was also evaluated. Finally, the expression of proteins in the brain of mice was measured by western blot. Administration of suvorexant with morphine significantly reduced morphine-induced tolerance. Also, suvorexant attenuated the naloxone-precipitated opioid withdrawal. Suvorexant decreased morphine-enhanced levels of CREB and p-ERK proteins but did not affect the expression of NMDA and AMPA proteins compared to the morphine group. Suvorexant reduced morphine-induced tolerance and dependence through the inhibition of orexin receptors as well as changes in CREB and p-ERK protein levels in the brain.

miR-155 influences cell-mediated immunity in Balb/c mice treated with aflatoxin M1

Aflatoxin M1 (AFM1) is a 4-hydroxylated metabolite of aflatoxin B1 (AFB1). It induces various toxicological effects including immunotoxicity. In the present study, we investigated the effects of AFM1 on immune system and its modulation by MicroRNA (miR)-155. AFM1 was administered intraperitoneally at doses of 25 and 50 µg/kg for 28 days to Balb/c mice and different immune system parameters were analyzed. The levels of miR-155 and targeted proteins were evaluated in isolated T cells from spleens of mice. Spleen weight was reduced in mice exposed to AFM1 compared to negative control. Proliferation of splenocytes in response to phytohemagglutinin-A was reduced in mice exposed to AFM1. IFN-γ was decreased in mice exposed to AFM1, whereas IL-10 was increased. Concentration of IL-4 did not change different in mice exposed to AFM1 compared to negative control. Exposure to AFM1 reduced the expression of miR-155. Significant upregulation of phosphatidylinositol-3, 4, 5-trisphosphate 5-phosphatase 1 (Ship1) and suppressor of cytokine signaling 1 (Socs1) was observed in isolated T cells from spleens of mice treated with AFM1, but the transcription factor Maf (c-MAF) was not affected. These results suggest that miR-155 and targeted proteins might be involved in the immunotoxicity observed in mice exposed to AFM1.

Evaluation of the effect of thymoquinone in d-galactose-induced memory impairments in rats: Role of MAPK, oxidative stress, and neuroinflammation pathways and telomere length

D-galactose (d-gal) induces aging and memory impairment via oxidative stress and neuroinflammation pathways. This study evaluated the neuroprotective activity of thymoquinone (TQ) against d-gal. d-gal (400 mg/kg, SC), d-gal plus TQ (2.5, 5, 10 mg/kg, i.p.), and TQ alone (2.5 and 10 mg/kg) for 8 weeks were administered to rats. The effect of TQ on learning and memory were studied using the Morris water maze test. Malondialdehyde (MDA) and glutathione (GSH) levels were determined in the hippocampus. The levels of MAPKs (p-ERK/ERK, p-P38/P38), cAMP response elements binding (p-CREB/CREB), advanced glycation end products (AGEs), inflammatory markers (TNFα, IL-1β), glial fibrillary acidic protein (GFAP), and brain-derived neurotrophic factor (BDNF) were analyzed by western blotting. Telomere length was evaluated using real-time PCR. Memory and learning impairment, MDA enhancement, GSH reduction, and neuroinflammation via increasing the TNFα, IL-1β, and GFAP contents were observed in d-gal group. TQ with d-gal, improved memory impairment, reduced oxidative stress, and alleviated neuroinflammation. The elevated level of AGEs decreased by TQ compared to d-gal. No changes were observed in the levels of p-ERK/ERK, p-CREB/CREB, p-P38/P38, BDNF, and telomere length following administration of d-gal or TQ plus d-gal. TQ improved memory deficits of d-gal through anti-oxidative and anti-inflammatory mechanisms.

The protective effect of melatonin on benzo(a)pyrene-induced brain injury: role of apoptosis and autophagy pathways

Benzo(a)pyrene (BaP), a toxic polycyclic aromatic hydrocarbon, is spread in different ways as an environmental pollutant. It has been proposed that BaP can induce toxicity through oxidative stress and apoptosis in vital organs. The present study evaluated the protective effect of melatonin, a circadian hormone of the pineal gland, on BaP-induced neurotoxicity focused on oxidative stress, autophagy, and apoptosis pathways. Thirty male mice in 5 groups were treated daily for 28 consecutive days: (I) control group (BaP and melatonin solvent), (II) BaP (75 mg/kg, orally), (III) and (IV) BaP + melatonin (10 and 20 mg/kg, i.p.), (V) melatonin (20 mg/kg). The oxidative stress markers were determined in the brain. Western blot was conducted for the level of LC3 II/I and Beclin1, as autophagy markers, caspase3 and Bcl2, as apoptosis proteins, and Sirt1 in the brain. The exposure of mice to BaP caused a marked increase in the malondialdehyde (MDA) level and decrease of glutathione (GSH) content in the brain. Furthermore, the Sirt1 level upregulated as well as LC3 II/I, Beclin1, and cleaved caspase3 proteins, while the level of Bcl2 did not change. Melatonin at 20 mg/kg concurrently with BaP restored the BaP alteration in the brain compared with the BaP group. In conclusion, BaP induced brain toxicity via the induction of oxidative stress, apoptosis, and autophagy, whereas melatonin afforded neuroprotection against BaP due to inhibition of these mechanisms.

An updated review of protective effects of rosemary and its active constituents against natural and chemical toxicities

Natural and chemical toxic agents cause severe adverse effects on people's health in a variety of exposing ways. Herbal medications have taken into consideration as alternative safe treatments for toxicities. Rosmarinus officinalis also known as rosemary belongs to the Lamiaceae family. Rosemary and its constituents including carnosic acid, rosmarinic acid, and carnosol have a lot of benefits such as anti-inflammatory, antioxidant, anti-mutagenic, anti-bacterial, antiviral, antinociceptive, and neuroprotective activities. In this literate review, we focused on the protective effects of rosemary and its main compounds against natural and chemical toxicities in both in vitro and in vivo studies. The protective effects of rosemary and its components are mostly mediated through different mechanisms such as the inhibition of oxidative stress, reduction of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-17 (IL-17), cyclooxygenase-2 (COX-2) and nuclear factor ĸB (NF-ĸB) as well as the modulation of apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways.

Osteopontin siRNA does not confer resistance to toxic effects of parthenolide in Jurkat cells

BACKGROUND

Osteopontin (OPN) plays a critical role in cell proliferation and drug resistance in cancer treatment and hematological malignancies. In T cell acute lymphoblastic leukemia, most initial therapies can induce remission while some patients then relapse and do not respond well to chemotherapy. The sesquiterpene lactone parthenolide (PTL) can induce apoptosis in a variety of cancer cell lines via inhibition of pro-inflammatory transcription factor nuclear factor kappa B and has anti-tumor activity in acute lymphoblastic leukemia treatment.

AIM

To study the role of OPN in conferring in vitro resistance to PTL in Jurkat cells.

METHODS

Jurkat cells were cultured with 8-20 μm PTL for 48 h. Transfection with OPN siRNA was provided. Apoptosis assays were performed with Annexin V-Alexa Fluor-488/PI. Quantitative real-time polymerase chain reaction was used to measure OPN gene expression using the 2-2^-ΔΔCt method.

RESULTS

PTL has cytotoxic and apoptotic effect on Jurkat cells with IC₅₀ values of 16.1 μm, and growth inhibition effect of PTL does not differ significantly in combination with OPN-siRNA. OPN gene expression is not affected by PTL.

CONCLUSIONS

Parthenolide induces apoptosis in Jurkat cells, but inhibition of osteopontin gene expression with siRNA does not reduce apoptotic effect of parthenolide.

Protective effect of crocin on bisphenol A - induced spatial learning and memory impairment in adult male rats: Role of oxidative stress and AMPA receptor

OBJECTIVES

Bisphenol A (BPA), a xenoestrogenic endocrine disrupting agent, is widely used in the production of polycarbonate plastics and has potential adverse effects on the developing nervous system, memory and learning abilities. The protective effect of the crocin, an important active constituent in Crocus sativus L, on memory impairment induced by BPA in rat was determined through evaluation of oxidative stress and the level of NMDA (N-methyl-D-aspartate receptors) and AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionicd acid) receptors.

MATERIALS AND METHODS

Rats were orally treated with BPA (100 mg/kg) or sesame seed oil in control group for 28 days. Crocin (10, 20, and 40 mg/kg, IP) was administrated in BPA-orally treated groups for 28 days. Memory and learning functions were evaluated by Morris water maze. The level of malondialdehyde (MDA) and glutathione (GSH) contents were determined in rat hippocampus. Additionally, the expression of NMDA and AMPA receptors were analyzed using Western blot method.

RESULTS

Administration of BPA significantly reduced memory and learning functions. Crocin significantly protected against learning and memory impairments induced by BPA. BPA administration markedly reduced GSH content and induced lipid peroxidation, while crocin was able to increase GSH content in rat hippocampus. The expression of NMDA receptor did not change in BPA-treated rats, while the significant reduction in AMPA receptor expression was observed. Moreover, crocin (20 mg/kg) significantly elevated the expression of AMPA receptor.

CONCLUSION

Crocin recovered spatial learning and memory defects induced by BPA in part through anti-oxidant activity and modulation the expression of AMPA receptor in rat hippocampus.

Tropisetron ameliorates cyclophosphamide-induced hemorrhagic cystitis in rats

Hemorrhagic cystitis is one of the most important complications of cyclophosphamide, a drug widely used in cancer chemotherapy and bone marrow transplantation. 5-HT₃ antagonists are anti-emetic agents and have been shown to have notable anti-inflammatory and antioxidant properties. This study was designed to investigate the possible protective effects of tropisetron against cyclophosphamide-induced hemorrhagic cystitis in rats. Hemorrhagic cystitis was induced in female rats by cyclophosphamide (270 mg/kg). Tropisetron (2.5, 5 and 7.5 mg/kg), granisetron (2.5 and 5 mg/kg), and ondansetron (5 mg/kg) were injected 15 min before, 4 and 8 h after cyclophosphamide. To evaluate the role of alpha7 nicotinic acetylcholine receptor (α7nAChR), its antagonist, methyllycaconitine (5 mg/kg) was administered 30 min before tropisetron. After 24 h, animals were killed under anesthesia. Macroscopic and histological changes were evaluated. Malondialdehyde (MDA), glutathione (GSH) and Evans blue were measured spectrophotometrically. Furthermore, the protein levels of p38 mitogen-activated protein kinases (P38 MAPK), p-P38, signal transducer and activator of transcription 3 (STAT3), p-STAT3 and Poly (ADP-ribose) polymerase (PARP) were determined using Western blot. Cyclophosphamide administration significantly induced histopathological damages and increased MDA, p-p38/p38, p-STAT3/STAT3, and PARP levels compared with the saline group. Tropisetron treatment diminished histopathological injuries as well as MDA level, and STAT3 activity compared to cyclophosphamide treated rats. Co-administration of methyllycaconitine with tropisetron, partially or completely reversed the protective effects of tropisetron. Our results showed that prophylactic administration of tropisetron markedly ameliorated the cyclophosphamide-induced bladder hemorrhage and inflammation in rats. These effects of tropisetron were α7nAChR dependent.

Protective effects of maternal administration of curcumin and hesperidin in the rat offspring following repeated febrile seizure: Role of inflammation and TLR4

Neuroinflammation has a key role in seizure generation and perpetuation in the neonatal period, and toll-like receptor 4 (TLR4) pathway has a prominent role in neuroinflammatory diseases. Administration of antioxidants and targeting TLR4 in the embryonic period may protect rat offspring against the next incidence of febrile seizure and its harmful effects. Curcumin and hesperidin are natural compounds with anti-inflammatory and antioxidant properties and have an inhibitory action on TLR4 receptors. We evaluated the effect of maternal administration of curcumin and hesperidin on infantile febrile seizure and subsequent memory dysfunction in adulthood. Hyperthermia febrile seizure was induced on postnatal days 9-11 on male rat pups with 24 h intervals, in a Plexiglas box that was heated to ~45 °C by a heat lamp. We used enzyme-linked immunosorbent assay, Western blotting, malondialdehyde (MDA), and glutathione (GSH) assessment for evaluation of inflammatory cytokine levels, TLR4 protein expression, and oxidative responses in the hippocampal tissues. For assessing working memory and long-term potentiation, the double Y-maze test and Schaffer collateral-CA1 in vivo electrophysiological recording were performed, respectively Our results showed that curcumin and hesperidin decreased TNF-α, IL-10, and TLR4 protein expression and reversed memory dysfunction. However, they did not provoke a significant effect on GSH content or amplitude and slope of recorded fEPSPs in the hippocampus. In addition, curcumin, but not hesperidin, decreased interleukin-1β (IL-1β) and MDA levels. These findings imply that curcumin and hesperidin induced significant protective effects on febrile seizures, possibly via their anti-inflammatory and antioxidant properties and downregulation of TLR4.

Melatonin inhibits Benzo(a)pyrene-Induced apoptosis through activation of the Mir-34a/Sirt1/autophagy pathway in mouse liver

Benzo(a)pyrene (BaP), an important environmental pollutant, is produced as the result of incomplete combustion of organic materials in many industries and food cooking process. It has been purposed that BaP induces hepatotoxicity through oxidative stress and apoptosis. Several studies have shown that melatonin can protect against chemical-induced apoptosis through autophagy pathway. In this study, we assessed the modulating effect of melatonin, a well-known antioxidant, on BaP-induced hepatotoxicity through induction of autophagy. Thirty male mice were treated daily for 28 consecutive days. BaP (75 mg/kg; oral gavage) and melatonin (10 and 20 mg/kg, i.p.) were administered to mice. The liver histopathology and the levels of apoptosis and autophagy proteins as well as the expression of miR-34a were determined. The BaP exposure induced severe liver histological injury and markedly enhanced AST, ALT and MDA level. Also, apoptosis proteins and hepatic miR-34a expression increased. However, the level of Sirt1 and autophagy markers such as LC3 II/I ratio and Beclin-1 reduced. The co-administration of melatonin reversed all changes caused by BaP. In summary, melatonin appears to be effective in BaP-induced hepatotoxicity maybe through the miR-34a/Sirt1/autophagy molecular pathway.

Effect of Topiramate on Morphine-induced Conditioned Place Preference (CPP) in Rats: Role of ERK and CREB Proteins in Hippocampus and Cerebral Cortex

In this study, the effect of topiramate, as an antiepileptic drug, was evaluated on morphine craving in rats. The conditioned place preference (CPP) test was used for this purpose. Repeated administration of morphine (10 mg/kg, i.p. for 4 days) induced significant CPP. Administration of topiramate (50 and 100 mg/kg, i.p. for 4 days) with each morphine administration decreased the acquisition of morphine-induced CPP. At the next step, the levels of extracellular signal-regulated kinase (ERK), p-ERK, cAMP responsive element binding (CREB), and p-CREB proteins were evaluated in hippocampus and cerebral cortex using western blot analysis. Following the repeated administration of morphine, the level of p-ERK protein markedly enhanced in both tissues, while topiramate could significantly reduce the phosphorylation of ERK in these brain regions. Additionally, the level of CREB and p-CREB proteins did not change in different groups. Memantine as a positive control reduced the acquisition of morphine-induced CPP. Also, memantine significantly decreased the level of p-ERK protein in hippocampus and cerebral cortex. These results demonstrated that topiramate can attenuate the acquisition of morphine-induced CPP in rats. This effect in part can be mediated through down regulation of p-ERK protein in hippocampus and cerebral cortex.

The immunotoxin activity of exotoxin A is sensitive to domain modifications

Immunotoxins are a class of recombinant proteins which consist of an antibody and a part of a bacterial or herbal toxin. Immunotoxins containing Pseudomonas aeruginosa exotoxin A (PEA) have been found to be very applicable in clinical trials. Many obstacles such as solubility and absorbency reduce their usability in solid tumors. The current study aims to overcome the mentioned barriers by addition and removal of functional and non-functional domains with a structural approach. In the experimental section, we took advantage of molecular dynamics simulations to predict the functionality of candidate immunotoxins which target human HER2 receptors and confirmed our findings with in vitro experiments. We found out when no changes were made to domain II of PEA, addition of solubilizing domains to immunotoxins would not reduce their targeting and anti-tumor activity, while increasing the yield of expression and stability. On the other side, when we replaced domain II with eleven amino acids of furin cleavage site (FCS), the activity of the immunotoxin was mainly affected by the FCS neighboring domains and linkers. A combination of seven beneficial point mutations in domain III was also assessed and reconfirmed that the toxicity of the immunotoxin would be reduced dramatically. The obtained results indicate that the addition or removal of domains cannot depict the activity of immunotoxins and the matter should be assessed structurally in advance.

Upregulation of Glutamate Transporter 1 by Clavulanic Acid Administration and Attenuation of Allodynia and Hyperalgesia in Neuropathic Rats

Introduction:

Clavulanic acid (CLAV) is structurally similar to ceftriaxone, a potent stimulator of glial GlutamateTransporter-1 (GLT-1) expression. The present study aims at exploring the anti-nociceptive effects of CLAV, a beta-lactamase inhibitor in rats underwent sciatic nerve Chronic Constriction Injury (CCI).

Methods:

CLAV (12.5, 25, 50 mg/kg) was administered intraperitoneally after the surgery for 14 consecutive days. Behavioral pain parameters were evaluated before and 3, 5, 7, 10 and 14 days after injury. Spinal GLT-1 level was measured via western blotting at days 7 and 14.

Results:

CCI led to mechanical allodynia, cold allodynia and thermal hyperalgesia which started on postoperative days 3 and continued until the end of study. We found that CLAV (12.5 and 25 mg/kg) significantly attenuated all pain related behaviors as compared to the CCI animals treated with normal saline. Protein level of GLT-1 was down-regulated on day 14 following CCI and this phenomenon was reversed by fourteen days treatment of CLAV at the low doses of 12.5 and 25 mg/kg.

Conclusion:

These results suggest that CLAV might provide a new therapeutic strategy for neuropathic pain and its effect might be partially associated with the up-regulation of GLT-1.