The combined effect of dichloroacetate and 3-bromopyruvate on glucose metabolism in colorectal cancer cell line, HT-29; the mitochondrial pathway apoptosis.

BACKGROUND: 5-Fluorouracil (5-FU) is regarded as the first line treatment for colorectal cancer; however, its effectiveness is limited by drug resistance. The ultimate goal of cancer therapy is induction of cancer cell death to achieve an effective outcome with minimal side effects. The present work aimed to assess the anti-cancer activities of mitocans which can be considered as an effective anticancer drug due to high specificity in targeting cancer cells. METHODS: MTT (3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) assay was performed to determine the effects of our mitocans on cell viability and cell death. Apoptosis and necrosis, caspase 3 activity, mitochondrial membrane potential and ROS production in HT29 cell lines were analyzed by ApopNexin™ FITC/PI Kit, Caspase- 3 Assay Kit, MitoTracker Green and DCFH-DA, respectively. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression level of pro-apoptotic (Bax) and anti-apoptotic (Bcl-2) genes in HT29 cell lines. RESULTS: Treatment with mitocans (3Br-P + DCA) inhibited the growth of HT29. Moreover, 3Br-P + DCA significantly induced apoptosis and necrosis, activation of caspase 3 activity, depolarize the mitochondrial membrane potential, and ROS production. At a molecular level, 3Br-P + DCA treatment remarkably down-regulated the expression of Bcl-2, while up-regulated the expression of Bax. CONCLUSION: Mitocans, in particular the combined drug, 3Br-P + DCA, could be regarded and more evaluated as a safe and effective compound for CRC treatment. Targeting hexokinase and pyruvate dehydrogenase kinase enzymes may be an option to overcome 5-FU -mediated chemo-resistant in colorectal cancer.

Liver histopathological alteration and dysfunction after bisphenol A administration in male rats and protective effects of naringin.

OBJECTIVE: Bisphenol A (BPA) is an organic synthetic compound, often used in manufacturing polycarbonate plastics. Researches have shown the role of BPA as an endocrine disruptor. The present study intended to evaluate the hepatoprotective properties of naringin, an active flavanone glycoside present in many citrus fruit, against hepatotoxicity induced by BPA. MATERIALS AND METHODS: Male Wistar rats were orally treated with 50 mg/kg BPA for 30 consecutive days for induction of toxicity and 40, 80 and 160 mg/kg naringin for the same period along with BPA or alone. RESULTS: This study demonstrated that BPA significantly increased serum levels of triglyceride, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), lipid peroxidation, and aspartate aminotransferase (AST) and significantly reduced catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity, glutathione (GSH) and caused periportal inflammation and microvesicular steatosis in rat tissue. However, BPA did not change serum levels of high-density lipoprotein-cholesterol (HDL-C), total cholesterol, alanine aminotransferase (ALT), or low-density lipoprotein-cholesterol (LDL-C). Furthermore, the results displayed that administration of 80 and 160 mg/kg naringin improved hepatotoxicity and altered lipid peroxidation level, serum values of triglyceride and liver enzymes, and oxidative stress factors that were induced by BPA. The effect of two doses of 80 and 160 mg/kg naringin was more noticeable than that of dose 40 mg/kg. CONCLUSION: The findings suggested the protective effects of naringin against BPA-induced hepatotoxicity via ameliorating liver histopathological alteration, suppressing oxidative stress and lipid-lowering properties.

Protective effects of selenium on Bisphenol A-induced oxidative stress in mouse testicular mitochondria and sperm motility.

OBJECTIVE: This study aimed to explore the impact of selenium (SE) on Bisphenol-A (BPA)-exposed sperm and isolated testicular mitochondria of mice. METHODS: Mouse sperm and isolated mitochondria were exposed to BPA (0.8 mM) and different concentrations of SE (50, 100, and 200 µM) for four hours. The viability of sperm and isolated mitochondria as well as the mitochondrial membrane potential (MMP) were evaluated. SOD (superoxide dismutase), GSH (glutathione), MDA (malondialdehyde), and ROS (reactive oxygen species) levels in testicular mitochondria were also examined. RESULTS: BPA concentration-dependently enhanced ROS and MDA levels in isolated mitochondria, while MMP and acclivity of GSH and SOD significantly reduced. BPA also considerably impaired spermatozoa survival and motility. SE concentration-dependently reduced mitochondrial oxidative stress, MMP, sperm survival, and total sperm motility. CONCLUSIONS: Our findings collectively suggested that SE concentration-dependently reversed BPA-caused mitochondrial toxicity and reduced sperm motility by suppressing oxidative stress.

Mesobuthus eupeus venom induced injury in the colorectal carcinoma cell line (HT29) through altering the mitochondria membrane stability.

OBJECTIVES: The purpose of this study was to investigate cytotoxicity and membrane toxicity effects induced by Mesobuthus eupeus venom (MEV) on the HT-29 cell line. MATERIALS AND METHODS: To determine the in vitro cytotoxicity via MTT assays, HT-29 (as cancer cell line) and Hek-293T (as normal cell) were treated through different concentrations of MEV, and cytotoxicity effects were then measured through assessment of mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS) generation, and apoptosis induction. The colony formation assay was performed to measure the antiproliferative effect of MEV on HT-29 cells. Nuclei alterations were also observed during apoptosis following DAPI staining. Besides, atomic force microscopy (AFM) was used to detect alterations in morphology and ultrastructure of the cells at a nanoscale level. RESULTS: According to MTT and clonogenic assays, MEV caused a significant decrease in cell viability and proliferation of HT-29 cells while it did not have any impact on normal cells and the IC50 value was found to be 10 µg/ml. Induction of apoptosis was also confirmed by flowcytometric analysis in HT-29 cells. Moreover, the results indicated that MEV had led to a suppression of proliferation and induction of apoptosis through increased ROS and depolarization of mitochondria. Furthermore, AFM imaging demonstrated apoptosis cell death after being treated with MEV in HT-29 cells. CONCLUSION: This study showed that MEV had an antiproliferative effect on HT-29 cells by inducing apoptosis through the mitochondria signaling pathway. These findings suggested that MEV could be used as a promising natural remedy for cancer treatment.

Taurine effects on Bisphenol A-induced oxidative stress in the mouse testicular mitochondria and sperm motility.

OBJECTIVES: This study was performed to investigate the protective effects of taurine (2-aminoethanesulfonic acid, TAU) on oxidative stress in the isolated mouse testicular mitochondria, mitochondrial membrane potential (MMP), viability and motility of the exposed sperms to the BPA. METHODS: We treated epididymal spermatozoa obtained from mice and isolated mouse testicular mitochondria with BPA (0.8 mmol/mL) and various doses of TAU (5, 10, 30 and 50 µmol/L). We used the MTT assay and Rhodamine 123 uptake to assess sperm viability and MMP. We assessed the oxidative stress through measuring ROS (reactive oxygen species), MDA (malondialdehyde), GSH (glutathione), and SOD (super-oxide dismutase) levels in the testicular mitochondrial tissue. RESULTS: BPA significantly elevated ROS, MDA and MMP levels, and markedly reduced SOD and GSH levels in the isolated mitochondria. BPA also considerably impaired spermatozoa viability and motility. Pretreatment with 30 and 50 µmol/L of TAU could considerably suppressed mitochondrial oxidative stress, enhanced MMP, and improved sperm motility and viability. CONCLUSION: TAU may attenuate the BPA-induced mitochondrial toxicity and impaired sperm motility via decreasing oxidative stress.

Multi-walled carbon nanotubes induce oxidative stress, apoptosis, and dysfunction in isolated rat heart mitochondria: protective effect of naringin.

Multi-walled carbon nanotubes (MWCNTs) are material with exclusive features that can be applied in different fields including industrial and medicine. It has been determined that the accumulation of MWCNTs in the organs is along with genotoxic and cytotoxic injuries. Previous studies have shown mitochondrial dysfunction in MWCNTs exposure with cell lines, but their exact mechanisms with isolated mitochondria have remained unclear. The present study evaluated toxicity induced by MWCNTs in isolated rat heart mitochondria and protective effect of naringin. Our results showed that MWCNTs toxicity caused the prevention of heart mitochondrial complex II activity. Treatment of isolated heart mitochondria with MWCNTs led to an increase in mitochondrial reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) collapse, and mitochondrial malondialdehyde (MDA) and a decrease in mitochondrial glutathione (GSH) level and mitochondrial catalase (CAT) activity. Pretreatment of isolated heart mitochondria with naringin decreased mitochondrial oxidative damage through decreasing lipid peroxidation, returned mitochondrial complex II changes, decreasing MMP collapse and ROS production, and restoration of GSH level and CAT activity. Our findings indicated that MWCNTs had toxic effects on isolated heart mitochondria by inducing oxidative stress and possibly apoptosis pathway. The protection effects of naringin may be accompanied by mitochondrial conservation by its antioxidant property or due to its free radical scavenging. Our findings indicated that naringin had a possible role in preventing the mitochondria complaints in the heart.

Protective effect of naringin against BPA-induced cardiotoxicity through prevention of oxidative stress in male Wistar rats.

Bisphenol A (BPA), which is an applied endocrine disrupting chemical in industry for producing epoxy resins and polycarbonate plastics and naringin, is an active flavanone glycoside of grapefruit and many citrus fruits. The present study evaluated the protective effect of naringin against cardiotoxicity induced by BPA. Male Wistar rats were divided into six groups. Control group received oral olive oil; and BPA group orally were administrated 50 mg/kg of BPA for 30 d consecutively to induce toxicity. 40, 80, and 160 mg/kg of naringin were orally administered for 30 consecutive, along with BPA. Naringin group orally received 160 mg/kg of naringin for 30 d consecutively. Animals were sacrificed and their biochemical, histological, and oxidative stress parameters were measured 24 h after the last treatment. Heart injury was induced by BPA as an evidence with a significant increase in levels of aspartate aminotransferase, lactate dehydrogenase, creatine kinase-MB, triglyceride, lipid peroxidation, and a significant decrease in levels of glutathione, superoxide dismutase, catalase, and glutathione peroxidase and triggered myocardial disorganization, myofibrillar loss, congestion of red blood cells, and the inflammation. However, there were not any changes in the total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and alanine aminotransferase. Moreover, our results indicated that administering 80 and 160 mg/kg of naringin significantly altered all examined endpoints that were induced by BPA. Both concentrations of 80 and 160 mg/kg of naringin were more effective than 40 mg/kg. These findings indicated that naringin had a protective effect against cardiotoxicity induced by BPA through lipid-lowering properties, antioxidant activity, and suppressed lipid peroxidation.

Evaluation of the Protective Effects of Doxycycline on Acetaminophen-Induced Hepatotoxicity in Mice.

Acetaminophen (APAP) toxicity threatens human health due to increased mortality associated with its overdose. Doxycycline (DC) because of its properties such as antioxidant and anti-inflammatory can be a good therapeutic strategy to treat the acute toxicity induced by APAP. Male mice were divided into six groups in two periods of 3 h and 24 h as normal saline, APAP 400 mg/kg, DC 100 mg/kg and groups treated by 25, 50 and 100 mg/kg DC just before APAP, respectively. At the end of the 3 h and 24 h periods, the hepatic index, biochemical parameters including serum aspartate transaminase (AST) and alanine transaminase (ALT) activity and hepatic catalase activity, glutathione (GSH) and malondialdehyde (MDA) levels in liver and histopathological changes were evaluated. The results indicated that DC had no apparent effect on the hepatic index but significantly normalized the level of biochemical parameters and reduced APAP induced liver damage. Overall, it could be concluded that DC can inhibit or resolve harmful effects of APAP through antioxidant and anti-inflammatory properties. However, more studies are needed to understand exact mechanism of DC and its application for clinical use.

3-Bromopyruvate potentiates TRAIL-induced apoptosis in human colon cancer cells through a reactive oxygen species- and caspase-dependent mitochondrial pathway.

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a promising anticancer cytokine with minimal toxicity towards normal cells. Nevertheless, most primary cancers are often intrinsically TRAIL-resistant or can acquire resistance after TRAIL therapy. This study aimed to investigate the inhibitory effect of co-treatment of 3-bromopyruvate (3-BP) as a potent anticancer agent with TRAIL on colon cancer cells (HT-29). The results of present study indicated that combined treatment with 3-BP and TRAIL inhibited the proliferation of HT-29 cells to a greater extent (88.4%) compared with 3-BP (54%) or TRAIL (11%) treatment alone. In contrast, the combination of 3-BP and TRAIL had no significant inhibitory effect on the proliferation of normal cells (HEK-293) (8.4%). At a cellular mechanistic level, the present study showed that 3-BP sensitized human colon cancer cells to TRAIL-induced apoptosis via reactive oxygen species generation, upregulation of Bax, downregulation of Bcl-2 and survivin, release of cytochrome c into the cytosol, and activation of caspase-3. In normal cells, 3-BP, TRAIL, or combination of both had no significant effect on the reactive oxygen species levels, release of cytochrome c, and caspase-3 activity. Therefore, the combination of 3-BP and TRAIL can be a promising therapeutic strategy for treatment of colon cancer.

High fat diet deteriorates the memory impairment induced by arsenic in mice: a sub chronic in vivo study.

Both arsenic (As) and obesity are associated with brain disorders. However, long term studies to evaluate their concomitant adverse effects on the brain functions are lacking. Present study was conducted to evaluate the long term co-exposure of As and high fat diet (HFD) on memory and brain mitochondrial function in mice. Male mice were randomly divided into 7 groups fed with HFD or ordinary diet (OD) and instantaneously exposed to As (25 or 50 ppm) in drinking water for, 4, 8, 12, 16 or 20 weeks. Step-down passive avoidance method was used for memory assessment and post exposure various parameters including mitochondrial damage, level of reactive oxygen species (ROS), malondialdeid (MDA) and glutathione (GSH) were determined. Results indicated that the retention latency decreased in As (25 and 50 ppm) and HFD received mice after 12 and 16 weeks respectively. Same results were observed at significantly shorter duration (8th week) when As was administered along with HFD as compared to control group. In the HFD alone fed mice increased the mitochondrial membrane damage, levels of ROS and MDA were observed while GSH contents decreased significantly. Concomitant administration of HFD and As amplified those mentioned toxic effects (p < 0.001). In conclusion, our findings demonstrated that the simultaneous HFD and As impaired memory at least three times more than exposing each one alone. These toxic effects could be due to the mitochondria originated oxidative stress along with the depleted antioxidant capacity of the brain of mice.

Single-walled and multiwalled carbon nanotubes induce oxidative stress in isolated rat brain mitochondria.

Single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) are broadly applicable across a variety of industrial fields. Despite their usefulness in many different applications, oxidative stress-induced toxicity of SWCNTs and MWCNTs has not been widely investigated. The present study examined the effects of SWCNTs and MWCNTs on rat brain mitochondria using the 3,4 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and indices of reactive oxygen species (ROS), based on measurements of malondialdehyde (MDA), glutathione (GSH), and mitochondrial membrane potential. Based on the MTT assay, exposure to SWCNTs and MWCNTs decreased mitochondrial survival and viability in a dose-dependent manner. Findings also indicated that MWCNTs and SWCNTs could damage mitochondrial membranes and induce the formation of ROS, as indicated by increased levels of MDA and decreased GSH content. The results of this study suggest that SWCNTs and MWCNTs likely damage brain tissue mitochondria by increasing oxidative stress and possibly activating the apoptosis pathway as well as other pathways of cytotoxicity.

Efficiency of naringin against reproductive toxicity and testicular damages induced by bisphenol A in rats.

OBJECTIVES: Bisphenol A (BPA) as a synthetic compound is applied in many plastic industries. BPA has been reported to have endocrine-disrupting feature with cytotoxic effects. The study aimed to evaluate the efficiency of Naringin against testicular toxicity induced by BPA in adult rats. MATERIALS AND METHODS: The animals were assigned into six groups of control, BPA-treated (50 mg/kg), BPA+Naringin-administrated (40, 80, 160 mg/kg) and Naringin-treated (160 mg/kg) for 30 days. At the end of experiments, testicular weight, total testicular protein, epididymal sperm count, testicular enzymes, serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone and estradiol, testicular enzymatic and non-enzymatic antioxidants and histopathology of testis tissue were evaluated by their own methods. RESULTS: The results showed a reduction in testicular weight, total testicular protein, epididymal sperm count, testicular enzymes (alkaline phosphatase and lactate dehydrogenase) and decrease in the serum TSH, LH, testosterone and estradiol in BPA-administrated rats. Furthermore, BPA reduced the enzyme activities of glutathione peroxidase, superoxide dismutase, and catalase in testis tissue. Also, BPA caused an induction in lipid peroxidation and increase in reactive oxygen species levels, whereas it decreased the glutathione content of testis tissue. Histological findings exhibited seminiferous tubules vacuoles, atrophy and separation of the germinal epithelium in BPA-administrated rats. Oral administration of Naringin along with BPA normalized the biochemical, morphological and histological changes and reduced the testicular toxic condition. CONCLUSION: These results demonstrated that Naringin significantly managed male reproductive toxicity by antioxidant capabilities, preventing morphological modifications and escalating defense mechanism, thereby reducing oxidative stress from BPA-induced damage.

Protective Effect of Naringin on Bisphenol A-Induced Cognitive Dysfunction and Oxidative Damage in Rats.

Bisphenol A (BPA) is one of the highest volume chemicals produced worldwide, which is used in many plastic industries. The present study aimed to evaluate the effect of BPA on cognitive functions and oxidative stress, and determine whether the naringin (NG) co-administration can modify the effect of this compound on cognitive functions and inhibit any possible oxidative stress in the brain tissue of rats. Adult male Wistar rats were divided into six groups. Group I: control, Group II: BPA-treated rats (50 mg/kg/day), Group III, IV, V: BPA+NG (40, 80, 160 mg/kg/day), Group VI: NG (160 mg/kg/day) alone. Cognitive functions were evaluated using step-down latency (SDL) on a passive avoidance apparatus, and transfer latency (TL) in elevated plus-maze. A significant decrease in SDL, prolongation of TL, noticeable oxidative impairment and increase in acetylcholinesterase activity were observed in the BPA-treated in comparison with the control group. Also, the co-administration of NG (160 mg/kg) antagonized the effect of BPA on SDL and TL, attenuated oxidative damage by lowering malondialdehyde and nitrite concentrations and restored superoxide dismutase, catalase, and glutathione S-transferase activities. On the other hand, acetylcholinesterase activity was reduced in the groups co-administred with NG (80 or 160 mg/kg) and BPA in comparison with the BPA alone-treated group. The present study highlighted the therapeutic potential of NG against BPA-induced cognitive impairment and oxidative damage.

Protective Effect of Gemfibrozil on Hepatotoxicity Induced by Acetaminophen in Mice: the Importance of Oxidative Stress Suppression.

Purpose: Gemfibrozil (GEM) apart from agonist activity at peroxisome proliferator-activated receptor-alpha (PPAR-α) has antioxidant and anti-inflammatory properties. Accordingly, the present study was designed to investigate the protective effect of GEM on acute liver toxicity induced by acetaminophen (APAP) in mice. Methods: In this study, mice divided in seven groups include, control group, APAP group, GEM group, three APAP groups pretreated with GEM at the doses of 25, 50 and 100 mg/kg respectively and APAP group pretreated with N-Acetyl cysteine. GEM, NAC or vehicle were administered for 10 days. In last day, GEM and NAC were gavaged 1 h before and 1 h after APAP injection. Twenty four hours after APAP, mice were sacrificed. Serum parameters include alanine aminotransferase (ALT), aspartate aminotransferase (AST) and liver tissue markers including catalase enzyme activity, reactive oxygen species (ROS), malondialdehyde and reduced glutathione (GSH) levels determined and histopathological parameters measured. Results: GEM led to significant decrease in serum ALT and AST activities and increase in catalase activity and hepatic GSH level and reduces malondialdehyde and ROS levels in the liver tissue. In confirmation, histopathological findings revealed that GEM decrease degeneration, vacuolation and necrosis of hepatocytes and infiltration of inflammatory cells. Conclusion: Present data demonstrated that GEM has antioxidant properties and can protect the liver from APAP toxicity, just in the same pathway that toxicity occurs by toxic ROS and that GEM may be an alternative therapeutic agent to NAC in APAP toxicity.

Protective effects of zingerone on oxidative stress and inflammation in cisplatin-induced rat nephrotoxicity.

Cisplatin is one of the most commonly used and highly effective cancer chemotherapeutic agents. Use of cisplatin is limited due to persistence of severe side effects such as nephrotoxicity, neurotoxicity, and hearing loss. Nephrotoxicity is the most common limiting side effect of cisplatin use. Zingerone is one of the active ingredients present in ginger plant that has anti-inflammatory and antioxidant effects. In this study, Wistar rats were assigned randomly to 6 groups with 5 animals in each group. The control group; cisplatin group which received 7.5 mg/kg of cisplatin intraperitoneally (i.p.) at the 4th day; zingerone group received 50 mg/kg of zingerone orally for 7 days. Three other groups were pretreated with 10, 20, and 50 mg/kg of zingerone orally for 7 days and cisplatin administered 7.5 mg/kg i.p. at the 4th day, respectively. The animals were sacrificed 72 h after cisplatin injection and blood samples were taken to evaluate the serum factors. Right kidneys were collected for histopathological studies and left kidneys were considered to measure the oxidative stress parameters and TNF-α cytokine. Co-administration of zingerone along with cisplatin resulted a statistically significant reduction in lactate dehydrogenase (LDH) activity, creatinine and BUN levels of serum in comparison with cisplatin alone group (P < 0.01). Zingerone significantly decreased the tissue levels of malondialdehyde (MDA) (P < 0.05) and significantly retained the enzyme activity of catalase (CAT) (P < 0.05) and glutathione peroxidase (GPX) (P < 0.05) in kidney tissue compared to cisplatin. Zingerone did not permit the reduction of glutathione (GSH) levels (P < 0.001) in kidney tissue and by reducing the level of tumor necrosis factor (TNF)-α (P < 0.05) suppressed the inflammation produced by cisplatin. Furthermore, zingerone improved histopathological changes such as vacuolation (fat deposit), brush border loss, infiltration of leukocytes, glomerular diameters and congestion of RBCs. However, our findings suggest that zingerone has nephroprotective effects in cisplatin rat model of nephrotoxicity mostly through suppression of oxidative stress and inflammation.

Betaine protects mice against acetaminophen hepatotoxicity possibly via mitochondrial complex II and glutathione availability.

Overdose of acetaminophen (APAP) is a common cause of acute liver failure. Oxidative stress and mitochondrial dysfunction are related to APAP-induced hepatotoxicity. This study investigated the protective role of betaine as a methyl donor and S-adenosylmethionine precursor against APAP hepatotoxicity in isolated mice liver mitochondria. We treated male NMRC mice with 125, 250, 500, and 1000 mg/kg betaine for 5 days followed by 300 mg/kg APAP 1 h later. At 24 h after APAP administration, animals were sacrificed and liver mitochondria were isolated by different centrifugation methods. Biochemical, histological and immunohistochemical analyses were then conducted. Pretreatment of mice with 250, 500, and 1000 mg/kg betaine ameliorated hepatotoxicity (serum ALT and AST activity and histopathology finding); reversed mitochondrial complex II activity, glutathione level, superoxide dismutase, glutathione peroxidase and catalase activity, glutamate cysteine ligase catalytic protein expression, and mitochondrial membrane potential; and suppressed mitochondrial lipid peroxidation and reactive oxygen species. A contradictory effect was observed in mice treated with APAP. Betaine (500 mg/kg) was chosen as the most effective dose to rescue APAP hepatotoxicity in mice. These findings confirmed that betaine plays a protective role against APAP hepatotoxicity via protecting mitochondrial complex II and regenerating mitochondrial GSH levels by increasing GCLC expression. Betaine displayed antioxidant actions different from other antioxidants via modifying cysteine supply in the transsulfuration pathway in the liver. These findings suggested the potential of betaine as an alternative agent for the treatment of hepatotoxicity induced by APAP.

Chronic exposure to arsenic and high fat diet additively induced cardiotoxicity in male mice.

Diet is one of the important risk factors that could potentially affect arsenic-induced cardiotoxicity. The present study was undertaken to investigate the effect of high fat diet on arsenic-induced cardiotoxicity in mice. Mice were divided into six different groups (n = 12), two control groups received either low fat diet (LFD) or high fat diet (HFD) along with deionized drinking water and four test groups given LFD + 25 ppm arsenic, LFD + 50 ppm arsenic, HFD + 25 ppm arsenic, and HFD + 50 ppm arsenic in drinking water for 5 months. The body weight, heart weight to body weight ratio, cardiac biochemical markers, lipid profile, and histological examination of heart were evaluated. The results demonstrated that arsenic exposure led to a significant decrease in heart glutathione level, catalase enzyme activity, and a significant increase in reactive oxygen species (ROS), malondialdehyde levels, and biochemical enzymes. The administration of HFD resulted in above-mentioned changes as well as an alteration in lipid profile; however, arsenic exposure alone or along with HFD caused a reduction in lipid profile factors, except HDL level. Our results revealed that HFD increased arsenic-induced heart injury in the mice. This effect may be because of reduction in antioxidant activities and/or increase in oxidative stress and ROS in mice heart tissues. These findings could be important for clinical intervention to protect against or prevent arsenic-induced cardiotoxicity in humans.

Effects of Combined Exposure to Chronic High-Fat Diet and Arsenic on Thyroid Function and Lipid Profile in Male Mouse.

The thyroid is one of the major endocrine glands that contribute to body and fat metabolism. The present study evaluated the effects of combined exposure to chronic high-fat diet (HFD) and arsenic on thyroid function and lipid profile. In this experimental study, 72 male Naval Medical Research Institute mice were divided into six groups and fed HFD or low-fat diet (LFD) while being exposed to 25 or 50 ppm of arsenic in drinking water for 20 weeks. After 24 h of the last experimental day, blood samples were collected for hormonal and biochemical measurements. The data indicated that exposure to HFD alone increased the levels of triiodothyronine (T3), thyroid-stimulating hormone (TSH), leptin, lipid profile, reactive oxygen species (ROS), and malondialdehyde (MDA) and decreased the levels of high-density lipoprotein, albumin, adiponectin, and glutathione sulfhydryl reductase (GSH), whereas exposure to arsenic alone decreased the levels of T3 and GSH and increased the levels of TSH, leptin, ROS, MDA, and T4/T3 ratio compared to those in the control LFD group. Furthermore, concomitant administration of HFD and arsenic decreased the lipid profile and levels of T4, albumin, total protein, T3, and GSH and increased the levels of TSH, adiponectin, leptin, ROS, MDA, and T4/T3 ratio compared to those in the control LFD or HFD group. In conclusion, combined exposure to HFD and arsenic induced hypothyroidism via reduction of thyroid hormones and enhancement of plasma TSH and T3 uptake levels concomitant with hypolipidemia, hyperleptinemia, hyperadiponectinemia, induction of oxidative stress, and reduction of GSH levels.

Protective effect of metformin on toxicity of butyric acid and arsenic in isolated liver mitochondria and langerhans islets in male mice: an in vitro study.

OBJECTIVES: Arsenic, a toxic metal in drinking water and butyric acid (BA) is a free fatty acid found in many foods. These two can induce oxidative stress in some tissues. The present study investigated the protective effect of metformin against toxicity induced by Arsenic (As) and BA in isolated mice liver mitochondria and pancreatic islets. MATERIALS AND METHODS: In this study, liver mitochondria were isolated by adopting different centrifugation methods and pancreatic islets isolated by a collagenase method. Mitochondria were incubated by BA (75 µM), As (100 µM) and metformin (0, 0.5, 1, 3, 10 mM) and the islets also incubated by BA (1000 µM), As (100 µM) and metformin (0, 1, 3, 10 mM) for 1 hr. At the end of study, mitochondrial viability (MTT), mitochondrial membrane potential (MMP), reactive oxygen species (ROS), malondial- dehyde (MDA), glutathione (GSH) and islets insulin secretion were measured employing specific relevant methods. RESULTS: As and BA significantly increased ROS, MDA and ΔΨm levels and decreased GSH level, succinate dehydrogenase activity and insulin secretion. On the other hand, pretreatment with metformin, returned mitochondrial complex II activity, reduced ROS, MDA and ΔΨm levels and increased GSH level and insulin secretion of pancreatic islets. CONCLUSION: As and BA in combination or in isolation induce oxidative stress in liver mitochondria and decrease insulin secretion of pancreatic islets. Metformin has a protective effect probably caused by its antioxidant feature. The findings suggest the potential role of metformin in mitochondria therapy and insulin secretion in many diseases.

Gamma-tocopherol enhances apoptotic effects of lovastatin in human colorectal carcinoma cell line (HT29).

Recently, we found that lovastatin, a HMG-CoA reductase inhibitor, and gamma-tocopherol, one of the significant types of vitamin E in diet, additively induced apoptosis in a colorectal carcinoma cell line. In this study we mechanistically monitored the loss of mitochondrial membrane potential, amount of cytosolic cytochrome c and caspase 3 activity after treatment by lovastatin and gamma-tocopherol. HT29 cells were treated with different doses of lovastatin and gamma-tocopherol for 48 and 72 h. Lovastatin and gamma-tocopherol in combination induced the release of cytochrome c, caspase 3 activation, and loss of mitochondrial membrane potential more significantly compared to their controls. Our data showed that lovastatin plus gamma tocopherol potently induced mitochondrial membrane potential collapse, cytochrome c release along with caspase 3 activation that reveals the importance of targeting programmed cell death signaling at different points of its signaling pathway for cancer therapy.