Involvement of mitochondrial/lysosomal toxic cross-talk in ecstasy induced liver toxicity under hyperthermic condition

Direct exposure with exogenous mitochondria reduce colistin-induced mitochondrial dysfunction and cellular damages in isolated rat renal proximal tubular cells

Kidney damage caused by colistin (polymyxin E) can bring about a decrease in creatinine clearance, potential proteinuria, cylindruria and oliguria in treated patients. It is therefore imperative to develop a new therapeutic strategy for reducing kidney damage after treatment with colistin. Mitochondrial damage is one of contributing factors in colistin-induced nephrotoxicity. Given the therapeutic benefits of mitochondrial transplantation by exogenous healthy mitochondria, we hypothesized that this strategy would be capable of ameliorating renal proximal tubular cells damage following exposure with colistin. For this purpose, we isolated rat renal proximal tubular cells (RPTCs) form kidney and exposed them with toxic concertation of colistin with/without rat healthy isolated mitochondria for 4 h. Cellular parameters such as lactate dehydrogenase (LDH), reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP), caspase 3 activation, lysosomal damage, glutathione and ATP content were measured. The results showed that administration of isolated mitochondria could improve colistin-induced nephrotoxicity and reduce mitochondrial dysfunction. Exogenous mitochondria reduced the activity of LDH, production of ROS, ATP and GSH depletion, loss of MMP, lysosomal damages and cell death. To the best of our knowledge, these results provide the first direct experimental evidence that direct exposure with exogenous mitochondria is capable of ameliorating cellular damage following treatment with colistin. These findings support that mitochondrial transplantation may be a promising therapeutic strategy for colistin-associated mitochondrial dysfunction in kidney cells.

Mitotherapy inhibits against tenofovir induced nephrotoxicity on rat renal proximal tubular cells

Tenofovir, as nucleotide reverse transcriptase inhibitors (NRTIs), is used to prevent and cure HIV/AIDS. Ample evidence confirmed that the nephrotoxicity of tenofovir has been linked to mitochondrial dysfunction. It seems that transplantation with healthy mitochondria instead of damaged mitochondria may be a beneficial approach to therapy. Therefore, it decided to investigate the impact of mitotherapy on tenofovir against renal proximal tubular cells (RPTCs) toxicity by measurement of oxidative stress and cytotoxicity biomarkers and restoring of mitochondrial function on isolated mitochondria. EC50 of tenofovir was achieved at 40 μM following 2 h incubation in Earle's solution (pH = 7.4; 37 °C). Freshly isolated mitochondria (80 μg/ml) were added to damage RPTCs affected by tenofovir in treated groups. One Way ANOVA analysis showed that healthy mitochondrial transplantation decreased oxidative stress biomarkers following tenofovir toxicity in RPTCs. Our data revealed that mitotherapy makes cell survival possible in RPTCs affected by tenofovir. In addition, it supposed that a novel and ideal strategy for the treatment of chemicals-induced nephrotoxicity.

Cold Atmospheric Plasma Versus Cisplatin Against Oral Squamous Cell Carcinoma: A Mitochondrial Targeting Study

Plasma therapy and the study of the effects of cold atmospheric plasma (CAP) on tissues and living cells have been considered by scientific researchers in recent years. CAP is used in the treatment of cancer, but its anti-cancer mechanism has not been fully studied. Therefore, we studied the toxicity effect of CAP by using argon as feed gas and the synergistic effects of CAP with cisplatin on tumor cells and mitochondria isolated from tumor legions of the rat model of oral squamous cell carcinoma (OSCC). For this reason, we determined the possible toxic alterations of CAP on mitochondrial upstream events and activation of caspase-3 as the key major downstream event of apoptosis. Also, the effects of cisplatin (10 µM) as a positive control and its synergistic effects with CAP (IC₅₀ concentration) were investigated. The results showed that CAP reduced mitochondrial dysfunction by reduction in succinate dehydrogenase (SDH) activity. Also, CAP in concentrations of 1200, 2400, and 4800 a.u. has been able to increase the level of reactive oxygen species (ROS), mitochondrial swelling, damage to the mitochondrial membrane, cytochrome c release, and activation of the final mediator of apoptosis (caspase-3) only in the OSCC group. CAP at 4800 a.u concentration had similar effects to cisplatin (10 µM). Synergistic effects between CAP (2400 a.u) and cisplatin (10 µM) have also been reported. Based on all results CAP showed positive and promising results on mitochondrial upstream parameters leading to activation of caspase-3, the final mediator of apoptosis only on OSCC cells and mitochondria without any significant effect on normal cells and mitochondria.

A review on the mitochondrial toxicity of "ecstasy" (3,4-methylenedioxymethamphetamine, MDMA)

3,4-Methylenedioxymethamphetamine (MDMA or "ecstasy") is a drug of abuse used by millions worldwide. MDMA human abuse and dependence is well described, but addictive properties are not always consistent among studies. This amphetamine is a substrate type releaser, binding to monoamine transporters, leading to a pronounced release of serotonin and noradrenaline and to a minor extent dopamine. The toxicity of MDMA is well studied at the pre-clinical level, with neurotoxicity and hepatotoxicity being particularly described. In this review, we describe the most relevant MDMA effects at the mitochondrial level found in in vitro and in vivo models, these later conducted in mice and rats. Most of these reports focus on the mitochondria of brain or liver. In in vitro models, MDMA causes depletion of ATP levels and inhibition of mitochondrial complex I and III, loss in mitochondrial membrane potential (ΔΨm) and induction of mitochondrial permeability transition. The involvement of mitochondria in the apoptotic cell death evoked by MDMA has also been shown, such as the release of cytochrome c. Additionally, MDMA or its metabolites impaired mitochondrial trafficking and increased the fragmentation of axonal mitochondria. In animal studies, MDMA decreased mitochondrial complex I activity and decreased ATP levels. Moreover, MDMA-evoked oxidative stress has been shown to cause deletion on mitochondrial DNA and impairment in mitochondrial protein synthesis. Although the concentrations and doses used in some studies do not always correlate to the human scenario, the mitochondrial abnormalities evoked by MDMA are well described and are in part responsible for its mechanism of toxicity.

Luteolin attenuates Fipronil-induced neurotoxicity through reduction of the ROS-mediated oxidative stress in rat brain mitochondria

Luteolin (LUT) as a natural compound found in vegetables and fruits has various pharmacological effects. Fipronil (FPN), as a pesticide, has been considered for its effect on the antioxidant system and induction of oxidative stress. This study was designed to investigate the protective effects of LUT against the oxidative stress and mitochondrial toxicity induced by FPN on the rat brain. Several parameters such as mitochondrial reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP) collapse, mitochondrial swelling, cytochrome c release, mitochondrial glutathione (GSH), lipid peroxidation (LPO) and Adenosine triphosphate (ATP) levels were assessed. Results indicated that the administration of LUT (25 μM) significantly improved oxidative stress and mitochondrial damages induced via FPN (6, 12 and 24 μM) in isolated mitochondria from the brain. These results show that LUT exerted protective effects against FPN-induced neurotoxicity in vitro through improving oxidative stress and mitochondrial damages.

Bucladesine Attenuates Spatial Learning and Hippocampal Mitochondrial Impairments Induced by 3, 4-Methylenedioxymethamphetamine (MDMA)

Neurotoxic effects of systemic administration of 3, 4- methylenedioxymethamphetamine (MDMA) has been attributed to MDMA and its metabolites. However, the role of the parent compound in MDMA-induced mitochondrial and memory impairment has not yet been investigated. Moreover, it is not yet studied that analogs of 3', 5'-cyclic adenosine monophosphate (cAMP) could decrease these neurotoxic effects of MDMA. We wished to investigate the effects of the central administration of MDMA on spatial memory and mitochondrial function as well as the effects of bucladesine, a membrane-permeable analog of cAMP, on these effects of MDMA. We assessed the effects of pre-training bilateral intrahippocampal infusion of MDMA (0.01, 0.1, 0.5, and 1 μg/side), bucladesine (10 and 100 μM) or combination of them on spatial memory, and different parameters of hippocampal mitochondrial function including the level of reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), mitochondrial swelling, mitochondrial outer membrane damage, the amount of cytochrome c release as well as hippocampal ADP/ATP ratio. The results showed that MDMA caused spatial memory impairments as well as mitochondrial dysfunction as evidenced by the marked increase in hippocampal ADP/ATP ratio, ROS level, the collapse of MMP, mitochondrial swelling, and mitochondrial outer membrane damage leading to cytochrome c release from the mitochondria. The current study also found that bucladesine markedly reduced the destructive effects of MDMA. These results provide evidence of the role of the parent compound (MDMA) in MDMA-induced memory impairments through mitochondrial dysfunction. This study highlights the role of cAMP/PKA signaling in MDMA-induced memory and mitochondrial defects.

Liver-Metabolizing Genes and Their Relationship to the Performance of Elite Spanish Male Endurance Athletes; a Prospective Transversal Study

Background

The genetic profile that is needed to define an endurance athlete has been studied during recent years. The main objective of this work is to approach for the first time the study of genetic variants in liver-metabolizing genes and their role in endurance performance by comparing the allelic and genotypic frequencies in elite endurance athletes to the non-athlete population.

Methods

Genotypic and allelic frequencies were determined in 123 elite endurance athletes (75 professional road cyclists and 48 endurance elite runners) and 122 male non-athlete subjects (sedentary). Genotyping of cytochrome P450 family 2 subfamily D member 6 (CYP2D6 rs3892097), glutathione-S transferase mu isoform 1 (GSTM1), glutathione S-transferase pi (GSTP rs1695) and glutathione S-transferase theta (GSTT) genes was performed by polymerase chain reaction (PCR). The combination of the polymorphisms for the “optimal” polygenic profile has been quantified using the genotype score (GS).

Results

Statistical differences were found in the genetic distributions between elite endurance athletes and non-athletes in CYP2D6 (p < 0.001) and GSTT (p = 0.014) genes. The binary logistic regression model showed a favourable OR (odds ratio) of being an elite endurance runner against a professional road cyclist (OR: 2.403, 95% CI: 1.213–4.760 (p = 0.002)) in the polymorphisms studied.

Conclusions

Genotypic distribution of liver-metabolizing genes in elite endurance athletes is different to non-athlete subjects, with a favourable gene profile in elite endurance athletes in terms of detoxification capacity.

Analysis of apoptosis related genes in nurses exposed to anti-neoplastic drugs

BACKGROUND

Anti-neoplastic agents are widely used in the treatment of cancer and some non-neoplastic diseases. These drugs have been proved to be carcinogens, teratogens, and mutagens. Concern exists regarding the possible dangers of the staff handling anti-cancer drugs. The long-term exposure of nurses to anti-neoplastic drugs is still a controversial issue. The purpose of this study was to monitor cellular toxicity parameters and gene expression in nurses who work in chemotherapy wards and compare them to nurses who work in other wards.

METHODS

To analyze the apoptosis-related genes overexpression and cytotoxicity effects, peripheral blood lymphocytes obtained from oncology nurses and the control group.

THE RESULTS

Significant alterations in four analyzed apoptosis-related genes were observed in oncology nurses. In most individual samples being excavated, Bcl-2 overexpression is superior to that of Bax. Prominent P53 and Hif-1α up-regulation were observed in oncology nurses. Moreover, all cytotoxicity parameters (cell viability, ROS formation, MMP collapse, Lysosomal membrane damage, Lipid peroxidation, Caspase 3 activity and Apoptosis phenotype) in exposed oncology nurses were significantly (p < 0.001) higher than those of unexposed control nurses. Up-regulation of three analyzed apoptosis-related genes were observed in nurses occupationally exposed to anti-cancer drugs.

CONCLUSION

Our data show that oxidative stress and mitochondrial toxicity induced by anti-neoplastic drugs lead to overexpression of apoptosis-related genes in oncology nurses.

A comparison of mitochondrial toxicity of mephedrone on three separate parts of brain including hippocampus, cortex and cerebellum

Mephedrone (4-methylmethcathinone) is a new and popular drug of abuse and also widely available on the internet and still legal in some parts of the world. The central nervous system is the target of mephedrone and recent evidence suggested that mephedrone could affect mitochondria in brain tissue. However, the underlying mechanisms of mephedrone toxicity in brain mitochondria have not yet been well understood. In this study, mitochondria from three separate parts of rat brain hippocampus, cortex, and cerebellum were obtained using differential centrifugation and were incubated with different concentrations of mephedrone (3, 6 and 12 μM). Then, the mitochondrial parameters toxicity were determined. The results showed that mephedrone (3, 6 and 12 μM) induced impairment in the activity of the mitochondrial complex II and IV. Also, mephedrone (3, 6 and 12 μM) increased mitochondrial reactive oxygen species (ROS) level, collapsed mitochondria membrane potential (MMP), induced swelling in the mitochondria and damaged the mitochondrial outer membrane (MOM) in the mitochondria obtained from hippocampus, cortex, and cerebellum, which in all cases is associated with the cytochrome c release. Furthermore, increased disturbance in oxidative phosphorylation was also shown by the decrease in ATP level in mephedrone-treated mitochondria indicating mitochondrial dysfunction in separate parts of the brain. This study suggests that mephedrone via increasing oxidative stress and impairment of the mitochondrial respiratory chain in the hippocampus, cortex, and cerebellum may play a key role in the neurotoxicity.

Toxicity of Fe2 O3 nanoparticles on human blood lymphocytes

Magnetic nanoparticles (NPs) are used to a large extent in the targeted delivery of therapeutic agents. In this study, we aimed to investigate the possible toxicity of Fe₂ O ₃ NPs on human cells, including blood lymphocytes. We isolated blood lymphocytes from healthy humans using Ficoll polysaccharide and subsequently by gradient centrifugation. Then, the toxicity parameters, including cell viability, reactive oxygen species (ROS) formation, lipid peroxidation, cellular glutathione (GSH) level, mitochondrial and lysosomal damage, were measured in blood lymphocytes after exposure to Fe ₂ O ₃ NPs. Our results indicated that Fe ₂ O ₃ NPs significantly (dependent on concentration) reduced the cell viability, and the IC ₅₀ was determined to be 1 mM. With increasing concentrations, we found that Fe ₂ O ₃ NPs-induced cell toxicity was associated with a significant increase in intracellular ROS and loss of mitochondrial membrane potential and lysosomal membrane leakiness. Consequently, these NPs at different concentrations affect GSH level and cause oxidative stress in human lymphocytes.

Selective toxicity of persian gulf sea cucumber holothuria parva on human chronic lymphocytic leukemia b lymphocytes by direct mitochondrial targeting

Natural products isolated from marine environment are well known for their pharmacodynamic potential in diversity of disease treatments such as cancer or inflammatory conditions. Sea cucumbers are one of the marine animals of the phylum Echinoderm. Many studies have shown that the sea cucumber contains antioxidants and anti-cancer compounds. Chronic lymphocytic leukemia (CLL) is a disease characterized by the relentless accumulation of CD5⁺ B lymphocytes. CLL is the most common leukemia in adults, about 25-30% of all leukemias. In this study B lymphocytes and their mitochondria (cancerous and non-cancerous) were obtained from peripheral blood of human subjects and B lymphocyte cytotoxicity assay, and caspase 3 activation along with mitochondrial upstream events of apoptosis signaling including reactive oxygen species (ROS) production, collapse of mitochondrial membrane potential (MMP) and mitochondrial swelling were determined following the addition of Holothuria parva extract to both cancerous and non-cancerous B lymphocytes and their mitochondria. Our in vitro finding showed that mitochondrial ROS formation, MMP collapse, and mitochondrial swelling and cytochrome c release were significantly (P < 0.05) increased after addition of different concentrations of H. parva only in cancerous BUT NOT normal non-cancerous mitochondria. Consistently, different concentrations of H. parva significantly (P < 0.05) increased cytotoxicity and caspase 3 activation only in cancerous BUT NOT normal non-cancerous B lymphocytes. These results showed that H. parva methanolic extract has a selective mitochondria mediated apoptotic effect on chronic lymphocytic leukemia B lymphocytes hence may be promising in the future anticancer drug development for treatment of CLL. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1158-1169, 2017.

Selective Toxicity of Non Polar Bioactive Compounds of Persian Gulf Sea Squirt Phallusia Nigra on Skin Mitochondria Isolated from Rat Model of Melanoma

Background:

Skin cancer is the most prevalent cancer and one of the major causes of mortality worldwide. Marin animals have attracted much attention in recent years as useful substances having application in medicine. It was shown that Phallusia nigra (P. nigra) known as sea squirt could play an important role in cancer therapy.

Methods:

This study was designed to figure out the probable selective toxicity of n-hexane, diethyl ether, methanolic and aqueous extracts of P. nigra on cancerous mitochondria isolated from the skin of melanoma induced rats. In our study, mitochondria were isolated from the skin tissue of both melanoma induced and normal healthyrats. Different concentrations of four different extracts of P. nigra (250, 500 and 1000 µg/ml) were added to mitochondrial samples obtained from both groups, separately.

Results:

Our results showed that n-hexane, diethyl ether and methanolic extracts (but not aqueous extract) of P. nigra in all concentrations applied (250, 500 and 1000 µg/ml) significantly induced toxic alterations only in the cancerous but not normal healthy skin mitochondria including; increased reactive oxygen species (ROS) formation, mitochondrial swelling, decreased mitochondrial membrane potential (MMP) and cytochrome c release. Flow-cytometry analysis demonstrated that n-hexane, diethyl ether and methanolic extracts of P. nigra progressively induced apoptosis and necrosis only on melanoma cells but not healthy skin cells.

Conclusions:

Our results suggest that non polar bioactive compounds in P. nigra may be hopeful candidates for further studies including molecular identification, confirmatory in vivo experiments and finally clinical trials designed for new drug treatment of melanoma skin cancer.

Melatonin reverses H-89 induced spatial memory deficit: Involvement of oxidative stress and mitochondrial function

Oxidative stress and mitochondrial dysfunction play indispensable role in memory and learning impairment. Growing evidences have shed light on anti-oxidative role for melatonin in memory deficit. We have previously reported that inhibition of protein kinase A by H-89 can induce memory impairment. Here, we investigated the effect of melatonin on H-89 induced spatial memory deficit and pursued their interactive consequences on oxidative stress and mitochondrial function in Morris Water Maze model. Rats received melatonin (50 and 100μg/kg/side) and H-89(10μM) intra-hippocampally 30min before each day of training. Animals were trained for 4 consecutive days, each containing one block from four trials. Oxidative stress indices, including thiobarbituric acid (TBARS), reactive oxygen species (ROS), thiol groups, and ferric reducing antioxidant power (FRAP) were assessed using spectrophotometer. Mitochondrial function was evaluated through measuring ROS production, mitochondrial membrane potential (MMP), swelling, outer membrane damage, and cytochrome c release. As expected from our previous report, H-89 remarkably impaired memory by increasing the escape latency and traveled distance. Intriguingly, H-89 significantly augmented TBARS and ROS levels, caused mitochondrial ROS production, swelling, outer membrane damage, and cytochrome c release. Moreover, H-89 lowered thiol, FRAP, and MMP values. Intriguingly, melatonin pre-treatment not only effectively hampered H-89-mediated spatial memory deficit at both doses, but also reversed the H-89 effects on mitochondrial and biochemical indices upon higher dose. Collectively, these findings highlight a protective role for melatonin against H-89-induced memory impairment and indicate that melatonin may play a therapeutic role in the treatment of oxidative- related neurodegenerative disorders.

Protective effects of physical exercise on MDMA-induced cognitive and mitochondrial impairment

Debate continues about the effect of 3, 4-methylenedioxymethamphetamine (MDMA) on cognitive and mitochondrial function through the CNS. It has been shown that physical exercise has an important protective effect on cellular damage and death. Therefore, we investigated the effect of physical exercise on MDMA-induced impairments of spatial learning and memory as well as MDMA effects on brain mitochondrial function in rats. Male wistar rats underwent short-term (2 weeks) or long-term (4 weeks) treadmill exercise. After completion of exercise duration, acquisition and retention of spatial memory were evaluated by Morris water maze (MWM) test. Rats were intraperitoneally (I.P) injected with MDMA (5, 10, and 15mg/kg) 30min before the first training trial in 4 training days of MWM. Different parameters of brain mitochondrial function were measured including the level of ROS production, mitochondrial membrane potential (MMP), mitochondrial swelling, mitochondrial outermembrane damage, the amount of cytochrome c release from the mitochondria, and ADP/ATP ratio. MDMA damaged the spatial learning and memory in a dose-dependent manner. Brain mitochondria isolated from the rats treated with MDMA showed significant increase in ROS formation, collapse of MMP, mitochondrial swelling, and outer membrane damage, cytochrome c release from the mitochondria, and finally increased ADP/ATP ratio. This study also found that physical exercise significantly decreased the MDMA-induced impairments of spatial learning and memory and also mitochondrial dysfunction. The results indicated that MDMA-induced neurotoxicity leads to brain mitochondrial dysfunction and subsequent oxidative stress is followed by cognitive impairments. However, physical exercise could reduce these deleterious effects of MDMA through protective effects on brain mitochondrial function.

Toxicity of methyl tertiary-butyl ether on human blood lymphocytes

Methyl tertiary-butyl ether (MTBE) is a synthetic solvent widely used as oxygenate in unleaded gasoline. Few studies have addressed the cellular toxicity of MTBE on some cell lines, and so far, no comprehensive study has been conducted to investigate the probable immunotoxicity of this compound. In this study, the toxicity of MTBE on human blood lymphocytes was evaluated. Blood lymphocytes were isolated from healthy male volunteers' blood, using Ficoll polysaccharide followed by gradient centrifugation. Cell viability, reactive oxygen species (ROS) formation, lipid peroxidation, glutathione levels, and damage to mitochondria and lysosome were determined in blood lymphocytes after 6-h incubation with different concentrations of MTBE (0.1, 0.5, 1, and 2 mM). Our results showed that MTBE, in particular, decreased cell viability, which was associated with significant increase at intracellular ROS level and toxic alterations in mitochondria and lysosomes in human blood lymphocytes. Moreover, it was shown that MTBE strongly provoked lipid peroxidation and also depleted glutathione level at higher concentrations. Interestingly, MTBE exhibited its cytotoxic effects at low concentrations that may resemble to its concentrations in human blood following occupational and environmental exposure. It is therefore concluded that MTBE was capable of inducing oxidative stress and damage to mitochondria and lysosomes in human lymphocytes at concentrations ranging from 5 to 40 μg/L, which may be present in human blood as a result of environmental exposure.

Selective Toxicity of Persian Gulf Sea Cucumber (Holothuria parva) and Sponge (Haliclona oculata) Methanolic Extracts on Liver Mitochondria Isolated from an Animal Model of Hepatocellular Carcinoma

BACKGROUND

Natural products isolated from marine environments are well known for their pharmacodynamic potential in diverse disease treatments, such as for cancer or inflammatory conditions. Sea cucumbers are marine animals of the phylum Echinoderm and the class Holothuroidea, with leathery skin and gelatinous bodies. Sponges are important components of Persian Gulf animal communities, and the marine sponges of the genus Haliclona have been known to display broad-spectrum biological activity. Many studies have shown that sea cucumbers and sponges contain antioxidants and anti-cancer compounds.

OBJECTIVES

This study was designed to determine the selective toxicity of Persian Gulf sea cucumber (Holothuria parva) and sponge (Haliclona oculata) methanolic extracts on liver mitochondria isolated from an animal model of hepatocellular carcinoma, as part of a national project that hopes to identify novel potential anticancer candidates among Iranian Persian Gulf flora and fauna.

MATERIALS AND METHODS

To induce hepatocarcinogenesis, rats were given diethylnitrosamine (DEN) injections (200 mg/kg i.p. by a single dose), and then the cancer was promoted with 2-acetylaminofluorene (2-AAF) (0.02 w/w) for two weeks. Histopathological evaluations were performed, and levels of liver injury markers and a specific liver cancer marker (alpha-fetoprotein), were determined for confirmation of hepatocellular carcinoma induction. Finally, mitochondria were isolated from cancerous and non-cancerous hepatocytes.

RESULTS

Our results showed that H. parva methanolic extracts (250, 500, and 1000 µg/mL) and H. oculata methanolic extracts (200, 400, and 800 µg/mL) increased reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP), mitochondrial swelling, and cytochrome c release in the mitochondria obtained from cancerous hepatocytes, but not in mitochondria obtained from non-cancerous liver hepatocytes. These extracts also induced caspase-3 activation, which is known as a final mediator of apoptosis, in the hepatocytes obtained only from cancerous, not non-cancerous, rat livers.

CONCLUSIONS

Our results suggest that H. parva and H. oculata may be promising therapeutic candidates for the treatment of HCC, following further confirmatory in vivo experiments and clinical trials.

The role of lysosomes in BDE 47-mediated activation of mitochondrial apoptotic pathway in HepG2 cells

Polybrominated diphenyl ethers (PBDEs) are a group of widely used flame retardants. The rising presence of PBDEs in human tissues has received considerable concerns with regard to potential health risks. While the mitochondrial-apoptotic pathway has been suggested in PBDEs-induced apoptosis, the role of lysosomes is yet to be understood. In the present study, HepG2 cells were exposed to BDE 47 at various concentrations and durations to establish the causal and temporal relationships among various cellular events, such as cell viability, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis, and expression of cytochrome C and caspase 3. The involvement of lysosomes was simultaneously studied by evaluating lysosomal membrane permeability (LMP) and changes in the expression of cathepsin B, a lysosome hydrolase. In addition, a cathepsin B inhibitor (10 μM CA-074) was used to determine the involvement of lysosomes and potential interactions between lysosomes and mitochondria. Our results showed that ROS production was an initial response of HepG2 to BDE 47 exposure, followed by a decreased MMP; a loss of MMP caused additional ROS generation which acted to induce LMP; an increased LMP resulted in a release of cathepsin B which aggravated the loss of MMP leading to release of cytochrome C and caspase 3 and subsequent apoptosis. Pretreatment with CA-074 did not abolish the initial ROS generation, however, all downstream events were dramatically alleviated. Taken together, our data indicate that lysosomes might be involved in BDE 47-mediated mitochondrial-apoptotic pathway in HepG2 cells, possibly through feedback interactions between mitochondria and lysosomes.

Attenuation of ecstasy-induced neurotoxicity by N-acetylcysteine

Exposure to 3, 4-methylenedioxymethamphetamine (MDMA) can lead to spatial memory impairments and hippocampal cell death. Numerous evidence indicates that the antioxidant N-acetylcysteine (NAC) exerts protective effects in the brain. The present study evaluates the effects of NAC on MDMA-induced neurotoxicity.

METHODS

We intraperitoneally injected 28 adult male Sprague-Dawley rats (200-250 g) with either 0, 10 mg/kg of MDMA, or 10 mg/kg of MDMA plus 100 mg/kg of NAC. Spatial memory was assessed with a Morris Water Maze (MWM). At the end of the study, rats' brains were removed to study the structure and ultrastructure of CA1, and measure Bcl-2 and Bax expressions in the hippocampus. In the MWM, NAC treatment significantly attenuated the MDMA-induced increase in distance traveled (p < 0.05) and escape latency (p < 0.001). The decreased time spent in the target quadrant in MDMA-treated animals was attenuated by NAC (p < 0.01). NAC significantly protected against MDMA-induced apoptosis and the up- and down-regulation of Bax and Bcl-2, respectively. These data have suggested that NAC could protect against behavioral changes and apoptosis in the hippocampus following administration of MDMA. NAC might be useful for the treatment of neurotoxicity in MDMA users.

The effects of ecstasy on liver function tests, blood glucose, and lipids profile of male rats

Background:

Ecstasy is used to improve mood and cordiality; however, based on some reports, it is neurotoxic to human users.

Objectives:

Because of the euphoria induced by MDMA (3,4-methylenedioxymethamphetamine) on the users, its consumption is increasing in almost all countries. This study was carried out to determine the effects of ecstasy administration in rats’ blood sugar, lipids profile, and liver function tests.

Materials and Methods:

The experiment was performed using 50 mature Wistar-Albino male rats. The rats were divided into five groups (n = 10). Sham control group (A), received tap water and ordinary rodent diet. The control (B) was administered saline but tests group C, D1, and D2 received single dose and multiple doses of MDMA, respectively. After experimental period, animals were deeply anesthetized by diethyl ether, sacrificed and the blood samples were collected for the evaluation of blood glucose, serum lipid and aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALK-P). Data were expressed as mean ± SD and statistical difference was considered significant at P < 0.05.

Results:

In C group, the values of blood sugar (193.8 ± 11.6 mg/dL), low density lipoprotein (LDL) (19.2 ± 7.9 mg/dL), and cholesterol (76.1 ± 10.6 mg/dL), were significantly increased compared with those of control A and B (135 ± 12.7), (140 ± 18.8), and (45.4 ± 9.8), (49.8 ± 2.1) (49.4 ± 10.6) groups. However, aspartate transaminase (AST) and alanine transaminase (ALT) were significantly increased in groups D1 (145.8 ± 14.7 U/L), (91.1 ± 8.1 U/L), and D2 (159.4 ± 13.8 U/L) and (75.4 ± 7.8) compared with those of group A (107.2 ± 8.1), (45.4 ± 9.8), B (79.8 ± 12.1), (49.8 ± 2.1), and C (115.6 ± 17.5), (52.1 ± 7.6 U/L). Cholesterol and LDL increased in groups C and D compared with group A.

Conclusions:

These results indicated that chronic administration of MDMA affects liver as well as lipoprotein profile in male rats. The exact mechanism of action needs further investigation.

Methamphetamine causes acute hyperthermia-dependent liver damage

Methamphetamine-induced neurotoxicity has been correlated with damage to the liver but this damage has not been extensively characterized. Moreover, the mechanism by which the drug contributes to liver damage is unknown. This study characterizes the hepatocellular toxicity of methamphetamine and examines if hyperthermia contributes to this liver damage. Livers from methamphetamine-treated rats were examined using electron microscopy and hematoxylin and eosin staining. Methamphetamine increased glycogen stores, mitochondrial aggregation, microvesicular lipid, and hydropic change. These changes were diffuse throughout the hepatic lobule, as evidenced by a lack of hematoxylin and eosin staining. To confirm if these changes were indicative of damage, serum aspartate and alanine aminotransferase were measured. The functional significance of methamphetamine-induced liver damage was also examined by measuring plasma ammonia. To examine the contribution of hyperthermia to this damage, methamphetamine-treated rats were cooled during and after drug treatment by cooling their external environment. Serum aspartate and alanine aminotransferase, as well as plasma ammonia were increased concurrently with these morphologic changes and were prevented when methamphetamine-induced hyperthermia was blocked. These findings support that methamphetamine produces changes in hepatocellular morphology and damage persisting for at least 24 h after drug exposure. At this same time point, methamphetamine treatment significantly increases plasma ammonia concentrations, consistent with impaired ammonia metabolism and functional liver damage. Methamphetamine-induced hyperthermia contributes significantly to the persistent liver damage and increases in peripheral ammonia produced by the drug.

Neurotoxicity of methamphetamine and 3,4-methylenedioxymethamphetamine

Amphetamines are a class of psychostimulant drugs that are widely abused for their stimulant, euphoric, empathogenic and hallucinogenic properties. Many of these effects result from acute increases in dopamine and serotonin neurotransmission. Subsequent to these acute effects, methamphetamine and 3,4 methylenedioxymethamphetamine (MDMA) produce persistent damage to dopamine and serotonin nerve terminals. This review summarizes the numerous interdependent mechanisms including excitotoxicity, mitochondrial damage and oxidative stress that have been demonstrated to contribute to this damage. Emerging non-neuronal mechanisms by which the drugs may contribute to monoaminergic terminal damage, as well as the neuropsychiatric consequences of this terminal damage are also presented. Methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) have similar chemical structures and pharmacologic properties compared to other abused substances including cathinone (khat), as well as a relatively new class of novel synthetic amphetamines known as 'bath salts' that have gained popularity among drug abusers.

Peripheral ammonia as a mediator of methamphetamine neurotoxicity

Ammonia is metabolized by the liver and has established neurological effects. The current study examined the possibility that ammonia contributes to the neurotoxic effects of methamphetamine (METH). The results show that a binge dosing regimen of METH to the rat increased plasma and brain ammonia concentrations that were paralleled by evidence of hepatotoxicity. The role of peripheral ammonia in the neurotoxic effects of METH was further substantiated by the demonstration that the enhancement of peripheral ammonia excretion blocked the increases in brain and plasma ammonia and attenuated the long-term depletions of dopamine and serotonin typically produced by METH. Conversely, the localized perfusion of ammonia in combination with METH, but not METH alone or ammonia alone, into the striatum recapitulated the neuronal damage produced by the systemic administration of METH. Furthermore, this damage produced by the local administration of ammonia and METH was blocked by the GYKI 52466 [4-(8-methyl-9H-1,3-dioxolo[4,5-h][2,3]benzodiazepin-5-yl)-benzamine hydrochloride], an AMPA receptor antagonist. These findings highlight the importance of ammonia derived from the periphery as a small-molecule mediator of METH neurotoxicity and more broadly emphasize the importance of peripheral organ damage as a possible mechanism that mediates the neuropathology produced by drugs of abuse and other neuroactive molecules.

The ugly side of amphetamines: short- and long-term toxicity of 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy'), methamphetamine and D-amphetamine

Amphetamine ('Speed'), methamphetamine ('Ice') and its congener 3,4-methylenedioxymethamphetamine (MDMA; 'Ecstasy') are illicit drugs abused worldwide for their euphoric and stimulant effects. Despite compelling evidence for chronic MDMA neurotoxicity in animal models, the physiological consequences of such toxicity in humans remain unclear. In addition, distinct differences in the metabolism and pharmacokinetics of MDMA between species and different strains of animals prevent the rationalisation of realistic human dose paradigms in animal studies. Here, we attempt to review amphetamine toxicity and in particular MDMA toxicity in the pathogenesis of exemplary human pathologies, independently of confounding environmental factors such as poly-drug use and drug purity.