Caffeic acid protects tissue antioxidants and DNA content in methamphetamine induced tissue toxicity in Sprague Dawley rats

Luteolin amends neural neurotransmitters, antioxidants, and inflammatory markers in the cerebral cortex of Adderall exposed rats

BACKGROUND

Adderall is a central nervous system stimulant while luteolin has neuroprotective activity. This study aimed to determine whether luteolin can amend neural neurotransmitters, antioxidants, and inflammatory markers in the cerebral cortex of Adderall exposed rats.

METHODS

Thirty-six male albino rats were divided into 6 equal groups, Control, Luteolin (1 g/kg)-treated, and Luteolin (2 g/kg)-treated groups: normal rats were orally administrated once a day with 2 ml distilled water, luteolin (1 g/kg), and luteolin (2 g/kg), respectively for 4 weeks. Adderall rats, Adderall rats + luteolin (1 g/kg)-treated, and Adderall rats + luteolin (2 g/kg)-treated groups: normal rats were orally administrated once a day with 10 mg/kg of Adderall, 3 days/week for 4 weeks, then these rats orally administrated daily once a day with 2 ml of distilled water, luteolin (1 g/kg), and luteolin (2 g/kg), respectively for another 4 weeks.

RESULTS AND CONCLUSION

Adderall decreased superoxide dismutase, glutathione peroxidase, catalase, NADPH oxidase, interleukin-10, serotonin, dopamine, norepinephrine, γ-aminobutyric acid, and acetylcoline estrase but increased malondialdehyde, conjugated dienes, oxidative index, tumour necrosis factor-α, interleukin-1β, and interleukin-6 levels in the cerebral cortex. Adderall increased the expression of glial fibrillary acidic protein, ionized calcium binding adaptor molecule 1, and anti-calbindin in the cerebral cortex of Adderall-treated rats. In Adderall-treated rats, daily oral administration of luteolin for 4 weeks brought all these parameters back to values that were close to control where higher dose was more effective than lower dose. The importance of this research is to provide natural compound that amends Adderall-related neural disturbances and this natural compound is cheap, avaliable without any side effect and it does not interfer with Adderall efficiency.

Linalool attenuates hypothalamus proteome disturbance facilitated by methamphetamine induced neurotoxicity in rats

BACKGROUND

One of the most powerful stimulants of the central nervous system is methamphetamine (METH). Linalool has a neuroprotective effect against ischemia injury by reducing oxidative stress and apoptosis. The present study investigated whether linalool can reverse the hypothalamus neurotoxicity and proteome disturbance in METH-treated rats.

BRIEF METHOD

A total of 36 male albino rats were split into two equal groups (normal and METH-treated). Three equal subgroups of normal rats were created; Control, Linalool (25 mg/kg), and Linalool (50 mg/kg); Normal rats were given daily oral doses of 1 ml of distilled water, 25 mg/kg linalool, and 50 mg/kg of linalool, respectively. METH groups were divided into 3 equal subgroups; METH-treated rats, Linalool (25 mg/kg)+METH-treated, and Linalool (50 mg/kg)+METH-treated subgroups; METH-treated rats received daily and oral doses of 1 ml distilled water, 25 mg/kg linalool, and 50 mg/kg of linalool, respectively.

RESULTS

According to the data obtained, METH caused a decrease of the sucrose preference test, travel distance test, and center square entries test, superoxide dismutase, glutathione peroxidase, catalase, NADPH oxidase, interleukin-10 but a rise in the center square duration test, tail suspension test, and forced swimming test, malondialdehyde, conjugated dienes, oxidative index, serotonin, dopamine, norepinephrine, γ-aminobutyric acid, tumour necrosis factor-α, interleukin-1β, interleukin-6 levels. When compared to the control group, rats treated with METH had lower sodium/potassium ATPase activity and missing of prothrombin, fibrinogen, and ceruloplasmin protein bands in the hypothalamus. In METH-treated rats, daily and oral co-administration with linalool brought all these parameters back to values that were close to control.

SIGNIFICANCE

According to obtained data, linalool could protect the hypothalamus against METH-induced neurotoxicity and proteome disturbance probably by modifying oxidative stress, neurotransmitters, inflammation, sodium/potassium-ATPase activity, proteome disturbance, and tissue histology in METH-treated rats where higher dose of linalool was more efficient than lower dose.

Nrf2 protects against methamphetamine-induced nephrotoxicity by mitigating oxidative stress and autophagy in mice

Methamphetamine (MA) is a widely abused drug that can cause kidney damage. However, the molecular mechanism remains unclear. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor that regulates resistance to oxidative and proteotoxic stress. In this study, we investigated the role of Nrf2 in MA-induced renal injury in mice. Nrf2 was pharmacologically activated and genetically knocked-out in mice. The animal model of MA-induced nephrotoxicity was established by injecting MA (2 mg/kg) intraperitoneally twice a day for 5 days. Histopathological alterations were shown in the MA-exposed kidneys. MA significantly increased renal function biomarkers and kidney injury molecule-1 (KIM-1) levels. MA decreased superoxide dismutase activity and increased malondialdehyde levels. Autophagy-related factors (LC3 and Beclin 1) were elevated in MA-treated mice. Furthermore, Nrf2 increased in the MA-exposed kidneys. Activation of Nrf2 may attenuate histopathological changes in the kidneys of MA-treated mice. Pre-administration of Nrf2 agonist significantly decreased KIM-1 expression, oxidative stress, and autophagy in the kidneys after MA toxicity. In contrast, Nrf2 knockout mice treated with MA lost renal tubular morphology. Nrf2 deficiency increased KIM-1 expression, oxidative stress, and autophagy in the MA-exposed kidneys. Our results demonstrate that Nrf2 may protect against MA-induced nephrotoxicity by mitigating oxidative stress and autophagy.

Methamphetamine-induced dopaminergic neurotoxicity as a model of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease with a high prevalence, approximately 1 % in the elderly population. Numerous studies have demonstrated that methamphetamine (MA) intoxication caused the neurological deficits and nigrostriatal damage seen in Parkinsonian conditions, and subsequent rodent studies have found that neurotoxic binge administration of MA reproduced PD-like features, in terms of its symptomatology and pathology. Several anti-Parkinsonian medications have been shown to attenuate the motor impairments and dopaminergic damage induced by MA. In addition, it has been recognized that mitochondrial dysfunction, oxidative stress, pro-apoptosis, proteasomal/autophagic impairment, and neuroinflammation play important roles in inducing MA neurotoxicity. Importantly, MA neurotoxicity has been shown to share a common mechanism of dopaminergic toxicity with that of PD pathogenesis. This review describes the major findings on the neuropathological features and underlying neurotoxic mechanisms induced by MA and compares them with Parkinsonian pathogenesis. Taken together, it is suggested that neurotoxic binge-type administration of MA in rodents is a valid animal model for PD that may provide knowledge on the neuropathogenesis of PD.

An Overview of Chemical and Biological Materials lead to Damage and Repair of Heart Tissue

BACKGROUND

Cardiovascular diseases (CVDs) are major causes of mortality in developing countries. One of the challenges during CVDs studies is the creation of a damaged model of the heart. Many injured models of cardiac diseases are created by using chemical and biological materials. Many approaches were applied to simulate heart injury for investigating CVDs. In previous years, animal models could be used as a useful pattern in many investigations about the pathogenesis of the heart. Nowadays it has been proven that there are many differences between human and animal models in terms of responses or reactions to treatments. For such reasons, researchers prefer to use cellular models alongside the animal models for studying heart diseases.

PURPOSE

In this review, we collected information about some chemical and biological materials used to create damaged-heart models both in vitro and in vivo. After explaining the materials that induce cardiac damage, we explicate some methods for repairing the damage of heart. Finally, the role of extracellular vesicles as an important biological candidate for repairing heart damage is briefly discussed.

CONCLUSION

This mini-review tried to explain some methods which can induce cardiac damage and repair of heart cells by use chemical and biological materials. We considered that various molecular pathways play a role in restoration and that most of these pathways are connected in a complex network and, to this end, different chemicals and drugs have been studied to date. Nonetheless, more studies are needed to ensure the performance and safety of the drugs and chemicals produced.

Glutathione peroxidase-1 and neuromodulation: Novel potentials of an old enzyme

Glutathione peroxidase (GPx) acts in co-ordination with other signaling molecules to exert its own antioxidant role. We have demonstrated the protective effects of GPx,/GPx-1, a selenium-dependent enzyme, on various neurodegenerative disorders (i.e., Parkinson's disease, Alzheimer's disease, cerebral ischemia, and convulsive disorders). In addition, we summarized the recent findings indicating that GPx-1 might play a role as a neuromodulator in neuropsychiatric conditions, such as, stress, bipolar disorder, schizophrenia, and drug intoxication. In this review, we attempted to highlight the mechanistic scenarios mediated by the GPx/GPx-1 gene in impacting these neurodegenerative and neuropsychiatric disorders, and hope to provide new insights on the therapeutic interventions against these disorders.

Caffeic acid attenuates gastric mucosal damage induced by ethanol in rats via nitric oxide modulation

Anti-oxidant and anti-inflammatory properties of caffeic acid (CA) have been reported recently. In this study, the therapeutic effects of CA on ethanol-induced ulcer and the roles of nitric oxide and cholinergic pathways in these effects were investigated. Ulcer was induced by ethanol via oral gavage. Ulcer induced rats were treated with either vehicle (ulcer group) or CA (100, 250 or 500 mg/kg, per oral gavage). Macroscopic evaluation showed that 250 mg/kg CA was the effective dose. To elucidate the action mechanism of CA, 10 mg/kg l-NAME or 1 mg/kg atropine sulfate was administered to 250 mg/kg CA treated groups. All rats were decapitated 1 h after ulcer induction and gastric samples were scored macroscopically and microscopically, and analyzed for myeloperoxidase (MPO), malondialdehyde (MDA), and glutathione (GSH) levels. ANOVA test was used for statistical analyses. Macroscopic and microscopic damage scores, MDA levels and MPO activity were increased while GSH levels were decreased in ulcer group. Treatment with 250 mg/kg and 500 mg/kg CA reduced macroscopic and microscopic damage scores, decreased MPO activity and MDA levels, and preserved the depleted glutathione significantly. l-NAME administration before CA treatment elevated MDA levels, MPO activity and depleted glutathione. However, atropine sulfate had no effect on biochemical parameters. We conclude that CA ameliorates ethanol-induced gastric mucosal damage, and NO pathway contributes to this effect. On the other hand, there is a lack of evidence for the contribution of the muscarinic cholinergic system.

Methamphetamine exposure modulated oxidative status and altered the reproductive output in Daphnia magna

Methamphetamine (METH) is a central nervous system stimulant drug whose use has increased in the last few years worldwide. After the ingestion of even a single dose, METH is excreted by the organism and enters the aquatic ecosystems, whereby concentrations up to hundreds of ng/L were measured in both sewage and surface waters. Although the environmental concentrations are currently quite low, the high biological activity of METH might cause adverse effects towards non-target organisms. However, to date the information on METH toxicity towards aquatic organisms is limited. Thus, the present study aimed at investigating biochemical and behavioral effects induced by METH exposure towards the Cladoceran Daphnia magna. A 21-days exposure to two environmental concentrations of METH (50 ng/L and 500 ng/L) was performed. At selected time points (7, 14 and 21 days) the amount of pro-oxidant molecules, the activity of antioxidant enzymes (SOD, CAT, GPx) and levels of lipid peroxidation (LPO) were measured as oxidative stress-related endpoints. Changes in swimming activity and reproductive output were assessed as behavioral endpoints. METH exposure affected the oxidative status of D. magna specimens at both tested concentrations, although no oxidative damage occurred. Although METH did not modulate the swimming activity of D. magna, a significant, positive effect on reproductive output, in terms of number of offspring was found. Our results showed that low concentrations of METH might represent a threat for D. magna, affecting the health status of this aquatic species at different level of biological organization.

Epigallocatechin Gallate Mitigates the Methamphetamine-Induced Striatal Dopamine Terminal Toxicity by Preventing Oxidative Stress in the Mouse Brain

Methamphetamine (METH) is a popular psychostimulant due to its long-lasting effects and inexpensive production. METH intoxication is known to increase oxidative stress leading to neuronal damage. Thus, preventing the METH-induced oxidative stress can potentially mitigate neuronal damage. Previously, our laboratory found that epigallocatechin gallate (EGCG), a strong antioxidant found in green tea, can protect against the METH-induced apoptosis and dopamine terminal toxicity in the striatum of mice. In the present study, we evaluated the anti-oxidative properties of EGCG on the METH-induced oxidative stress using CD-1 mice. First, we demonstrated that mice pretreated with EGCG 30 min prior to the METH injection (30 mg/kg, ip) showed protection against the striatal METH-induced reduction of tyrosine hydroxylase without mitigating hyperthermia. In addition, injecting a single high dose of METH caused the reduction of striatal glutathione peroxidase activity at 24 h after the METH injection. Interestingly, pretreatment with EGCG 30 min prior to the METH injection prevented the METH-induced reduction of glutathione peroxidase activity. Moreover, we utilized Western blots to quantify the glutathione peroxidase 4 protein level in the striatum. The results showed that METH decreased striatal glutathione peroxidase 4 protein level, and the reduction was prevented by EGCG pretreatment. Finally, we observed that the METH-induced increase of striatal catalase and copper/zinc superoxide dismutase protein levels were also attenuated by pretreatment with EGCG. Taken together, our data indicate that EGCG is an effective agent that can be used to mitigate the METH-induced striatal toxicity in the mouse brain.

Role of Mitochondria in Methamphetamine-Induced Dopaminergic Neurotoxicity: Involvement in Oxidative Stress, Neuroinflammation, and Pro-apoptosis-A Review

Methamphetamine (MA), an amphetamine-type psychostimulant, is associated with dopaminergic toxicity and has a high abuse potential. Numerous in vivo and in vitro studies have suggested that impaired mitochondria are critical in dopaminergic toxicity induced by MA. Mitochondria are important energy-producing organelles with dynamic nature. Evidence indicated that exposure to MA can disturb mitochondrial energetic metabolism by inhibiting the Krebs cycle and electron transport chain. Alterations in mitochondrial dynamic processes, including mitochondrial biogenesis, mitophagy, and fusion/fission, have recently been shown to contribute to dopaminergic toxicity induced by MA. Furthermore, it was demonstrated that MA-induced mitochondrial impairment enhances susceptibility to oxidative stress, pro-apoptosis, and neuroinflammation in a positive feedback loop. Protein kinase Cδ has emerged as a potential mediator between mitochondrial impairment and oxidative stress, pro-apoptosis, or neuroinflammation in MA neurotoxicity. Understanding the role and underlying mechanism of mitochondrial impairment could provide a molecular target to prevent or alleviate dopaminergic toxicity induced by MA.

The Role of Oxidative Stress in Methamphetamine-induced Toxicity and Sources of Variation in the Design of Animal Studies

BACKGROUND

The prevalence of methamphetamine (MA) use has increased in recent years. In order to assess how this drug produces its effects, both clinical and preclinical studies have recently begun to focus on oxidative stress as an important biochemical mechanism in mediating these effects.

OBJECTIVE

The purpose of this review is to illustrate the variation in the design of preclinical studies investigating MA exposure on oxidative stress parameters in animal models.

METHOD

The experimental variables investigated and summarised include MA drug treatment, measurements of oxidative stress and antioxidant treatments that ameliorate the harmful effects of MA.

RESULTS

These preclinical studies differ greatly in their experimental design with respect to the dose of MA (ranging between 0.25 and 20 mg/kg), the dosing regime (acute, binge or chronic), the time of measurement of oxidative stress (0.5 h to 2 wks after last MA administration), the antioxidant system targeted and finally the use of antioxidants including the route of administration (i.p. or p.o.), the frequency of exposure and the time of exposure (preventative or therapeutic).

CONCLUSION

The findings in this paper suggest that there is a large diversity among these studies and so the interpretation of these results is challenging. For this reason, the development of guidelines and how best to assess oxidative stress in animal models may be beneficial. The use of these simple recommendations mean that results will be more comparable between laboratories and that future results generated will give us a greater understanding of the contribution of this important biochemical mechanism and its implications for the clinical scenario.

Behavioral and genotoxic evaluation of rosmarinic and caffeic acid in acute seizure models induced by pentylenetetrazole and pilocarpine in mice

The goal of this study was to investigate the effects of rosmarinic acid (RA) and caffeic acid (CA) in the acute pentylenetetrazole (PTZ) and pilocarpine (PIL) seizure models. We also evaluated the effect of RA and CA on the diazepam (DZP)-induced sleeping time test and its possible neuroprotective effect against the genotoxic damage induced by PTZ and PIL. Mice were treated intraperitoneally (i.p.) with saline, RA (2 or 4 mg/kg), or CA (4 or 8 mg/kg) alone or associated to low-dose DZP. After, mice received a single dose of PTZ (88 mg/kg) or PIL (250 mg/kg) and were monitored for the percentage of seizures and the latency to first seizure (LFS) >3 s. Vigabatrin and DZP were used as positive controls. In the DZP-induced sleeping time test, mice were treated with RA and CA and 30 min after receiving DZP (25 mg/kg, i.p.). The alkaline comet assay was performed after acute seizure tests to evaluate the antigenotoxic profiles of RA and CA. The doses of RA and CA tested alone did not reduce the occurrence of seizures induced by PTZ or PIL. The association of 4 mg/kg RA + low-dose DZP was shown to increase LFS in the PTZ model, compared to the group that received only the DZP. In the DZP-induced sleeping time test, the latency to sleep was reduced by 4 mg/kg RA and 8 mg/kg CA. The PTZ-induced genotoxic damage was not prevented by RA or CA, but the PIL-induced genotoxic damage was decreased by pretreatment with 4 mg/kg RA (in cortex) and 4 mg/kg CA (in hippocampus). In conclusion, RA and CA presented neuroprotective effect against PIL-induced genotoxic damage and reduced the latency to DZP-induced sleep. Of the rosmarinic acid, 4 mg/kg enhanced the DZP effect in the increase of latency to clonic PTZ-induced seizures.

The overexpression of Thioredoxin-1 suppressing inflammation induced by methamphetamine in spleen

BACKGROUND

Methamphetamine (METH) is an addictive psychostimulant and has been shown to induce oxidative stress and inflammation in various tissues. Thioredoxin-1 (Trx-1) plays the roles in regulating redox and inhibiting inflammation. Whether Trx-1 is involved in METH-induced inflammation is still unknown.

METHODS

The present study was designed to investigate inflammatory factors in spleen of wild type and Trx-1 overexpression transgenic mice after METH treatment.

RESULTS

We found the mRNA level of Trx-1 was decreased and mRNA level of Trx-1 binding protein-2 (TBP-2) was increased. The mRNA levels of tumor necrosis factor-α (TNF-α), interferon-γ(IFN-γ), interleukin-2 (IL-2), T-bet and signal transducer and activators of transcription 4 (STAT 4) were increased and the mRNA levels of IL-10, GA-TA-binding protein-3 (GATA-3) and STAT 6 were decreased. Overexpression of Trx-1 reversed the above effects induced by METH.

CONCLUSION

The present study showed for the first time that Trx-1 overexpression suppressed the inflammation induced by METH.

The cross-talk of HIV-1 Tat and methamphetamine in HIV-associated neurocognitive disorders

Antiretroviral therapy has dramatically improved the lives of human immunodeficiency virus 1 (HIV-1) infected individuals. Nonetheless, HIV-associated neurocognitive disorders (HAND), which range from undetectable neurocognitive impairments to severe dementia, still affect approximately 50% of the infected population, hampering their quality of life. The persistence of HAND is promoted by several factors, including longer life expectancies, the residual levels of virus in the central nervous system (CNS) and the continued presence of HIV-1 regulatory proteins such as the transactivator of transcription (Tat) in the brain. Tat is a secreted viral protein that crosses the blood–brain barrier into the CNS, where it has the ability to directly act on neurons and non-neuronal cells alike. These actions result in the release of soluble factors involved in inflammation, oxidative stress and excitotoxicity, ultimately resulting in neuronal damage. The percentage of methamphetamine (MA) abusers is high among the HIV-1-positive population compared to the general population. On the other hand, MA abuse is correlated with increased viral replication, enhanced Tat-mediated neurotoxicity and neurocognitive impairments. Although several strategies have been investigated to reduce HAND and MA use, no clinically approved treatment is currently available. Here, we review the latest findings of the effects of Tat and MA in HAND and discuss a few promising potential therapeutic developments.

Caffeic acid ethanolamide prevents cardiac dysfunction through sirtuin dependent cardiac bioenergetics preservation

BACKGROUND

Cardiac oxidative stress, bioenergetics and catecholamine play major roles in heart failure progression. However, the relationships between these three dominant heart failure factors are not fully elucidated. Caffeic acid ethanolamide (CAEA), a synthesized derivative from caffeic acid that exerted antioxidative properties, was thus applied in this study to explore its effects on the pathogenesis of heart failure.

RESULTS

In vitro studies in HL-1 cells exposed to isoproterenol showed an increase in cellular and mitochondria oxidative stress. Two-week isoproterenol injections into mice resulted in ventricular hypertrophy, myocardial fibrosis, elevated lipid peroxidation, cardiac adenosine triphosphate and left ventricular ejection fraction decline, suggesting oxidative stress and bioenergetics changes in catecholamine-induced heart failure. CAEA restored oxygen consumption rates and adenosine triphosphate contents. In addition, CAEA alleviated isoproterenol-induced cardiac remodeling, cardiac oxidative stress, cardiac bioenergetics and function insufficiency in mice. CAEA treatment recovered sirtuin 1 and sirtuin 3 activity, and attenuated the changes of proteins, including manganese superoxide dismutase and hypoxia-inducible factor 1-α, which are the most likely mechanisms responsible for the alleviation of isoproterenol-caused cardiac injury

CONCLUSION

CAEA prevents catecholamine-induced cardiac damage and is therefore a possible new therapeutic approach for preventing heart failure progression.

Independent and co-morbid HIV infection and Meth use disorders on oxidative stress markers in the cerebrospinal fluid and depressive symptoms

Both HIV infection and Methamphetamine (Meth) use disorders are associated with greater depressive symptoms and oxidative stress; whether the two conditions would show additive or interactive effects on the severity of depressive symptoms, and whether this is related to the level of oxidative stress in the CNS is unknown. 123 participants were evaluated, which included 41 HIV-seronegative subjects without substance use disorders (Control), 25 with recent (<6 months) moderate to severe Meth use disorders (Meth), 34 HIV-seropositive subjects without substance use disorders (HIV) and 23 HIV+Meth subjects. Depressive symptoms were assessed with the Center for Epidemiologic Studies-Depression Scale (CES-D), and oxidative stress markers were evaluated with glutathione (GSH), 4-hydroxynonenal (HNE), and activities of gamma-glutamyltransferase (GGT) and glutathione peroxidase (GPx) in the cerebrospinal fluid (CSF). Compared with Controls, HIV subjects had higher levels of HNE (+350%) and GGT (+27%), and lower level of GSH (-34%), while Meth users had higher levels of GPx activity (+23%) and GSH (+30 %). GGT correlated with GPx, and with age, across all subjects (p < 0.0001). CES-D scores correlated with CSF HNE levels only in Control and HIV groups, but not in Meth and HIV+Meth groups. HIV and Meth use had an interactive effects on depressive symptoms, but did not show additive or interactive effects on oxidative stress. The differential relationship between depressive symptoms and oxidative stress response amongst the four groups suggest that depressive symptoms in these groups are mediated through different mechanisms which are not always related to oxidative stress.

Effect of caffeic acid derivatives on polychlorinated biphenyls induced hepatotoxicity in male mice

Chronic exposure to coplanar polychlorinated biphenyls (PCBs), a potent inducer of toxic reactive oxygen species (ROS), in the environment and food can cause liver diseases. It remains unknown whether caffeic acid derivatives (CADs) exerted protective effect on PCB-induced hepatotoxicity. We sought to evaluate the activities of 3 CADs on PCB169-induced oxidative stress and DNA damage in the liver. Male ICR mice were administered with 1 μmol/mL PCB169 at 5 mL/kg body weight for 2 weeks. The mice were given CADs by gastric gavage for 3 weeks. We found that PCB169 decreased the growth rate and reduced the levels of superoxide dismutase (SOD), glutathione (GSH) and GSH peroxidase (GPx). It increased the liver weight, malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels and CYP1A1 activity in the liver tissues and plasma of mice (P<0.05). Pretreatment of mice with CADs restored the above parameters to normal levels. There was a synergistic protective effect between CADs in preventing MDA and 8-OHdG formation and inducing CYP1A1 and phase II metabolism enzyme (SOD, GPx) activities (P<0.05). In conclusion, PCB169 induced hepatotoxicity and pretreatment with CADs had synergistic protective effects on liver damage.

Chlorogenic and caftaric acids in liver toxicity and oxidative stress induced by methamphetamine

Methamphetamine intoxication can cause acute hepatic failure. Chlorogenic and caftaric acids are the major dietary polyphenols present in various foods. The aim of this study was to evaluate the protective role of chlorogenic and caftaric acids in liver toxicity and oxidative stress induced by methamphetamine in rats. Thirty-two male albino rats were divided into 4 equal groups. Group 1, which was control group, was injected (i.p) with saline (1 mL/kg) twice a day over seven-day period. Groups 2, 3, and 4 were injected (i.p) with methamphetamine (10 mg/kg) twice a day over seven-day period, where groups 3 and 4 were injected (i.p) with 60 mg/kg chlorogenic acid and 40 mg/kg caftaric acid, respectively, one day before methamphetamine injections. Methamphetamine increased serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, bilirubin, cholesterol, low-density lipoprotein, and triglycerides. Also, malondialdehyde in serum, liver, and brain and plasma and liver nitric oxide levels were increased while methamphetamine induced a significant decrease in serum total protein, albumin, globulin, albumin/globulin ratio, brain serotonin, norepinephrine and dopamine, blood and liver superoxide dismutase, and glutathione peroxidase levels. Chlorogenic and caftaric acids prior to methamphetamine injections restored all the above parameters to normal values. In conclusion, chlorogenic and caftaric acids before methamphetamine injections prevented liver toxicity and oxidative stress where chlorogenic acid was more effective.

The metabolic impact of methamphetamine on the systemic metabolism of rats and potential markers of methamphetamine abuse

Although the stimulating and psychotropic effects of methamphetamine (METH) on the nervous system are well documented, the impact of METH abuse on biological metabolism and the turnover of peripheral transmitters are poorly understood. Metabolomics has the potential to reveal the effect of METH abuse on systemic metabolism and potential markers suggesting the underlying mechanism of toxicity. In this study, male Sprague Dawley rats were intraperitoneally injected with METH at escalating doses of mg kg(-1) for 5 consecutive days and then were withdrawn for 2 days. The metabolites in the serum and urine were profiled and the systemic effects of METH on metabolic pathways were evaluated. Multivariate statistical analysis showed that METH caused distinct deviations, whereas the withdrawal of METH restored the metabolic patterns towards baseline. METH administration elevated energy metabolism, which was manifested by the distinct depletion of branched-chain amino acids, accelerated tricarboxylic-acid cycle and lipid metabolism, reduced serum glycerol-3-phosphate, and elevated serum and urinary 3-hydroxybutyrate and urinary glycerol. In addition to the increased serum levels of the excitatory amino acids glutamate and aspartate (the inhibitory neurotransmitters in the brain), a marked decline in serum alanine and glycine after METH treatment suggested the activation and decreased inhibition of the nervous system and hence elevated nervous activity. Withdrawal of METH for 2 days efficiently restored all but a few metabolites to baseline, including serum creatinine, citrate, 2-ketoglutarate, and urinary lactate. Therefore, these metabolites are potential markers of METH use, and they may be used to facilitate the diagnosis of METH abuse.

A novel caffeic acid-1-piperonylpiperazine hybridization compound HBU-47 inhibits LPS-mediated inflammation in RAW264.7 macrophage cells

In the present study, we synthesized a new hybrid compound by coupling caffeic acid and 1-piperonylpiperazine. The synthetic compound, acetyl-caffeic acid-1-piperonylpiperazine (HBU-47), showed potent anti-inflammatory effects inhibiting lipopolysaccharide (LPS)-induced production of nitric oxide (NO) in RAW264.7 macrophage cells. HBU-47 inhibited LPS-caused induction of inducible NO synthase (iNOS), cyclooxygenase-2, interleukin-6 and interleukin-1β in RAW264.7 cells in time- and dose-dependent manner. Compared to HBU-47, neither caffeic acid nor 1-piperonylpiperazine displayed significant inhibition of LPS responses. HBU-47 did not affect LPS-caused activation of mitogen-activated kinases (MAPKs) or IκB-α degradation. Instead, LPS-mediated NF-κB activation and DNA bindings of p65, p50 and c-Rel to the NF-κB binding site of iNOS promoter were inhibited by HBU-47. Overall, our data suggest that the novel caffeic acid hybrid compound downregulates inflammatory responses through inhibition of NF-κB and NF-κB-dependent gene expressions, thus, further suggesting its efficacy as a promising therapeutic agent.

Oxidative stress status in recently abstinent methamphetamine abusers

AIM

Methamphetamine (METH) administration is associated with excessive oxidative stress. It is not known whether the systemic oxidative stress indices would alter during early abstinence in METH abusers with positive urine testing for recent METH exposure.

METHODS

Sixty-four non-treatment-seeking METH abusers enrolled from a controlled environment and 60 healthy controls participated in the study. Fasting serum malondialdehyde (MDA) levels and anti-oxidant indices, including superoxide dismutase (SOD) and catalase (CAT) activity, and glutathione (GSH) levels, were measured at baseline and 2 weeks after the first measurement. We compared the differences of these oxidative stress indices between METH abusers and controls and examined the changes of the indices 2 weeks after baseline in the METH group.

RESULTS

At baseline, the recently abstinent METH abusers had significantly higher MDA levels, lower SOD activity, and higher CAT activity and GSH levels compared to healthy controls. CAT and GSH values were positively correlated with MDA but negatively correlated with SOD. These oxidative stress indices did not significantly correlate with age, smoking amount, Alcohol Use Disorder Identification Test scores, or METH use variables. After 2 more weeks of abstinence, the indices did not alter nor normalize.

CONCLUSION

Compared to controls, we found that METH abusers have persistently higher systemic oxidative stress throughout early abstinence. The compromised SOD as well as elevated CAT activity and GSH levels may act together as a compensatory mechanism to counteract excessive oxidative stress induced by METH. Whether the oxidative stress could improve after a longer period of abstinence needs to be examined in future studies.