EGb 761 reduces Ca2+ influx and apoptosis after pentylenetetrazole treatment in a neuroblastoma cell line.

Background: Transient receptor potential (TRP) channels have been found to have significant implications in neuronal outgrowth, survival, inflammatory neurogenic pain, and various epileptogenic processes. Moreover, there is a growing body of evidence indicating that transient receptor potential (TRP) channels have a significant impact on epilepsy and its drug-resistant subtypes. Objective: We postulated that EGb 761 would modulate TRPA1 channels, thereby exhibiting anti-inflammatory and neuroprotective effects in a neuroblastoma cell line. Our rationale was to investigate the impact of EGb 761 in a controlled model of pentylenetetrazole-induced generalized epilepsy. Methodology: We evaluated the neuroprotective, antioxidant and anti-apoptotic effects of EGb 761 both before and after the pentylenetetrazole application in a neuroblastoma cell line. Specifically, we focused on the effects of EGB 761 on the activity of Transient receptor potential (TRP) channels. Results: EGb 761 applications both before and after the pentylenetetrazole incubation period reduced Ca release and restored apoptosis, ROS changes, mitochondrial depolarization and caspase levels, suggesting a prominent prophylactic and therapeutic effect of EGb 761 in the pentylenetetrazole-induced epileptogenesis process. Conclusion: Our basic mechanistic framework for elucidating the pathophysiological significance of fundamental ion mechanisms in a pentylenetetrazole treated neuroblastoma cell line provided compelling evidence for the favorable efficacy and safety profile of Egb 761 in human-relevant in vitro model of epilepsy. To the best of our knowledge, this is the first study to investigate the combined effects of EGb 761 and pentylenetetrazole on TRP channels and measure their activation level in a relevant model of human epileptic diseases.

Protective and Therapeutic Role of Ginkgo Biloba Extract Through TRPV1 Channels in an in Vitro Alzheimer's Disease Model.

Introduction: The effect of Ginkgo biloba (GB) on mitochondria-dependent TRPV1 ion channels in neuroblastoma cells was investigated by creating an Alzheimer's disease (AD) model. Methods: Okadaic acid was applied on SH-SY5Y cells to create an AD model. After cellular differentiation, the study was organized with the seven main groups, examining the effect of GB on calcium depended TRPV1 channels in neuroblastoma cells AD, has been established in vitro. Results: The higher Ca2+ concentration was detected in the GB+AD, AD and AD+GB groups when compared with the control (p<0.001). The Ca2+ level was lower in GB+AD and AD+GB groups than in the AD group (p<0.001). Also, cytosolic Ca2+ concentration was lower in the GB+AD than in the AD+GB group (p<0.05), the apoptosis and intracellular reactive oxygen species (ROS) values were higher in the GB+AD, AD and AD+GB groups than in the control (p<0.001). The apoptosis and intracellular ROS values were higher in AD group than in the GB+AD and AD+GB group (p<0.001) and the apoptosis level was higher in AD+GB group than GB+AD group (p<0.001) and the mitochondrial depolarization, caspase 3 and caspase 9 levels were higher in the GB+AD, AD and AD+GB groups when compared to the control group (p<0.001). Also, the values were lower in the GB+AD group, AD group and AD+GB groups when compared with the GB+AD+capsazepine group, AD+capsazepine group and AD+GB+capsazepine respectively (p<0.001). Conclusion: These results show us that GB has a protective effect besides its therapeutic effect in Alzheimer's disease via TRPV1 channel.

Potential Effects of Melatonin on TRPA1 Channels in the Prevention and Treatment of Alzheimer's Disease.

Introduction: Alzheimer's disease (AD) is the most common cause of dementia and is defined as a progressive neurodegenerative disease. Main clinical features of AD are progressive impairment in learning and memory loss. Several studies have indicated that mitochondria play a critical role in the pathogenesis of AD. In this study, we investigated the effect of melatonin on mitochondria-dependent TRPA1 ion channels in neuroblastoma cells by creating an in vitro model of Alzheimer's disease. Methods: Okadaic acid was applied to SH-SY5Y (human neuroblastoma cell line) cells to create an AD model. After cellular differentiation, the following 7 main groups were created: Group 1 (Control), Group 2 (Mel+AD), Group 3 (Mel+AD+AP18), Group 4 (AD), Group 5 (AD+AP18), Group 6 (AD+Mel), and Group 7 (AD+Mel+AP18), and Alzheimer's disease was determined in vitro by examining the effect of melatonin on calcium-dependent TRPA1 channels in neuroblastoma cells. Results: The Ca2+concentration was greater in the melatonin+AD, AD and AD+melatonin groups than in the control (p<0.001). However, there was no statistically significant difference between Mel+AD+AP18, AD+Mel+AP18 and the control. We determined that Ca2+ levels were lower in the melatonin+AD and AD+melatonin groups than in the AD group (p<0.001 and p<0.05). Additionally, cytosolic Ca2+ concentrations were found to be lower in the melatonin+AD group than in the AD+melatonin group (p<0.05). In evaluating the apoptosis and oxidative stress levels, we found that the apoptosis and intracellular ROS values were higher in the melatonin+AD, AD and AD+melatonin groups than in the control (p<0.001). In this respect, the mitochondrial depolarization and caspase-3 and caspase-9 levels were higher in the melatonin+AD, AD and AD+melatonin groups than in the control group (p<0.001). Additionally, the mitochondrial depolarization, caspase-3 and caspase-9 values were higher in the AD group than in the melatonin+AD and AD+melatonin groups (p<0.001), while mitochondrial depolarization and caspase-3 levels were lower in the melatonin+AD group than in the AD+melatonin group (p<0.001). However, in the same groups, there was no statistically significant difference in caspase-9 results. Additionally, the caspase-9 values were lower in the melatonin+AD group, AD group and AD+melatonin groups than in the melatonin+AD+AP18, AD+AP18 and AD+melatonin+AP18 groups, respectively (p<0.001 and p<0.05). Conclusion: Our results suggest that melatonin may be an effective option in the treatment and prophylaxis of Alzheimer's disease by reducing cytosolic Ca2+ concentration, apoptosis and intracellular ROS through TRPA1 channels.

Agomelatine attenuates calcium signaling and apoptosis via the inhibition of TRPV1 channel in the hippocampal neurons of rats with chronic mild stress depression model.

Chronic stress plays a key role in inducing various clinical disorders through mechanistic pathways, including oxidative stress and apoptosis. Transient receptor potential vanilloid 1 (TRPV1) channels, which are permeable to cations, mainly Ca2+, are susceptible to oxidative stress. Agomelatine (AGOM) is an antidepressant drug analogous to the antioxidant melatonin hormone, although its action has not been fully clarified yet. We aimed to investigate the protective role of AGOM on TRPV1-induced Ca2+ signaling and apoptosis in rats with chronic mild stress (CMS). The rats were divided into six main groups: control, dimethyl sulfoxide (DMSO), AGOM, CMS, CMS+DMSO, and CMS+AGOM. Five weeks of CMS were applied to rats in the CMS groups. The induction of CMS was confirmed with the sucrose preference test. The AGOM treatments were administered in the last three weeks of the experiment. The depression-like behavior, TRPV1-mediated cytosolic Ca2+ influx, lipid peroxidation, apoptosis, caspase - 3, and - 9 levels increased in the hippocampal neurons of CMS groups, although cell viability level was diminished by the CMS exposure. However, AGOM treatment downregulated stress-related behaviors, hippocampal oxidant and apoptotic markers by modulating the TRPV1 activity. In conclusion, TRPV1-mediated Ca2+ signaling and apoptosis may play a role in the etiopathogenesis of experimental depression. By regulating these changes with AGOM treatment, a positive contribution may be made to depression treatment.

Effects of homocysteine and memantine on oxidative stress related TRP cation channels in in-vitro model of Alzheimer's disease.

Memantine (MEM) has been used to treat patients with Alzheimer' disease though inhibition of reactive oxygen species (ROS), Ca2+ entry and glutamate receptor. The Ca2+ permeable TRPA1, TRPM2 and TRPV1 channels are activated in the hippocampus by ROS, and antioxidant MEM as a potent TRPA1, TRPM2 and TRPV1 channel antagonist may reduce Aß-induced oxidative stress and apoptosis in the neurons. In the current study, we investigated the neuroprotective properties of MEM in Aß-induced hippocampal neuron cultures. Freshly isolated hippocampal neurons of mice were divided into eight groups as control, Aß, Hcy, MEM, Aß + Hcy, Aß + Hcy + MEM, Aß + MEM and Hcy + MEM. The neurons were exposed to incubated with Aß (20 µM for 24 h), Hcy (250 µM for 30 min) and MEM (10 µM for 24 h). TRPA1, TRPM2 and TRPV1 of the eight groups were further stimulated by cinnamaldehyde, cumene hydyroperoxide and capsaicin, respectively although they were further inhibited by AP-18, N-(p-Amylcinnamoyl) anthranilic acid (ACA) and capsazepine (CPZ). The [Ca2+] concentration, apoptosis, caspase 3, caspase 9 activations, mitochondrial membrane depolarization and intracellular ROS production values in the neurons were higher in Aß and Hcy groups than in control although they were lower in the MEM group than in Aß and Hcy groups. The values were further decreased by MEM + AP-18, MEM + CPZ and MEM + ACA treatments as compared to MEM only. Aß and Hcy-induced decrease of cell viability level was increased by MEM treatment although Aß and Hcy-induced increase of caspase 3, caspase 9, PARP1, TRPA1, TRPM2 and TRPV1 expression levels were decreased by MEM treatments. In conclusion, TRPA1, TRPM2 and TRPV1 channels are involved in Aß and Hcy-induced neuronal death, and modulation of the activity of these channels by MEM treatment may account for their neuroprotective activity against apoptosis, excessive ROS production, and Ca2+ entry.

Correction to: Selenium enhances TRPA1 channel-mediated activity of temozolomide in SH-SY5Y neuroblastoma cells.

The original version of this article unfortunately contained few errors. The dose of sodium selenite was incorrectly indicated as 100 µM in the published version of "Selenium enhances TRPA1 channel-mediated activity of temozolomide in SH-SY5Y neuroblastoma cells". The correct indication of sodium selenite is 5 µM. Additionally the authors accidenttally referred to reference 11 instead of reference 10 in Group 6.

Selenium enhances TRPA1 channel-mediated activity of temozolomide in SH-SY5Y neuroblastoma cells.

PURPOSE: Neuroblastoma is a malignant solid tumor that originates from the sympathetic nervous system in early childhood. Temozolomide is used for treatment in high-risk groups with low treatment response of neuroblastomas. TRPA1 channels in neuroblastoma cells are calcium permeable channels that can be activated by reactive oxygen species (ROT). In this study, we aimed to evaluate the level of activity of temozolomide and selenium in neuroblastoma cells via TRPA1 channels. METHOD: Seven main groups were formed using SH-SY5Y neuroblastoma cells. The control was divided into temozolomide (TMZ) (100 µM, 24 h), TMZ+SEL+AP18, SEL (sodium selenite, 100 µM, 24 h), and SEL+AP18 groups. Intergroup calcium signaling, intracellular reactive oxygen species, caspase-3 and caspase-9, and mitochondrial depolarization analyses were performed by channel activation with TRPA1 agonist cinnamaldehyde in all groups. RESULTS: Cytosolic calcium concentration, apoptosis, caspase-3 and caspase-9 activation, mitochondrial membrane depolarization, and ROT levels were higher in TMZ (p < 0.001), TMZ+SEL (p < 0.001), and SEL (p < 0.05) groups than the control group. TRPA1 was lower in TTMZ+AP18, TMZ+SEL+AP18, and SEL+AP18 groups with channel blockers than respectively TMZ, TMZ+SEL, and SEL groups without channel blockers (p < 0.05). CONCLUSION: The use of selenium with temozolomide increased the apoptotic efficacy of temozolomide via TRPA1 channels on tumor cells.

Hypericum perforatum L. supplementation protects sciatic nerve injury-induced apoptotic, inflammatory and oxidative damage to muscle, blood and brain in rats.

OBJECTIVES: This study was conducted to explore whether Hypericum perforatum L. (HPL) as a potent antioxidant protects against oxidative stress, cytokine production and caspase expression in muscle (soleus), brain and blood of sciatic nerve injury (SNI)-induced rats. METHODS: Thirty-five rats were equally divided into five groups. The first and second were used as untreated control and sham control groups, respectively. The third, fourth and fifth were sham + HPL, SNI and SNI + HPL groups, respectively. The third and fifth groups received 30 mg/kg HPL via gastric gavage for 28 days. KEY FINDINGS: High levels of muscle, brain and red blood cell (RBC) lipid peroxidation, plasma cytokine (TNF-α, IL-1ß and IL-2), muscle PARP, caspase 3 and 9 expression levels were decreased by HPL treatments. Plasma glutathione peroxidase (GPx) activity, α-tocopherol and melatonin, muscle, brain and RBC reduced glutathione (GSH) concentrations were decreased by SNI induction, whereas their values were increased by HPL treatments. ß-carotene and retinol concentrations did not change in the five groups. CONCLUSION: HPL may play a role in preventing SNI-induced inflammatory, oxidative and apoptotic blood, muscle and brain damages through upregulation of the GSH and GPx values but downregulation of PARP, caspase level and cytokine production in SNI-induced rats.

Corrigendum: The neuroprotective action of dexmedetomidine on apoptosis, calcium entry and oxidative stress in cerebral ischemia-induced rats: Contribution of TRPM2 and TRPV1 channels.

This corrects the article DOI: 10.1038/srep37196.

Zoledronic Acid, Bevacizumab and Dexamethasone-Induced Apoptosis, Mitochondrial Oxidative Stress, and Calcium Signaling Are Decreased in Human Osteoblast-Like Cell Line by Selenium Treatment.

Increased intracellular free calcium ion (Ca2+) concentration induces excessive oxidative stress and apoptosis. Medical procedures such as zoledronic acid (Zol), bevacizumab (Bev), and dexamethasone (Dex) are usually used in the treatment of bone diseases (osteoporosis, Paget's disease, etc.) and to prevent metastasis in the bone although the procedures induce osteonecrosis of the jaw through excessive production of reactive oxygen species (ROS). Recently, we observed regulator roles of selenium (Se) on apoptosis and Ca2+ entry through transient receptor potential vanilloid 1 (TRPV1) channels in the cancer cell lines. Therefore, Se may modulate Zol, Bev, and Dex-induced oxidative stress and apoptosis through regulation of TRPV1 channel. In the current study, we investigated the protective effects of Se on apoptosis and oxidative stress through TRPV1 in Zol, Bev, and Dex-induced osteoblast-like cell line. We used human osteoblast-like cell line (Saos-2), and the cells were divided into 12 groups as control, Zol, Bev, Dex, Se, Zol+Se, Bev+Se, Dex+Se, Zol+Dex, Zol+Dex+Se, Zol+Bev, and Zol+Bev+Se which were incubated with drugs (Zol, Bev, Dex, and Se) for 24 h. The cytosolic free Ca2+ concentration was increased by Zol, Bev, Dex, Zol+Bev, and Zol+Dex, although it was reduced by Se treatment. However, Zol, Bev, and Dex-induced increase in apoptosis, caspase 3, caspase 9, poly (ADP-ribose) polymerase 1 expression levels, and intracellular ROS production values in the cells were decreased by Se treatments. In conclusion, we observed that Zol, Bev, and Dex-induced apoptosis, mitochondrial oxidative stress, and calcium signaling are decreased in human osteoblast-like cell line by the Se treatment. Our findings may be relevant to the etiology and treatment of Zol, Bev, and Dex-induced osteonecrosis by Se.

Short-Term Ketamine Treatment Decreases Oxidative Stress Without Influencing TRPM2 and TRPV1 Channel Gating in the Hippocampus and Dorsal Root Ganglion of Rats.

Calcium ions (Ca2+) are important second messengers in neurons. Ketamine (KETAM) is an anesthetic and analgesic, with psychotomimetic effects and abuse potential. KETAM modulates the entry of Ca2+ in neurons through glutamate receptors, but its effect on transient receptor potential melastatin 2 (TRPM2) and transient receptor potential vanilloid 1 (TRPV1) channels has not been clarified. This study investigated the short-term effects of KETAM on oxidative stress and TRPM2 and TRPV1 channel gating in hippocampal and dorsal root ganglion (DRG) neurons of rats. Freshly isolated hippocampal and DRG neurons were incubated for 24 h with KETAM (0.3 mM). The TRPM2 channel antagonist, N-(p-amylcinnamoyl)anthranilic acid (ACA), inhibited cumene hydroperoxide and ADP-ribose-induced TRPM2 currents in the neurons, and capsazepine (CPZ) inhibited capsaicin-induced TRPV1 currents. The TRPM2 and TRPV1 channel current densities and intracellular free calcium ion concentration of the neurons were lower in the neurons exposed to ACA and CPZ compared to the control neurons, respectively. However, the values were not further decreased by the KETAM + CPZ and KETAM + ACA treatments. KETAM decreased lipid peroxidation levels in the neurons but increased glutathione peroxidase activity. In conclusion, short-term KETAM treatment decreased oxidative stress levels but did not seem to influence TRPM2- and TRPV1-mediated Ca2+ entry.

Modulation of Diabetes-Induced Oxidative Stress, Apoptosis, and Ca2+ Entry Through TRPM2 and TRPV1 Channels in Dorsal Root Ganglion and Hippocampus of Diabetic Rats by Melatonin and Selenium.

Neuropathic pain and hippocampal injury can arise from the overload of diabetes-induced calcium ion (Ca2+) entry and oxidative stress. The transient receptor potential (TRP) melastatin 2 (TRPM2) and TRP vanilloid type 1 (TRPV1) are expressed in sensory neurons and hippocampus. Moreover, activations of TRPM2 and TRPV1 during oxidative stress have been linked to neuronal death. Melatonin (MEL) and selenium (Se) have been considered potent antioxidants that detoxify a variety of reactive oxygen species (ROS) in neurological diseases. In order to better characterize the actions of MEL and Se in diabetes-induced peripheral pain and hippocampal injury through modulation of TRPM2 and TRPV1, we tested the effects of MEL and Se on apoptosis and oxidative stress in the hippocampal and dorsal root ganglion (DRG) neurons of streptozotocin (STZ)-induced diabetic rats. Fifty-eight rats were divided into six groups. The first group was used as control. The second group was used as the diabetic group. The third and fourth groups received Se and MEL, respectively. Intraperitoneal Se and MEL were given to diabetic rats in the fifth and sixth groups. On the 14th day, hippocampal and DRG neuron samples were freshly taken from all animals. The neurons were stimulated with a TRPV1 channel agonist (capsaicin) and a TRPM2 channel agonist (cumene hydroperoxide). We observed a modulator role of MEL and Se on intracellular free Ca2+ concentrations, current densities of TRPM2 and TRPV1 channels, apoptosis, caspase 3, caspase 9, mitochondrial depolarization, reduced glutathione, glutathione peroxidase, lipid peroxidation, and intracellular ROS production values in the neurons. In addition, procaspase 3 and 9 activities in western blot analyses of the brain cortex were also decreased by MEL and Se treatments. In conclusion, in our diabetes experimental model, TRPM2 and TRPV1 channels are involved in the Ca2+ entry-induced neuronal death and modulation of this channel activity by MEL and Se treatment may account for their neuroprotective activity against apoptosis and Ca2+ entry. Graphical Abstract Possible molecular pathways of involvement of melatonin and selenium in diabetes-induced apoptosis, oxidative stress, and calcium accumulation through TRPM2 and TRPV1 channels in the hippocampus and DRG neurons of rats. The TRPM2 channel is activated by ADP-ribose and oxidative stress although it is inhibited by ACA. The TRPV1 channel is activated by oxidative stress and capsaicin and it is blocked by capsazepine (CPZ). Diabetes can result in augmented ROS release in hippocampal and DRG neurons through polyol reactions, leading to Ca2+ uptake through TRPM2 and TRPV1 channels. Mitochondria were reported to accumulate Ca2+ provided intracellular Ca2+ rises, thereby leading to the depolarization of mitochondrial membranes and release of apoptosis-inducing factors such as caspase 3 and caspase 9. Melatonin and selenium reduce TRPM2 and TRPV1 channel activation through the modulation of polyol oxidative reactions and selenium-dependent glutathione peroxidase (GSH-Px) antioxidant pathways.

The Protective Role of Selenium on Scopolamine-Induced Memory Impairment, Oxidative Stress, and Apoptosis in Aged Rats: The Involvement of TRPM2 and TRPV1 Channels.

Inhibition of Ca2+ entry into the hippocampus and dorsal root ganglion (DRG) through inhibition of N-methyl-D-aspartate (NMDA) receptor antagonist drugs is the current standard of care in neuronal diseases such as Alzheimer's disease, dementia, and peripheral pain. Oxidative stress activates Ca2+-permeable TRPM2 and TRPV1, and recent studies indicate that selenium (Se) is a potent TRPM2 and TRPV1 channel antagonist in the hippocampus and DRG. In this study, we investigated the neuroprotective properties of Se in primary hippocampal and DRG neuron cultures of aged rats when given alone or in combination with scopolamine (SCOP). Thirty-two aged (18-24 months old) rats were divided into four groups. The first and second groups received a placebo and SCOP (1 mg/kg/day), respectively. The third and fourth groups received intraperitoneal Se (1.5 mg/kg/ over day) and SCOP + Se, respectively. The hippocampal and DRG neurons also were stimulated in vitro with a TRPV1 channel agonist (capsaicin) and a TRPM2 channel agonist (cumene hydroperoxide). We found that Se was fully effective in reversing SCOP-induced TRPM2 and TRPV1 current densities as well as errors in working memory and reference memory. In addition, Se completely reduced SCOP-induced oxidative toxicity by modulating lipid peroxidation, reducing glutathione and glutathione peroxidase. The Se and SCOP + Se treatments also decreased poly (ADP-ribose) polymerase activity, intracellular free Ca2+ concentrations, apoptosis, and caspase 3, caspase 9, and mitochondrial membrane depolarization values in the hippocampus. In conclusion, the current study reports on the cellular level for SCOP and Se on the different endocytotoxic cascades for the first time. Notably, the research indicates that Se can result in remarkable neuroprotective and memory impairment effects in the hippocampal neurons of rats. Graphical abstract Possible molecular pathways of involvement of selenium (Se) in scopolamine (SCOP) induced apoptosis, oxidative stress, and calcium accumulation through TRPM2 and TRPV1 channels in the hippocampus neurons of aged rats. The TRPM2 channel is activated by ADP-ribose and oxidative stress, although it is inhibited by ACA. The TRPV1 channel is activated by oxidative stress and capsaicin, and it is blocked by capsazepine (CPZ). The beta-amyloid plaque induces oxidative stress in hippocampus. SCOP can result in augmented ROS release in hippocampal neurons, leading to Ca2+ uptake through TRPM2 and TRPV1 channels. Mitochondria were reported to accumulate Ca2+ provided that intracellular Ca2+ rises, thereby leading to the depolarization of mitochondrial membranes and release of apoptosis-inducing factors such as caspase 3 and caspase 9. Se reduced TRPM2 and TRPV1 channel activation through the modulation of aging oxidative reactions and Se-dependent glutathione peroxidase (GSH-Px) antioxidant pathways.

Selenium potentiates the anticancer effect of cisplatin against oxidative stress and calcium ion signaling-induced intracellular toxicity in MCF-7 breast cancer cells: involvement of the TRPV1 channel.

BACKGROUND: In breast cancers, calcium signaling is a main cause of proliferation and apoptosis of breast cancer cells. Although previous studies have implicated the transient receptor potential vanilloid 1 (TRPV1) cation channel, the synergistic inhibition effects of selenium (Se) and cisplatin in cancer and the suppression of ongoing apoptosis have not yet been investigated in MCF-7 breast cancer cells. This study investigates the anticancer properties of Se through TRPV1 channel activity in MCF-7 breast cancer cell line cultures when given alone or in combination with cisplatin. MATERIALS: The MCF-7 cells were divided into four groups: the control group, the Se-treated group (200 nM), the cisplatin-treated group (40 µM) and the Se + cisplatin-treated group. RESULTS: The intracellular free calcium ion concentration and current densities increased with TRPV1 channel activator capsaicin (0.01 mM), but they decreased with the TRPV1 blocker capsazepine (0.1 mM), Se, cisplatin, and Se + cisplatin incubations. However, mitochondrial membrane depolarization, apoptosis, and the caspase 3, and caspase 9 values increased in the Se-treated group and the cisplatin-treated group, although Western blot (procaspase 3 and 9) results and the cell viability levels decreased with the Se and Se + cisplatin treatments. Apoptosis and caspase-3 were further increased with the Se + cisplatin treatment. Intracellular reactive oxygen species production increased with the cisplatin treatment, but not with the Se treatment. CONCLUSION: This study's results report, for the first time, that at a cellular level, Se and cisplatin interact on the same intracellular toxic cascade, and the combination of these two drugs can result in a remarkable anticancer effect through modulation of the TRPV1.

Selenium attenuates apoptosis, inflammation and oxidative stress in the blood and brain of aged rats with scopolamine-induced dementia.

A potent antioxidant, selenium might modulate dementia-induced progression of brain and blood oxidative and apoptotic injuries. The present study explores whether selenium protects against experimental dementia (scopolamine, SCOP)-induced brain, and blood oxidative stress, apoptosis levels, and cytokine production in rats. Thirty-two rats were equally divided into four groups. The first group was used as an untreated control. The second group was treated with SCOP to induce dementia. The third and fourth groups received 1.5 mg/kg selenium (sodium selenite) and SCOP + selenium, respectively. Dementia was induced in the second and forth groups by intraperitoneal SCOP (1 mg/kg) administration. Brain, plasma, and erythrocyte lipid peroxidation levels as well as plasma TNF-α, interleukin (IL)-1ß, and IL-4 levels were high in the SCOP group though they were low in selenium treatments. Selenium and selenium + SCOP treatments increased the lowered glutathione peroxidase activity, reduced glutathione, vitamins A and E concentrations in the brain, erythrocytes and plasma of the SCOP group. Apoptotic value expressions as active caspase-3, procaspase-9, and PARP were also increased by SCOP, while they were decreased by selenium and selenium + SCOP treatments. In conclusion, selenium induced protective effects against experimental dementia-induced brain, and blood oxidative injuries and apoptosis through regulation of cytokine production, vitamin E, glutathione concentrations, and glutathione peroxidase activity.

Duloxetine Reduces Oxidative Stress, Apoptosis, and Ca2+ Entry Through Modulation of TRPM2 and TRPV1 Channels in the Hippocampus and Dorsal Root Ganglion of Rats.

Overload of Ca2+ entry and excessive oxidative stress in neurons are the two main causes of depression. Activation of transient receptor potential (TRP) vanilloid type 1 (TRPV1) and TRP melastatin 2 (TRPM2) during oxidative stress has been linked to neuronal survival. Duloxetine (DULOX) in neurons reduced the effects of Ca2+ entry and reactive oxygen species (ROS) through glutamate receptors, and this reduction of effects may also occur through TRPM2 and TRPV1 channels. In order to better characterize the actions of DULOX in peripheral pain and hippocampal oxidative injury through modulation of TRPM2 and TRPV1, we tested the effects of DULOX on apoptosis and oxidative stress in the hippocampal and dorsal root ganglion (DRG) neurons of rats. Freshly isolated hippocampal and DRG neurons were incubated for 24 h with DULOX. In whole-cell patch-clamp and intracellular-free calcium ([Ca2+]) concentration (Fura-2) experiments, cumene hydroperoxide and ADP-ribose-induced TRPM2 currents in the neurons were inhibited by N-(p-amylcinnamoyl) anthranilic acid (ACA) and capsaicin-induced TRPV1 currents were inhibited by capsazepine (CPZ) incubations. TRPM2 and TRPV1 channel current densities, [Ca2+] concentration, apoptosis, caspase 3, caspase 9, mitochondrial depolarization, and intracellular ROS production values in the neurons were lower in the DULOX group than in controls. In addition, the above values were further decreased by DULOX + CPZ and DULOX + ACA treatments. In conclusion, TRPM2 and TRPV1 channels are involved in Ca2+ entry-induced neuronal death and modulation of the activity of these channels by DULOX treatment may account for their neuroprotective activity against apoptosis, excessive ROS production, and Ca2+ entry.

The neuroprotective action of dexmedetomidine on apoptosis, calcium entry and oxidative stress in cerebral ischemia-induced rats: Contribution of TRPM2 and TRPV1 channels.

Dexmedetomidine (DEX) may act as an antioxidant through regulation of TRPM2 and TRPV1 channel activations in the neurons by reducing cerebral ischemia-induced oxidative stress and apoptosis. The neuroprotective roles of DEX were tested on cerebral ischemia (ISC) in the cultures of rat primary hippocampal and DRG neurons. Fifty-six rats were divided into five groups. A placebo was given to control, sham control, and ISC groups, respectively. In the third group, ISC was induced. The DEX and ISC+DEX groups received intraperitoneal DEX (40 µg/kg) 3, 24, and 48 hours after ISC induction. DEX effectively reversed capsaicin and cumene hydroperoxide/ADP-ribose-induced TRPV1 and TRPM2 densities and cytosolic calcium ion accumulation in the neurons, respectively. In addition, DEX completely reduced ISC-induced oxidative toxicity and apoptosis through intracellular reactive oxygen species production and depolarization of mitochondrial membrane. The DEX and ISC+DEX treatments also decreased the expression levels of caspase 3, caspase 9, and poly (ADP-ribose) polymerase in the hippocampus and DRG. In conclusion, the current results are the first to demonstrate the molecular level effects of DEX on TRPM2 and TRPV1 activation. Therefore, DEX can have remarkable neuroprotective impairment effects in the hippocampus and DRG of ISC-induced rats.

Raloxifene and Tamoxifen Reduce PARP Activity, Cytokine and Oxidative Stress Levels in the Brain and Blood of Ovariectomized Rats.

It is well known that 17ß-estradiol (E2) has an antioxidant role on neurological systems in the brain. Raloxifene (RLX) and tamoxifen (TMX) are selective estrogen receptor modulators. An E2 deficiency stimulates mitochondrial functions for promoting apoptosis and increasing reactive oxygen species (ROS) production. However, RLX and TMX may reduce the mitochondrial ROS production via their antioxidant properties in the brain and erythrocytes of ovariectomized (OVX) rats. We aimed to investigate the effects of E2, RLX, and TMX on oxidative stress, apoptosis, and cytokine production in the brain and erythrocytes of OVX rats.Forty female rats were divided into five groups. The first group was used as a control group. The second group was the OVX group. The third, fourth, and fifth groups were OVX + E2, OVX + TMX, and OVX + RLX groups, respectively. E2, TMX, and RLX were given subcutaneously to the OVX + E2 and OVX + TMX, OVX + RLX groups for 14 days after the ovariectomy respectively.While brain and erythrocyte lipid peroxidation levels were high in the OVX group, they were low in the OVX + E2, OVX + RLX, and OVX + TMX groups. OVX + E2, OVX + RLX, and OVX + TMX treatments increased the lowered glutathione peroxidase activity in erythrocytes and the brain and reduced glutathione and vitamin E concentrations in the brain. ß-carotene and vitamin A concentrations in the brain and TNF-α and interleukin (IL)-1ß levels in the plasma of the five groups were not significantly changed by the treatments. However, increased plasma IL-4 levels and Western blot results for brain poly (ADP-ribose) polymerase (PARP) in the OVX groups were decreased by E2, TMX, and RLX treatments, although proapoptotic procaspase 3 and 9 activities were increased by the treatments.In conclusion, we observed that E2, RLX, and TMX administrations were beneficial on oxidative stress, inflammation, and PARP levels in the serum and brain of OVX rats by modulating antioxidant systems, DNA damage, and cytokine production.

Synergic Effects of Doxorubicin and Melatonin on Apoptosis and Mitochondrial Oxidative Stress in MCF-7 Breast Cancer Cells: Involvement of TRPV1 Channels.

Transient receptor transient receptor potential vanilloid 1 (TRPV1) is a Ca(2+)-permeable channel gated by oxidative stress and capsaicin (CAP) and modulated by melatonin (MEL) and capsazepine (CPZ). A combination of doxorubicin (DOX) and MEL may offer a potential therapy for breast cancer by exerting antitumor and anti-apoptotic effects and modulating Ca(2+) influx and TRPV1 activity. We aimed to investigate the effects of MEL and DOX on the oxidative toxicity of MCF-7 human breast cancer cells, in addition to the activity of the TRPV1 channel and apoptosis. The MCF-7 cells were divided into the following six treatment groups: control, incubated with MEL (0.3 mM), incubated with 0.5 µM DOX, incubated with 1 µM DOX, incubated with MEL + 0.5 µM DOX, or incubated with MEL + 1 µM DOX. The intracellular free Ca(2+) concentration was higher in the DOX groups than in the control, and the concentration was decreased by MEL. The intracellular free Ca(2+) concentration was further increased by treatment with the TRPV1 channel activator CAP (0.01 mM), and it was decreased by the CPZ (0.1 mM). The intracellular production of reactive oxygen species, mitochondrial membrane depolarization, apoptosis level, procaspase 9 and PARP activities, and caspase 3 and caspase 9 activities were higher in the DOX and MEL groups than in the control. Apoptosis and the activity of caspase 9 were further increased in the DOX plus MEL groups. Taken together, the findings indicate that MEL supported the effects of DOX by activation of TRPV1 and apoptosis, as well as by inducing MCF-7 cell death. As the apoptosis and caspase activity of cancer cells increase because of their elevated metabolism, MEL may be useful in supporting their apoptotic capacity.

Modulation of oxidative stress, apoptosis, and calcium entry in leukocytes of patients with multiple sclerosis by Hypericum perforatum.

OBJECTIVES: Hypericum perfortarum (HP, St John's wort) is a modulator of Ca(2+) entry in neutrophils and it may modulate intracellular free Ca(2+) ([Ca(2+)]i) entry in leukocytes of patients with multiple sclerosis (MS). We investigated effects of HP on oxidative stress, apoptosis, and [Ca(2+)]i concentrations in serum and leukocytes of patients with MS. METHODS: Neutrophils of nine newly diagnosed MS patients and nine healthy subjects within four subgroups were used in the study. The first group was a control; the second group was patients with MS. The neutrophils from patient group were incubated non-specific TRPM2 channel blocker (2-APB), voltage-gated calcium channel blockers, verapamil and diltiazem (V + D) with HP before N-formyl-L-methionyl-L-leucyl-L-phenylalanine stimulation, respectively. RESULTS: Neutrophil and serum lipid peroxidation, neutrophil apoptosis and [Ca(2+)]i levels in patients with MS were higher than in control although their levels were decreased by HP, 2-APB, and V + D incubations. The modulator role of V + D in MS and MS + HP groups was higher than in the 2-APB group. Neutrophilic glutathione peroxidase (GSH-Px) and serum vitamin A and E concentrations were lower in the MS group than in control. However, the neutrophil GSH-Px activity was increased by HP incubation. The neutrophil reduced glutathione, serum vitamin C and ß-carotene concentrations did not change in control and patients. DISCUSSION: We observed that HP-induced protective effects on oxidative stress and [Ca(2+)]i concentrations by modulating transient receptor potential and voltage gated calcium channel in the patients with MS. Thus, it may provide useful treatment of neutrophil activity in the patients.