Hypericum perforatum modulates apoptosis and calcium mobilization through voltage-gated and TRPM2 calcium channels in neutrophil of patients with Behcet's disease

An overview of programmed cell death: Apoptosis and pyroptosis-Mechanisms, differences, and significance in organism physiology and pathophysiology

Regulated cell death is an essential and heterogeneous process occurring in the life cycle of organisms, from embryonic development and aging to the regulation of homeostasis and organ maintenance. Under this term, we can distinguish many distinct pathways, including apoptosis and pyroptosis. Recently, there has been an increasing comprehension of the mechanisms governing these phenomena and their characteristic features. The coexistence of different types of cell death and the differences and similarities between them has been the subject of many studies. This review aims to present the latest literature in the field of pyroptosis and apoptosis and compare their molecular pathway's elements and significance in the physiology and pathophysiology of the organism.

Caspase-9: A Multimodal Therapeutic Target With Diverse Cellular Expression in Human Disease

Caspase-9, a cysteine-aspartic protease known for its role as an initiator of intrinsic apoptosis, regulates physiological cell death and pathological tissue degeneration. Its nonapoptotic functions, including regulation of cellular differentiation/maturation, innate immunity, mitochondrial homeostasis, and autophagy, reveal a multimodal landscape of caspase-9 functions in health and disease. Recent work has demonstrated that caspase-9 can drive neurovascular injury through nonapoptotic endothelial cell dysfunction. CASP9 polymorphisms have been linked with various cancers, neurological disorders, autoimmune pathologies and lumbar disc disease. Clinical reports suggest alterations in caspase-9 expression, activity or function may be associated with acute and chronic neurodegeneration, retinal neuropathy, slow-channel myasthenic syndrome, lumbar disc disease, cardiomyopathies, atherosclerosis and autoimmune disease. Healthy tissues maintain caspase-9 activity at low basal levels, rendering supraphysiological caspase-9 activation a tractable target for therapeutic interventions. Strategies for selective inhibition of caspase-9 include dominant negative caspase-9 mutants and pharmacological inhibitors derived from the XIAP protein, whose Bir3 domain is an endogenous highly selective caspase-9 inhibitor. However, the mechanistic implications of caspase-9 expression and activation remain indeterminate in many pathologies. By assembling clinical reports of caspase-9 genetics, signaling and cellular localization in human tissues, this review identifies gaps between experimental and clinical studies on caspase-9, and presents opportunities for further investigations to examine the consequences of caspase activity in human disease.

Resveratrol diminishes bisphenol A-induced oxidative stress through TRPM2 channel in the mouse kidney cortical collecting duct cells

Bisphenol A (BisPH-A) is a latent danger that threatens our health, which we frequently exposure in our modern life (e.g. the widespread use of drinking water in plastic pet bottles). But the BisPH-A induced transient receptor potential melastatin 2 (TRPM2)-mediated oxidative stress and apoptosis in these cells has not been studied yet. Calcium (Ca²⁺) plays an important role in a versatile intracellular signal transduction that works over a wide range to regulate oxidative stress processes. TRPM2 is activated by oxidative stress and it has emerged as an important Ca²⁺ signaling mechanism in a variety of cells, contributing many cellular functions including cell death. Resveratrol (RESV), which belongs to the polyphenol group, acts as an antioxidant, eliminating cellular oxidative stress and increasing the body's resistance to diseases. The current study aimed to elucidate the effect of antioxidant resveratrol on TRPM2-mediated oxidative stress induced by BisPH-A exposure in the mouse kidney cortical collecting duct cells (mpkCCD_cl4). The cells were divided into four groups as control, resveratrol (50 µM for 24 h), BisPH-A (100 µM for 24 h) and BisPH-A + RESV. Intracellular free Ca²⁺ concentrations and TRPM2 channel currents were high in BisPH-A treated cells, but decreased with resveratrol treatment. In addition, BisPH-A induced mitochondrial membrane depolarization, reactive oxygen species (ROS), caspase 3, caspase 9 and apoptosis values were decreased by the resveratrol treatment. In conclusion, resveratrol protected cells from BisPH-A induced oxidative damage. In this study, we showed that TRPM2 channel mediates this protective effect of resveratrol.

Modulator role of infliximab and methotrexate through the transient receptor potential melastatin 2 (TRPM2) channel in neutrophils of patients with rheumatoid arthritis: a pilot study

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory disease causing symmetric polyarthritis. In this study, we aimed to investigate the effects of infliximab (INF) and methotrexate (MTX) on apoptosis, oxidative stress, and calcium signaling in the neutrophils of RA patients.

MATERIAL AND METHODS

Neutrophils were isolated from 10 patients with newly diagnosed RA and 10 healthy controls. They were divided into four groups (control, RA, RA + MTX, RA + INF) and incubated with MTX and INF. In the cell viability (MTT) test, the ideal non-toxic dose and incubation time of MTX were found to be 0.1 mM and 1 h, respectively. The neutrophils were also incubated with the TRPM2 channel blocker N-(p-amylcinnamoyl) anthranilic acid (ACA).

RESULTS

Intracellular free Ca²⁺ concentration, intracellular reactive oxygen species (ROS) production, mitochondrial depolarization, lipid peroxidation, apoptosis, and caspase 3 and caspase 9 activities were found to be significantly higher in the neutrophils of RA patients compared to controls. MTT, reduced glutathione (GSH) level, and glutathione peroxidase (GSHPx) activity were significantly lower in the neutrophils of RA patients. However, MTT, GSH and GSHPx values were detected to be significantly increased with INF and MTX therapies. The Ca²⁺ concentrations were further decreased by the ACA therapy.

CONCLUSIONS

Our results suggest that INF and MTX are useful antagonists in apoptosis and mitochondrial oxidative stress in the neutrophils of RA patients. INF and MTX decreased the Ca²⁺ concentration through inhibition of the TRPM2 channel in the neutrophils of RA patients. It may be a new pathway in the mechanisms of anti-rheumatic drugs.

Low levels of pannexin-1 in Behçet's syndrome

OBJECTIVE

Behçet's syndrome (BS) is a chronic, multisystemic and inflammatory syndrome. In our study, we aimed to compare the initiator, effector and inflammatory caspases and pannexin channel protein, which is thought to have an activity in inflammation, in the inflammatory process of BS, with healthy subjects, to investigate their level in patients and their relationship with the clinical findings.

METHOD

Forty-six patients who were under follow-up for BS in the Sivas Cumhuriyet University Medical Faculty Department of Internal Diseases, Rheumatology Unit, between January 2017 and June 2017 and 44 healthy controls (HC) who did not have any rheumatic, systemic or metabolic diseases, were enrolled in this study.

RESULTS

The mean serum pannexin-1 level was 6.36 (4.21-527.2) pg/mL in the BS group and 255.8 (5.38-2000) pg/mL in the HC group. Serum pannexin-1 levels were statistically significantly lower in the BS group (P < 0.0001). The measured mean serum caspase-3 level was 12.04 (11.25-43.69) pg/mL in the group with BS and 12.1 (11.19-484.3) pg/mL in the HC group (P = 0.143), mean serum caspase-9 level was 22 (5.14-29.33) pg/mL in the BS group and 22.01 (11.23-850) pg/mL in the HC group (P = 0.593), mean serum caspase-14 level was 6 (5.2-8.21) pg/mL in the BS group and 6.15 (5.7-353) pg/mL in the HC group (P = 0.053).

CONCLUSION

Comparison of serum caspase-3, caspase-9 and caspase-14 levels in subjects with BS and in the HC group did not reveal any statistically significant differences. On the other hand, serum pannexin-1 levels were statistically significantly lower in the BS group.

Neutrophils and redox stress in the pathogenesis of autoimmune disease

Polymorphonuclear leukocytes, or neutrophils, are specialist phagocytic cells of the innate immune system. Their primary role is host defence against micro-organisms, which they kill via phagocytosis, followed by release of reactive oxygen species (ROS) and proteolytic enzymes within the phagosome. ROS are generated via the action of the NADPH oxidase (also known as NOX2), in a process termed the 'Respiratory Burst'. This process consumes large amounts of oxygen, which is converted into the highly-reactive superoxide radical O₂^- and H₂O₂. Subsequent activation of myeloperoxidase (MPO) generates secondary oxidants and chloroamines that are highly microbiocidal in nature, which together with proteases such as elastase and gelatinase provide a toxic intra-phagosomal environment able to kill a broad range of micro-organisms. However, under certain circumstances such as during an auto-immune response, neutrophils can be triggered to release ROS and proteases extracellularly causing damage to host tissues, modification of host proteins, lipids and DNA and dysregulation of oxidative homeostasis. This review describes the range of ROS species produced by human neutrophils with a focus on the implications of neutrophil redox products in autoimmune inflammation.

Effects of L-carnitine supplementation on biomarkers of oxidative stress, antioxidant capacity and lipid profile, in patients with pemphigus vulgaris: a randomized, double-blind, placebo-controlled trial

BACKGROUND/OBJECTIVES

Pemphigus vulgaris (PV), as an autoimmune disease including mucosa and the skin, is associated with several complications and comorbidities. The present study planned to determine the effect of L-carnitine (LC) supplementation on biomarkers of oxidative stress (OS), antioxidant capacity and lipid profile in PV patients.Subjects/MethodsFifty two control and patients with PV, participated in the current randomized, double-blind, placebo-controlled clinical trial. The patients were allocated randomly to receive 2 g per day LC tartrate subdivided into two equal doses of 1 g before breakfast and dinner (n=26) or placebo (n=26) for 8 weeks. Anthropometric, lipid profile and OS values were determined at baseline and end of intervention period.

RESULTS

LC intake significantly reduced serum levels of triglycerides, total-, LDL- cholesterol and oxidative stress index (OSI; P<0.05). In addition, supplementation with LC resulted to a meaningful increase in levels of total antioxidant capacity (TAC) (P=0.05) and serum carnitine (P<0.001). LC intake revealed non-significant change in serum total oxidant capacity (P=0.15) and HDL- cholesterol (P=0.06) in comparison to the placebo.

CONCLUSIONS

LC consumption may have favorable results on TAC, OSI and lipid profiles in patients with PV. The results were in line with the idea that LC supplementation can be associated with positive effects on metabolic status and OS of patients with PV.European Journal of Clinical Nutrition advance online publication, 23 August 2017; doi:10.1038/ejcn.2017.131.

5-Fluorouracil-induced mitochondrial oxidative cytotoxicity and apoptosis are increased in MCF-7 human breast cancer cells by TRPV1 channel activation but not Hypericum perforatum treatment

5-Fluorouracil (5-FU) is a widely used chemotherapy agent for breast cancer, although drug resistance is a critical issue regarding the use of this agent in the disease. Calcium signaling is a well-known main cause of proliferation and apoptosis in breast cancer cells. Although previous studies have implicated TRPV1 inhibitor, anticancer, and apoptotic roles of Hypericum perforatum (HPer) in several cells, the synergistic inhibition effects of HPer and 5-FU in cancer and the stimulation of ongoing apoptosis have not yet been clarified in MCF-7 cells. Therefore, we investigated the apoptotic and antioxidant properties of 5-FU with/without HPer through activation of TRPV1 in MCF-7 cells. The MCF-7 cells were divided into four groups: the control group, the HPer-treated group (0.3 mM), the 5-FU-treated group (25 μM), and the 5-FU+HPer-treated group. The intracellular free calcium ion concentration ([Ca²⁺]_i) increased with 5-FU treatments, but they decreased with the HPer and HPer+5-FU treatments. The [Ca²⁺]_i is further decreased in the four groups by TRPV1 channel antagonist (capsazepine and 0.01 mM) treatments. However, mitochondrial membrane depolarization and apoptosis levels, and the PARP1, caspase 3, and caspase 9 expression levels were increased by 5-FU treatment, although the values were decreased by the HPer and 5-FU+HPer treatments. Cell viability level was also decreased by 5-FU treatment. In conclusion, antitumor and apoptosis effects of 5-FU are up-regulated by activation of TRPV1 channels, but its action was down-regulated by HPer treatment. It seems that HPer cannot be used for increasing the antitumor effect of 5-FU through modulation of the TRPV1.

Inhibition of the TRPM2 and TRPV1 Channels through Hypericum perforatum in Sciatic Nerve Injury-induced Rats Demonstrates their Key Role in Apoptosis and Mitochondrial Oxidative Stress of Sciatic Nerve and Dorsal Root Ganglion

Sciatic nerve injury (SNI) results in neuropathic pain, which is characterized by the excessive Ca²⁺ entry, reactive oxygen species (ROS) and apoptosis processes although involvement of antioxidant Hypericum perforatum (HP) through TRPM2 and TRPV1 activation has not been clarified on the processes in SNI-induced rat, yet. We investigated the protective property of HP on the processes in the sciatic nerve and dorsal root ganglion neuron (DRGN) of SNI-induced rats. The rats were divided into five groups as control, sham, sham+HP, SNI, and SNI+HP. The HP groups received 30 mg/kg HP for 4 weeks after SNI induction. TRPM2 and TRPV1 channels were activated in the neurons by ADP-ribose or cumene peroxide and capsaicin, respectively. The SNI-induced TRPM2 and TRPV1 currents and intracellular free Ca²⁺ and ROS concentrations were reduced by HP, N-(p-amylcinnamoyl) anthranilic acid (ACA), and capsazepine (CapZ). SNI-induced increase in apoptosis and mitochondrial depolarization in sciatic nerve and DRGN of SNI group were decreased by HP, ACA, and CapZ treatments. PARP-1, caspase 3 and 9 expressions in the sciatic nerve, DRGN, skin, and musculus piriformis of SNI group were also attenuated by HP treatment. In conclusion, increase of mitochondrial ROS, apoptosis, and Ca²⁺ entry through inhibition of TRPM2 and TRPV1 in the sciatic nerve and DRGN neurons were decreased by HP treatment. The results may be relevant to the etiology and treatment of SNI by HP.

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-1β 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. β-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.

The Use of Gene Ontology Term and KEGG Pathway Enrichment for Analysis of Drug Half-Life

A drug's biological half-life is defined as the time required for the human body to metabolize or eliminate 50% of the initial drug dosage. Correctly measuring the half-life of a given drug is helpful for the safe and accurate usage of the drug. In this study, we investigated which gene ontology (GO) terms and biological pathways were highly related to the determination of drug half-life. The investigated drugs, with known half-lives, were analyzed based on their enrichment scores for associated GO terms and KEGG pathways. These scores indicate which GO terms or KEGG pathways the drug targets. The feature selection method, minimum redundancy maximum relevance, was used to analyze these GO terms and KEGG pathways and to identify important GO terms and pathways, such as sodium-independent organic anion transmembrane transporter activity (GO:0015347), monoamine transmembrane transporter activity (GO:0008504), negative regulation of synaptic transmission (GO:0050805), neuroactive ligand-receptor interaction (hsa04080), serotonergic synapse (hsa04726), and linoleic acid metabolism (hsa00591), among others. This analysis confirmed our results and may show evidence for a new method in studying drug half-lives and building effective computational methods for the prediction of drug half-lives.

Glutathione Peroxidase Level in Patients with Vitiligo: A Meta-Analysis

Abnormality of glutathione peroxidase (GPx) is involved in the etiology and pathogenesis of vitiligo. However, the results were controversial. Aim. The purpose of this meta-analysis is to compare the levels of GPx between vitiligo patients and healthy controls. Methods. Relevant published articles were searched according to eligibility criteria. A meta-analysis was conducted to pool estimates of the standardized mean difference (SMD) with 95% confidence interval (CI). Results. Twenty-three studies with a total of 1076 vitiligo patients and 770 healthy controls were included. The pooled meta-analysis showed that patients with vitiligo had equivalent levels of GPx with the healthy controls (SMD = −0.47, 95% CI: −1.03 to 0.08, and p = 0.095). Further subgroup analysis showed that the GPx levels of Asian patients or segmental vitiligo patients were, respectively, lower than those of healthy controls (Asian: SMD = −0.47, 95% CI: −1.08 to 0.14, and p = 0.001; segmental: SMD = −3.59, 95% CI: −6.38 to −0.80, and p = 0.012). Furthermore, the GPx levels in serum/plasma were significantly decreased in either stable or active vitiligo patients, comparing to healthy controls (stable: SMD = −2.01, 95% CI: −3.52 to −0.49, and p = 0.009; active: SMD = −2.34, 95% CI: −4.07 to −0.61, and p = 0.008). Conclusion. This meta-analysis showed a significant association between low GPx level and vitiligo.

Anti-tumor Necrosis Factor Alpha (Infliximab) Attenuates Apoptosis, Oxidative Stress, and Calcium Ion Entry Through Modulation of Cation Channels in Neutrophils of Patients with Ankylosing Spondylitis

Ankylosing Spondylitis (AS) is known to be associated with increased neutrophil activation and oxidative stress, however, the mechanism of neutrophil activation is still unclear. We have hypothesized that the antioxidant and anti-tumor necrosis factor properties of infliximab may affect intracellular Ca(2+) concentration in the neutrophils of AS patients. The objective of this study was to investigate the effects of infliximab on calcium signaling, oxidative stress, and apoptosis in neutrophils of AS patients. Neutrophils collected from ten patients with AS and ten healthy controls were used in the study. In a cell viability test, the ideal non-toxic dose and incubation time of infliximab were found as 100 μM and 1 h, respectively. In some experiments, the neutrophils were incubated with the voltage-gated calcium channel (VGCC) blockers verapamil + diltiazem (V + D) and the TRPM2 channel blocker 2-aminoethyl diphenylborinate (2-APB). Intracellular Ca(2+) concentration, lipid peroxidation, apoptosis, caspase 3, and caspase 9 values were high in neutrophils of AS patients and were reduced with infliximab treatment. Reduced glutathione level and glutathione peroxidase activity were low in the patients and increased with infliximab treatment. The intracellular Ca(2+) concentrations were low in 2-APB and V + D groups. In conclusion, the current study suggests that infliximab is useful against apoptotic cell death and oxidative stress in neutrophils of patients with AS, which seem to be dependent on increased levels of intracellular Ca(2+) through activation of TRPM2 and VGCC.

Cytotoxic Activity and Apoptosis Induction of Hypericum scabrum L

Background:

One of the acquired biological hallmarks of tumor multistep development is the resistance of cancer cells to apoptosis; therefore, induction of apoptosis is an important therapeutic approach. Hypericum species are spread throughout the world and have been investigated for their biological properties.

Objectives:

Our previous studies had demonstrated cytotoxicity of Hypericum scabrum L. methanol extract against some tumor cell lines, suggesting the species for further studies. The objectives of the present study were to determine the most cytotoxic fraction of Hypericum scabrum L. and to assess the apoptosis induction ability of the most effective fraction as well as its methanol extract. The laboratory evidence has been presented to support the potency of Iranian Traditional Medicine (ITM) medicinal plants as a source of different biological activity surveys and drug discoveries.

Materials and Methods:

The present research is a descriptive study. The sampling strategy was based on ITM data of cancer phytotherapy. Hypericum scabrum was collected from Alborz province, Iran (2012) and the herbarium specimen was taxonomically identified. The petroleum ether, dichloromethane, and methanol fractions have been evaluated for cytotoxicity against M-CF7, A-549, HT-29, and HepG-2 cell lines through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assay. The apoptosis induction ability has been assessed by activated caspase-3 inspection and Annexin V FITC/PI (propidium iodide) assays.

Results:

Di-chloromethane fraction demonstrated IC₅₀ values of 25.72 μg/mL and 24.73 μg/mL against HT-29 and HepG-2 cell lines, respectively and IC₅₀ values of petroleum ether fraction were 22.6 μg/mL and 18.31 μg/mL against HT-29 and HepG-2, respectively. The methanol fraction did not show cytotoxic activity. Both the methanol extract and the petroleum ether fraction of Hypericum scabrum L. revealed apoptosis induction ability.

Conclusions:

Considering the strong historical background about the therapeutic potential of the genus Hypericum and the considerable cytotoxic and apoptosis induction ability of Hypericum scabrum, this species is suggested for future biological studies.

Sensitization of H2O2-induced TRPM2 activation and subsequent interleukin-8 (CXCL8) production by intracellular Fe(2+) in human monocytic U937 cells

Transient receptor potential melastatin 2 (TRPM2) is an oxidative stress-sensitive Ca(2+)-permeable channel. In monocytes/macrophages, H2O2-induced TRPM2 activation causes cell death and/or production of chemokines that aggravate inflammatory diseases. However, relatively high concentrations of H2O2 are required for activation of TRPM2 channels in vitro. Thus, in the present study, factors that sensitize TRPM2 channels to H2O2 were identified and subsequent physiological responses were examined in U937 human monocytes. Temperature increase from 30°C to 37°C enhanced H2O2-induced TRPM2-mediated increase in intracellular free Ca(2+) ([Ca(2+)]i) in TRPM2-expressing HEK 293 cells (TRPM2/HEK cells). The H2O2-induced TRPM2 activation enhanced by the higher temperature was dramatically sensitized by intracellular Fe(2+)-accumulation following pretreatment with FeSO4. Thus intracellular Fe(2+)-accumulation sensitizes H2O2-induced TRPM2 activation at around body temperature. Moreover, intracellular Fe(2+)-accumulation increased poly(ADP-ribose) levels in nuclei by H2O2 treatment, and the sensitization of H2O2-induced TRPM2 activation were almost completely blocked by poly(ADP-ribose) polymerase inhibitors, suggesting that intracellular Fe(2+)-accumulation enhances H2O2-induced TRPM2 activation by increase of ADP-ribose production through poly(ADP-ribose) polymerase pathway. Similarly, pretreatment with FeSO4 stimulated H2O2-induced TRPM2 activation at 37°C in U937 cells and enhanced H2O2-induced ERK phosphorylation and interleukin-8 (CXCL8) production. Although the addition of H2O2 to cells under conditions of intracellular Fe(2+)-accumulation caused cell death, concentration of H2O2 required for CXCL8 production was lower than that resulting in cell death. These results indicate that intracellular Fe(2+)-accumulation sensitizes TRPM2 channels to H2O2 and subsequently produces CXCL8 at around body temperature. It is possible that sensitization of H2O2-induced TRPM2 channels by Fe(2+) may implicated in hemorrhagic brain injury via aggravation of inflammation, since Fe(2+) is released by heme degradation under intracerebral hemorrhage.

Hypericum perforatum Attenuates Spinal Cord Injury-Induced Oxidative Stress and Apoptosis in the Dorsal Root Ganglion of Rats: Involvement of TRPM2 and TRPV1 Channels

Oxidative stress and cytosolic Ca(2+) overload have important roles on apoptosis in dorsal root ganglion (DRG) neurons after spinal cord injury (SCI). Hypericum perforatum (HP) has an antioxidant property in the DRGs due to its ability to modulate NADPH oxidase and protein kinase C pathways. We aimed to investigate the protective property of HP on oxidative stress, apoptosis, and Ca(2+) entry through transient receptor potential melastatin 2 (TRPM2) and transient receptor potential vanilloid 1 (TRPV1) channels in SCI-induced DRG neurons of rats. Rats were divided into four groups as control, HP, SCI, and SCI + HP. The HP groups received 30 mg/kg HP for three concessive days after SCI induction. The SCI-induced TRPM2 and TRPV1 currents and cytosolic free Ca(2+) concentration were reduced by HP. The SCI-induced decrease in glutathione peroxidase and cell viability values were ameliorated by HP treatment, and the SCI-induced increase in apoptosis, caspase 3, caspase 9, cytosolic reactive oxygen species (ROS) production, and mitochondrial membrane depolarization values in DRG of SCI group were overcome by HP treatment. In conclusion, we observed a protective role of HP on SCI-induced oxidative stress, apoptosis, and Ca(2+) entry through TRPM2 and TRPV1 in the DRG neurons. Our findings may be relevant to the etiology and treatment of SCI by HP. Graphical Abstract Possible molecular pathways of involvement of Hypericum perforatum (HP) on apoptosis, oxidative stress, and calcium accumulation through TRPM2 and TRPV1 channels in DRG neurons of SCI-induced rats. The TRPM2 channel is activated by ADP-ribose and oxidative stress through activation of ADP-ribose pyrophosphate although it was inhibited by N-(p-amylcinnamoyl) anthranilic acid (ACA) and 2-aminoethyl diphenylborinate (2APB). The TRPV1 channel is activated by oxidative stress and capsaicin and it is blocked by capsazepine. Injury in the DRG can result in augmented ROS release, leading to Ca(2+) uptake through TRPM2 and TRPV1 channels. Mitochondria were reported to accumulate Ca(2+), provided intracellular Ca(2+) rises, thereby leading to depolarization of mitochondrial membranes and release of apoptosis-inducing factors such as caspase 3 and caspase 9. HP via regulation of NADPH oxidase and PKC inhibits TRPM2 and TRPV1 channels. The molecular pathway may be a cause of SCI-induced pain and neuronal death, and the subject should be urgently investigated.

Selenium reduces oxidative stress and calcium entry through TRPV1 channels in the neutrophils of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common inflammatory disease with an uncertain pathogenesis, although one consistent finding is increased neutrophil activity. It has been recently reported that the essential antioxidant element selenium has protective effects on oxidative stress and cytosolic Ca(2+) concentrations in human neutrophil. We aimed to investigate the effects of selenium on oxidative stress and Ca(2+) levels through TRPV1 channels in neutrophils from patients with PCOS. Blood samples were obtained for neutrophil isolation from ten female patients with PCOS and ten healthy female subjects. Neutrophils isolated from PCOS group were investigated in four settings: (1) PCOS, (2) after incubation with TRPV1 channel blocker capsazepine (CPZ), (3) after incubation with selenium (sodium selenite), and (4) with combination (CPZ + selenium) exposure. Intracellular free Ca(2+) concentrations were higher in the patients than those in the controls, although their levels were reduced after CPZ and selenium incubations. The cytosolic Ca(2+) concentrations in neutrophils obtained from PCOS group were further decreased after incubation with CPZ + selenium, as compared with those exposed to neither agent. Lipid peroxidation levels were higher in the PCOS group than those in the control although neutrophil glutathione peroxidase (GSH-Px) and reduced glutathione (GSH) values were decreased. The lipid peroxidation level was lower in the CPZ and selenium groups than that in the PCOS group although GSH and GSH-Px values were higher in the treatment with selenium and CPZ. In conclusion, we observed the importance of Ca(2+) influx into the neutrophils through TRPV1 channels in the pathogenesis of the patients with PCOS. The selenium appeared to provide a protective effect against oxidative stress and Ca(2+) entry through modulation of neutrophil TRPV1 calcium channels.