Health risk assessment of heavy metal toxicity in the aquatic environment of the Persian Gulf.

This study aims to explore the potential health risks linked to four heavy metals/metalloids (Pb, Cd, As, Hg) present in four commercially important fish species (Scombromorus commerson, Pseudorhombus elevatus, Thunnus tonggol and Otolithes ruber) in the Persian Gulf. Metals in fish muscle tissue were analyzed via ICP-MS. The analysis revealed that Scombromorus commerson (except for Pb) and Thunnus tonggol (except for As) exhibited the highest and lowest contamination levels, respectively. The Hazard Index findings highlighted arsenic and mercury as the most hazardous elements. However, the Target Hazard Quotient values for each metal and fish species remained within safe thresholds. The highest and lowest Total Carcinogenic Risk was concerning Pseudorhombus elevates (As: 7.41-E05), and Thunnus thonggol (Pb: 3.21-E07), respectively. TCR analysis suggests that the cancer risk of studied metals was below the negligible level (TCR < 10-6) or within the acceptable level (10-6 < TCR < 10-4), potentially not posing carcinogenic risks through extended consumption.

Arsenic and Benzo[a]pyrene Co-exposure Effects on MDA-MB-231 Cell Viability and Migration.

Although humans are frequently exposed to multiple pollutants simultaneously, research on their harmful effects on health has typically focused on studying each pollutant individually. Inorganic arsenic (As) and benzo[a]pyrene (BaP) are well-known pollutants with carcinogenic potential, but their co-exposure effects on breast cancer cell progression remain incompletely understood. This study aimed to assess the combined impact of BaP and As on the viability and migration of MDA-MB-231 cells. The results indicated that even at low levels, both inorganic As (0.01 µM, 0.1 µM, and 1 µM) and BaP (1 µM, 2.5 µM), individually or in combination, enhanced the viability and migration of the cells. However, the cell cycle analysis revealed no significant differences between the control group and the cells exposed to BaP and As. Specifically, exposure to BaP alone or in combination with As (As 0.01 µM + BaP 1 µM) for 24 h led to a significant increase in vimentin gene expression. Interestingly, short-term exposure to As not only did not induce EMT but also modulated the effects of BaP on vimentin gene expression. However, there were no observable changes in the expression of E-cadherin mRNA. Consequently, additional research is required to evaluate the prolonged effects of co-exposure to As and BaP on the initiation of EMT and the progression of breast cancer.

Sumatriptan mitigates bleomycin-induced lung fibrosis in male rats: Involvement of inflammation, oxidative stress and α-SMA.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung condition that produces symptoms including coughing which may cause by excessive accumulation of scar tissue inflammatory and oxidative stress exacerbation. Sumatriptan, utilized for migraine treatment as a selective 5-HT1B/1D receptor agonist, has demonstrated significant anti-inflammatory and antioxidant properties in multiple preclinical investigations. Operating primarily on serotonin receptors, sumatriptan leverages the diverse physiological functions of serotonin, playing a pivotal role in regulating both inflammation and oxidative stress which is particularly relevant in the context of IPF. MATERIALS & METHODS: Thirty-five male Wistar rats were divided to five group, including: Sham (without IPF induction), control (BLM 5 mg/kg, intraperitoneally), and three fibrosis group with sumatriptan (0.5, 1, and 3 mg/kg, i.p. for 2 weeks) administration. IPF was induced by injection of BLM (single dose, 5 mg/kg intratracheally). Lung tissues were separated for measurement of myeloperoxidase (MPO) as an oxidative stress hallmark, and tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-ß), and transforming growth factor-ß (TGF-ß) as inflammatory markers as well as alpha smooth muscle actin (α-SMA). Also, for histological investigations, tissue damages were assessed by Hematoxylin-eosin (H&E) and Masson's trichrome staining method. RESULTS: BLM-induced fibrosis could increase α-SMA, MPO, TNF-α, IL-1ß, and TGF-ß, while treatment with sumatriptan has reversed the α-SMA, MPO, and IL-1ß levels. Moreover, the results of H&E and Masson's trichrome staining indicated that sumatriptan (1 and 3 mg/kg) reduced tissue damages, alveolar wall thickness, collagen accumulation, and pulmonary fibrosis induced by BLM. CONCLUSION: According to the data achieved from this study, Sumatriptan appears to have therapeutic benefits in IPF, possibly via reducing α-SMA as well as inflammation and the toxicity caused by oxidative stress.

Chronic Cinacalcet improves skin flap survival in rats: the suggested role of the nitric oxide pathway.

Cinacalcet is a calcimimetic medicine that has been used to treat secondary hyperparathyroidism and parathyroid cancer. Various studies have proposed the positive role of calcium and its receptor in skin wound healing. Furthermore, Cinacalcet interacts with other skin repair-related mechanisms, including inflammation and nitric oxide pathways. The present study evaluated the effect of Cinacalcet on the random-pattern skin flap survival. Eighty-four Wistar male rats were used. Multiple doses of Cinacalcet (30, 3, 1, 0.3, and 0.05 mg/kg) were used in 3 different routes of administration before the surgery. Histopathological evaluations, quantitative assessment of IL-6, TNF-α, and nitric oxide (NO), and the expression of calcium-sensing receptor (CaSR) and E-cadherin were evaluated in the skin tissue. To assess the role of NO, a NO synthase inhibitor, N-nitro-L-arginine methyl ester hydrochloride (L-NAME), was used, and histopathological effects were investigated. Cinacalcet pretreatment at the IP chronic 1 mg/kg dose significantly increased the skin flap survival rate and enhanced the NO tissue level compared to the control. However, the administration of L-NAME abolished its protective effects. IP Chronic 1 mg/kg of Cinacalcet could also decline the levels of IL-6 and TNF-α and also increase the expression of CaSR and E-cadherin in the flap tissue compared with the control group. Chronic Cinacalcet at 1 mg/kg could improve skin flap survival, probably mediated by the CaSR, NO, and inflammation-related pathways.

Disrupting Development: Unraveling the Interplay of Aryl Hydrocarbon Receptor (AHR) and Wnt/ß-Catenin Pathways in Kidney Development Under the Influence of Environmental Pollutants.

Understanding the intricate molecular mechanisms governing aryl hydrocarbon receptor (AHR) and Wnt/ß-Catenin pathways crosstalk is of paramount importance for elucidating normal development. We investigated the repercussions of aberrant activation of these signaling pathways on kidney development. HEK-293 cells were subjected to AHR and Wnt activators and inhibitors for 3 and 24 h. Subsequently, pregnant adult female BALB/c mice were administered treatments at gestation day 9 (GD-9), and embryos were analyzed at GD-18 using a combination of cellular, molecular, stereological, and histopathological techniques. Our results demonstrated a noteworthy escalation in oxidative stress and gene expression endpoints associated with apoptosis. Moreover, stereological analyses exhibited alterations in cortex, proximal tubule, and kidney tissue vessels volumes. Remarkably, co-treatment with 6-formylindolo [3,2-b] carbazole (FICZ) and cadmium (Cd) resulted in a significant reduction in glomerulus volume, while elevating the volumes of distal tubule, Henle loop, and connective tissue, compared to the control group. Histopathological investigations further confirmed structural changes in the loop of Henle and proximal tubule, alongside a decline in glomerular volume. Additionally, the expression levels of AHR and Ctnnb1 genes significantly increased in the Cd-treated group compared to the control group. Enhanced expression of apoptosis-related genes, including Bcl-x, Bax, and Caspase3, along with alterations in mitochondrial membrane potential and cytochrome C release, was observed. In contrast, Gsk3 gene expression was significantly decreased. Our findings robustly establish that chemical pollutants, such as Cd, disrupt the AHR and Wnt/ß-Catenin physiological roles during developmental stages by inhibiting the metabolic degradation of FICZ.

Effect of crocin and quercetin supplementation in cryopreservation medium on post-thaw human sperm quality.

Biochemical and physical changes during the cryopreservation process adversely affect sperm function required for fertilization. Recently, many studies have been conducted to find effective pre-freezing treatments to limit these damages. The present study aimed to investigate the effects of pre-freezing treatment with quercetin and crocin, individually or in combination, on sperm parameters after thawing procedure. For this, semen samples from 20 normozoospermic men were collected and then each sample was divided into five equal parts: 1. fresh group 2. frozen-thawed group without addition of antioxidants 3. frozen-thawed group containing 1 mM crocin, 4. frozen-thawed group containing 50 µM quercetin, and 5. frozen-thawed group containing a combination of 1 mM crocin and 50 µM quercetin. Pre-cryopreservation and post-thaw sperm motility, morphology, viability, DNA fragmentation, reactive oxygen species [1] (ROS) levels, and mitochondrial membrane potential [2] (MMP) were investigated. Cryopreservation significantly reduced sperm quality. Both crocin and quercetin individually improved sperm progressive motility, decreased ROS levels, reduced DNA fragmentation, and marginally increased MMP, though crocin seems to be more successful in protecting sperm quality. More interestingly, the combined addition of crocin and quercetin to the sperm-freezing medium did not show positive effects on sperm quality. Crocin and quercetin may play a role in mitigating the cryopreservation-induced injury to sperm.

The Role of the Kynurenine/AhR Pathway in Diseases Related to Metabolism and Cancer.

The Aryl hydrocarbon receptor (AhR) is a xenobiotic and endobiotic receptor, which regulates many cellular processes from contaminant metabolism to immunomodulation. Consequently, it is also involved in pathophysiological pathways and now represents a potential therapeutical target. In this review, we will highlight the ancestral function of the protein together with an illustration of its ligand's battery, emphasizing the different responses triggered by these high diverse molecules. Among them, several members of the kynurenine pathway (one key process of tryptophan catabolism) are AhR agonists and are subsequently involved in regulatory functions. We will finally display the interplay between Tryptophan (Trp) catabolism and dysregulation in metabolic pathways drawing hypothesis on the involvement of the AhR pathway in these cancer-related processes.

Arsenic trioxide-induced cytotoxicity in A549 cells: The role of necroptosis.

INTRODUCTION: Lung cancer is one of the deadliest cancers globally. Arsenic trioxide (ATO) is still present as a highly effective drug in treating acute promyelocytic leukemia (APL). Chemotherapy resistance is one of the major problems in cancer therapy. Necroptosis, can overcomes resistance to apoptosis, and can promote cancer treatment. This study examines the necroptosis pathway in A549 cancer cells exposed to ATO. METHODS: We used the MTT test to determine the ATO effects on the viability of A549 cells at three different time intervals. Also, the reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were performed in three-time intervals. The effect of ATO on apoptosis was evaluated by Annexin V / PI staining and, the RIPK1 and MLKL gene expression were measured by Real-Time PCR. RESULTS: The ATO has dose and time-dependent cytotoxic effects, so at 24, 48, and 72 h, the IC50 doses were 33.81 '11.44 '2.535 µM respectively. A 50 µM ATO is the most appropriate to increase the MMP loss significantly at all three times. At 24 and 48 h after exposure of cells to ATO, the ROS levels increased. The RIPK1 gene expression increased significantly compared to the control group at concentrations of 50 and 100 µM; however, MLKL gene expression decreased. CONCLUSIONS: The A549 cells, after 48 h exposure to ATO at 50 and 100 µM, induces apoptosis and necroptosis. Due to the reduced expression of MLKL, it can be concluded that ATO is probably effective in the metastatic stage of cancer cells.

Oxytocin protective effects on zebrafish larvae models of autism-like spectrum disorder.

Objectives: Autism is a complicated neurodevelopmental disorder characterized by social interaction deficiencies, hyperactivity, anxiety, communication disorders, and a limited range of interests. The zebrafish (Danio rerio) is a social vertebrate used as a biomedical research model to understand social behavior mechanisms. Materials and Methods: After spawning, the eggs were exposed to sodium valproate for 48 hr, after which the eggs were divided into eight groups. Except for the positive and control groups, there were six treatment groups based on oxytocin concentration (25, 50, and 100 µM) and time point (24 and 48 hr). Treatment was performed on days 6 and 7, examined by labeling oxytocin with fluorescein-5-isothiocyanate (FITC) and imaging with confocal microscopy and the expression levels of potential genes associated with the qPCR technique. Behavioral studies, including light-dark background preference test, shoaling behavior, mirror test, and social preference, were performed on 10, 11, 12, and 13 days post fertilization (dpf), respectively. Results: The results showed that the most significant effect of oxytocin was at the concentration of 50 µM and the time point of 48 hr. Increased expression of shank3a, shank3b, and oxytocin receptor genes was also significant at this oxytocin concentration. Light-dark background preference results showed that oxytocin in the concentration of 50 µM significantly increased the number of crosses between dark and light areas compared with valproic acid (positive group). Also, oxytocin showed an increase in the frequency and time of contact between the two larvae. We showed a decrease in the distance in the larval group and an increase in time spent at a distance of one centimeter from the mirror. Conclusion: Our findings showed that the increased gene expression of shank3a, shank3b, and oxytocin receptors improved autistic behavior. Based on this study some indications showed that oxytocin administration in the larval stage could significantly improve the autism-like spectrum.

Metformin exerts synergistic anti-proliferative effects with liraglutide in human umbilical vein endothelial cells (HUVECs).

Objectives: Metformin (Met) and liraglutide (Lira) have been approved to treat type 2 diabetes mellitus and have cardioprotective effects. Materials and Methods: Human umbilical vein endothelial cells (HUVECs) were incubated with Met, Lira, or their combination in this study. Results: Results showed that the synergistic inhibitory effect of the two drugs on HUVECs proliferation was significant (75%) after 48 hr drug exposure. In addition, either Lira or Met alone had a marked tendency to inhibit the migration of HUVECs (42% and 39%). Almost a complete inhibition (97%) was demonstrated in combinational use after 48 hr treatment. After combining these two drugs, the apoptosis rate raised to 68%, which was a significant approval of synergistic apoptosis induction of Met and Lira. The combinational group indicated a substantial increase in VEGF, PDGF, and MMP-9 at 24 hr compared with the control. Conclusion: This study showed that combination therapy with Lira and Met could effectively reduce cell proliferation, induce apoptosis, and inhibit cell migration in the HUVECs. This study provides evidence to support using Met in combination with Lira as a treatment option for patients with type-2 diabetes and cancer.

Sodium Selenite Modulates IDO1/Kynurenine, TLR4, NF-κB and Bcl2/Bax Pathway and Mitigates Acetic Acid-Induced Colitis in Rat.

BACKGROUND/AIMS: Colitis is a main presentation of inflammatory bowel disease (IBD) and yet, has no definitive cure. Currently, corticosteroids, anti-tumor necrosis factor (anti-TNF) agents and 5-aminosalicylic acid derivatives are prescribed for management of colitis. Except their failure rate, they are not always tolerated because of their severe adverse effects. Additive formulas with fewer adverse effects may improve the treatment of colitis. METHODS: In this study, colitis was induced with intra-rectal injection of three concentrations of acetic acid (4, 6 and 8 v/v). Each group received sodium selenite (0.5 mg/kg) or saline, gavaged on days 0 and 1 for treatment. Two days after induction of colitis, rats were sacrificed and the end part of their colons were resected for macroscopic and microscopic evaluation and molecular measurement. RESULTS: Sodium selenite improved macroscopic and microscopic view of the colon, decreased cryptitis, crypt abscess and inflammatory cells infiltration and partly maintained mucosal structure. Sodium selenite markedly reduced tissue levels of malondialdehyde (MDA), TNF-α and interferon γ (INF-γ) and decreased myeloperoxidase (MPO) activity. Treatment with sodium selenite also significantly downregulated IL17, IL22, indoleamine 2,3-dioxygenase (IDO1), and kynurenine levels. Western blotting revealed that sodium selenite prevented apoptosis by increasing bcl2/Bax ratio. Furthermore, our findings showed that sodium selenite significantly downregulated the upstream inflammatory molecules such as nuclear factor kappa B (NF-κB) and toll-like receptor 4 (TLR4) in colitis. CONCLUSION: These findings show that sodium selenite alleviates inflammatory response and oxidative stress and protects against colitis.

Neuroprotective effect of sumatriptan in pentylenetetrazole-induced seizure is mediated through N-methyl-D-aspartate/nitric oxide and cAMP response element-binding protein signaling pathway.

Seizure occurs as a result of uncontrolled electrical disturbances within the brain. Various biomolecules such as N-methyl-D-aspartate (NMDA), nitric oxide (NO), and cAMP response element-binding protein (CREB) have been implicated in the pathophysiology of seizure. Sumatriptan is a specific 5-Hydroxytryptamine 1B/1D receptor agonist and has neuroprotective effects in various neuropsychiatric disorders. In the current study, we tried to investigate the possible interaction of sumatriptan with NMDA/NO and CREB signaling pathway in PTZ induced seizure. For this purpose, various agonist and antagonist of NMDA such as MK-801 and Ketamine, NO precursor L-ARG, and NOS inhibitors L-NAME and 7-NI were co-administered with sumatriptan in PTZ induced seizure model. The level of nitrite in mice hippocampus was determined by Griess reaction. The gene expression of NR1, NR2A, NR2B, and CREB were quantified by quantitative real time-polymerase chain reaction (qRT-PCR). Furthermore, the involved neuronal nitric oxide synthase (nNOS) protein expression was examined via western blot analysis. Effective dose of sumatriptan (1.2 mg/kg) alone and subeffective dose of sumatriptan (0.3 mg/kg) in combination with NMDA and/or NO antagonist showed significant (P < 0.001) anticonvulsant activity in mice. Furthermore, sumatriptan significantly inhibited the PTZ-induced mRNA expression of NR2A (P < 0.0001), NR2B (P < 0.05), and CREB (P < 0.01). Also, the expression of nNOS protein in PTZ treated group was reversed by sumatriptan (P < 0.01). Hence, current findings suggest that the anticonvulsant effect of sumatriptan was due to down regulation of NMDA/NO and CREB signaling pathway.

Cigarette smoke-induced toxicity consequences of intracellular iron dysregulation and ferroptosis.

Despite numerous studies on the mechanisms of cigarette smoking toxicity over the past three decades, some aspects remain obscure. Recent developments have drawn attention to some hopeful indicators that allow us to advance our awareness of cigarette-induced cell death. Ferroptosis is considered a type of governed death of cells distinguished by the iron-dependent lipid hydroperoxide deposition to fatal concentrations. Ferroptosis has been linked with pathological settings such as neurodegenerative diseases, cancer, heart attack, hemorrhagic stroke, traumatic brain injury, ischemia-reperfusion injury, and renal dysfunction. This review tries to explain the causal role of ferroptosis cascade in cigarette smoke-mediated toxicity and cell death, highlighting associations on potential action mechanisms and proposing suggestions for its detoxifying and therapeutic interventions.

ß-Sitosterol Alters the Inflammatory Response in CLP Rat Model of Sepsis by Modulation of NFκB Signaling.

PURPOSE: Sepsis originates from the host inflammatory response, especially to bacterial infections, and is considered one of the main causes of death in intensive care units. Various agents have been developed to inhibit mediators of the inflammatory response; one prospective agent is ß-sitosterol (ßS), a phytosterol with a structure similar to cholesterol. This study is aimed at evaluating the effects of ßS on the biomarkers of inflammation and liver function in cecal ligation and puncture- (CLP-) induced septic rats. METHODS: Thirty male Wistar rats were divided equally into six groups as follows: sham, CLP, CLP+dexamethasone (DX, 0.2 mg/kg), CLP+ßS (1 mg/kg), CLP+imipenem (IMI, 20 mg/kg), and CLP+IMI (20 mg/kg)+ßS (1 mg/kg). Serum levels of IL-1ß, IL-6, IL-10, AST, ALT, and liver glutathione (GSH) were assessed by ELISA. Liver expression levels of TNF-α and NF-κBi mRNAs were evaluated by RT-qPCR. RESULTS: Serum concentrations of IL-1ß, IL-6, IL-10, ALT, and AST and mRNA levels of TNF-α and NF-κBi were all significantly higher in septic rats than in normal rats (p < 0.05). Liver GSH content was markedly lower in the CLP group than that in the sham group. ßS-treated rats had remarkably lower levels of IL-1ß, IL-6, IL-10, TNF-α, NF-κBi, AST, and ALT (51.79%, 62.63%, 41.46%, 54.35%, 94.37%, 95.30%, 34.87%, and 46.53% lower, respectively) and greater liver GSH content (35.71% greater) compared to the CLP group (p < 0.05). CONCLUSION: ßS may play a protective role in the septic process by mitigating inflammation. This effect is at least partly mediated by inhibition of the NF-κB signaling pathway. Thus, ßS can be considered as a supplementary treatment in septic patients.

The role of macrophage polarization and function in environmental toxicant-induced cancers.

Macrophages are a critical member of the innate immune system and can intensify tumor invasiveness and assist the growth of neoplastic cells. Moreover, they have the capability to reinforce immunosuppression and angiogenesis. Various investigations suggest that health-related issues, including inflammatory disorders and neoplastic diseases may be caused by environmental toxicant exposure. However, it is still unclear what role these environmental toxicants play in causing carcinogenesis by disturbing the mechanisms of migration, polarization, differentiation, and immune-stimulatory functions of macrophages. Accordingly, in this article, we will explore the interaction between environmental chemicals and inflammatory macrophage processes at the molecular level and their association with tumor progression and carcinogenesis.

Growth Promotion and Increased ATP-Binding Cassette Transporters Expression by Liraglutide in Triple Negative Breast Cancer Cell Line MDA-MB-231.

BACKGROUND: Glucagon-like petide-1 (GLP-1) agonists such as liraglutide are widely employed in type 2 diabetes due to their glucose reducing properties and small risk of hypoglycemia. Recently, it has been shown that GLP-1agonists can inhibit breast cancer cells growth. Nonetheless, concerns are remained about liraglutide tumor promoting effects as stated by population studies. MATERIAL AND METHODS: We evaluated the effects liraglutide on proliferation of MDA-MB-231 cells by MTT assay and then ATP-binding cassette (ABC) transporters expressions assessed by Real time PCR. Statistical comparisons were made using one-way analysis of variance followed by a post hoc Dunnett test. RESULTS: Here, we report that liraglutide can stimulate the growth of highly invasive triple negative cell line MDA-MB-231; which can be attributed to AMPK-dependent epithelial-mesenchymal transition (EMT) happening in MDA-MB-231 context. Toxicity effects were only observed with concentrations far above the serum liraglutide concentration. ATP-binding cassette (ABC) transporters expressions were upregulated, indicating the possible drug resistance and increased EMT. CONCLUSION: In conclusion, these results suggest that liraglutide should be used with caution in patients who are suffering or have the personal history of triple negative breast cancer. However, more detailed studies are required to deepen understanding of liraglutide consequences in triple negative breast cancer. ▶Graphical Abstract.

The Inhibitory Effect of Curcumin on Hypoxia Inducer Factors (Hifs) as a Regulatory Factor in the Growth of Tumor Cells in Breast Cancer Stem-Like Cells.

Hypoxia in the microenvironment is related to chemotherapy resistance, tumor progression, and metastasis. Curcumin, as a phenolic compound extracted from the turmeric, has been used as an anti-cancer agent with low toxicity in recent years. Since curcumin has inhibitory activities against hypoxia-inducible factors (HIFs) in several cancers, this study was conducted to examine the effect of curcumin on MCF-7 cells and cancer stem-like cells (CS-LCs) under hypoxic and normoxic conditions. CS-LCs were isolated from MCF-7 cells using the magnet activated cell sorting (MACS) method based on CD44 +/ CD24 - surface markers. The effects of curcumin on the viability of MCF-7 cells and CS-LCs were examined in hypoxic and normoxic conditions using the MTT test. The effects of curcumin on apoptosis and cell cycle of CS-LCs and MCF-7 cells were analyzed using flow cytometry. Moreover, the inhibitory effects of curcumin on the levels of HIF-1 and HIF-2α protein in CS-LCs were investigated using the western blot method. Early apoptosis occurred in CSC-LCs more than MCF-7 cells under hypoxic conditions. Flow cytometry assay showed that curcumin caused cell cycle arrest of CSC-LCs and MCF-7 at the G2/M phase under hypoxic conditions while under normoxic conditions, arrest occurred at the G0/G1 phase in MCF-7 cells and at S and G2/M phases in CS-LCs. Based on the results, the curcumin inhibited the expression of HIF-1 by degrading ARNT in CS-LCs.In conclusion, curcumin has inhibitory effects on MCF- 7 cells and CS- LCs and thus may be used as an antitumor agent.

Protective Role of EGCG Against Malathion Induced Genotoxicity Using Human Lymphocytes.

BACKGROUND: Green tea (Camellia sinensis), which is the most common drink across the world after water, has many antioxidant properties. Epigallocatecin-3-gallate (EGCG) is a flavonoid which accounts for 33-50% of green tea solids. It functions as a powerful antioxidant, preventing oxidative damage in healthy cells, with antiangiogenic and antitumor activities and as a modulator of tumor cell response to chemotherapy. Malathion is an organophosphate pesticide which is widely used in agriculture, veterinary and industries. Oxidative stress has been identified as one of malathion's main molecular mechanisms. The purpose of this study was to evaluate protective role of EGCG against malathion induced genotoxicity using human lymphocyte model. Blood samples from 8 non-smoker healthy volunteers with no history of chemotherapy were collected and divided into six groups: Control, EGCG (50 µM), EGCG (20 µM), Malathion (24 µM), EGCG (50 µM)+Malathion (24 µM) and EGCG (20 µM)+Malathion (24 µM). For genotoxicity assay, we employed micronuclei test. For antioxidant capacity evaluation, GSH content and MDA levels were measured. Malathion showed significant genotoxic damage compared to the intact lymphocytes, however, treatment with EGCG at both concentrations were reduced the genotoxic effect of malathion. Malathion induced lipid peroxidation, while pre-treatment with EGCG at both concentrations, significantly protected the lymphocytes against malathion induced lipid peroxidation. Malathion significantly reduced GSH content, but pre-treatment with EGCG significantly recovered GSH content. Overall this study demonstrated that EGCG (at both concentrations) significantly prevents human lymphocytes against malathion induced genotoxicity and oxidative damage.

GDF15 induced apoptosis and cytotoxicity in A549 cells depends on TGFBR2 expression.

GDF15 plays a paradoxical role during carcinogenesis; it inhibits tumour growth in the early stages and promotes tumour cell proliferation in the late stages of cancer. Besides, GDF15 can induce apoptosis in some cancer cells including A549 but not in some others. Moreover, as a potential receptor for GDF15, TGFBR2 is inactivated during carcinogenesis in many types of cancers, and it is not present in cells with no GDF15 induced apoptosis. Thus, we tested whether GDF15 overexpression and/or TGFBR2 silencing can affect the GDF15 induced apoptosis in A549 cells. The full and mature forms of GDF15 were cloned and overexpressed in A549 cells. The TGFBR2 was silenced using specific siRNA and confirmed by real-time PCR. Results indicated that overexpression of full and mature forms of GDF15 as well as TGFBR2 knocked down reduced A549 cell viability in 24 and 48 hours. Flow cytometric analysis of annexin V/PI indicated induction of apoptosis in A549 cells by overexpression of GDF15 or silencing TGFBR2. Interestingly, the silencing of TGFBR2 inhibited the GDF15 induced cytotoxicity and apoptosis in A549 cells. Overexpression of GDF15 activated caspase-9 and caspase-3 and inhibited ERK1/2 and p38 phosphorylation in A549 cells. TGFBR2 knocked down inhibited GDF15 effects on caspases, ERK1/2, and p38MAPK activation. Our results indicated that the effect of GDF15 on apoptosis and activation of MAPK in A549 cells depends on TGFBR2 expression. These findings may point to mechanisms in which GDF15 exerts dual effect during carcinogenesis with regard to TGFBR2 expression. SIGNIFICANCE OF THE STUDY: GDF15 plays a tumour suppressor or promotor roles during carcinogenesis. The expression of GDF15 induced cytotoxicity, apoptosis, and inhibition of MAPK in A549 cells. All these effects were blocked by silencing TGFBR2 expression. These findings may point to mechanisms in which GDF15 exerts dual effect during carcinogenesis with regard to TGFBR2 expression.

Signaling Crosstalk of FHIT, p53, and p38 in etoposide-induced apoptosis in MCF-7 cells.

Fragile histidine trail (FHIT) is a tumor suppressor in response to DNA damage which has been deleted in various tumors. However, the signaling mechanisms and interactions of FHIT with regard to apoptotic proteins including p53 and p38 in the DNA damage-induced apoptosis are not well described. In the present study, we used etoposide-induced DNA damage in MCF-7 as a model to address these crosstalks. The time course study showed that the expression of FHIT, p53, and p38MAPK started after 1 hour following etoposide treatment. FHIT overexpression led to increase p53 expression, p38 activation, and augmented apoptosis following etoposide-induced DNA damage compared to wild-type cells. However, FHIT knockdown blocked p53 expression, delayed p38 activation, and completely inhibited etoposide-induced apoptosis. Inhibition of p38 activity prevented induction of p53, FHIT, and apoptosis in this model. Thus, activation of p38 upon etoposide treatment leads to increase in FHIT and p53 expression. In p53 knockdown MCF-7, the FHIT induction was hampered but p38 activation was induced in lower doses of etoposide. In p53 knockdown cells, inhibition of p38 induced FHIT expression and apoptosis. Our data demonstrated that the exposure of MCF-7 cells to etoposide increases apoptosis through a mechanism involving the activation of the p38-FHIT-p53 pathway. Moreover, our findings suggest signaling interaction for these pathways may represent a promising therapy for breast cancer.