Hexavalent Chromium Induced Oxidative Stress and Toxicity on isolated human lymphocytes

Introduction: The most toxic form of chromium (Cr) in the environment is the oxyanion chromate (Cr (VI)). In this form it is soluble and is transported into the cells. Chromate structurally resemble phosphate and sulfate, and can be transported into cells by the anion carrier.  Methods and Results: In this study, toxicity effects of Cr (VI) on isolated human lymphocytes was studied using accelerated cytotoxicity mechanisms screening (ACMS) technique. Human lymphocytes were isolated from blood of healthy persons using Ficoll-paque PLUS standard method. The trypan blue dye was used to cytotoxicity assay. The mechanistic parameters including reactive oxygen species (ROS), lysosomal membrane destabilization, mitochondrial membrane potential (MMP) collapse, lipid peroxidation, GSH and GSSG levels were assessed after 1, 2 and 3 hrs in potassium dichromate treated lymphocytes. The results indicate that toxicity of Cr (VI) was concentration dependent in human lymphocytes. Cr (VI) significantly (p<0.05) induced ROS production, MMP reduction, lysosomal membrane destabilization and lipid peroxidation in human lymphocytes. There was also a decrease in intracellular GSH and raise in extracellular GSSG levels in Cr (VI) treated lymphocytes.  Conclusion: OOur findings revealed that ROS formation with subsequent cellular damages is the molecular mechanism for Cr (VI) induced human blood lymphocyte toxicity

Mitochondrial Transplantation Attenuates Toxicity in Human Lymphocytes Caused by Clozapine and Risperidone

Background: Clozapine (CLZ) and risperidone (RIS) are drugs that have the ability to disrupt mitochondrial function. Also, these drugs increase the level of free radicals. Mitochondrial dysfunction plays a role in the etiology of various diseases. Replacement and treatment of defective mitochondria with healthy mitochondria have been considered. Mitochondrial therapy (mitotherapy) or exogenous mitochondria transplantation is a method that can be used to replace dysfunctional mitochondria with healthy mitochondria. This method can help in the treatment of diseases related to mitochondria. Methods: In this study, we investigated the transplantation effect of isolated lymphocyte mitochondria on the toxicity induced by CLZ and RIS on human blood lymphocytes. Lymphocytes were isolated using the Ficoll standard method. Mitochondria of human lymphocytes were used for mitotherapy. This study was conducted in 6 groups. After treatment, the level of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), reduced glutathione (GSH) content, oxidized glutathione (GSSG) content, and adenosine triphosphate (ATP) content were evaluated. Results: Our data showed that CLZ (70 µm) and RIS (24 nM) caused cytotoxicity on human blood lymphocytes which are associated with ROS generation, collapse in MMP, decrease in GSH content, increase in GSSG content and change in ATP content. Mitochondria transplantation results showed that adding mitochondria of lymphocytes could protect the lymphocytes against the toxicity effects caused by CLZ and RIS. Furthermore, the results showed that pre-incubation with cytochalasin D considerably reserved the protective effects of mitotherapy in the human lymphocytes. Conclusion: We proposed that mitochondria transplantation or mitotherapy-affected blood lymphocytes with exogenous mitochondria could be used to treat CLZ and RIS-induced toxicity

Selective toxicity of Caspian cobra (Naja oxiana) venom on liver cancer cell mitochondria

Objective: To explore the cytotoxicity effects of Caspian cobra (Naja oxiana or N. oxiana) venom on hepatocytes and mitochondria obtained from the liver of HCC rats. Methods: In this study, HCC was induced by diethylnitrosamine (DEN), as an initiator, and 2-acetylaminofluorene (2-AAF), as a promoter. Rat liver hepatocytes and mitochondria for evaluation of the selective cytotoxic effect of N. oxiana venom were isolated and mitochondria and cellular parameters related to apoptosis signaling were then determined. Results: Our results showed a raise in mitochondrial reactive oxygen species (ROS) level, swelling in mitochondria, mitochondrial membrane potential (Δψm) collapse and release of cytochrome c after exposure of mitochondria only isolated from the HCC group with the crude venom of the N. oxiana (12.5, 25, and 50 μg/mL). This crude venom also induced caspase-3 activation (P < 0.001) in the hepatocytes obtained only from the HCC rat liver. Conclusions: Based on the over all results, we suggested that N. oxiana may be considered as a promising complementary therapeutic agent for the treatment of HCC

A Search for Anti-Carcinogenic and Cytotoxic Effects of Persian Gulf Sea Snake (Enhydrina schistosa) Venom on Hepatocellular Carcinoma Using Mitochondria Isolated from Liver: Cytotoxic effects of Enhydrina schistosa venom

Common techniques for the treatment of Hepatocellular carcinoma (HCC) have not been successful, and thus the design and discovery of new compounds with better anti-cancer function are needed. Snake venom is among the most important compounds used by researchers to the treatment of various cancers. This study was designed to evaluate the toxicity effect of Persian Gulf snake venom (Enhydrina schistosa) on hepatocytes and mitochondria isolated from HCC rats model. HCC has been induced in rats with diethylnitrosamine (DEN) and 2-acetylaminofluorene (2-AAF). Then rat hepatocytes were isolated with collagen perfusion technique. The results showed that E. schistosa (5, 10, 20 and 40 μg/ml) increases the level of reactive oxygen species (ROS) generation, collapse in mitochondrial membrane potential (MMP), swelling in mitochondria, and cytochrome c release only in hepatocytes and mitochondria isolated from the HCC group. These results proposed that E.schistosa could be considered as a promising complementary therapeutic agent for the treatment of HCC

Mitochondrial, lysosomal and DNA damages induced by acrylamide attenuate by ellagic acid in human lymphocyte.

Acrylamide (AA), is an important contaminant formed during food processing under high temperature. Due to its potential neurotoxicity, reproductive toxicity, hepatotoxicity, immunotoxicity, genotoxicity and carcinogenicity effects, this food contaminant has been recognized as a human health concern. Previous studies showed that acrylamide-induced toxicity is associated with active metabolite of acrylamide by cytochrome P450 enzyme, oxidative stress, mitochondrial dysfunction and DNA damage. In the current study, we investigated the role of oxidative stress in acrylamide's genotoxicity and therapeutic potential role of ellagic acid (EA) in human lymphocytes. Human lymphocytes were simultaneously treated with different concentrations of EA (10, 25 and 50 μM) and acrylamide (50 μM) for 4 h at 37°C. After 4 hours of incubation, the toxicity parameters such cytotoxicity, ROS formation, oxidized/reduced glutathione (GSH/GSSG) content, malondialdehyde (MDA) level, lysosomal membrane integrity, mitochondria membrane potential (ΔΨm) collapse and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were analyzed using biochemical and flow cytometry evaluations. It has been found that acrylamide (50 μM) significantly increased cytotoxicity, ROS formation, GSH oxidation, lipid peroxidation, MMP collapse, lysosomal and DNA damage in human lymphocytes. On the other hand, cotreatment with EA (25 and 50 μM) inhibited AA-induced oxidative stress which subsequently led to decreasing of the cytotoxicity, GSH oxidation, lipid peroxidation, MMP collapse, lysosomal and DNA damage. Together, these results suggest that probably the co-exposure of EA with foods containing acrylamide could decrease mitochondrial, lysosomal and DNA damages, and oxidative stress induced by acrylamide in human body

Dracocephalum: Novel Anticancer Plant Acting on Liver Cancer Cell Mitochondria

Dracocephalum kotschyi Boiss. (Labiatae) is a native Iranian medicinal plant which has been used in combination with Peganum harmala L. as a remedy for many forms of human cancer especially leukemia and gastrointestinal malignancies. Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. In this investigation HCC was induced by a single intraperitoneal injection of diethylnitrosamine (DEN) in corn oil at 200 mg/kg body weight to rats. Two weeks after DEN administration, cancer development was promoted with dietary 2-acetylaminofluorene (2-AAF) (0.02%, w/w) for 2 weeks. Serum alpha-fetoprotein (AFP) concentration, serum alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) activities were also determined for confirmation of hepatocellular carcinoma induction. Then rat hepatocytes were isolated with collagen perfusion technique and tumoral hepatocytes were sorted by flow cytometry. Finally isolated mitochondria obtained from both tumoral and nontumoral hepatocytes were used for any probable toxic effect of Dracocephalum kotschyi ethanolic extract. Our results showed that D. kotschyi extract (250 µg/mL) induced reactive oxygen species (ROS) formation, mitochondrial membrane permeabilization (MMP), and mitochondrial swelling and cytochrome c release only in tumoral but not nontumoral hepatocyte. These findings propose Dracocephalum kotschyi as a promising candidate for future anticancer research

Embryotoxic Effects of Atorvastatin on Mouse Fetus: Embryo toxicity of atorvastatin

Although the biokinetics, metabolism, and chemical toxicity of atorvastatin calcium are well known, until recently little attention was paid to the potential toxic effects of atorvastatin calcium on re-production and development in mammals. In recent years, it has been shown that atorvastatin calcium is a developmental toxicant given orally or subcutaneously (SC) to mice. Decreased fertility, embryo/fetal toxicity including teratogenicity, and reduced growth of the offspring have been observed following atorvastatin calcium exposure at different gestation periods. On the other hand, an in vitro study using fetal isolated mitochondria nowadays has been recognized as a confident tool to evaluate the developmental toxicity of a number of chemicals. Although the developmental toxicity induced by atorvastatin has been investigated, the precise cellular mechanism of atorvastatin -induced embryo-toxicity has not been thoroughly recognized yet. For investigating the effects of atorvastatin calcium on pregnant animals, three groups (control, sham and test) of NMRI mice were chosen. In test group,50mg/kg,100mg/kg and 150mg/kgof atorvastatin calcium were intraperitonealy administered at 11 day of gestation, in sham group only normal saline injected to interior peritoneum as indicated in the test group and in Control group which was considered as the comparison base line of our research, no injection was made. Caesarean sections were performed at 15 day of the gestation; and their placentas were examined externally. Based on our results atorvastatin calcium caused significant external anomalies, and caused a significant decrease (p&lt;0.001) in the weight and diameter of placentas, the number of the embryos, their body weight and crown-rump length of fetuses

Assessment of the Skin and Heart Tissue Damage Following Inhalation of Carbon Nanotubes in Wistar Rats Using Isolated Mitochondria: Carbon nanotubes induced skin and heart tissue damage

The unique properties of carbon nanotubes (CNTs) have led to their use in various fields. But, the toxicity of CNTs has been reported in biological and environmental systems. The aim of this research is to study the effect of multi-wall carbon nanotubes (MWCNTs) through inhalation chamber on the mitochondrial damage and oxidative stress using the mitochondria obtained from the skin and heart. Rats were exposed to 5 mg/m3 of MWCNTs (10 nm) aerosol for 5 hours /day, 5 days/week for 2 weeks in a whole-body exposure chamber. After 2-weeks exposure, Heart and skin mitochondria were evaluated for evaluation of toxicity parameters. The results showed that nanoparticles significantly decreased mitochondrial succinate dehydrogenase (SDH) activity and increased the level of reactive oxygen species (ROS), collapse in mitochondria membrane potential (MMP), swelling in mitochondria, and cytochrome release. In conclusion, we suggested that 5 mg/m3 of MWCNTs (10 nm) induce ROS mediated cytotoxicity by directly targeting mitochondria in both skin and heart tissue

Identification of (Z)-2,3-Diphenylacrylonitrile as Anti-Cancer Molecule in Persian Gulf Sea Cucumber Holothuria parva

Hepatocellular carcinoma (HCC), also named cancerous hepatoma, is the most common type of malignant neoplasia of the liver. In this research, we screened the Persian Gulf sea cucumber Holothuria parva (H. parva) methanolic sub-fractions for the possible existence of selective toxicity on liver mitochondria isolated from an animal model of HCC. Next, we purified the most active fraction. Thus the structure of the active molecule was identified. HCC was induced by diethylnitrosamine (DEN) and 2-acetylaminofluorene (2-AAF) protocol. Rat liver mitochondria for evaluation of the selective cytotoxic effects of sub-fractions of H. parva were isolated and then mitochondrial parameters were determined. Our results showed that C1 sub-fraction of methanolic extract of H. parva considerably increased reactive oxygen species (ROS) generation, collapse of mitochondrial membrane potential (MMP), swelling in mitochondria and cytochrome c release only on HCC liver mitochondria. Furthermore, the methanolic extract of H. parva was investigated furthermore and the active fraction was extracted. In this fraction, (Z)-2,3-diphenylacrylonitrile molecule, which is also known as α-cyanostilbene, was identified by mass analysis. This molecule increased ROS generation, collapse of MMP, swelling in mitochondria and finally cytochrome c release only on HCC liver mitochondria. The derivatives of (Z)-2,3-diphenylacrylonitrile in other natural products were also reported as an anti-cancer agent. These results suggest the eligibility of the (Z)-2,3-diphenylacrylonitrile as a complementary therapeutic agent for patients with HCC