The effect of antioxidants in Ehrlich Ascites Cancer.

A fundamental goal in molecular oncology is to unravel the underlying mechanisms which cause the cell transformation. In line with this approach, genome-wide functional screening approaches have revealed exciting insights into heterogeneous nature of cancer. Rapidly expanding horizons of research have unraveled myriad of pathways which play instrumental role in carcinogenesis and metastasis. Oxidative stress has also been reported to be significantly involved in cancer onset and progression. In line with this approach, oxidative stress modulating chemicals have always been sharply divided into antioxidants and oxidative stress-inducing agents. Conceptual and experimental advancements have enabled us to critically analyze full potential of these two different groups of chemicals in cancer chemoprevention. Different antioxidants are currently being analyzed in different phases of clinical trials. Although it has been reported in the literature that antioxidant supplements reduce tumor cells in some tumors or cause volume reduction in solid tumor sizes, there is no definite consensus. Therefore, an antioxidant supplement guideline based on more detailed clinical research and as a result of these is needed to achieve the best care for cancer patients and to avoid risky treatments for cancer patients.

Myocardial Iron Overload in an Experimental Model of Sudden Unexpected Death in Epilepsy.

Uncontrolled repetitive generalized tonic-clonic seizures (GTCS) are the main risk factor for sudden unexpected death in epilepsy (SUDEP). GTCS can be observed in models such as Pentylenetetrazole kindling (PTZ-K) or pilocarpine-induced Status Epilepticus (SE-P), which share similar alterations in cardiac function, with a high risk of SUDEP. Terminal cardiac arrhythmia in SUDEP can develop as a result of a high rate of hypoxic stress-induced by convulsions with excessive sympathetic overstimulation that triggers a neurocardiogenic injury, recently defined as "Epileptic Heart" and characterized by heart rhythm disturbances, such as bradycardia and lengthening of the QT interval. Recently, an iron overload-dependent form of non-apoptotic cell death called ferroptosis was described at the brain level in both the PTZ-K and SE-P experimental models. However, seizure-related cardiac ferroptosis has not yet been reported. Iron overload cardiomyopathy (IOC) results from the accumulation of iron in the myocardium, with high production of reactive oxygen species (ROS), lipid peroxidation, and accumulation of hemosiderin as the final biomarker related to cardiomyocyte ferroptosis. Iron overload cardiomyopathy is the leading cause of death in patients with iron overload secondary to chronic blood transfusion therapy; it is also described in hereditary hemochromatosis. GTCS, through repeated hypoxic stress, can increase ROS production in the heart and cause cardiomyocyte ferroptosis. We hypothesized that iron accumulation in the "Epileptic Heart" could be associated with a terminal cardiac arrhythmia described in the IOC and the development of state-potentially in the development of SUDEP. Using the aforementioned PTZ-K and SE-P experimental models, after SUDEP-related repetitive GTCS, we observed an increase in the cardiac expression of hypoxic inducible factor 1α, indicating hypoxic-ischemic damage, and both necrotic cells and hemorrhagic areas were related to the possible hemosiderin production in the PTZ-K model. Furthermore, we demonstrated for the first time an accumulation of hemosiderin in the heart in the SE-P model. These results suggest that uncontrolled recurrent seizures, as described in refractory epilepsy, can give rise to high hypoxic stress in the heart, thus inducing hemosiderin accumulation as in IOC, and can act as an underlying hidden mechanism contributing to the development of a terminal cardiac arrhythmia in SUDEP. Because iron accumulation in tissues can be detected by non-invasive imaging methods, cardiac iron overload in refractory epilepsy patients could be treated with chelation therapy to reduce the risk of SUDEP.