Syngeneic and Xenogeneic Transplantations of Mesenchymal Stromal Cells Modify the Production of Reactive Oxygen Species by Blood Mononuclears of Mice.

In vivo modifying effects of bone marrow mesenchymal stromal cells of humans and laboratory mice on ROS production by mouse blood mononuclears are studied by luminol-dependent zymosan-induced chemiluminescence after syngeneic and xenogeneic transplantation into systemic blood flow. The chemiluminescent activity of mouse blood mononuclears has increased early (1 day) after syngeneic (mouse mesenchymal stromal cells) and xenogeneic (human mesenchymal stromal cells) transplantation. Later, 7-21 days after syngeneic and xenogeneic transplantation, the chemiluminescent activity of mouse mononuclears is suppressed. The probable mechanisms of involvement of the transplanted mesenchymal stromal cells in reprogramming of the blood mononuclear phagocytes from proinflammatory (M1) to anti-inflammatory (M2) phenotype under conditions of their in vivo interactions are discussed; a frequent manifestation of this reprogramming is transition of the phase of activation into inhibition of ROS-producing activity of macrophages.

Ellagic acid, a polyphenolic compound, selectively induces ROS-mediated apoptosis in cancerous B-lymphocytes of CLL patients by directly targeting mitochondria.

To investigate the effects ofellagic acid (EA) on the cytotoxicity, B-lymphocytes isolated from CLL patients and healthy individuals. Flow cytometric assay was used to measure the percentage of apoptosis versus necrosis, intracellular active oxygen radicals (ROS), mitochondrial membrane potential (MMP) and the caspase-3 activity and then mitochondria were isolated from both groups B-lymphocytes and parameters of mitochondrial toxicity was investigated. Based on our results EA decreased the percentage of viable cells and induced apoptosis. EA increased ROS formation, mitochondria swelling, MMP decrease and cytochrome c release in mitochondria isolated from CLL BUT NOT healthy B-lymphocytes while pre-treatment with cyclosporine A and Butylated hydroxyl toluene (BHT) prevented these effects. Our results suggest that EA can act as an anti cancer candidate by directly and selectively targeting mitochondria could induce apoptosis through mitochondria pathway with increasing ROS production which finally ends in cytochrome c release, caspase 3 activation and apoptosis in cancerous B-lymphocytes isolated from CLL patients.