5-Fluorouracil (5-FU) is a potent anti-neoplastic agent commonly used for the treatment of various malignancies. But it has varied detrimental effects such as nephrotoxicity, cardiotoxicity etc which limits its widespread clinical practice. Chlorogenic acid (CGA), esterified product of caffeic and quinic acids, is one of the most abundant polyphenol in human diet found in fruits and coffee drinks, possessing an array of biological properties like anti- oxidant, anti-inflammatory and anti-carcinogenic. In the present study, we investigated protective effect of CGA against 5-FU induced nephrotoxicity in wistar rats. The possible mechanism of nephrotoxicity may be ROS induced apoptosis and inflammation via up-regulating ROS generation, P53, bax, caspase-3, TNF-α, cox-2, iNOS, and down regulating Bcl-2. CGA was administered to Wistar rats daily for 20 consecutive days at 60 and 120 mg/kg body weight orally and on day 19, a single intra-peritoneal injection of 150 mg/kg body weight 5-FU was given. CGA ameliorated 5-FU induced LPO, increase in serum toxicity markers and replenished deficit in antioxidant armory. CGA also down regulated apoptotic and inflammatory tissue damage induced by 5-FU. Histological findings further supported biochemical and immunohistochemical results. Therefore results of the present study suggest that CGA may be used in combinational therapy to improve therapeutic index of 5-FU after further preclinical and clinical testing. doi: 10.1016/j.freeradbiomed.2016.10.336 296 Combination of Cold Atmospheric Helium Plasma and Mild Hyperthermia Causes a Synergistic Enhancement in Cell Death Mainly via Up-Regulation of Intracellular Reactive Oxygen Species Mati Ur Rehman 1 , Moniruzzaman Rouwan 1 , Qing-Li Zhao 1 , Paras Jawaid 1 , and Takashi Kondo 1 1 University of Toyama, Japan Cold atmospheric plasmas (CAPs) have been proposed as a novel therapeutic method for its anti-cancer potential. However, its biological effects in combination with other physical modalities remain to be elusive. Therefore, this study was aimed to determine the effects of cold atmospheric helium plasma (He-CAP), (PN- 120TPG, NU Global, Japan) in combination with mild hyperthermia (HT, 42°C for 20 min). Human lymphoma U937 cells were exposed to HT, immediately after He-CAP treatment. He-CAP in combination with HT showed enhanced cell death, which was accompanied by increased intracellular ROS production, particularly H2O2 and O2 ●– generation. Interestingly, later the He- CAP-induced O2 ●– generation subsides, however the combined treatment showed increased intracellular O2 ●– level, and enhancement of cell death. In contrast, no such effects were observed with either treatment alone. Taken together, these findings suggest that He-CAP can enhance the apoptotic effects of mild HT; due to the increased in intracellular reactive oxygen species (ROS) generation as He-CAP has been known to caused marked induction of ROS in the aqueous medium. These findings would be helpful when establishing a therapeutic strategy for CAP in combination with mild HT. doi: 10.1016/j.freeradbiomed.2016.10.337 297 Fire and Brimstone: Turning the Gun on Cancer Des Richardson 1 1 University of Sydney, Australia Oxidative stress plays a role in the development of drug resistance in cancer cells. Cancer cells must constantly and rapidly adapt to changes in the tumor microenvironment, due to alterations in the availability of nutrients, such as glucose, oxygen and key transition metals (e.g., iron and copper). This nutrient flux is typically a consequence of rapid growth, poor vascularization and necrosis. It has been demonstrated that stress factors, such as hypoxia and glucose deprivation up-regulate master transcription factors, namely hypoxia inducible factor-1α (HIF-1α), which transcriptionally regulate the multi-drug resistance (MDR), transmembrane drug efflux transporter, P-glycoprotein (Pgp). Interestingly, in addition to the established role of plasma membrane Pgp in MDR, a new paradigm of intracellular resistance has emerged that is premised on the ability of lysosomal Pgp to transport cytotoxic agents into this organelle. This mechanism is enabled by the topological inversion of Pgp via endocytosis resulting in the transporter actively pumping agents into the lysosome. In this way, classical Pgp substrates, such as doxorubicin (DOX), can be actively transported into this organelle. Within the lysosome, DOX becomes protonated upon acidification of the lysosomal lumen, causing its accumulation. This process efficiently traps DOX, preventing its cytotoxic interaction with nuclear DNA. These studies highlight a novel strategy by which redox-active and protonatable Pgp substrates can utilize lysosomal Pgp to gain access to this compartment, resulting in catastrophic lysosomal membrane permeabilization and cell death. Importantly, this mechanism is key to the activity of novel anti- cancer agent, di-2-pyridylketone 4-cyclohexyl-4-methyl-3- thiosemicarbazone (DpC), that has entered multi-centre clinical trials for the treatment of a wide variety of advanced and resistant tumors (NCT02688101). Hence, a key MDR mechanism that utilizes Pgp (the "gun") to sequester redox active drugs (“fire and brimstone”) within lysosomes can be "turned on" MDR cancer cells to destroy them from within. doi: 10.1016/j.freeradbiomed.2016.10.338 298 Leaf Extract from Senna Velutina Promotes Antioxidant Activity and Cytotoxic Effect in Leukemic Cells Edson Lucas dos Santos 1 , Jaqueline Ferreira Campos 1 , David Tsuyoshi Hiramatsu de Castro 1 , Marcio José Damião 1 , Ana Paula de Araujo Boleti 1 , Heron F. Vieira Torquato 2 , Carlos Alexandre Carollo 3 , Edgar J. Paredes-Gamero 2 , and Kely de Picoli Souza 1 1 Federal University of Grande Dourados, Brazil, 2 Federal University of São Paulo, Brazil, 3 Federal University of Mato Grosso do Sul, Brazil The search for new molecules with therapeutic properties, including antioxidant and anticarcinogenic activities, is facilitated by the vast biodiversity and bio-prospecting potential in Brazil. Therefore, this study aimed to investigate the chemical composition of an ethanol extract of Senna velutina leaves and to evaluate its antioxidant and cytotoxic activities in in Jurkat and K562 leukemic cells. The antioxidant properties were evaluated with a DPPH free SfRBM / SFRRI 2016 S129