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Free radicals and other reactive oxygen species (ROS) are constantly formed in the human body. Free-radical mechanisms have been implicated in the pathology of several human diseases. Free radicals are generated physiologically during immune activation. Neopterin, an early marker of immune activation is released from monocyte-macrophages with the induction of interferon-gamma. Its biological levels are known to be increased in different types of pathologies including cancer. Neopterin is also known to be related with oxidative stress. In this study, the antioxidant effect of neopterin and silymarin, melatonin and homocystein was evaluated by NO, SO, and DPPH radicals scavenging assays. Possible cytotoxic effects of the compounds were evaluated in 3 different cell lines by MTT and LDH assays. According to the results all the compounds have the radical scavenging activities. Therefore, none of them have a significant cytotoxic potential. However, only neopterin has a significant proliferative effect at very high concentrations. The results should be confirmed and reevaluated by in vivo and in vitro experiments.

Purpose: Gemcitabine is nucleoside analogue and used for various carcinomas like non-small cell lung cancer. Nanoparticle-based therapeutic agents have been developed for use in cancer therapy. Trimethyl chitosan (TMC) is methylated derivative of chitosan. TMC can be preferable because of the limited solubility of chitosan. Magnetic nanoparticles can be concentrated at cancerous tissue which provide targeted cancer therapy. In this study, we tried to develop and compare magnetically targeted trimethyl chitosan and chitosan nanoparticles for gemcitabine delivery in lung cancer therapy.Methods: Chitosan was trimethylated using methyl iodide. Magnetic nanoparticles were synthesized using co-precipitation method. TMC and chitosan nanoparticles were prepared by cross-linking method with tripolyphosphate. Gemcitabine was loaded onto nanoparticles via adsorption technique. After that characterization studies were performed and in vitro drug release tests were carried out. In order to determine cytotoxicites against A549-luc-C8 and CRL5809 cell lines, MTT assays were performed.Results and conclusion: Trimethylation of chitosan was verified with FTIR analysis. Gemcitabine was loaded with 54.7 and 30.3% on magnetic TMC nanoparticles and chitosan nanoparticles, respectively. According to drug release experiments, both carrier system had controlled drug release profile. IC 50 values of gemcitabine loaded magnetic TMC nanoparticles were lower than that of magnetic chitosan nanoparticles. In conclusion, it was suggested that trimethyl chitosan nanoparticles had greater potential than chitosan nanoparticles for further analysis as a magnetically targeted therapy agent for lung cancer.

Oxidative stress is related to many pathologies and diseases including diabetes, atherosclerosis and cancer. Increase or decrease of reactive oxygen species can affect disease progression and treatment. Hence, both the development and treatment of diseases involve reactive oxygen species and antioxidants. Especially in the last decade, antioxidants became popular in the prevention of diseases and aging. Antioxidants exert their effects either by chain breaking or prevention of free radicals. In this study, the radical scavenging capacities and cytotoxic potentials of 5 non-enzymatic antioxidants were evaluated by in vitro analysis. The scavenging activities of ascorbic acid, glutathione, L-cysteine, N-acetyl-cysteine and uric acid against NO, SO, DPPH radicals were analyzed. MTT and LDH assays were performed in order to evaluate the cytotoxic activities of the compounds in HeLa, HepG2 and Hep2 cell lines. All the compounds showed comparable antioxidant activities. On the other hand, cytotoxic effect of the compound was not significant except at high concentrations. The results was approved ones again all the compounds have strong radical scavenging activity and all the antioxidants may use for treatment of inflammatory diseases.