9 HESA-A inhibits the growth of cancer cells in a concentration dependent and selective manner.9 It increases the appetite, and can be considered as an immune-modulator, anti-inflammatory, and anti-viral agent. Although HESA-A shows some clinical effects, its precise biological mechanisms remain unclear. It has been shown that in rabbits under oxidative stress challenges, treatment with HESA-A led to an increase in total

antioxidant and antierythrocytelysis.10 In addition, the hepatoprotective effect of HESA-A against hepatic damage in Inhibitors,research,lifescience,medical rabbits was demonstrated in previous study.8 Since HESA-A revealed considerable effects in the treatment of psoriasis SKI-606 supplier vulgaris, a T cell-mediated inflammatory disorder, it seems that it has immunomodulator

characteristics too.5 Such findings indicate that HESA-A may have antioxidant activity. Inhibitors,research,lifescience,medical Furthermore, the finding that HESA-A is rich in trace elements such as Cu, Mn, Se and Zn, which are involved in enzymatic detoxification and antioxidant systems,10 suggests that HESA-A may possess antioxidative effects. Given such evidences, the present study aimed to test whether or not HESA-A has antioxidant properties. To answer such a question, the cytotoxic effects of hydrogen peroxide (H2O2) on Chinese hamster Inhibitors,research,lifescience,medical ovary (CHO) and human embryonic kidney (HEK293T) cell lines were determined following exposure of the two cell lines to HESA-A by cell proliferation and antioxidant assays. Materials and Methods Cell Culture Inhibitors,research,lifescience,medical The CHO andHEK293T cell lines were obtained from national cell bank of Iran (Pasteur Institute of Iran). The cells were grown in RPMI 1640 medium (Gibco-BRL, Germany) containing 10% heat-inactivated fetal bovine serum (Gibco-BRL, Germany) and 1% penicillin streptomycin solution (10,000 Inhibitors,research,lifescience,medical units of penicillin and 10 mg of streptomycin) in a humidified atmosphere of 5% CO2 at 37 C. The cells were cultured in 25 cm2 cell culture flasks. For experimental purposes,

cells were seeded at a density of 2×104 cells/well in 96-well plates 24 h before any treatment. Then, they were treated with 5-20 mM concentrations of H2O2 for different time lengths. HESA-A compound was diluted in phosphate buffered saline (PBS) and the cells were separately treated with 100-1000 ng/ml of HESA-A for different durations. The AZD1480 concentration CHO and HEK293T cells were also exposed to various concentrations of HESA-A (100, 200, 300, 500 ng/ml), followed by treatment with different concentrations of H2O2. Controls were maintained under normal condition. Cell Proliferation Assays Cytotoxic effects of HESA-A and H2O2 on CHO and HEK293T cell lines were assessed by 3-(4,5-dimethlthiazol-2-yl)-2,5-diphenyltetrazolium Bromide (MTT). The MTT assay was performed as described previously by Roudkenar et al.