Is arbutin an effective antioxidant for the discount of oxidative and nitrosative stress in Hep-G2 cells exposed to tert-butyl hydroperoxide?

AIM: Oxidative and nitrosative stress triggers an extensive damage to the tissues. Many herbal and chemical medicines have claimed to possess antioxidant properties. Arbutin exists in some plants such as Pyrus Biossierana Bushe. In this study, an inhibitory effect of arbutin against tert-butyl hydroperoxide induced cytotoxicity was studied using SYTOX TM Green assay for cell viability. The antioxidant effects of arbutin on the generation of malondialdehyde, nitric oxide, activity of oxidative enzyme (Superoxide dismutase and catalyze) and the amount of total thiol in Hep-G2 cells exposed to tert-butyl hydroperoxide were evaluated. METHODS: Hep-G2 cells were cultured in 24-well plates. After 24 hours, the cells were pretreated with the arbutin at different concentrations (0, 100 and 150 µM). 24 hours later, tert-butyl hydroperoxide at different concentrations (0, 150, 200 and 250 µM) was added into the culture media. RESULTS: Arbutin was able to decrease malondialdehyde and nitric oxide concentrations in arbutin treated group in comparison with the control group (p < 0.00001). The catalase and superoxide dismutase enzymes in these cells were significantly decreased in a dose depend manner in the presence of arbutin in comparison with the control group (p < 0.00001). In addition, arbutin was capable of increasing the tert-butyl hydroperoxide mediated reduction in the total thiol amount in comparison with the control group (p < 0.00001.) CONCLUSION: Our investigation demonstrated that tert-butyl hydroperoxide evoked a reactive oxygen and nitrogen species overproduction in Hep-G2 cells. The cells treated with arbutin showed a dose-dependent reduction of tert-butyl hydroperoxide induced reactive oxygen and nitrogen species generation (Fig. 6, Ref. 34).

Assessment of allergen-specific IgE by immunoblotting method in atopic dermatitis.

SUMMARY: Background and Objectives. Stimulating the immune system by exposure to various allergens to produce specific IgE has a significant role in the pathogenesis of atopic dermatitis. Identifying disease-causing allergens, prevention of exposure to those allergens, and immunotherapy will play an important role in the treatment of Atopic Disease. The purpose of this study was to determine the common allergens of northwest of Iran in patients with atopic dermatitis that are resistant to treatment. Materials and methods. In this descriptive-analytical study, serum levels of total IgE and frequency of specific IgE were measured by Immunoblotting against 20 common allergens in 150 cases of patients with atopic dermatitis, attending to dermatology and asthma and allergy clinics from 2010 to 2011. The control group consisted of individuals who had been clinically healthy. Results. In the 90% of patients that were included in this study, total IgE levels were higher than in healthy people with mean serum levels of total IgE 227.51 ± 103 IU/ml. 136 patients (90.6%) had specific IgE for at least one allergen. The frequency of positive allergens among the patients who were included in this study were 53.34%, 26.8%, and 19.56% respectively in plants and fungus allergens group, animal allergens group and food allergens group. After avoiding of the allergens (which they had been sensitized to), 60% of patients were cured with immune therapy, and total IgE serum levels in the control group were not increased. Conclusion. Identifying the abundant allergens such as cultivated rye, Timothy grass, house dust mite, birch, cat, horse, potato, dog, egg white, cow milk, in order to advise patients to avoid them or to do immunotherapy and desensitization, is useful in this area.