Background and aims: The role of genetic factors and oxidative damage in the etiopathogenesis of periodontal disease is well documented in the literature. The MICRONUCLEUS TEST is a sensitive method that indicates DNA damage. The aim of the present study was to investigate the micronuclei frequency in different forms of periodontitis in comparison with healthy controls.Materials and methods: Micronuclei frequency was analyzed in the peripheral lymphocytes of 10 patients with chronic periodontitis (CP), 10 patients with generalized aggressive periodontitis (GAP) and 10 healthy controls. Various clinical parameters like the probing depth, clinical attachment level, and percentages of sites with bleeding and plaque were recorded. After the slides were processed, they were stained with 5% Geimsa solution and 1000 cells per sample were counted for the presence of micronuclei.Results: The mean micronuclei observed in the control group, CP group, and GAP group were 9.8, 10.1 and 9.9, respectively. The differences between the groups were not significant (P=0.978).Conclusion: The results indicated that the cytogenetic damages in the periodontitis groups were not different from those in the control group. The role of cytogenetic damage in peripheral blood cells may have a limited prognostic value in the etiopathogenesis of periodontal tissues and further studies are necessary to assess cytogenetic damage in periodontal tissues to clarify local tissue destruction in periodontal disease.

Introduction: Tetracyclic antidepressants-mirtazapin is one of antidepressants drug that exhibits both noradrenergic and serotonergic activity. It is commonly used to treat major depressive disorder. The genotoxic effect of mirtazapine has not been examined previously. The purpose of this study was to investigate the genotoxic and cytotoxic effects of mirtazapine on human peripheral blood lymphocytes.Methods: The genotoxic and cytotoxic effects of mirtazapine on human peripheral lymphocytes were examined by MICRONUCLEUS (MN) TEST. The human lymphocytes were treated with 10, 25, 40 and 55 mg/mL concentrations of mirtazapine for 24 and 48 hours treatment periods.Results: MN formation was not significantly induced at 24- and 48-h treatment periods when compared with control but Nuclear division index (NDI) significantly decreased at all concentrations for two treatment periods.Conclusion: Mirtazapine was not genetoxic but was cytotoxic in human peripheral blood lymphocytes. According to this study mirtazapine has cytotoxic effects on human’s cells.

Crude oil is enriched in polycyclic aromatic hydrocarbons (PAHs). Many PAH analogs have proved to potentially damage DNA. DNA damage can be assessed using various biomarkers to find out the degree of genotoxicity of pollutants following in vitro exposure. In this research the comet assay and MICRONUCLEUS (MN) TEST were used to detect DNA damages and cytogenetic changes following crude oil exposure. For this purpose, freshwater bivalve mollusks (Anodonta cygnea) were exposed for ten days to 0.25, 0.5 and 1.0 ppm of crude oil. For the comet assay and for the MN TEST, hemolymph and gill cells of mussels were sampled respectively. Statistically, significant increase of DNA damage and micronuclei were found with 0.25, 0.5 and 1.0 ppm of crude oil. This study was performed to ascertain that A. cygnea is a good bioindicator of pollutants in aquatic environments; also identified hemolymph and gill of A.cygnea are most effective and practical tissues for genotoxicity studies.

Background: Although numerous natural or synthetic drugs have been TESTed for their radioprotective capacity, yet no suitable drug has been introduced for routine clinical use. In this study the radioprotective effect of "a new herbal immunomodulator" commercially known as IMOD, specifically made to decrease the side effects of HIV virus, was investigated on mouse bone marrow cells.Materials and Methods: Female NMRI mice (in a group of five) were exposed to 2 Gy gamma radiation following three days of intravenously injection (IV) of IMOD at various doses. Mice were sacrificed 48 and 72 h after irradiation. Bone marrow was flushed and slides for bone marrow smears were prepared according to standard method. After staining slides in May Grunwald and Giemsa, polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) were scored for presence of MICRONUCLEUS (MN).Results: The results showed that gamma irradiation increased the frequency of micronuclei dramatically and excreted cytotoxic effect of cell proliferation. Injection of various doses of IMOD before irradiation however, led to a considerable reduction in the frequency of micronuclei in bone marrow erythrocytes as well as cellular toxicity.Conclusion: Results indicated radioprotective capability of IMOD with a dose reduction factor (DRF) of about 2.3 at a dose of 20 mg/kg body weight. The considerably high DRF might be indicative that IMOD besides being an immunomodulator might also posses’ antioxidant property.

Background: Despite its various clinical applications, cyclophosphamide (CP), an alkylating chemotherapeutic agent, has demonstrated numerous side effects, including genetic toxicity. Objectives: This study investigated the protective action of Origanum vulgare L., a powerful antioxidant plant, on the genotoxicity of CP in the mice blood lymphocytes. Methods: The mice were pre-treated orally with different doses of 50, 100, 200, or 400 mg/ kg O. vulgare ethanolic extract once a day for 7 consecutive days. One hour after the final dose of O. vulgare, each animal received a single intraperitoneal administration of 200 mg/ kg CP. After 24 hours, the preventive effect of O. vulgare was evaluated using an in vitro MICRONUCLEUS (Mn) TEST in cytokinesis-blocked lymphocytes, which is a reliable genotoxicity TEST. All doses of O. vulgare caused significant reductions in the CP-induced Mn formation, which served as an indicator of DNA damage in the peripheral blood lymphocytes. Results: The total reduction of the Mn in binucleated lymphocytes were 67% and 75% for doses of 200 and 400 mg/kg of O. vulgare, respectively (P<0. 001). The antioxidant plant demonstrated dose-dependent protective effects against CP-induced Mn formation and genotoxicity in the blood lymphocytes of the mice. O. vulgare can reduce the damage to DNA through its potent antioxidation activity and free radical scavenging properties. Conclusion: Since it is widely used as a safe herbal medicine for many diseases, O. vulgare could be used to relieve the adverse effects of cyclophosphamide, especially against the genetic damages of normal cells in patients undergoing chemotherapy.

Citral is a major constituent of Cymbopogon citratus or lemongrass oil. The anti-clastogenic effect of citral (20 mg/kg) was TESTed against the known mutagens cyclophoshamide, mitomycin-C and nickel metal (NiCI2) in mice. MICRONUCLEUS (MN) frequency was evaluated in both bone marrow and peripheral blood erythrocytes. The sampling was done after 24 h, 48 hand 72 h of clastogen treatment. Results show that citral had significantly (p < 0.01) decreased the frequency of MN induced by the three clastogens in bone marrow and peripheral blood erythrocytes.

Contact dermatitis is an inflammatory skin disease due to contact with different substances and caused by two mechanisms: allergy and irritation. Contact dermatitis is a common skin disease and the most common occupational dermatosis. Differentiating between allergic and irritant contact dermatitis is essential in the identification of etiologic factor(s) and hence, its control and prognosis. This differentiation can be done only by patch TEST. Unfortunately, this simple, safe and useful TEST is always neglected. We review the basics of patch TEST, the method of performance, reading and interpretation of its results, possible side effects and results of studies done with patch TEST in different countries.