In vitro Antigenotoxicity of Ulva rigida C. Agardh (Chlorophyceae) Extract against Induction of Chromosome Aberration, Sister Chromatid Exchange and Micronuclei by Mutagenic Agent MMC

Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts （URE）, and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C （MMC）. Methods Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts （URE） were studied using chromosome aberration （CA）, sister chromatid exchange （SCE）, and micronuclei （MN） tests in human lymphocytes cultured in vitro. Results The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 lag/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC （P〈0.0001）. Conclusion Although URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.

Sister chromatid exchange and DNA damage in human lymphocytes induced by air-dust in Lanzhou City: involvement in free radicals

The air-dust samples collected from petro-chemical industrial region in the suburb of Lanzhou and from a certain rural region 64 km away from the city were extracted, with a mixed solvent (benzene: hexane: isopropanol=7:2:1) for 8 hours. A strong free radical signal at g= 2.00 of air-dust itself and a hyperfine splitting EPR signal of extract from air-dust have been detected. The sister chromatid exchange frequency (SCE) was increased by extracts of both dusts from the industrial region and from the rural region. If a chemical is able to increase SCE up to twice as high as the control, this chemical is considered to be mutagenic and/or carcinogenic. The double SCE frequency concentration is 23 μg/ml for the dust extract obtained from the industrial region and 47μg/ml for that from the rural region. Extracts were able to damage to DNA template. Results indicated that the mutagenicity and/or carcinogenicity of the extracts obtained from the petro-chemical industrial region were stronger than that of the extracts from the rural region.

Is there a connection between synthetic bone grafts and sisters chromatide exchange?

Background: In oral and maxillofacial surgery, synthetic bone grafts are most widely used as bone substitutes, due to the limited sources of autologous bone. The aim of this study was to examine the influence of three different synthetic bone grafts (Cerasorb, Fortoss and Perioglass) on sisters chromatide exchanges (SCEs) in peripheral lymphocytes. Materials and Methods: Peripheral blood samples taken from 68 patients (45 females and 23 males), who underwent oral surgery procedures, such as apical resection, cyst enucleation or periodontal curretage, were obtained for SCE a day before and two months after the surgeries. A control group included 30 patients, while the study group was made of the patients who underwent bone grafting with Cerasorb? (11 patients), Fortoss? VITAL (10 patients) or Perioglass? (17 patients). Results: Comparing with the results of the study group before and after the treatment, it was concluded that the results were statistically significant (p = 0.001). In the Perioglass? subgroup, a greater statistical significance (p = 0.003) was noted, than that in either the Cerasorb? (p = 0.620) or Fortoss? (p = 0.210) subgroups, in which there was no statistical significance. Conclusions: Although further investigations may be necessary, our results suggest that the synthetic bone grafts might have an influence on SCE in peripheral lymphocytes.