(1988). Duplicate slides were prepared and stained with ethidium bromide. We screened 50 cells per sample with a fluorescent microscope (Carl Zeiss

GmbH, Oberkochen, Germany) equipped with a 515–560 nm excitation filter, a 590 nm barrier filter, and a 40 × objective. The level of click here DNA damage was assessed with an image analysis system (TriTek CometScore, version 1.5; TriTek Corp., Sumerduck, Virginia, USA), and the tail moment was calculated. The statistical analysis was performed with the SigmaStat program, version 3.5 (Systat, Richmond, California, USA). The Kolmogorov–Smirnov test was used in order to determine the normal distribution of data in all assays. Because see more the data distribution was not normal, we used the non-parametric Mann–Whitney test and compared the

test groups with the positive control (TSP). The Kruskal–Wallis test was used in order to assess the cytotoxicity in mouse bone marrow cells. Particulate PAH concentrations are summarized in Table 2. There was a clear difference between the burning season and the non-burning season in terms of the PAH content of the TSP. In the burning season, we detected specific PAHs derived from sugarcane burning. According to Simoneit (2002), the PAHs phenanthrene, fluoranthene, and pyrene, as well as, to a lesser extent, anthracene and benzo[a]anthracene, are emitted mainly during HSP90 the burning of Gramineae species. In our study, there were high concentrations of the

PAHs benz[e]acephenanthrylene, benz[a]anthracene, benzo[a]pyrene, benzo[k]fluoranthene, fluoranthene, and indeno[1,2,3-cd]pyrene, all of which are considered genotoxic and carcinogenic ( WHO. World Health Organization, 1998 and IARC. International Agency for Research on Cancer, 2009), during the sugarcane burning season. There was also a high concentration of benzo[a]pyrene—3.24 ng/m3. In the Tradescantia micronucleus test, an antimutagenic effect was observed with ethanolic extract of C. sylvestris at 0.13 0.25, and 0.50 mg/ml, all of which proved to protect against DNA damage induced by organic TSP collected during the sugarcane burning season ( Table 3). It is known that plants such as T. pallida are good bioindicators of genotoxic agents, demonstrating whether a mutagen is potentially hazardous to human health ( Ma, 1981, Carvalho-Oliveira et al., 2005 and Leal et al., 2007). In fact, the Tradescantia micronucleus test was very useful here, as a screening test of the antimutagenic activity of the ethanolic extract, before we proceeded to the mouse assays. Table 4 shows that C. sylvestris ethanolic extract was able to reduce the DNA damage caused by TSP collected during the sugarcane burning season, in the micronucleus test and in the comet assay, whereas casearin X reduced only the DNA damage assessed by the comet assay ( Table 5).