The complete description of the effects of bracken fern has been reviewed recently ( Gil da Costa et al., 2012a). Our previous studies showed that ptaquiloside is an immunosuppressor that caused a reduction in mouse splenic NK cell-mediated cytotoxicity and IFNγ production (Latorre et al., 2009). Moreover, we verified that selenium supplementation can prevent this reduction in NK-mediated cytotoxicity (Latorre et al., 2011). A greater incidence of chemical-induced preneoplasic

lesions are noted in mice immunosuppressed with bracken fern (Caniceiro et al., 2011), and our findings may be of great relevance in avoiding the increased susceptibility to cancer caused by the plant. The molecular mechanism underlying

ptaquiloside-induced Selleckchem NLG919 immunosuppression and its prevention by selenium are unknown. Thus, the objective of this study was to verify the mechanism of action of ptaquiloside-induced immunosuppression in splenic NK cells using gene expression microarray analysis. We performed transcriptome analysis in splenic NK cells from mice treated for 14 days with ptaquiloside (5.3 mg/kg) and/or selenium (1.3 mg/kg) to identify gene transcripts altered by ptaquiloside that could be linked to the immunosuppression and that would be prevented by selenium. Fifty eight sixty-day-old CH5424802 research buy selleck screening library male C57BL/6J mice, bred in the Department of Pathology at the School of Veterinary Medicine and Animal Sciences, were used. The mice were housed in controlled temperature (22–25 °C), relative humidity (50–65%) and lighting (12 h/12 h

light/dark cycle) conditions. Drinking water and standard diet (Nuvilab-CR1®, Nuvital Nutrientes LTDA) were provided ad libitum. All procedures were performed following the Guide for the Care and Use of Laboratory Animals NIH publication No. 85-23 (http://www.nap.edu/readingroom/books/labrats/) and were reviewed and approved by the Bioethics Committee of the FMVZ-USP (process #1061/2007). Ptaquiloside was purified from dried P. aquilinum crosiers using a previously described procedure ( Oelrichs et al., 1995) that was later modified. In brief, ground plant material (100 g) was extracted using a Soxhlet apparatus with CHCl3 (48 h) followed by a 1:1 mixture of CHCl3/MeOH (48 h). The CHCl3/MeOH extract was evaporated to dryness at 40 °C under reduced pressure (rotary evaporation). The residue was collected in H2O (100 ml) and extracted twice with diethyl ether (100 ml) and then twice with n-butanol (100 ml). The n-butanol extract was concentrated under reduced pressure (rotary evaporator), and the residue was subjected to flash column chromatography [silica gel eluted using an EtOAc/MeOH gradient (0–12% MeOH)].