, 2001). Considering that C. serrata n-hexane extract

inhibited in vitro AChE of all tested brain areas from Wistar rats, we can suggest cholinergic side-effects of this extract and its consequently toxicity in mammals. Although in vivo studies of C. serrata n-hexane extract or their individual compounds are necessary in order to confirm the mammal toxicity, since processes of absorption may interfere on xenobiotic effects. On the other hand, inhibition of AChE is an important approach in the management for Alzheimer’s disease, senile dementia, ataxia, myasthenia gravis and Parkinson’s disease ( Brenner, 2000 and Rahman and Choudhary, 2001). Accordingly, the discovery of new molecules from plants can be a potential therapeutic CP-690550 ic50 strategy for the prevention and treatment of AD. To the best of our knowledge, we herein report the first findings on cholinesterase inhibitory activity of C. serrata. The n-hexane extract of C. serrata inhibited AChE activity on the larvae of R.

microplus and in brain structures of rats. We can suppose that this effect may be related to its ticks toxicity. Moreover, the chemistry LDK378 is not exhausted at this point and it is important to find out what or which substances are responsible for inhibitory AChE properties of n-hexane extract from C. serrata. Additionally, in vivo studies, using both ticks and mammals, must be performed. This work was supported by the Brazilian funding agencies: Conselho Nacional de Desenvolvimento Científico

e Tecnológico – CNPq (Dr. I.R. Siqueira, 2010; Dr. G.L.V. Poser, 2010; C. Vanzella, 2010; J.C. from Santos); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES (F. Moysés, 2010). “
“The cattle tick Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae) is one of the most important parasites of cattle in tropical and subtropical countries. In Brazil, it is responsible for annual losses of about U$2 billion due to mortality, decrease in both milk production and weight gain, deteriorating effects on leather quality, costs for acaricide drugs and transmission of cattle fever disease agents ( Grisi et al., 2002). The control of R. microplus mainly relies on the use of chemical products mostly without following any technical criteria (leading to an excessive number of applications and too low volume of product per animal) which contributes to accelerating the development of resistance to acaricides ( Alonso-Díaz et al., 2006, Mendes et al., 2007 and Mendes et al., 2011). In Brazil, the first record of cattle tick resistance to organophosphates and pyrethroids was in the 1970s and 1980s, respectively ( Arteche, 1972 and Leite, 1991). Resistance persisted and now it is found throughout the country ( Alonso-Díaz et al., 2006, Andreotti et al., 2011 and Mendes et al., 2011).