ABSTRACT Tonic immobility (TI) is a way to measure fear, as characterized by the reduced capacity to respond to external stimuli. The time spent in TI indicates the level of fear. Since TI is measured as the time until event occurrence, survival analysis stands out as a suitable statistical method to treat these data. We aimed to investigate the influence of possible factors (lines, sex and age) on fear behavior in meat quail (Coturnix coturnix) measured through TI by using survival analysis (non parametric Kaplan-Meyer method via logrank test). The dataset was composed by TI information provided by 50 animals from each line (UFV1 and UFV2) in each age (14 and 28 days of age), totalizing 200 records. Despite the slight difference between the two evaluated ages, there was no significance for this factor between each studied line, UFV1 (P= 0.1493) and UFV2 (P= 0.2583). The logrank test indicated significant difference (P= 0.0407) between levels of line/sex groups at 14 days of age. We noted that males from UFV2 line presented higher fear behavior in relation to males from UFV1 line. No significant differences were observed for this factor when considering 28 days of age.

O objetivo deste trabalho foi levantar os avanços ocorridos para a compreensão da atuação terapêutica de Cimicifuga racemosa, um fitoterápico utilizado no tratamento dos sintomas do climatério em mulheres nas quais a terapia de reposição hormonal (TRH) é contra-indicada. A revisão bibliográfica possibilitou concluir que existem quatro principais hipóteses para esclarecer a base mecanística de ação: indução de apoptose por meio da ativação de caspases, inibição do ciclo celular em G1 por alteração de proteínas reguladoras, efeito central em receptor 5HT e ação estrogênica evidenciada pela inibição seletiva dos receptores nicotínicos da acetilcolina. Porém, é incipiente a produção científica abordando as bases moleculares que sustentem os referidos mecanismos de ação. Ainda há necessidade de elucidação quanto à possível existência de pelo menos mais um receptor estrogênico que possa ser o alvo de ligação para as substâncias ativas de C. racemosa, bem como avançar no conhecimento da atividade reguladora seletiva de receptores estrogênicos já evidenciada em estudos de farmacologia experimental.

The aim of this survey was to assemble the advances in the comprehension of the therapeutic action of Cimicifuga racemosa, a phytotherapic drug used in the treatment of climacteric symptoms in women to whom the usual hormonal replacement therapy (HRT) is counter-indicated. This literature review led to the conclusion that there are four main hypotheses to elucidate the mechanistic basis of action: apoptosis induction by means of caspase activation, cell cycle inhibition at G1 step through disturbance of regulatory proteins, central effect on 5HT receptors, and estrogenic action evidenced by selective inhibition of nicotinic acetylcholine receptors. However, scientific literature is still incipient in supporting the molecular bases for the previously proposed mechanisms of action. There is also the need to elucidate a probable new estrogen receptor that might be the target for active substances from C. racemosa, as well as to advance on the knowledge of the selective modulation of estrogen receptors, which has already been evidenced by experimental pharmacology.