Xylodiol from Xylopia langsdorfiana induces apoptosis in HL60 cells

An atisane diterpene was isolated from Xylopia langsdorfiana St. Hilaire & Tulasne, Annonaceae, leaves, ent-atisane-7α,16α-diol (xylodiol). Preliminary study showed that xylodiol was cytotoxic and induced differentiation on human leukemia cell lines. However, the molecular mechanisms of xylodiol-mediated cytotoxicity have not been fully defined. Thus, we investigated the anti-tumor effect of xylodiol in human leukemia HL60 cell line. Xylodiol induced apoptosis and necrosis. HL60 cells treated with xylodiol showed biochemical changes characteristic of apoptosis, including caspases-8, -9 and -3 activation and loss of mitochondrial transmembrane potential (∆ Ψm). However, there was a condensation rather than swelling of mitochondria. Moreover, the formation of condensed mitochondria and the loss of ∆ Ψm occurred downstream of caspase activation. Cyclosporine A did not protect HL60 cells from the cytotoxic effects of xylodiol, suggesting that the loss of ∆ Ψm is a late event in xylodiol-induced apoptosis. Oxidative stress was involved in xylodiol-induced apoptosis. Thus, we conclude that activated caspases cleave cellular proteins resulting in mitochondrial damage leading to mitochondrial condensation, loss of ∆ Ψm and ROS release from the mitochondria. ROS can further induce and maintain a collapse of ∆ Ψm leading to cellular damage through oxidation of lipids and proteins resulting in apoptotic cell death.

Comparação da oscilação postural estática na posição sentada entre jovens e idosos saudáveis / Comparing static sitting postural sway of healthy young and older adults

OBJETIVOS: Descrever uma nova metodologia de análise da oscilação postural estática sentada e comparar os resultados de jovens e idosos saudáveis. MÉTODOS: Participaram do estudo 38 indivíduos saudáveis, 17 jovens (idade média 23±2,38 anos) e 21 idosos (idade média 67±2,42 anos). A oscilação postural foi mensurada por meio do sistema eletromagnético Polhemus® 3Space Isotrack II. As avaliações foram feitas nas condições olhos abertos (OA) e fechados (OF), com os voluntários sentados sem apoio plantar e sem encosto em suportes de madeira (superfície estável-SE) e de espuma (superfície instável-SI). Cada condição sensorial foi avaliada durante 90 segundos. Os parâmetros analisados foram: deslocamento máximo (Dmáx), trajetória total (Traj) e velocidade média (Vel) nos planos sagital (X) e frontal (Y). RESULTADOS: Nas condições OA e OF em SE, foram encontradas oscilações nos planos X e Y dos parâmetros Traj e Vel maiores em jovens que em idosos. Em SI, foram observadas maiores Traj Y e Vel Y nos jovens, sem diferença significativa entre os grupos quanto a Traj X e Vel X com olhos fechados. Em relação ao Dmáx, tanto no plano X quanto no Y, em todas as condições sensoriais, só houve diferença significativa na condição OASE no plano sagital, sendo maior nos jovens. CONCLUSÕES: Jovens saudáveis oscilam mais que os idosos saudáveis na posição sentada. Além disso, a ferramenta utilizada mostrou ser útil para análise da oscilação postural estática na posição sentada, possibilitando o surgimento de estudos que a associem com o efeito de diversas tarefas motoras.

OBJECTIVES: To describe a new method to analyze the static sitting postural sway and to compare the results of healthy young and older adult subjects. METHODS: Thirty-eight healthy subjects took part in the study, including 17 young adults (mean age 23±2.38 years old) and 21 older adults (mean age 67±2.42 years old). The device used to quantify trunk sway was the magnetic field sensor Polhemus® 3Space Isotrack II. The measurements were taken in the eyes-opened (EO) and eyes-closed (EC) condition with the subjects seated first on a wooden stable surface (SS) then on a foam unstable surface (US) without back or foot support. Each sensory condition was assessed for 90 seconds. The analyzed parameters were: maximum amplitude (Amp), total trajectory (Traj) and mean velocity (Vel) in the sagittal (X) and frontal (Y) planes. RESULTS: In the EO and EC conditions on SS, young adults presented greater postural sway in the X and Y planes on the Traj and Vel parameters. In the US, young adults showed greater Y Traj and Y Vel in the EO and EC conditions, and there was no significant difference between the groups with regard to X Traj and X Vel in the EC condition. The young adults presented greater Amp only in the EOSS condition in the X plane. CONCLUSIONS: The young adult subjects presented greater sway in the sitting position than the older adult subjects. In addition, the Polhemus® device was a useful tool to analyze static sitting postural sway and can be used in future studies that associate static sitting postural sway with the effect of various motor tasks.