Diallyl sulfide inhibits murine WEHI-3 leukemia cells in BALB/c mice in vitro and in vivo.

It is well documented that enhanced garlic (Allium sativum) consumption leads to decrease in the cancer incidences. Diallyl sulfide (DAS), one of the components of garlic, induces cytotoxicity and apoptosis in many cancer cell lines. The present studies are focused on the in vivo effects of DAS on leukemia WEHI-3 cells in the BALB/c mice. We examined the effects of DAS on the cytotoxicity of WEHI-3 cells and results indicated that DAS decreased the percentage of viable WEHI-3 cells and these effects are dose-dependent. We examined the effects of DAS on WEHI-3 in vivo and the results indicated that DAS decreased the percentage of Mac-3 and CD11b, indicating that the differentiation of the precursor of macrophage cells was inhibited. DAS stimulated the percentage of CD3 and CD19, indicating that the differentiation of the precursor of T and B cells promoted. The weights of liver and spleen indicated that DAS decreased the weight of these organs after being compared to the control groups. One of the major characteristic of WEHI-3 leukemia is the enlarged spleen in murine after intraperitoneal (i.p.) injection of WEHI-3 cells. In conclusion, DAS affects WEHI-3 cells both in vitro and in vivo.

Capsaicin-induced apoptosis in human hepatoma HepG2 cells.

Capsaicin, a pungent ingredient of red pepper, has been reported to possess antitumor activities. In this study, the effects of capsaicin on human HepG2 cells were investigated. Capsaicin reduced viability by PI incorporation in HepG2 cells in a dose and time dependent manner. Capsaicin promoted intracellular Ca2+ production and reactive oxygen species (ROS). The alpha psi(m) significantly decreased after capsaicin treatment for 24 h. Co-treatment of HepG2 cells with capsaicin and BAPTA (an intracellular Ca2+ chelator) significantly reduced intracellular Ca2+ levels, prevented alpha psi(m) disruption and inhibited apoptosis induction. The protein levels of Bcl-2 decreased and Bax increased in the mitochondrial fraction while the Bax protein decreased, and p53 and cytochrome c protein levels increased in the cytosolic fraction in HepG2 cells after capsaicin treatment for 24 h by Western blot. Immunostaining and confocal microscopic analysis also showed that capsaicin promoted cytoplasmic GADD153 expression and GRP78 nuclear translocation. The caspase-3 activity significantly increased after capsaicin treatment for 24 h. Our results indicated that the capsaicin-induced apoptosis in HepG2 cells may result from the elevation of intracellular Ca2+ production, ROS, disruption of alpha psi(m), regulation of Bcl-2 family protein expression and caspase-3 activity.