Induction of caspase-3-dependent apoptosis in human leukemia HL-60 cells by δ-elemene.

  Î´-Elemene, an antitumor component, is a chemical compound isolated from Curcuma wenyujin, a Chinese traditional herb. We examined whether δ-elemene could inhibit cell growth and cell cycle progression and induce apoptosis in human leukemia HL-60 cells. The results demonstrated that δ-elemene induces significant apoptosis of HL-60 cells, as shown by MTT assay, annexin V (AnV) binding of externalized phosphatidylserine (PS), and the mitochondrial probe JC-1 using flow cytometry. HL-60 cells treated with δ-elemene showed high percentages in the early apoptotic and late apoptoctic/necrotic stages, as well as caspase-3 activation of HL-60 cells. By monitoring the changes in cell cycle profiles, we confirmed that δ-elemene could interfere with the cell cycle in the G2/M phase and induce apoptosis in HL-60 cells in a time-dependent manner. Caspase-3 plays a direct role in proteolytic cleavage of the cellular proteins responsible for progression to apoptosis. Therefore we examined apoptosis in HL-60 cells after exposure to δ-elemene and measured caspase-3 activities with or without Z-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk, a broad-spectrum caspase inhibitor) pretreatment using flow cytometric analysis. The results showed that δ-elemene could induce caspase-3 activation as detected by the decrease in δ-elemene-induced caspase-3 activities after treatment with z-VAD-fmk. In the present study, δ-elemene activated typical caspase-dependent apoptosis in HL-60 cells, as demonstrated by an inhibitory effect of z-VAD-fmk on this cell death. During δ-elemene-induced apoptosis, cytochrome c and apoptosis-inducing factor were released into the cytosol and BAX was translocated from the cytosol to mitochondria. However, these were not prevented by z-VAD-fmk. In conclusion, our study demonstrated that δ-elemene could induce G2/M cell cycle transition and trigger apoptosis through a caspase-3-dependent pathway.

B-cell lymphoma-2 over-expression protects δ-elemene-induced apoptosis in human lung carcinoma mucoepidermoid cells via a nuclear factor kappa B-related pathway.

δ-Elemene, an antitumor component, is a chemical compound isolated from Curcuma wenyujin, a Chinese traditional herb. We examined whether δ-elemene could affect apoptosis in human lung carcinoma mucoepidermoid NCI-H292 cells, and test whether and how the over-expression of B-cell lymphoma-2 (Bcl-2) and B-cell lymphoma extra large (Bcl-xL) could off-set the effect of δ-elemene on cell growth. The result demonstrated that δ-elemene significantly induced apoptosis of NCI-H292, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, DNA fragmentation measurement, Annexin V (AnV) binding of externalized phosphatidylserine and the mitochondrial probe JC-1 using flow cytometry. Treatment of NCI-H292 with δ-elemene increased both p38 mitogen-activated protein kinase (MAPK) and inducible nitric oxide synthese (iNOS) levels, suggesting these two molecules maybe relate to the apoptotic effect of δ-elemene. The cells with Bcl-2 or Bcl-xL over-expression showed an elevation of nuclear factor kappa B (NF-kappa B) activity, accompanying a significant reduction of δ-elemene-induced apoptosis. Furthermore, inhibition of NF-kappa B by IkBαSR, which is a powerful inhibitor of NF-kappa B, restored the ability of δ-elemene to induce apoptosis in the cells transfected with Bcl-2. These data strongly indicated that the apoptotic effect of δ-elemene on NCI-H292 was closely associated with the activity of NF-kappa B, which was up-regulated by Bcl-2 and Bcl-xL. In conclusion, δ-elemene induced apoptosis in NCI-H292 cells. The apoptotic effect of δ-elemene could be significantly offset by over-expression of either Bcl-2 or Bcl-xL. Bcl-2 and Bcl-xL were able to increase the activity of NF-kappa B, which was a known anti-apoptotic molecule in human lung cancer cells.

Cell apoptosis induced by delta-elemene in colorectal adenocarcinoma cells via a mitochondrial-mediated pathway.

The chemical compound delta-elemene, isolated from the Chinese herbal medicine plant Curcuma Wenyujin, has been known to exert antitumor activity. In this study we demonstrated that apoptotic cell death induced by delta-elemene in DLD-1 cells was concentration-and time-dependent, and had little inhibition of the normal human liver cell line WRL-68. Apoptosis was further confirmed and quantified by DNA fragmentation ELISA, Annexin V (AnV) binding of externalized phosphatidylserine and the mitochondrial probe JC-1 using flow cytometry. The rapid increase in intracellular reactive oxygen species (ROS) levels was involved in the mechanism of cell death. Western blot analysis demonstrated that delta-elemene activated the caspase-signaling pathway, leading to the proteolysis conversion of pro-caspase-3 to activate caspase-3, and the subsequent cleavage of the caspase substrate PARP. In the process of the induction of apoptotic cell death, Bax translocated into mitochondria, a reduction in Deltapsim was observed and a release of cytochrome c and apoptosis inducing factor (AIF) from mitochondria into the cytosol occurred, indicating that cell death induced by delta-elemene was through a mitochondrial-mediated pathway.

[Research on active part of Sambucus chinensis against hepatitis mice induced by CCl4].

OBJECTIVE: To investigate the best extraction process of Sambucus chinensis against hepatitis and research on its active part. METHODS: We studied the protective effects of different extracts of Sambucus chinensis distilled by different extraction process on mice acute hepatic injury induced by CCl4, and searched for the active part of Sambucus chinensis against hepatitis from the best extract by extraction with different solvent and purification with macroporous adsorption resin, then studied their protective effects on mice acute hepatic injury induced by CCl4. RESULTS: The extraction of Sambucus chinensis by 75% alcohol showed very significantly protective effects on mice acute hepatic injury induced by CCl4 and the effects were better than that of other extraction process. The extraction eluted by 30% alcohol after purification with macroporous adsorption resin and extracted by EtOAc in the extraction of Sambucus chinensis by 75% alcohol all showed significantly protective effects on mice acute hepatic injury induced by CCl4, and the effects of the extraction eluted by 30% alcohol after purification with macroporous adsoption resin were better than extraction with EtOAc. CONCLUSIONS: The best extraction solvent is 75% alcohol. The active part of Sambucus chinensis against hepatitis is the extraction eluted by 30% alcohol after purification with macroporous adsorption resin and extraction with EtOAc.

Effect of delta-elemene on Hela cell lines by apoptosis induction.

This study was designed to investigate the apoptosis-inducing activity of delta-elemene on Hela cells in vitro. MTT assay and Hoechst 33258/PI fluorescence microscopy were used for this investigation. Apoptosis was further confirmed and quantified by DNA fragmentation ELISA, Annexin V (AnV) binding of externalized phosphatidylserine and the mitochondrial probe JC-1 using flow cytometry. Generation of reactive oxygen species (ROS) was detected using CM-H2DCFDA. Western blots analysis was performed using antibodies against the pro-caspase-3, or PRAP (Poly (ADP-ribose) polymerase). The results showed that delta-elemene exhibited a marked antiproliferative effect on Hela cells in dose- and time-dependent manners, and had little inhibition to normal human liver cell line WRL-68. It was demonstrated that delta-elemene was capable of inducing DNA fragmentation in a dose- and time-dependent manner. AnV positivity and the disturbance of the polarized mitochondrial transmembrane potential (Deltapsim) suggested that delta-elemene induced apoptotic death of Hela cells. Western blot analysis demonstrated that delta-elemene activated the caspase-signaling pathway, leading to the proteolysis conversion of pro-caspase-3 to activate caspase-3, and the subsequent cleavage of the caspase substrate PARP. Further, it was noted that the apoptotic effect of delta-elemene could be attenuated by L-Glutathione (GSH) or z-DEVD-fmk. It suggested that the increase in ROS generation might be involved in the mechanism of delta-elemene induced cell apoptosis.