Moringa oleifera fruit induce apoptosis via reactive oxygen species-dependent activation of mitogen-activated protein kinases in human melanoma A2058 cells.

The present study was performed to determine the effect of Moringa oleifera fruit extract on the apoptosis of human melanoma A2058 cells. A2058 cells were treated for 72 h with Moringa oleifera fruit extract at 50-100 µg/ml, and cell viability with apoptotic changes was examined. The involvement of reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs) was examined. It was revealed that Moringa oleifera fruit extract significantly inhibited the cell viability and promoted apoptosis of A2058 cells in a concentration-dependent manner. Moringa oleifera fruit extract-treated A2058 cells exhibited increased activities of cleaved caspase-9 and caspase-3. It also caused an enhancement of MAPK phosphorylation and ROS production. The pro-apoptotic activity of Moringa oleifera fruit extract was significantly reversed by pretreatment with the c-Jun N-terminal kinase (JNK) inhibitor SP600125, extracellular-signal-regulated kinase (ERK) inhibitor PD98058 or ROS inhibitor N-acetyl-L-cysteine. Taken together, Moringa oleifera fruit extract is effective in inducing mitochondrial apoptosis of A2058 cells, which is mediated through induction of ROS formation, and JNK and ERK activation. Moringa oleifera fruit extract may thus have therapeutic benefits for human melanoma A2058 cells.

Fucoidan reduces oxidative stress by regulating the gene expression of HO­1 and SOD­1 through the Nrf2/ERK signaling pathway in HaCaT cells.

Fucoidan, a sulfated polysaccharide, is found in edible brown algae. In the present study, the molecular mechanisms of fucoidan against mild oxidative stress in human keratinocytes were investigated. The current study indicated that fucoidan significantly augmented the antioxidants heme oxygenase­1 (HO­1) and superoxide dismutase­1 (SOD­1) via the upregulation of nuclear factor erythroid 2­related factor 2 (Nrf2) and markedly reduced the cytoplasmic stability of kelch­like ECH­associated protein 1. The upregulation of HO­1 and SOD­1 detected in the fucoidan­treated cells may be responsible for the increased resistance to mild oxidative stress, indicating that fucoidan may augment the activities of antioxidant enzymes via stimulating Nrf2. This is the first report, to the best of our knowledge, to demonstrate that fucoidan attenuates oxidative stress by regulating the gene expression of SOD­1 and HO­1 via the Nrf2/extracellular signal­regulated kinase signaling pathway.

Hyperoside and rutin of Nelumbo nucifera induce mitochondrial apoptosis through a caspase-dependent mechanism in HT-29 human colon cancer cells.

The present study demonstrates the mechanism of 2 flavonol glycosides, hyperoside and rutin, in the induction of apoptosis in HT-29 human colon cancer cells through the bioactivity-guided fractionation and isolation method. The chemical structure of hyperoside and rutin, isolated from the roots of Nelumbo nucifera, were established using extensive 1- and 2-dimensional nuclear magnetic resonance experiments and absolute high resolution fast-atom bombardment mass spectrometry, ultraviolet-visible and Fourier transform infrared spectroscopy spectral analytical methods. The treatment of HT-29 colon cancer cells with hyperoside and rutin significantly decreased cell viability in a dose-dependent manner. The concomitant activation of the mitochondria-dependent apoptotic pathway of hyperoside and rutin occurred via modulation of Bcl-2-associated X protein and B-cell lymphoma 2 expression, resulting in the activation of cleaved caspases-3, -8 and -9 and cleaved poly-(ADP-ribose) polymerase. The findings of the present study indicate that hyperoside and rutin induce apoptosis in HT-29 human colon cancer cells, and that this phenomenon is mediated via the death receptor-mediated and mitochondria-mediated apoptotic pathways. These results suggest that hyperoside and rutin may be useful in the development of a colon cancer therapy protocol.

Comparative Evaluation of Physicochemical Properties of Pine Needle Powders Prepared by Different Drying Methods.

Systematic study of how different drying methods, namely hot-air drying, vacuum-drying, and freeze-drying, affect color, browning index, degree of rehydration, water solubility, and vitamin C content is critical for utilizing pine needle powders (PNP) as a novel ingredient in functional foods. Samples prepared by vacuum-drying showed a significantly higher L*-value, whereas higher a*- and b*-values were detected in the hot-air dried samples (P<0.05). The browning index was significantly higher in samples prepared by vacuum-drying compared to samples prepared by freeze-drying (P<0.05). Freeze-dried PNP exhibited a significantly higher degree of rehydration than hot-air dried samples (P<0.05). Water solubilities of freeze-dried and hot-air dried samples were significantly higher than that of vacuum-dried sample (P<0.05). Vitamin C was less destroyed during freeze-drying compared to hot-air or vacuum-drying (P<0.05). Freeze-dried samples displayed a clear porous structure and appeared to have a bigger space, whereas hot-air dried samples showed lower porosity than vacuum and freeze-dried samples.

[10]-Gingerol induces mitochondrial apoptosis through activation of MAPK pathway in HCT116 human colon cancer cells.

The present study was designed to investigate the molecular mechanisms of [10]-gingerol activity against HCT116 human colon cancer cells. [10]-Gingerol inhibited the proliferation of HCT116 cells by 50% at a concentration of 30 µM, and this inhibition was dose-dependent accompanied by the morphological changes indicative of apoptosis. Furthermore, flow cytometric analysis showed that [10]-gingerol increased DNA in the sub-G1 phase of the cell cycle, and the extent of apoptosis was confirmed by Annexin V and PI double staining. Analysis of the mechanism of these events indicated that [10]-gingerol-treated cells exhibited an increased ratio of Bax/Bcl-2, resulting in the activation of caspase-9, caspase-3, and poly-ADP-ribose polymerase in a dose-dependent manner, which are hallmarks of apoptosis. Moreover, [10]-gingerol-induced apoptosis was accompanied by phosphorylation of the mitogen-activated protein kinase (MAPKs) family, c-Jun N-terminal kinase (JNK), p38 MAPK (p38), and extracellular signal-regulated kinase (ERK). This is the first report to demonstrate the cytotoxic effect of [10]-gingerol on human colon cancer cells, as well as the first to describe its possible chemotherapeutic potentials.

Effect of 7, 8-dihydroxyflavone on the up-regulation of Nrf2-mediated heme oxygenase-1 expression in hamster lung fibroblasts.

The cytoprotective mechanism of 7, 8-dihydroxyflavone (DHF) against oxidative stress-induced cell damage with respect to its stimulatory effect on the expression of heme oxygenase-1 (HO-1), a potent antioxidant enzyme, was investigated in the present study. Up-regulation of HO-1 expression by DHF was both dose and time dependent in lung fibroblast V79-4 cells. DHF also increased the protein expression level of the transcription factor nuclear factor erythroid-2-related factor 2 (Nrf2), and induced the translocation of Nrf2 from the cytosol into the nucleus, leading to elevated HO-1 expression. The siNrf2 RNA-transfection attenuated HO-1 expression induced by DHF treatment. In addition, DHF induced the activation of extracellular signal-regulated kinase (ERK), while U0126 (a specific pharmacological inhibitor of ERK kinase) abrogated DHF-activated Nrf2 and HO-1 expression. This suggests that DHF increased the levels of Nrf2 and HO-1 via ERK-dependent pathways. Furthermore, DHF significantly prevented the reduction of cell viability in response to oxidative stress; however, U0126 attenuated the protective effect of DHF. Taken together, these results demonstrate that DHF protected cells from oxidative stress via the activation of an ERK/Nrf2/HO-1 signaling pathway.

7,8-Dihydroxyflavone protects human keratinocytes against oxidative stress-induced cell damage via the ERK and PI3K/Akt-mediated Nrf2/HO-1 signaling pathways.

This study investigated the effect of 7,8-dihydroxyflavone (DHF) on the expression and activity of heme oxygenase-1 (HO-1), an enzyme with potent antioxidant properties, as well as the molecular mechanisms involved. DHF markedly upregulated HO-1 mRNA and protein expression in human keratinocytes (HaCaT cells), resulting in increased HO-1 activity. DHF also increased the protein level of transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates HO-1 expression by binding to the antioxidant response element (ARE) within the HO-1 gene promoter, in a time-dependent manner. Moreover, DHF decreased the expression of Kelch-like ECH-associated protein 1, a repressor of Nrf2 activity, and induced the translocation of Nrf2 from the cytosol into the nucleus, thereby allowing its association with the ARE site. DHF activated extracellular-regulated kinase (ERK) and protein kinase B (PKB, Akt) in keratinocytes, while the ERK and Akt inhibitors attenuated DHF-enhanced Nrf2 and HO-1 expression. DHF also protected the keratinocytes against hydrogen peroxide- and ultraviolet B-induced oxidative damage, while HO-1, ERK and Akt inhibitors markedly suppressed DHF-mediated cytoprotection. Taken together, the results suggested that DHF activates ERK- and Akt-Nrf2 signaling cascades in HaCaT cells, leading to the upregulation of HO-1 and cytoprotection against oxidative stress.

The green algae Ulva fasciata Delile extract induces apoptotic cell death in human colon cancer cells.

This study investigated the mechanisms underlying the cytotoxicity of the green algae Ulva fasciata Delile. U. fasciata extract (UFE) inhibited the growth of HCT 116 human colon cancer cells by 50% at a concentration of 200 µg/ml. In addition, UFE stimulated the production of intracellular reactive oxygen species, an effect that was abolished by pretreatment with N-acetyl cysteine, which also inhibited the cytotoxic effects of UFE. UFE also induced morphological changes indicative of apoptosis, such as the formation of apoptotic bodies, DNA fragmentation, an increase in the population of apoptotic sub-G(1) phase cells, and mitochondrial membrane depolarization. Concomitant activation of the mitochondria-dependent apoptotic pathway occurred via modulation of Bax and Bcl-2 expression, resulting in disruption of the mitochondrial membrane potential and activation of caspase-9 and caspase-3. This is the first report to demonstrate the cytotoxic effect of U. fasciata on human colon cancer cells and to provide a possible mechanism for this activity.

Sesquiterpenes and other constituents from Dendranthema zawadskii var. latilobum.

Six new germacranolides, zawadskinolides A-F (1-6), and a new eudesmane glucoside, chrysantiloboside (7) were isolated from the aerial parts of Dendranthema zawadskii var. latilobum, along with thirteen known constituents. Their structures were elucidated by means of spectroscopic evidence. Bioassay showed that flavonoids such as apigenin (9), (-)-eriodictyol (10) and nepetin (12), as well as the sesquiterpene lactone, zawadskinolide F (6), inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells with IC50 values of 66.15, 132.55, 35.44, and 91.32 µM, respectively.

Antibacterial effects of vulgarone B from Artemisia iwayomogi alone and in combination with oxacillin.

The antibacterial activities of vulgarone B, a component of Artemisia iwayomogi essential oil, were evaluated against some antibiotic-susceptible and -resistant human pathogens. Moreover, the effects of combining antibiotics, such as oxacillin, with vulgarone B were determined in this study. Significant inhibitory activities of Artemisia oils against antibiotic-susceptible and -resistant bacteria were confirmed by broth microdilution methods. The effects of vulgarone B on bacterial morphology and DNA were observed by scanning electron microscope and electrophoresis, respectively. In checkerboard microtiter tests, vulgarone B and A. iwayomogi oil combined with oxacillin resulted in synergism, or additive effects. Moreover, the safety of Artemisia oil and vulgarone B were confirmed in vivo. Both vulgarone B and the essential oil fraction of A. iwayomogi showed significant inhibitory activities against strains of antibioticsusceptible and -resistant bacteria. The oils showed synergism or additive effects when combined with oxacillin against two strains of Staphylococcus aureus. The antibiotic mechanism involved might be related to DNA cleavage. Thus, vulgarone B and the essential oil fraction of A. iwayomogi may be promising candidates for a safe, effective, natural agent active against antibiotic-resistant S. aureus, especially when combined with oxacillin.

Cytoprotective activity of annphenone against oxidative stress-induced apoptosis in V79-4 lung fibroblast cells.

We have elucidated the cytoprotective effect of annphenone (2,4-dihyroxy-6-methoxy-acetophenone 4-O-beta-D-glucopyranoside) against oxidative stress-induced apoptosis. Annphenone scavenged intracellular reactive oxygen species (ROS) and increased antioxidant enzyme activities. It thereby prevented lipid peroxidation and DNA damage, which was demonstrated by the inhibition of the formation of thiobarbituric acid reactive substance (TBARS), inhibition of the comet tail and decreased phospho-H2A.X expression. Annphenone protected Chinese hamster lung fibroblast (V79-4) cells from cell death via the inhibition of apoptosis induced by hydrogen peroxide (H2O2), as shown by decreased apoptotic nuclear fragmentation, decreased sub-G1 cell population and inhibited mitochondrial membrane potential (Deltapsi) loss. Taken together, these findings suggest that annphenone exhibits antioxidant properties by inhibiting ROS generation and thus protecting cells from H2O2-induced cell damage.

Cyanidin and Malvidin from Oryza sativa cv. Heugjinjubyeo mediate cytotoxicity against human monocytic leukemia cells by arrest of G(2)/M phase and induction of apoptosis.

Oryza sativa cv. Heugjinjubyeo (Gramineae), anthocyanin-pigmented rice, having dark purple grains, is known broadly as enriched rice with an improved taste. Two bioactive compounds were isolated from the 0.5% HCl-ethyl alcohol soluble fraction of the aleurone layer of O. sativa cv. Heugjinjubyeo through an activity-monitored fractionation and isolation method. From spectral analysis, the cytotoxic components were the anthocyanidins cyanidin (1) and malvidin (2) The 50% growth inhibitory concentrations (IC(50)) of cyanidin and malvidin on U937, human monocytic leukemia cells, were 60 and 40 microg/mL, respectively. These compounds showed cytotoxicity through the arrest of the G(2)/M phase of cell cycle and induction of apoptosis.