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Recently, we demonstrated that myricetin exhibits cytoprotective effects against H(2)O(2)-induced cell damage via its antioxidant properties. In the present study, myricetin was found to inhibit H(2)O(2)-induced apoptosis in Chinese hamster lung fibroblast (V79-4) cells, as shown by decreased apoptotic bodies, nuclear fragmentation, sub-G(1) cell population, and disruption of mitochondrial membrane potential (Δψ(m)), which are increased in H(2)O(2)-treated cells. Western blot data showed that in H(2)O(2)-treated cells, myricetin increased the level of Bcl-2, which is an anti-apoptotic factor, and decreased the levels of Bax, active caspase-9 and -3, which are pro-apoptotic factors. And myricetin inhibited release of cytochrome c from mitochondria to cytosol in H(2)O(2)-treated cells. Myricetin-induced survival correlated with Akt activity, and the rescue of cells by myricetin treatment against H(2)O(2)-induced apoptosis was inhibited by the specific PI3K (phosphoinositol-3-kinase) inhibitor. Myricetin-mediated survival also inhibited the activation of p38 mitogen activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK), which are members of MAPK. Our studies suggest that myricetin prevents oxidative stress-induced apoptosis via regulation of PI3K/Akt and MAPK signaling pathways.

Background and Objective: Histone deacetylase inhibitors (HDACi) exert antitumor effects through the induction of apoptosis. This study was to investigate the effects of HDACi on survivin gene expression, cell proliferation and apoptosis in human myeloma cell line U266., Methods: U266 cells were exposed to different concentrations of MS-275, a histone deacetylase inhibitor, at different time courses. Cell viability was measured using the trypan blue exclusion assay. Changes in cell morphology were observed with Wright-Giemsa staining. Cell cycle was analyzed using flow cytometry. Protein expressions of poly (ADP-ribose) polymerase (PARP), caspase-3, survivin, P21 and CDK4 were detected by Western blot., Results: MS-275 inhibited the growth of U266 cells in a dose-and time-dependent manner. After exposure to 1.39 micromol/L MS-275 for 48 h, the cell cycle was arrested at the G0/G1 phase, and the cell viability was decreased by 50%. After the treatment with 2 micromol/L MS-275 for 24 h and 36 h, the ratios of U266 cells at the G0/G1 phase were increased to 66.39% and 89.80%, respectively. Obvious changes in morphology of U266 were observed under microscopy. Cleaved PARP appeared, along with an increased protein level of P21 and a decrease of survivin and CDK4 levels in U266 cells treated with MS-275., Conclusion: MS-275 could suppress the proliferation, induce apoptosis and reduce the expression of survivin in human myeloma cell line U266, which may be associated with the down-regulation of survivin.

The antioxidant property of butin was investigated for cytoprotective effect against H(2)O(2)-induced cell damage. This compound showed intracellular reactive oxygen species (ROS) scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, inhibition of lipid peroxidation, and DNA damage. This radical scavenging activity of butin protected cell damage exposed to H(2)O(2). Also, butin reduced the apoptotic cells induced by H(2)O(2), as demonstrated by the decreased DNA fragmentation, apoptotic body formation, and caspase 3 activity. In addition, butin restored the activity and protein expression of cellular antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT) in H(2)O(2)-treated cells. Taken together, these findings suggest that butin protected cells against H(2)O(2)-induced cell damage via antioxidant property.

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.

The protective properties of irisolidone (a metabolite of kakkalide by intestinal bacteria) against hydrogen peroxide (H(2)O(2)) induced cell damage were investigated. Irisolidone was found to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and the intracellular reactive oxygen species (ROS), thereby preventing lipid peroxidation and DNA damage. Irisolidone inhibited apoptosis in Chinese hamster lung fibroblast (V79-4) cells induced by H(2)O(2) via radical scavenging activity. This was achieved by the activation of the extracellular signal regulated kinase (ERK) and DNA binding activity of activator protein-1 (AP-1) (a downstream transcription factor of ERK) by irisolidone.

Background: Protective effects of Gynura bicolor aqueous extract (GAE) at three concentrations upon nerve growth factor (NGF) differentiated-PC12 cells against H2O2 induced injury were examined. Methods: NGF differentiated-PC12 cells were treated with GAE at 0.25%, 0.5% or 1%. 100 μM H2O2 was used to treat cells with GAE pre-treatments. After incubating at 37 °C for 12 hr, experimental analyses were processed. Results: H2O2 exposure decreased cell viability, increased plasma membrane damage, suppressed Bcl-2 mRNA expression and enhanced Bax mRNA expression. GAE pre-treatments reversed these changes. H2O2 exposure reduced mitochondrial membrane potential, lowered Na+-K+-ATPase activity, and increased DNA fragmentation and Ca2+ release. GAE pre-treatments attenuated these alterations. H2O2 stimulated the production of reactive oxygen species (ROS), interleukin (IL)-1beta, IL-6 and tumor necrosis factor-alpha, lowered glutathione content, and reduced glutathione peroxidase (GPX) and catalase activities. GAE pretreatments maintained GPX and catalase activities; and concentration-dependently diminished the generation of ROS and inflammatory cytokines. H2O2 enhanced mRNA expression of nuclear factor kappa (NF-κ) B and p38. GAE pre-treatments decreased mRNA expression of NF-κB and p38. Conclusion: These findings suggested that GAE might be a potent neuronal protective agent.

Background: Protective effects of Gynura bicolor aqueous extract (GAE) at three concentrations upon nerve growth factor (NGF) differentiated-PC12 cells against H2O2 induced injury were examined. Methods: NGF differentiated-PC12 cells were treated with GAE at 0.25%, 0.5% or 1%. 100'μM H2O2 was used to treat cells with GAE pre-treatments. After incubating at 37''C for 12 hr, experimental analyses were processed. Results: H2O2 exposure decreased cell viability, increased plasma membrane damage, suppressed Bcl-2 mRNA expression and enhanced Bax mRNA expression. GAE pre-treatments reversed these changes. H2O2 exposure reduced mitochondrial membrane potential, lowered Na+-K+-ATPase activity, and increased DNA fragmentation and Ca2+ release. GAE pre-treatments attenuated these alterations. H2O2 stimulated the production of reactive oxygen species (ROS), interleukin (IL)-1beta, IL-6 and tumor necrosis factor-alpha, lowered glutathione content, and reduced glutathione peroxidase (GPX) and catalase activities. GAE pretreatments maintained GPX and catalase activities; and concentration-dependently diminished the generation of ROS and inflammatory cytokines. H2O2 enhanced mRNA expression of nuclear factor kappa (NF-κ) B and p38. GAE pre-treatments decreased mRNA expression of NF-κB and p38. Conclusion: These findings suggested that GAE might be a potent neuronal protective agent. [ABSTRACT FROM AUTHOR]

Abstract The purpose of present HUVE cells and mice study was to investigate the combined effects of carnosine and asiatic acid (AA) against diabetic progression. In HUVE cells, high glucose decreased cell viability, reduced Bcl-2 mRNA expression and increased Bax mRNA expression. The co-treatment of 0.5 μM carnosine plus 0.5 μM AA led to greater cell viability and Bcl-2 mRNA expression than 1 μM carnosine or 1 μM AA treatment alone. This combination more significantly decreased the production of DNA fragmentation, tumor necrosis factor (TNF)-alpha, reactive oxygen species (ROS), and nuclear factor kappa B binding activity than carnosine or AA treatment alone. In diabetic mice, the combination of 0.25% carnosine plus 0.25% AA in diet resulted in higher final body weight, and lower levels of plasma glucose and triglyceride than 0.5% carnosine or 0.5% AA treatment alone. Carnosine and AA combination caused more reduction in renal levels of leukin-6, TNF-alpha and ROS than carnosine or AA treatment alone. This combination also more significantly limited renal cyclooxygenase-2 activity and p-p38 phosphorylation than carnosine or AA treatment alone. These novel findings support that this combination is a more powerful remedy for diabetic control. Graphical abstract Effects of carnosine (Car) and/or AA upon NF-κB p50/65 binding activity (OD value/mg protein). HUVE cells were pre-treated with 1 μM Car, 1 μM AA or 0.5 μM Car+0.5 μM AA for 24 h incubation at 37 °C. Then, cells were treated with DMEM containing high glucose (33 mM), and followed by incubating for another 24 h at 37 °C. Normal group had no Car, AA, or high glucose. Control group had no Car or AA, but with high glucose. Data are mean ± SD (n = 6). Values with different alphabet among bars are significantly different at P < 0.05 as analyzed by Dunnett's t -test. Image 1 Highlights • HUVE cell line and diabetic mice were used to examine the combined effects of carnosine and asiatic acid (AA). • Co-treatment of carnosine plus AA led to grater HUVE cell viability and Bcl-2 mRNA expression. • In diabetic mice, carnosine and AA combination caused more reduction in renal IL-6, TNF-alpha and ROS generation. • This combination led to more decrease in renal cyclooxygenase-2 activity and p-p38 phosphorylation. • These findings support that this combination is a powerful remedy for diabetic control. [ABSTRACT FROM AUTHOR]

Abstract: The content of several phenolic acids and flavonoids in aqueous extract (AE) and ethanol extract (EE) of daylily flower (Hemerocallis fulva L.) was analyzed. The effects of AE or EE at 0.5%, 1%, or 2% in HUVE cells against high glucose‐induced cell death, oxidative, and inflammatory damage were examined. Results showed that seven phenolic acids and seven flavonoids could be detected in AE or EE, in the range of 29 to 205 and 41 to 273 mg/100 g, respectively. Compared with the control groups, high glucose raised the activity of caspase‐3 and caspase‐8; suppressed Bcl‐2 mRNA expression and increased Bax mRNA expression; and induced HUVE cells apoptosis. The pretreatments from AE or EE at 1% or 2% reduced caspase‐3 activity and Bax mRNA expression, and enhanced cell viability. High glucose decreased glutathione content; stimulated the production of reactive oxygen species, interleukin‐6, tumor necrosis factor‐alpha, and prostaglandin E2; raised the activity of cyclooxygenase‐2 and nuclear factor kappa B p50/65 binding; and reduced the activity of glutathione peroxidase, glutathione reductase, and catalase in HUVE cells. AE pretreatments at 1% and 2% reversed these changes. These novel findings suggested that daylily flower was rich in phytochemicals, and could be viewed as a potent functional food against diabetes. [ABSTRACT FROM AUTHOR]

Objective This study aimed to investigate the effects of FTY720 on inducing cell growth inhibition and enhancing the cytotoxicity of anti-cancer drugs in the human colon cancer cell line HCT-8 and its multidrug-resistant cell line HCT-8/5-fluorouracil ( HCT-8/5- Fu). Methods Cell viability and apoptosis after being treated with FTY720 alone or in combination with doxorubicin ( DOX) and etoposide ( VP16) were tested in HCT-8 and HCT-8/5- Fu cells. The changes in P-glycoprotein ( P-gp) and multidrug resistance protein 1 ( MRP1) were determined at the mRNA and functional levels. Results FTY720 showed anti-proliferative activity against cancer cells in a dose-dependent and time-dependent manner and could enhance the cytotoxicity of DOX and VP16 in both HCT-8 and HCT-8/5- Fu cell lines. In addition, treatment with FTY720 resulted in the promotion of VP16-induced cell apoptosis and an increased accumulation of intracellular DOX and two specific fluorescent substrates of P-gp and MRP1 through the inhibition of efflux and the suppression of gene expression. Conclusion FTY720 exerts its chemosensitization effect in HCT-8 and HCT-8/5- Fu cell lines by promoting cell apoptosis and inhibiting P-gp and MRP1, which could be applied as a potential co-adjuvant therapeutic modality. [ABSTRACT FROM AUTHOR]

Saturated fatty acid is one of the important nutrients, but contributes to lipotoxicity in the liver, causing hepatic steatosis. Aqueous pepino leaf extract (AEPL) in the previous study revealed alleviated liver lipid accumulation in metabolic syndrome mice. The study aimed to investigate the mechanism of AEPL on saturated long-chain fatty acid-induced lipotoxicity in HepG2 cells. Moreover, the phytochemical composition of AEPL was identified in the present study. HepG2 cells treated with palmitic acid (PA) were used for exploring the effect of AEPL on lipid accumulation, apoptosis, ER stress, and antioxidant response. The chemical composition of AEPL was analyzed by HPLC-ESI-MS/MS. AEPL treatment reduced PA-induced ROS production and lipid accumulation. Further molecular results revealed that AEPL restored cytochrome c in mitochondria and decreased caspase 3 activity to cease apoptosis. In addition, AEPL in PA-stressed HepG2 cells significantly reduced the ER stress and suppressed SREBP-1 activation for decreasing lipogenesis. For defending PA-induced oxidative stress, AEPL promoted Nrf2 expression and its target genes, SOD1 and GPX3, expressions. The present study suggested that AEPL protected from PA-induced lipotoxicity through reducing ER stress, increasing antioxidant ability, and inhibiting apoptosis. The efficacy of AEPL on lipotoxicity was probably concerned with kaempferol and isorhamnetin derived compounds. [ABSTRACT FROM AUTHOR]

Abstract: We elucidated the cytoprotective effects of hyperoside (quercetin-3-O-galactoside) against hydrogen peroxide (H2O2)-induced cell damage. We found that hyperoside scavenged the intracellular reactive oxygen species (ROS) detected by fluorescence spectrometry, flow cytometry, and confocal microscopy. In addition, we found that hyperoside scavenged the hydroxyl radicals generated by the Fenton reaction (FeSO4 +H2O2) in a cell-free system, which was detected by electron spin resonance (ESR) spectrometry. Hyperoside was found to inhibit H2O2-induced apoptosis in Chinese hamster lung fibroblast (V79-4) cells, as shown by decreased apoptotic nuclear fragmentation, decreased sub-G1 cell population, and decreased DNA fragmentation. In addition, hyperoside pretreatment inhibited the H2O2-induced activation of caspase-3 measured in terms of levels of cleaved caspase-3. Hyperoside prevented H2O2-induced lipid peroxidation as well as protein carbonyl. In addition, hyperoside prevented the H2O2-induced cellular DNA damage, which was established by comet tail, and phospho histone H2A.X expression. Furthermore, hyperoside increased the catalase and glutathione peroxidase activities. Conversely, the catalase inhibitor abolished the cytoprotective effect of hyperoside from H2O2-induced cell damage. In conclusion, hyperoside was shown to possess cytoprotective properties against oxidative stress by scavenging intracellular ROS and enhancing antioxidant enzyme activity. [Copyright &y& Elsevier]

Abstract: The radioprotective effect of eckol against γ-ray radiation-induced oxidative stress and its possible protective mechanisms were investigated. Eckol was found to reduce the intracellular reactive oxygen species generated by γ-ray radiation. Moreover, eckol also protected against radiation-induced cellular DNA damage and membrane lipid peroxidation, which are the main targets of radiation-induced damage. In addition, eckol recovered the cell viability damaged by radiation via the inhibition of apoptosis. Irradiated cells with eckol treatment reduced the expression of bax, the activation of caspase 9 and caspase 3, which were induced by radiation. However, irradiated cells with eckol recovered the expression of bcl-2 and mitochondrial cytochrome c which were decreased by radiation. The anti-apoptotic effect of eckol exerted via the inhibition of mitogen-activated protein kinase kinase-4 (MKK4/SEK1)-c-Jun NH2-terminal kinase (JNK)-activator protein 1 (AP-1) cascades induced by radiation. In summary, the results suggest that eckol protects cells against the oxidative stress induced by radiation via the reduction of reactive oxygen species and the attenuation of activation in SEK1-JNK-AP-1 pathway. [Copyright &y& Elsevier]

To develop an HCT-8/5-FUmultidrug-resistant colorectal cancer cell line and to elucidate the effect of Andrographolid (AG), an extract from Andrographis paniculate, a medicinal herb on the HCT-8/5-FUmultidrug-resistant colorectal cancer cell line.An HCT-8 colorectal cancer cell line was used and a high concentration of 5-Fluorouracid (5-FU) was introduced at the beginning to induce drug resistance, then the concentration of 5-FU was increased in gradients. Approximately 7 months later, the cells grew stably in 2.0 µg/mL of 5-FU, and the cell line was named HCT-8/5-FUmultidrug-resistant colorectal cancer cell line. The resistant index of HCT-8/5-FUcells to 5-FU, adriamycin (ADM), cisplatin (DDP) was checked by MTT test, and a growth curve was drawn. The morphological changes were observed by both light and electron microscope. The function ofP-170 was detected by rhodamine staining. After the application of AG and co-administration of 5-FU, ADM and DDP, the growth curves and inhibition rate as well as apoptosis rate of HCT-8/5-FUat different concentrations of AG were evaluated by MTT and flow cytometry. Rhodamine staining was used to investigate the possible mechanism involved by AG.The resistance index of HCT-8/5-FUto 5-FU was 16.6, and a cross-resistance to ADM and DDP was noticed. Compared with parental cells, HCT-8/5-FUcell's growth rate did not change significantly but the cell's morphology was remarkably changed as compared with parental cells. Overexpression ofP-170 by HCT-8/5-FUcell was indicated through rhodamine staining. AG at a low concentration showed weak inhibitory effect on HCT-8/5-FU. However, a remarkable inhibitory and apoptosis rate was shown when AG was co-administered with 5-FU, ADM and DDP, respectively. Interestingly AG alone could not induce apoptosis and change the cell cycles. AG might affect the expression of P-170, which was indicated by rhodamine staining.The HCT-8/5-FUmultidrug-resistant colorectal cancer cell line has been successfully developed and because it has cross-resistance to 5-FU, ADM and DDP, it might serve as an ideal multidrug resistance (MDR) model for colorectal cancer research. The mechanism of HCT-8/5-FUresistance to chemotherapeutic agents might be related to the overexpression ofP-170. Low concentrations of AG alone have no significant inhibition on HCT-8/5-FUand fail to induce apoptosis and to change cell cycles. AG might act as a chemosensitizer when co-administered with 5-FU, ADM and DDP, and the mechanism of reversal modulation of multidrug resistance by AG in the HCT-8/5-FUresistant cell line might be related to its downregulation of overexpression ofP-170. [ABSTRACT FROM AUTHOR]