The protective role of Coenzyme Q10 in metallothionein-3 expression in liver and kidney upon rats' exposure to lead acetate.

Metallothionein-3 (MT3) is an antioxidant protein that alters after exposure to heavy metals. In this study, we investigated the hepatic and renal expression of MT3 gene following exposure to lead acetate (PbAc) alone and PbAc plus CoQ10 as an adjuvant antioxidant. Twenty-four rats were allocated into three groups, including control, PbAc (free access to drinking water contaminated with PbAc at 1 g/100 ml), and PbAc plus CoQ10 (10 mg/kg/day Oral). After 28 consecutive days of treatment, the mRNA expression of MT3 and Cyt-c genes and MT3 protein levels were assessed using real-time PCR and immunosorbent assay. The serum lipid profile was also monitored in the three groups. PbAc exposure significantly reduced the hepatic and renal MT3 mRNA and protein expression compared to the control group. This reduction was significantly increased with addition of CoQ10 to levels near those of the control group. The hepatic and renal expression of Cyt-c mRNA increased after treatment with PbAc, while such effect was reversed after addition of CoQ10. Alteration in lipid profile including increased cholesterol and low-density lipoprotein levels were observed after PbAc exposure which were counteracted by CoQ10. Our results confirm the cytotoxic effects of acute lead exposure manifested as changes in the serum lipid profile and cellular levels of Cyt-c mRNA. These cytotoxic effects may have been caused by decreased MT3 gene expression and be reduced by the protective role of CoQ10.

Lifelong quercetin enrichment and cardioprotection in Mdx/Utrn+/- mice.

Duchenne Muscular Dystrophy (DMD) is associated with progressive cardiac pathology; however, the SIRT1/PGC1-α activator quercetin may cardioprotect dystrophic hearts. We tested the extent to which long-term 0.2% dietary quercetin enrichment attenuates dystrophic cardiopathology in Mdx/Utrn+/- mice. At 2 mo, Mdx/Utrn+/- mice were fed quercetin-enriched (Mdx/Utrn+/--Q) or control diet (Mdx/Utrn+/-) for 8 mo. Control C57BL/10 (C57) animals were fed a control diet for 10 mo. Cardiac function was quantified by MRI at 2 and 10 mo. Spontaneous physical activity was quantified during the last week of treatment. At 10 mo hearts were excised for histological and biochemical analysis. Quercetin feeding improved various physiological indexes of cardiac function in diseased animals. Mdx/Utrn+/--Q also engaged in more high-intensity physical activity than controls. Histological analyses of heart tissues revealed higher expression and colocalization of utrophin and α-sarcoglycan. Lower abundance of fibronectin, cardiac damage (Hematoxylin Eosin-Y), and MMP9 were observed in quercetin-fed vs. control Mdx/Utrn+/- mice. Quercetin evoked higher protein abundance of PGC-1α, cytochrome c, ETC complexes I-V, citrate synthase, SOD2, and GPX compared with control-fed Mdx/Utrn+/- Quercetin decreased abundance of inflammatory markers including NFκB, TGF-ß1, and F4/80 compared with Mdx/Utrn+/-; however, P-NFκB, P-IKBα, IKBα, CD64, and COX2 were similar between groups. Dietary quercetin enrichment improves cardiac function in aged Mdx/Utrn+/- mice and increases mitochondrial protein content and dystrophin glycoprotein complex formation. Histological analyses indicate a marked attenuation in pathological cardiac remodeling and indicate that long-term quercetin consumption benefits the dystrophic heart. NEW & NOTEWORTHY: The current investigation provides first-time evidence that quercetin provides physiological cardioprotection against dystrophic pathology and is associated with improved spontaneous physical activity. Secondary findings suggest that quercetin-dependent outcomes are in part due to PGC-1α pathway activation.

Methanol extract of Flacourtia indica aerial parts induces apoptosis via generation of ROS and activation of caspases in human colon cancer HCT116 cells.

Different plant parts of Flacourtia indica have long been used in Ayurvedic medicine. Previous studies have demonstrated that the methanolic extract of F. indica possess anti-inflammatory properties. The present study was aimed at investigating the anticancer effects of methanol extract of Flacourtia indica (FIM) aerial parts in human colon cancer (HCT116) cells. Treatment of cells with FIM at a concentration of 500 µg/ml for 24 hours significantly reduced cell viability and induced apoptosis, which was associated with the increased cytoplasmic expression of cytochrome c, activation of caspase-3, and the cleavage of poly-(ADP-ribose) polymerase. Incubation with FIM also inhibited the levels of Bcl-2, Bcl-xl and survivin, which are the markers of cell proliferation, whereas the expression of Bax remained unchanged. Treatment with FIM led to the generation of reactive oxygen species (ROS) in a concentration-dependent manner. Pharmacological inhibition of ROS generation by pretreatment of cells with N-acetyl cysteine abrogated FIM-induced apoptosis in HCT116 cells. Thus, these results demonstrate that FIM has anti-proliferative and pro-apoptotic effects in HCT116 cells and the effects are, at least in part, due to the ROS dependent activation of caspases.

ERKs and mitochondria-related pathways are essential for glycyrrhizic acid-mediated neuroprotection against glutamate-induced toxicity in differentiated PC12 cells

The present study focuses on the neuroprotective effect of glycyrrhizic acid (GA, a major compound separated from Glycyrrhiza Radix, which is a crude Chinese traditional drug) against glutamate-induced cytotoxicity in differentiated PC12 (DPC12) cells. The results showed that GA treatment improved cell viability and ameliorated abnormal glutamate-induced alterations in mitochondria in DPC12 cells. GA reversed glutamate-suppressed B-cell lymphoma 2 levels, inhibited glutamate-enhanced expressions of Bax and cleaved caspase 3, and reduced cytochrome C (Cyto C) release. Exposure to glutamate strongly inhibited phosphorylation of AKT (protein kinase B) and extracellular signal-regulated kinases (ERKs); however, GA pretreatment enhanced activation of ERKs but not AKT. The presence of PD98059 (a mitogen-activated protein/extracellular signal-regulated kinase kinase [MEK] inhibitor) but not LY294002 (a phosphoinositide 3-kinase [PI3K] inhibitor) diminished the potency of GA for improving viability of glutamate-exposed DPC12 cells. These results indicated that ERKs and mitochondria-related pathways are essential for the neuroprotective effect of GA against glutamate-induced toxicity in DPC12 cells. The present study provides experimental evidence supporting GA as a potential therapeutic agent for use in the treatment of neurodegenerative diseases.

ERKs and mitochondria-related pathways are essential for glycyrrhizic acid-mediated neuroprotection against glutamate-induced toxicity in differentiated PC12 cells.

The present study focuses on the neuroprotective effect of glycyrrhizic acid (GA, a major compound separated from Glycyrrhiza Radix, which is a crude Chinese traditional drug) against glutamate-induced cytotoxicity in differentiated PC12 (DPC12) cells. The results showed that GA treatment improved cell viability and ameliorated abnormal glutamate-induced alterations in mitochondria in DPC12 cells. GA reversed glutamate-suppressed B-cell lymphoma 2 levels, inhibited glutamate-enhanced expressions of Bax and cleaved caspase 3, and reduced cytochrome C (Cyto C) release. Exposure to glutamate strongly inhibited phosphorylation of AKT (protein kinase B) and extracellular signal-regulated kinases (ERKs); however, GA pretreatment enhanced activation of ERKs but not AKT. The presence of PD98059 (a mitogen-activated protein/extracellular signal-regulated kinase kinase [MEK] inhibitor) but not LY294002 (a phosphoinositide 3-kinase [PI3K] inhibitor) diminished the potency of GA for improving viability of glutamate-exposed DPC12 cells. These results indicated that ERKs and mitochondria-related pathways are essential for the neuroprotective effect of GA against glutamate-induced toxicity in DPC12 cells. The present study provides experimental evidence supporting GA as a potential therapeutic agent for use in the treatment of neurodegenerative diseases.

Isoangustone A induces apoptosis in SW480 human colorectal adenocarcinoma cells by disrupting mitochondrial functions.

Licorice and its components have been reported to posses various anti-tumor activities, but its active ingredients and underlying mechanisms are not well understood yet. In the present study, a group of representative licorice-derived compounds that could be detected in rat plasma or urine were screened for anti-tumor activity. Among these compounds, isoangustone A (IAA) was found to promptly inhibit the viability of SW480 human colorectal adenocarcinoma cells in a time- and concentration-dependent manner. Further analyses indicate that IAA activated caspase-dependent pro-apoptotic signaling and induced significant apoptosis, while had little effect on cell cycle. IAA strongly inhibited Akt phosphorylation within 5 min; however, overexpression of constitutively activated Akt could not rescue IAA-mediated inhibition, indicating that inhibition of Akt was not involved in IAA-induced apoptosis. Further examinations show that IAA induced dissipation of mitochondria membrane potential and release of cytochrome C within 1h, accompanied by swelling of mitochondrial matrix and disrupting of mitochondrial outer membrane, and followed by decreasing of cellular ATP. The above results suggest that IAA induced apoptosis in colorectal cancer cells principally by inducing mitochondrial outer membrane permeabilization, and deserves further investigations as a novel anti-colorectal cancer agent.

Essential oil from Chenopodium ambrosioides and main components: activity against Leishmania, their mitochondria and other microorganisms.

Chenopodium ambrosioides is an aromatic herb used by native people to treat parasitic diseases. The aim of this work is to compare the in vitro anti-leishmanial activity of the essential oil (EO) from C. ambrosioides and its major components (ascaridole, carvacrol and caryophyllene oxide) and study their mechanism of action and activity against a panel of microorganism. Antileishmanial activity and cytotoxicity of the EO and major components was study. In addition, experiments to elucidate the mechanism of action were perform and activities against other microorganisms (bacteria, fungi and protozoa) were evaluate. All products were active against promastigote and amastigote forms of Leishmania. Ascaridole exhibited the better antileishmanial activity and the EO the highest selectivity index. The exploration of the mechanism suggests that the products cause a breakdown of mitochondrial membrane potential and a modification of redox indexes. Only EO showed antiprotozoal effect against Plasmodium falciparum and Trypanosoma brucei; while no activity against bacteria and fungi was observed. Our results demonstrate the potentialities of EO in cellular and molecular system, which could be consider in future studies to develop new antileishmanial drugs with a wide anti-parasitic spectrum.

Effect of arecoline on regeneration of injured peripheral nerves.

The present study provides in vitro and in vivo evaluation of arecoline on peripheral nerve regeneration. In the in vitro study, we found that arecoline at 50 µg/ml could significantly promote the survival and outgrowth of cultured Schwann cells as compared to the controls treated with culture medium only. In the in vivo study, we evaluated peripheral nerve regeneration across a 10-mm gap in the sciatic nerve of the rat, using a silicone rubber nerve chamber filled with the arecoline solution. In the control group, the chambers were filled with normal saline only. At the end of the fourth week, morphometric data revealed that the arecoline-treated group at 5 µg/ml significantly increased the number and the density of myelinated axons as compared to the controls. Immunohistochemical staining in the arecoline-treated animals at 5 µg/ml also showed their neural cells in the L4 and L5 dorsal root ganglia ipsilateral to the injury were strongly retrograde-labeled with fluorogold and lamina I-II regions in the dorsal horn ipsilateral to the injury were significantly calcitonin gene-related peptide-immunolabeled compared with the controls. In addition, we found that the number of macrophages recruited in the distal sciatic nerve was increased as the concentration of arecoline was increased. Electrophysiological measurements showed the arecoline-treated groups at 5 and 50 µg/ml had a relatively larger nerve conductive velocity of the evoked muscle action potentials compared to the controls. These results indicate that arecoline could stimulate local inflammatory conditions, improving the recovery of a severe peripheral nerve injury.

Comparison the neuropreotective effect of Cortex Phellodendri chinensis and Cortex Phellodendri amurensis against beta-amyloid-induced neurotoxicity in PC12 cells.

Cortex Phellodendron chinensis (CPC) and Cortex Phellodendron amurensis (CPA) derived from the dried bark of Phellodendron chinense Schneid. or Phellodendron amurense Rupr., respectively, are used interchangeably in clinical practice under the name "Huang Bai" for centuries in Chinese medicine for the treatment of various inflammatory conditions. Previous study in our laboratory demonstrated that CPC and CPA had different anti-diarrheal, anti-bacterial and anti-inflammatory effects. In this present study, we aimed to compare the protective effect of ethanol extract of Cortex Phellodendri chinensis (ECPC) and Cortex Phellodendri Amurensis (ECPA) against beta-amyloid (Aß)-induced neurotoxicity in PC12 cells, a typical model of Alzheimer's disease. The results showed that ECPC and ECPA contain four common chemical markers such as berberine, but palmatine and jatrorrhizin were not found in CPC in contrast to the presence in CPA. In addition, both ECPC and ECPA can significantly increase the cell viability in Aß-treated PC12 cells. Moreover, ECPC and ECPA can markedly elevate the ratio of the protein and mRNA levels of Bcl-2/Bax, while remarkably decrease the release of cytochrome c, and the protein and mRNA expression of caspase-3. Interestingly, ECPA has better protective effect than ECPC against Aß-induced neurotoxicity in PC12 cells. These results indicate that both ECPC and ECPA have potential protective effect against Aß-induced neurotoxicity in PC12 cells, and ECPA is more potential of the two species to be used in traditional medicine as a neuroprotective agent for the treatment of AD. The neuroprotective effect of the two species may be mediated, at least in part, via suppressing of the cellular apoptosis.

Reduction in lipopolysaccharide-induced apoptosis of fibroblasts obtained from a patient with gingival overgrowth during nifedipine-treatment.

OBJECTIVE: We have previously demonstrated that the mechanism of nifedipine (NIF)-induced gingival overgrowth is related to the observation that proliferation and cell cycle progression of gingival fibroblasts derived from NIF reactive patient (NIFr) are greater than those from NIF non-reactive patient (NIFn). Gingival overgrowth has also been reported to be a result of inhibited apoptosis of gingival fibroblasts. Apoptosis in fibroblasts is induced by lipopolysaccharide (LPS). Thus, we focused upon evaluating whether there is a difference in LPS-induced apoptosis between NIFn and NIFr. METHODS: Both NIFn and NIFr were arrested in DMEM containing 0.5% FBS, stimulated by LPS, and assayed for apoptosis, cell cycle analysis, Western blotting, and caspase activity. RESULTS: Compared to NIFn, the number of apoptotic cells was significantly decreased and the percentage of cells in S and G(2)/M phase was significantly increased in NIFr. The levels of Bax and cytochrome c proteins in NIFr were not up-regulated by LPS compared with NIFn. Both NIFn and NIFr displayed the following changes in protein expression: increased Bad, decreased Bcl-xL, and unchanged Bcl-2 and p53. Caspase-3 and -9 activities were significantly increased by LPS in NIFn but were unchanged in NIFr. Caspase-2 activity remained constant whilst caspase-8 activity significantly increased upon LPS treatment in both NIFn and NIFr. CONCLUSION: Bad, Bax, cytochrome c, p53, and caspases-2, -3, -8, and -9 are pro-apoptotic proteins. Bcl-2 and Bcl-xL are anti-apoptotic proteins. Thus, the mechanism of NIF-induced gingival overgrowth might be related to decreased apoptosis in NIFr through a reduction of Bax, cytochrome c, and caspase-3 and -9.

Orientin-induced cardioprotection against reperfusion is associated with attenuation of mitochondrial permeability transition.

In this study, we provide new evidence that orientin from bamboo leaves (Phyllostachys nigra) protect H9c2 cardiomyocytes against ischemia/reperfusion (I/R) injury through the mitochondrial apoptotic pathway. A previous work has identified that orientin could protect myocardium against ischemia/reperfusion injury. Mitochondria are both critical determinants of cardioprotection and crucial targets of cardioprotective signaling. Their role during reperfusion is conspicuously critical because the conditions promote apoptosis through the mitochondrial pathway and necrosis though irreversible damage to mitochondria, which is in association with mitochondrial permeability transition (MPT). After myocardial ischemia, opening of the mPTP is a critical determinant of cell death. The relationship of orientin and mPTP in mediating reperfusion-induced cardiomyocytes injury is still elusive. Here, our results indicate that the protective effect of orientin in H9c2 cells subjected to I/R injury is associated with depression of the mPTP opening, resultant mitochondrial dysfunction, and apoptosis. Further investigation of cellular mechanisms revealed that these effects were associated with inhibition of reactive oxygen species (ROS) generation, repolarization of mitochondrial membrane potential (Δψ(m)), suppression of mitochondrial cytochrome C release, enhancement of the Bcl-2 level, and inhibition of Bax and Smac/DIABLO levels. Furthermore, these beneficial effects of orientin were blocked by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin, and orientin could enhance Akt phosphorylation. In summary, we demonstrate that orientin protects H9c2 cardiomytocytes against I/R-induced apoptosis by modulating the mPTP opening, and this role of orientin may involve the PI3K/Akt signaling pathway.

Typhonium flagelliforme induces apoptosis in CEMss cells via activation of caspase-9, PARP cleavage and cytochrome c release: its activation coupled with G0/G1 phase cell cycle arrest.

ETHNOPHARMACOLOGICAL RELEVANCE: The plant Typhonium flagelliforme (TF), commonly known as 'rodent tuber' in Malaysia, is often used as traditional remedy for cancer, including leukemia. AIM OF THE STUDY: We had previously identified morphologically that the linoleic acid rich fraction (DCM/F7) from the tubers of this plant induces selective anti-proliferative effects and apoptosis in CEMss cells. In this present study, we subjected the same DCM/F7 fraction to cell based activity analyses in order to determine the possible mechanism of cell death in leukemic CEMss cells in vitro. MATERIALS AND METHODS: Extraction of Typhonium flagelliforme tuber has done and fractionation has been done by vacuum liquid column chromatography. The anti-proliferative activity was assayed using MTT and the apoptosis detection was done by Annexin V and DNA laddering assay. Colorimetric caspase assay and immunoblot analysis were employed to detect the expression of protein associated with cell death. Cell cycle analysis was done using flow cytometry. RESULTS: We found that the cancer inhibitory effect of the DCM/F7 fraction in CEMss cells was 3 ± 0.08 µg/ml (IC(50)). An early apoptotic induction in CEMss cells was observed by Annexin V assay, which showed a clear dose-dependent DNA fragmentation being observed in gel electrophoresis at 10 and 20 µg/ml. The DCM/F7 fraction at 3 µg/ml significantly arrested CEMss cells at G0/G1 phase (p<0.05). A constant but increasing pattern-related Sub-G0/G1 index was observed between 12 and 72 h treatment. In relation to this, we further investigated the biochemical events leading to cell death and found that the DCM/F7 fraction increased the cellular levels of caspase-3 and -9 on treated cells. Our results indicated that cytochrome c from mitochondria into the cytosol increased gradually as the DCM/F7 concentration increases, which later lead to the subsequent cleavage of PARP in to 85kDa fragments. On the contrary, Bcl-2 protein was found to decrease concomitantly during treatment. CONCLUSIONS: Collectively, results presented in this study demonstrated that the DCM/F7 fraction inhibited the proliferation of leukemia cells, leading to the programmed cell death, which was confirmed to be through the mitochondrial pathway.

cis-4-decenoic acid provokes mitochondrial bioenergetic dysfunction in rat brain.

AIMS: In the present work we investigated the in vitro effect of cis-4-decenoic acid, the pathognomonic metabolite of medium-chain acyl-CoA dehydrogenase deficiency, on various parameters of bioenergetic homeostasis in rat brain mitochondria. MAIN METHODS: Respiratory parameters determined by oxygen consumption were evaluated, as well as membrane potential, NAD(P)H content, swelling and cytochrome c release in mitochondrial preparations from rat brain, using glutamate plus malate or succinate as substrates. The activities of citric acid cycle enzymes were also assessed. KEY FINDINGS: cis-4-decenoic acid markedly increased state 4 respiration, whereas state 3 respiration and the respiratory control ratio were decreased. The ADP/O ratio, the mitochondrial membrane potential, the matrix NAD(P)H levels and aconitase activity were also diminished by cis-4-decenoic acid. These data indicate that this fatty acid acts as an uncoupler of oxidative phosphorylation and as a metabolic inhibitor. cis-4-decenoic acid also provoked a marked mitochondrial swelling when either KCl or sucrose was used in the incubation medium and also induced cytochrome c release from mitochondria, suggesting a non-selective permeabilization of the inner mitochondrial membrane. SIGNIFICANCE: It is therefore presumed that impairment of mitochondrial homeostasis provoked by cis-4-decenoic acid may be involved in the brain dysfunction observed in medium-chain acyl-CoA dehydrogenase deficient patients.

Effect of parthenolide on proliferation and apoptosis in gastric cancer cell line SGC7901.

OBJECTIVE: To investigate the effect of parthenolide (PAR) on proliferation and apoptosis in gastric cancer cell line SGC7901. METHODS: Human gastric cancer cell line SGC7901 cells were incubated with various concentration of PAR. After various periods of incubation, the proliferation of SGC7901 cells was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide methyl thiazolyl tetrazolium (MTT) assay. Apoptosis was measured by the annexin V-fluorescein isothiocyanate fluoresceine isothiocyanate (FITC)/propidium iodide (PI) double labeled staining method and the morphology of the cell was observed under a fluorescent microscope. Mitochondrial potential was measured by flow cytometry after Rhodamine 123 staining. The expressions of cytochrome C and the Bcl-2 family of proteins, including Bcl-2, Bax, Bid and tBid were measured by Western blot. Caspase 3 and 8 activities were measured by enzyme-linked immunosorbent assay. RESULTS: Treatment with PAR induced apoptosis as confirmed by annexin V-FITC/PI assay. PAR-induced apoptosis was associated with intracellular events including the decline of mitochondrial potential, increased release of cytochrome C from the mitochondria, decreased expression of Bcl-2, increased expression of Bax, Bid and tBid and activation of caspase 3 and 8. CONCLUSION: These results suggest that possibly via activation of the mitochondrial pathway, PAR causes mitochondrial damage leading to the release of cytochrome C and by regulating the expression of the Bcl-2 family of proteins and activating caspases which leads to results in apoptotic cell death in SGC7901 cells. Our results might be helpful in formulating new therapeutic approaches using Chinese herbal medicine.

Catalpol protects primary cultured cortical neurons induced by Abeta(1-42) through a mitochondrial-dependent caspase pathway.

It has been reported that catalpol, an iridoid glucoside, isolated from the root of Rehmannia glutinosa, protected cells from damage induced by a variety of toxic stimulus such as LPS, MPP(+) and rotenone. Here, we further evaluated the effect of catalpol against Abeta(1-42)-induced apoptosis in primary cortical neuron cultures. In the present study, the primary cortical neuron culture treated with Abeta(1-42) was severed as cell model of Alzheimer's disease (AD) in vitro. By exposure to Abeta(1-42) (5 microM) for 72 h in cultures, neuronal apoptosis occurred characterized by enhancement of activities of caspases and reactive oxygen species (ROS) as well as Bax increase, loss of mitochondrial membrane potential and cytochrome c release. Pretreatment with catalpol (0.5mM) for 30 min prior to Abeta(1-42) treatment attenuated neuronal apoptosis not only by reversing intracellular ROS accumulation, Bax level, mitochondrial membrane potential and, cytochrome c release to some extent, but also through regulating the activity and cleavage of caspase-3 and caspase-9. Thus, catalpol protects primary cultured cortical neurons induced by Abeta(1-42) through a mitochondrial-dependent caspase pathway.

Combination treatment with arsenic trioxide and irradiation enhances apoptotic effects in U937 cells through increased mitotic arrest and ROS generation.

Arsenic compounds have been used as anti-cancer agents in traditional Chinese medicine. Ionizing radiation (IR) is one of the most effective tools in the clinical treatment of cancer. The induction of apoptotic cell death is a significant mechanism of tumor cells under the influence of radio-/chemotherapy, and resistance to these treatments has been linked to some cancer cell lines with a low propensity for apoptosis. A combination of different anti-tumoral treatment modalities is advantageous in limiting non-specific toxicity often observed by an exceedingly high dose of single regimen. The present study aimed at investigating the enhanced effects and mechanisms in cell cycle distribution and apoptosis of U937 cells, a human pre-monocytic leukemia cell line lacking functional p53 protein, after combination treatment with irradiation and As(2)O(3). Our results indicated that combined treatment led to activation of cdc-2, which is related to the expression of cyclin B. In addition, combined treatment increased apoptotic cell death in U937 cells, which is correlated with the induction of mitotic arrest, the increase in intracellular reactive oxygen species (ROS) generation, the decrease in B-cell leukemia/lymphoma 2 (Bcl-2) and B-cell leukemia/lymphoma XL (Bcl-XL) levels, the loss of mitochondria membrane potential, and the activation of caspase-3. We found that combining radiation and As(2)O(3) may be an effective strategy against p53-deficient leukemia cells.

Cirsilineol inhibits proliferation of cancer cells by inducing apoptosis via mitochondrial pathway.

Cirsilineol (4',5-dihydroxy-3',6,7-trimethoxyflavone) is a compound isolated from the herb of Artemisia vestita Wall (Compositae). In this study, we aimed at examining the anti-proliferative activity of cirsilineol against multiple types of cancer cells and the underlying mechanisms. Cirsilineol significantly inhibited proliferation of Caov-3, Skov-3, PC3 and Hela cells in a concentration-dependent manner. The compound also dose-dependently induced apoptosis in Caov-3 cells, as determined by annexin V/propidium iodide staining. Besides, cirsilineol induced a remarkable change in mitochondrial membrane potential and caused release of cytochrome c to cytosol. Furthermore, the compound caused a marked activation of capase-3, caspase-9 and poly (ADP-ribose) polymerase (PARP). These results suggested that the induction of apoptosis via the mitochondrial pathway was involved in the anti-proliferative activity of cirsilineol against cancer cells.

Zinc inhibits ethanol-induced HepG2 cell apoptosis.

Alcohol consumption produces a variety of metabolic alterations in liver cells, associated with ethanol oxidation and with nonoxidative metabolism of ethanol, among others apoptosis of hepatocytes. As zinc is known as a potent antioxidant and an inhibitor of cell apoptosis, the aim of this paper was to investigate whether zinc supplementation could inhibit ethanol-induced HepG2 apoptosis, and whether this inhibition was connected with attenuation of oxidative stress and modulation of FasR/FasL system expression. The results indicated that zinc supplementation significantly inhibited ethanol-induced HepG2 cell apoptosis (measured by cytochrome c release from mitochondria and caspase-3 activation) by attenuation of reactive oxygen species (ROS) production, increase in the cellular level of GSH, inhibition of ethanol-induced sFasR and FasL overexpression and caspase-8 activation. These results indicate that zinc can inhibit ethanol-induced hepatocyte apoptosis by several independent mechanisms, among others by an indirect antioxidative effect and probably by inhibition of caspase-8 and caspase-9 activation.

Yin-Chen-Hao-Tang ameliorates obstruction-induced hepatic apoptosis in rats.

The accumulation of hydrophobic bile acids in the liver is considered to play a pivotal role in the induction of apoptosis of hepatocytes during cholestasis. Thus, factors that affect apoptosis may be used to modulate liver fibrosis. Yin-Chen-Hao-Tang (YCHT) decoctions have been recognised as a hepatoprotective agent for jaundice and various types of liver diseases. We used an experimental rat model of bile-duct ligation (BDL) to test whether YCHT plays a regulatory role in the pathogenesis of hepatic apoptosis. BDL-plus-YCHT groups received 250 or 500 mg kg (-1) YCHT by gavage once daily for 27 days. YCHT significantly ameliorated the portal hypertensive state and serum TNF-alpha compared with the vehicle-treated control group. In BDL-plus-YCHT-treated rats, hepatic glutathione contents were significantly higher than than in BDL-only rats. BDL caused a prominent liver apoptosis that was supported by an increase in Bax and cytochrome c protein and increased expression of Bax and Bcl-2 messenger RNA. The normalising effect of YCHT on expression of Bax and Bcl-2 mRNA was dependent on the dose of YCHT, 500 mg kg (-1) having the greater effect on both Bax and Bcl-2 of mRNA levels. Additionally, YCHT treatment down-regulated both hepatic caspase-3 and -8 activities of BDL rats. This study demonstrates the anti-apoptotic properties of YCHT and suggests a potential application of YCHT in the clinical management of hepatic disease resulting from biliary obstruction.

Extract of Coptidis rhizoma induces cytochrome-c dependent apoptosis in immortalized and malignant human oral keratinocytes.

Coptidis rhizoma (C. rhizoma) had been demonstrated as an antioxidant and anticancer agent, however, its antioral cancer mechanism still remains unclear. Using water extracts of C. rhizoma, growth and apoptosis-related experiments for the treatment of multi-stage of oral cancer were carried out on immortalized human oral keratinocytes (IHOK), primary oral cancer cells (HN4), metastatic oral cancer cells (HN12) and human skin keratinocytes (HaCaT) by MTT assay, three-dimensional (3-D) raft cultures, western blotting, cell cycle analysis, nuclear staining and cytochrome c expression related to the apoptosis signaling pathway. C. rhizoma inhibited the proliferation of immortalized and malignant oral keratinocytes in a dose- and time-dependent manner. In 3-D organotypic culture, C. rhizoma-treated cells showed less maturation than the control cells, displaying low surface keratinization and decreased epithelial thickness. The major mechanism of growth inhibition by C. rhizoma appears to be the induction of apoptosis, which is supported by the results of the cell cycle analysis, FITC-annexin V staining, DNA fragmentation assay and DAPI staining. The induction of apoptosis by C. rhizoma was more prominent in immortalized keratinocytes than in malignant oral keratinocytes. Cytochrome-c release from mitochondria, accompanied by the activation of caspase-3, was observed in C. rhizoma-treated IHOK and oral cancer cells. These results suggest that C. rhizoma has apoptotic effects in immortalized and malignant oral keratinocytes via the mitochondrial signaling pathway.