Antiinflammatory triterpenoids from the fruiting bodies of Fomitopsis pinicola

Twelve undescribed lanostane-type triterpenes, and twenty-two known triterpenes were isolated and identified from a medicinal bracket fungus Fomitopsis pinicola (Sw.) P. Karst. The structures of these compounds were determined by spectroscopic and spectrometric analyses. The antiinflammatory potential of thirty-two triterpene compounds was evaluated using neutrophils as an assay model, and pinicolasin J was the most potent inhibitor of superoxide anion generation and elastase release, with IC₅₀ values of 1.81 ± 0.44 and 2.50 ± 0.64 μM, respectively. This study provides scientific insight into the nutritional supplement value and medicinal development of Fomitopsis pinicola.

Anti-inflammatory principles from Lindera aggregata

Four new sesquiterpenes (1-4), one new alkaloid (5), and one new benzenoid glycoside (6) were characterized from Lindera aggregata, and their structures were elucidated according to their spectrometric analytical data. Among these isolates, 3 and 4 were constructed as possessing unprecedented carbon skeletons from the natural source. Some of these purified constituents were examined for their anti-inflammatory bioactivity. Among the tested compounds, linderaggredin C (3), (+)-N-methyllaurotetanine, and (+)-isoboldine displayed the significant inhibition of superoxide anion generation in human neutrophils with IC₅₀ values of 7.45 ± 0.74, 8.36 ± 0.11, and 5.81 ± 0.59 μM, respectively.

Bioassay-guided purification of sesquiterpenoids from the fruiting bodies of Fomitopsis pinicola and their anti-inflammatory activity

Twelve undescribed sesquiterpenoids, fomitopins A–L (1–12), were isolated via bioassay-guided purification from the bracket fungus Fomitopsis pinicola which has been reported to exhibit anti-microbial and anti-inflammatory activities.

Relaxant and vasoprotective effects of ginger extracts on porcine coronary arteries

Ginger (Zingiber officinale Roscoe) is a popular Chinese herbal medicine, which is considered to warm the stomach and dispel cold in traditional Chinese medicine. Ginger is widely used to treat stomach disorders, and it has been reported to exhibit antithrombotic activity via the inhibition of platelet aggregation and thromboxane B2 production in vitro. Cardiovascular disease is associated with the aberrant functioning of the heart and circulatory system; the relatively narrow vessels of the circulation are commonly affected and blocked by atherosclerosis, which may result in angina or heart attack. Numerous drugs and medicines are used to treat myocardial infarction; however, they are often associated with numerous side effects. Therefore, it is important to identify substitutive drugs with no unbearable side effects. In the present study, the relaxant effects of ginger crude extract (GCE) were determined on porcine coronary arteries. The DPPH radical scavenging assay, lucigenin‑enhanced chemiluminescence assay and western blot analysis were used to individually detect antioxidant assay of ginger extraction or superoxide anion produced by endothelial cells and molecular signaling. The results indicated that GCE induced relaxation of porcine coronary arteries in an endothelium‑dependent manner. GCE increased vasoprotection via the suppression of nitric oxide synthase and cyclooxygenase. In addition, GCE possessed antioxidant ability, as determined using 1,1‑diphenyl‑2‑picrylhydrazyl and lucigenin‑enhanced chemiluminescence assays. Taken together, the present study demonstrated that GCE exerts marked vasoprotective effects and free radical‑scavenging activities in porcine coronary arteries.

Anti-Inflammatory and Neuroprotective Constituents from the Peels of Citrus grandis

A series of chromatographic separations performed on the ethanol extracts of the peels of Citrus grandis has led to the characterization of forty compounds, including seventeen coumarins, eight flavonoids, two triterpenoids, four benzenoids, two steroids, one lignan, one amide, and five other compounds, respectively. The chemical structures of the purified constituents were identified on the basis of spectroscopic elucidation, including 1D- and 2D-NMR, UV, IR, and mass spectrometric analysis. Most of the isolated compounds were examined for their inhibition of superoxide anion generation and elastase release by human neutrophils. Among the isolates, isomeranzin (3), 17,18-dihydroxybergamottin (12), epoxybergamottin (13), rhoifolin (19), vitexicarpin (22) and 4-hydroxybenzaldehyde (29) displayed the most significant inhibition of superoxide anion generation and elastase release with IC₅₀ values ranged from 0.54 to 7.57 μM, and 0.43 to 4.33 μM, respectively. In addition, 7-hydroxy-8-(2′-hydroxy-3′-methylbut-3′-enyl)coumarin (8) and 17,18-dihydroxybergamottin (12) also exhibited the protection of neurons against Aβ-mediated neurotoxicity at 50 μM.

Chemical Constituents and Anti-inflammatory Principles from the Fruits of Forsythia suspensa

Fifty compounds were isolated from the fruits of Forsythia suspensa, including 13 new compounds characterized as eight new diterpenoids (1-8), three new lignans (9-11), a new iridoid (12), and a new triterpenoid (13). Their structures were established on the basis of spectroscopic and spectrometric analysis. Most of the isolated compounds were examined for their anti-inflammatory activity in vitro. The results showed that several compounds displayed significant inhibition of fMLP/CB-induced superoxide anion generation and elastase release, with IC₅₀ values ranging from 0.6 ± 0.1 to 8.6 ± 0.8 μg/mL and from 0.8 ± 0.3 to 7.3 ± 1.1 μg/mL, respectively.

Effect of Miconazole on [Ca²⁺]i and Cytotoxicity in ZR-75-1 Human Breast Cancer Cells

The effect of the antifungal drug miconazole on Ca²⁺ signaling in human breast cancer cells is unknown. This study examined the effect of miconazole on cytosolic free Ca²⁺ concentrations ([Ca²⁺]i) in ZR-75-1 human breast cancer cells. The Ca²⁺-sensitive fluorescent dye fura-2 was used to measure [Ca²⁺]i. Miconazole induced [Ca²⁺]i rises concentration-dependently. The response was reduced by 60% by removing extracellular Ca²⁺. Miconazole-induced Ca²⁺ entry was abolished by the protein kinase C (PKC) inhibitor GF109203X, and nifedipine, but was insensitive to econazole, SKF96365 and the protein kinase C activator phorbol 12-myristate 13 acetate (PMA). In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) or thapsigargin (TG) greatly inhibited miconazole-evoked [Ca²⁺]i rises. Conversely, treatment with miconazole abolished TG and BHQ-evoked [Ca²⁺]i rises. Inhibition of phospholipase C (PLC) with U73122 abolished miconazole-induced [Ca²⁺]i rises. At concentrations of 30-50 μM, micronazole killed cells in a concentration-dependent manner. This cytotoxic effect was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl (BAPTA/AM). Together, in ZR-75-1 cells, miconazole induced [Ca²⁺]i rises by evoking PLC-dependent Ca²⁺ release from the endoplasmic reticulum, and PKC-regulated nifedipine-sensitive Ca²⁺ entry. Miconazole-caused cell death was not triggered by a preceding [Ca²⁺]i rise.

Effect of NPC15199 on [Ca²⁺]i and viability in SCM1 human gastric cancer cells

NPC15199 is a synthesized compound that inhibits inflammation in some models. However, whether NPC15199 affects Ca²⁺ homeostasis in human gastric cancer is unclear. This study examined the effect of NPC15199 on cytosolic free Ca²⁺ concentrations ([Ca²⁺]i) and viability in SCM1 human gastric cancer cells. The Ca²⁺-sensitive fluorescent dye fura-2 was used to measure [Ca²⁺]i. NPC15199 evoked [Ca²⁺]i rises concentration-dependently. The response was reduced by removing extracellular Ca²⁺. NPC15199-evoked Ca²⁺ entry was not inhibited by store-operated channel inhibitors (nifedipine, econazole and SKF96365) and protein kinase C (PKC) activator (phorbol 12-myristate 13 acetate, PMA), or PKC inhibitor (GF109203X). In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) nearly abolished NPC15199-evoked [Ca²⁺]i rises. Conversely, treatment with NPC15199 also nearly abolished thapsigargin or BHQ-evoked [Ca²⁺]i rises. Inhibition of phospholipase C (PLC) with U73122 did not affect NPC15199-evoked [Ca²⁺]i rises. NPC15199 at concentrations of 100-900 μM induced concentration-dependent, Ca²⁺-independent decrease in viability. Together, in SCM1 cells, NPC15199 induced [Ca²⁺]i rises that involved Ca²⁺ entry through PKC-insensitive non-store-operated Ca²⁺ channels and PLC-independent Ca²⁺ release from the endoplasmic reticulum. NPC15199 also induced Ca²⁺-independent cell death.

The investigation of minoxidil-induced [Ca2+]i rises and non-Ca2+-triggered cell death in PC3 human prostate cancer cells

Minoxidil is clinically used to prevent hair loss. However, its effect on Ca²⁺ homeostasis in prostate cancer cells is unclear. This study explored the effect of minoxidil on cytosolic-free Ca²⁺ levels ([Ca²⁺]_i) and cell viability in PC3 human prostate cancer cells. Minoxidil at concentrations between 200 and 800 μM evoked [Ca²⁺]_i rises in a concentration-dependent manner. This Ca²⁺ signal was inhibited by 60% by removal of extracellular Ca²⁺. Minoxidil-induced Ca²⁺ influx was confirmed by Mn²⁺-induced quench of fura-2 fluorescence. Pre-treatment with the protein kinase C (PKC) inhibitor GF109203X, PKC activator phorbol 12-myristate 13 acetate (PMA), nifedipine and SKF96365 inhibited minoxidil-induced Ca²⁺ signal in Ca²⁺ containing medium by 60%. Treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-ditert-butylhydroquinone (BHQ) in Ca²⁺-free medium abolished minoxidil-induced [Ca²⁺]_i rises. Conversely, treatment with minoxidil abolished BHQ-induced [Ca²⁺]_i rises. Inhibition of phospholipase C (PLC) with U73122 abolished minoxidil-evoked [Ca²⁺]_i rises. Overnight treatment with minoxidil killed cells at concentrations of 200-600 μM in a concentration-dependent fashion. Chelation of cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/AM (BAPTA/AM) did not prevent minoxidil's cytotoxicity. Together, in PC3 cells, minoxidil induced [Ca²⁺]_i rises that involved Ca²⁺ entry through PKC-regulated store-operated Ca²⁺ channels and PLC-dependent Ca²⁺ release from the endoplasmic reticulum. Minoxidil-induced cytotoxicity in a Ca²⁺-independent manner.

Effect of 2,5-dimethylphenol on Ca(2+) movement and viability in PC3 human prostate cancer cells

The phenolic compound 2,5-dimethylphenol is a natural product. 2,5-Dimethylphenol has been shown to affect rat hepatic and pulmonary microsomal metabolism. However, the effect of 2,5-dimethylphenol on Ca(2+ )signaling and cyotoxicity has never been explored in any culture cells. This study explored the effect of 2,5-dimethylphenol on cytosolic free Ca(2+ )levels ([Ca(2+)]i) and cell viability in PC3 human prostate cancer cells. 2,5-Dimethylphenol at concentrations between 500 μM and 1000 μM evoked [Ca(2+)]i rises in a concentration-dependent manner. This Ca(2+ )signal was inhibited by approximately half by the removal of extracellular Ca(2+). 2,5-Dimethylphenol-induced Ca(2+ )influx was confirmed by Mn(2+)-induced quench of fura-2 fluorescence. Pretreatment with the protein kinase C (PKC) inhibitor GF109203X, nifedipine or the store-operated Ca(2+ )entry inhibitors (econazole or SKF96365) inhibited 2,5-dimethylphenol-induced Ca(2+ )signal in Ca(2+)-containing medium by ∼30%. Treatment with the endoplasmic reticulum Ca(2+ )pump inhibitor thapsigargin in Ca(2+)-free medium abolished 2,5-dimethylphenol-induced [Ca(2+)]i rises. Conversely, treatment with 2,5-dimethylphenol abolished thapsigargin-induced [Ca(2+)]i rises. Inhibition of phospholipase C (PLC) with U73122 reduced 2,5-dimethylphenol-evoked [Ca(2+)]i rises by ∼80%. 2,5-Dimethylphenol killed cells at concentrations of 350-1000 μM in a concentration-dependent fashion. Chelation of cytosolic Ca(2+ )with 1,2-bis(2-aminophenoxy)ethane-N, N, N', N'-tetraacetic acid/AM (BAPTA/AM) did not prevent 2,5-dimethylphenol's cytotoxicity. Together, in PC3 cells, 2,5-dimethylphenol induced [Ca(2+)]i rises that involved Ca(2+ )entry through PKC-regulated store-operated Ca(2+ )channels and PLC-dependent Ca(2+ )release from the endoplasmic reticulum. 2,5-Dimethylphenol induced cytotoxicity in a Ca(2+)-independent manner.

Ca2+ Signaling and Cell Death Induced by Protriptyline in HepG2 Human Hepatoma Cells

The effect of protriptyline on Ca²⁺ physiology in human hepatoma is unclear. This study explored the effect of protriptyline on [Ca²⁺ ]_i and cytotoxicity in HepG2 human hepatoma cells. Protriptyline (50-150 μM) evoked [Ca²⁺ ]_i rises. The Ca²⁺ entry was inhibited by removal of Ca²⁺ . Protriptyline-induced Ca²⁺ entry was confirmed by Mn²⁺ -induced quench of fura-2 fluorescence. Except nifedipine, econazole, SKF96365, GF109203X, and phorbol 12-myristate 13 acetate did not inhibit Ca²⁺ entry. Treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) inhibited 40% of protriptyline-induced response. Treatment with protriptyline abolished BHQ-induced response. Inhibition of phospholipase C (PLC) suppressed protriptyline-evoked response by 70%. At 20-40 μM, protriptyline killed cells which was not reversed by the Ca²⁺ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Together, in HepG2 cells, protriptyline induced [Ca²⁺ ]_i rises that involved Ca²⁺ entry through nifedipine-sensitive Ca²⁺ channels and PLC-dependent Ca²⁺ release from endoplasmic reticulum. Protriptyline induced Ca²⁺ -independent cell death.

The effect of gallic acid on cytotoxicity, Ca(2+) homeostasis and ROS production in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes

Gallic acid, a polyhydroxylphenolic compound, is widely distributed in various plants, fruits and foods. It has been shown that gallic acid passes into blood brain barrier and reaches the brain tissue of middle cerebral artery occlusion rats. However, the effect of gallic acid on Ca(2+) signaling in glia cells is unknown. This study explored whether gallic acid affected Ca(2+) homeostasis and induced Ca(2+)-associated cytotoxicity in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes. Gallic acid (20-40 μM) concentration-dependently induced cytotoxicity and intracellular Ca(2+) level ([Ca(2+)]i) increases in DBTRG-05MG cells but not in CTX TNA2 cells. In DBTRG-05MG cells, the Ca(2+) response was decreased by half by removal of extracellular Ca(2+). In Ca(2+)-containing medium, gallic acid-induced Ca(2+) entry was inhibited by store-operated Ca(2+) channel inhibitors (2-APB, econazole and SKF96365). In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin abolished gallic acid-induced [Ca(2+)]i increases. Conversely, incubation with gallic acid also abolished thapsigargin-induced [Ca(2+)]i increases. Inhibition of phospholipase C with U73122 abolished gallic acid-induced [Ca(2+)]i increases. Gallic acid significantly caused cytotoxicity in DBTRG-05MG cells, which was partially prevented by prechelating cytosolic Ca(2+) with BAPTA-AM. Moreover, gallic acid activated mitochondrial apoptotic pathways that involved ROS production. Together, in DBTRG-05MG cells but not in CTX TNA2 cells, gallic acid induced [Ca(2+)]i increases by causing Ca(2+) entry via 2-APB, econazole and SKF96365-sensitive store-operated Ca(2+) entry, and phospholipase C-dependent release from the endoplasmic reticulum. This Ca(2+) signal subsequently evoked mitochondrial pathways of apoptosis that involved ROS production.

The effect of oleuropein from olive leaf (Olea europaea) extract on Ca²⁺ homeostasis, cytotoxicity, cell cycle distribution and ROS signaling in HepG2 human hepatoma cells

Oleuropein, a phenolic compound found in the olive leaf (Olea europaea), has been shown to have biological activities in different models. However, the effects of oleuropein on Ca(2+) homeostasis, cytotoxicity, cell cycle distribution and ROS signaling in liver cells have not been analyzed. Oleuropein induced [Ca(2+)]i rises only in HepG2 cells but not in AML12, HA22T or HA59T cells due to the different status of 3-hydroxy-3-methylglutaryl-CoA reductase expression. In HepG2 cells, this Ca(2+) signaling response was reduced by removing extracellular Ca(2+), and was inhibited by the store-operated Ca(2+) channel blockers 2-APB and SKF96365. In Ca(2+)-free medium, pretreatment with the ER Ca(2+) pump inhibitor thapsigargin abolished oleuropein-induced [Ca(2+)]i rises. Oleuropein induced cell cycle arrest which was associated with the regulation of p53, p21, CDK1 and cyclin B1 levels. Furthermore, oleuropein elevated intracellular ROS levels but reduced GSH levels. Treatment with the intracellular Ca(2+) chelator BAPTA-AM or the antioxidant NAC partially reversed oleuropein-induced cytotoxicity. Together, in HepG2 cells, oleuropein induced [Ca(2+)]i rises by releasing Ca(2+) from the ER and causing Ca(2+) influx through store-operated Ca(2+) channels. Moreover, oleuropein induced Ca(2+)-associated cytotoxicity that involved ROS signaling and cell cycle arrest. This compound may offer a potential therapy for treatment of human hepatoma.

Endoplasmic reticulum stress contributes to arsenic trioxide-induced intrinsic apoptosis in human umbilical and bone marrow mesenchymal stem cells

Arsenic trioxide is an old drug and has been used for a long time in traditional Chinese and Western medicines. However, the cancer treatment of arsenic trioxide has heart and vascular toxicity. The cytotoxic effects of arsenic trioxide and its molecular mechanism in human umbilical mesenchymal stem cells (HUMSC) and human bone marrow-derived mesenchymal stem cells (HMSC-bm) were investigated in this study. Our results showed that arsenic trioxide significantly reduced the viability of HUMSC and HMSC-bm in a concentration- and time-dependent manner. Arsenic trioxide is able to induce apoptotic cell death in HUMSC and HMSC-bm, as shown from the results of morphological examination, flow cytometric analyses, DAPI staining and comet assay. The appearance of arsenic trioxide also led to an increase of intracellular free calcium (Ca(2+) ) concentration and the disruption of mitochondrial membrane potential (ΔΨm). The caspase-9 and caspase-3 activities were time-dependently increased in arsenic trioxide-treated HUMSC and HMSC-bm. In addition, the proteomic analysis and DNA microarray were carried out to investigate the expression level changes of genes and proteins affected by arsenic trioxide treatment in HUMSC. Our results suggest that arsenic trioxide induces a prompt induction of ER stress and mitochondria-modulated apoptosis in HUMSC and HMSC-bm. A framework was proposed for the effect of arsenic trioxide cytotoxicity by targeting ER stress.

Effect of sertraline on Ca²⁺ fluxes in rabbit corneal epithelial cells

The effect of sertraline, a selective serotonin reuptake inhibitor (SSRI), on cytosolic free Ca²⁺ concentrations ([Ca²⁺](i)) in a rabbit corneal epithelial cell line (SIRC) is unclear. This study explored whether sertraline changed basal [Ca²⁺](i) levels in suspended SIRC cells by using fura-2 as a Ca²⁺-sensitive fluorescent dye. Sertraline at concentrations between 10-100 μM increased [Ca²⁺](i) in a concentration-dependent manner. The Ca²⁺ signal was reduced by 23% by removing extracellular Ca²⁺. Sertraline induced Mn²⁺ influx, leading to quench of fura-2 fluorescence, suggesting Ca²⁺ influx. This Ca²⁺ influx was inhibited by phospholipase A₂ inhibitor aristolochic acid, but not by store-operated Ca²⁺ channel blockers and protein kinase C/A modulators. In Ca²⁺-free medium, pretreatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin, cyclopiazonic acid or 2,5-di-tert-butylhydroquinone greatly inhibited sertraline-induced Ca²⁺ release. Inhibition of phospholipase C with U73122 abolished sertraline-induced [Ca²⁺](i) rise. At concentrations of 5-50 μM, sertraline killed cells in a concentration-dependent manner. The cytotoxic effect of 25 μM sertraline was not reversed by prechelating cytosolic Ca²⁺ with BAPTA/AM. Collectively, in SIRC cells, sertraline induced [Ca²⁺](i) rises by causing phospholipase C-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ influx via phospholipase A₂-sensitive Ca²⁺ channels. Sertraline-caused cytotoxicity was mediated by Ca²⁺-independent pathways.

γ- and δ-Lactams from the Leaves of Clausena lansium

Eight new clausenamides, including three γ-lactams (1-3), four δ-lactams (4-7), and an amide (8), and seven known lactams, including compounds 9-11, which were purified from natural sources for the first time, were characterized from the leaves of Clausena lansium. Their structures were elucidated using spectroscopic methods, and the absolute configurations were determined using electronic circular dichroism and single-crystal X-ray diffraction analyses with Cu Kα radiation. Compound 2 (50 μM) protected 22.24% of cortical neurons against Aβ25-35-induced cell death.

The Mechanism of Safrole-Induced [Ca²⁺]i Rises and Non-Ca²⁺-Triggered Cell Death in SCM1 Human Gastric Cancer Cells

Safrole is a carcinogen found in plants. The effect of safrole on cytosolic free Ca²⁺ concentrations ([Ca²⁺](i)) and viability in SCM1 human gastric cancer cells was explored. The Ca²⁺-sensitive fluorescent dye fura-2 was applied to measure [Ca²⁺](i). Safrole at concentrations of 150-450 μM induced a [Ca²⁺](i) rise in a concentration-dependent manner. The response was reduced by 60% by removing extracellular Ca²⁺. Safrole-evoked Ca²⁺ entry was not altered by nifedipine, econazole, SKF96365, and protein kinase C activator or inhibitor. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) abolished safrole-evoked [Ca²⁺](i) rises. Conversely, treatment with safrole abolished thapsigargin or BHQ-evoked [Ca²⁺](i) rises. Inhibition of phospholipase C (PLC) with U73122 abolished safrole-induced [Ca²⁺](i) rises. At 250-550 μM, safrole decreased cell viability concentration-dependently, which was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl (BAPTA/AM). Annexin V/propidium iodide staining data suggest that safrole (350-550 μM) induced apoptosis concentration-dependently. These studies suggest that in SCM1 human gastric cancer cells, safrole induced [Ca²⁺](i) rises by inducing PLC-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ influx via non-store-operated Ca²⁺ entry pathways. Safrole-induced cell death may involve apoptosis.

Effect of NPC-14686 (Fmoc-l-Homophenylalanine) on Ca²⁺ Homeostasis and Viability in OC2 Human Oral Cancer Cells

The effect of the anti-inflammatory compound NPC-14686 on intracellular Ca²⁺ concentration ([Ca²⁺](i)) and viability in OC2 human oral cancer cells was investigated. The Ca²⁺-sensitive fluorescent probe fura-2 was used to examine [Ca²⁺](i). NPC-14686 induced [Ca²⁺](i) rises in a concentration-dependent fashion. The effect was reduced approximately by 10% by removing extracellular Ca²⁺. NPC-14686- elicited Ca²⁺ signal was decreased by nifedipine, econazole, SKF96365, and GF109203X. In Ca²⁺-free medium, incubation with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) abolished NPC-14686-induced [Ca²⁺](i) rises. Conversely, pretreatment with NPC-14686 abolished thapsigargin or BHQ-induced [Ca²⁺](i) rises. Inhibition of phospholipase C with U73122 abolished NPC-14686-induced [Ca²⁺](i) rises. At 20-100 μM, NPC-14686 inhibited cell viability, which was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'- tetraacetic acid-acetoxymethyl ester (BAPTA/AM). NPC-14686 between 20 μM and 40 μM also induced apoptosis. Collectively, in OC2 cells, NPC-14686 induced [Ca²⁺](i) rises by evoking phospholipase C-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ entry via protein kinase C-regulated store-operated Ca²⁺ channels. NPC-14686 also caused Ca²⁺-independent apoptosis.

The Mechanism of Ca(2+) Movement in the Involvement of Baicalein-Induced Cytotoxicity in ZR-75-1 Human Breast Cancer Cells

Baicalein (5,6,7-trihydroxyflavone) (1) has been found to be active against a wide variety of cancer cells. However, the molecular mechanism underlying the effects of 1 on the induction of Ca(2+) movement and cytotoxicity in human breast cancer cells is unknown. This study examined the relationship between 1-induced Ca(2+) signaling and cytotoxicity in ZR-75-1 human breast cancer cells. The in vitro investigations reported herein produced the following results: (i) Compound 1 increased intracellular Ca(2+) concentration ([Ca(2+)]i) in a concentration-dependent manner. The signal was decreased by approximately 50% by removal of extracellular Ca(2+). (ii) Compound 1-triggered [Ca(2+)]i increases were significantly suppressed by store-operated Ca(2+) channel blockers 2-aminoethoxydiphenyl borate (2-APB) and the PKC inhibitor GF109203X. (iii) In Ca(2+)-free medium, compound 1-induced [Ca(2+)]i increases were also inhibited by GF109203X. Furthermore, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) or 2,5-ditert-butylhydroquinone (BHQ) abolished 1-induced [Ca(2+)]i increases. Inhibition of phospholipase C (PLC) with U73122 abolished 1-induced [Ca(2+)]i increases. (iv) Compound 1 (20-40 μM) caused cytotoxicity, increased reactive oxygen species (ROS) production, and activated caspase-9/caspase-3. Furthermore, compound 1-induced apoptosis was significantly inhibited by prechelating cytosolic Ca(2+) with BAPTA-AM (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester) or by decreasing ROS with the antioxidant NAC (N-acetylcysteine). Together, baicalein (1) induced a [Ca(2+)]i increase by inducing PLC-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via PKC-dependent, 2-APB-sensitive store-operated Ca(2+) channels. Moreover, baicalein (1) induced Ca(2+)-associated apoptosis involved ROS production in ZR-75-1 cells.

Effect of Antidepressant Doxepin on Ca²⁺ Homeostasis and Viability in PC3 Human Prostate Cancer Cells

The effect of the antidepressant doxepin on cytosolic Ca²⁺ concentrations ([Ca²⁺](i)) and viability in PC3 human prostate cancer cells was explored. The Ca²⁺-sensitive fluorescent dye fura-2 was applied to measure [Ca²⁺](i). Doxepin at concentrations of 500-1000 μM induced a [Ca²⁺](i) rise in a concentration-dependent manner. The response was reduced partly by removing Ca²⁺. Doxepin-evoked Ca²⁺ entry was suppressed by Ca²⁺ entry blockers (nifedipine, econazole, SK&F96365), and protein kinase C (PKC) modulators. In the absence of extracellular Ca²⁺, incubation with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) partly inhibit doxepin-induced [Ca²⁺](i) rise. Incubation with doxepin nearly inhibited thapsigargin or BHQ-induced [Ca²⁺](i) rise. Inhibition of phospholipase C (PLC) with U73122 failed to alter doxepin-induced [Ca²⁺](i) rise. At concentrations of 200-250 μM, doxepin killed cells in a concentration-dependent manner. This cytotoxic effect was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'- tetraacetic acid/acetoxy methyl (BAPTA/AM). Annexin V/PI staining data implied that doxepin (200 and 250 μM) did not induce apoptosis. Collectively, in PC3 cells, doxepin induced a [Ca²⁺](i) rise by evoking PLC-independent Ca²⁺ release from stores including the endoplasmic reticulum and Ca²⁺ entry via PKC-sensitive store-operated Ca²⁺ channels. Doxepin caused cell death that was independent of [Ca²⁺](i) rises.

Hypolipidemic activity of Taraxacum mongolicum associated with the activation of AMP-activated protein kinase in human HepG2 cells

This study investigated the hypolipidemic effect and potential mechanisms of T. mongolicum extracts. T. mongolicum was extracted by refluxing three times with water (TM-1), 50% ethanol (TM-2) and 95% ethanol (TM-3). TM-2 contained components with the most effective hypolipidemic potentials in HepG2 cells. Extended administration of TM-2 stimulated a significant reduction in body weight and levels of serum triglyceride LDL-C and total cholesterol in rats. To evaluate the bioactive compounds, we successively fractionated TM-2 with n-hexane (TM-4), dichloromethane (TM-5), ethyl acetate (TM-6), and water (TM-7). TM-4 fraction had the most effective hypolipidemic potential in HepG2 cells, and it decreased the expression of fatty acid synthase (FASN) and inhibited the activity of acetyl-coenzyme A carboxylase (ACC) through the phosphorylation of AMP-activated protein kinase (AMPK). Linoleic acid, phytol and tetracosanol are bioactive compounds identified from TM-4. These results suggest that T. mongolicum is expected to be useful for hypolipidemic effects.

Effect of fluoxetine on [Ca²⁺]i and cell viability in OC2 human oral cancer cells

Fluoxetine is a serotonin-specific reuptake inhibitor that has been used as an antidepressant. This study examined the effect of fluoxetine on cytosolic free Ca²⁺ concentrations ([Ca2⁺]i) and viability in OC2 human oral cancer cells. The Ca²⁺-sensitive fluorescent dye fura-2 was used to measure [Ca²⁺]i, and the water soluble tetrazolium (WST-1) regent was used to measure viability. Fluoxetine induced [Ca²⁺]i rises concentration-dependently. The response was reduced by half by removing extracellular Ca²⁺. Fluoxetine-induced Ca²⁺ entry was enhanced by activation of protein kinase C (PKC) with phorbol 12-myristate 13 acetate (PMA) but was inhibited by inhibition of the enzyme with GF109203X. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) or thapsigargin abolished fluoxetine-evoked [Ca²⁺]i rise. Conversely, treatment with fluoxetine inhibited BHQ/thapsigargin-evoked [Ca²⁺]i rise. Inhibition of phospholipase C (PLC) with U73122 abolished fluoxetine-induced [Ca²⁺]i rise. At 20-80 μM, fluoxetine decreased cell viability concentration-dependently, which was not altered by chelating cytosolic Ca²⁺ with 1,2-bis(2- aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). At 20-60 μM, fluoxetine induced apoptosis as detected by annexin V/propidium iodide (PI) staining. Together, in OC2 cells, fluoxetine induced [Ca²⁺]i rises by evoking PLC-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ entry via PKC-regulated mechanisms. Fluoxetine also caused Ca²⁺-independent apoptosis.

Effect of methoxychlor on Ca²⁺ homeostasis and apoptosis in HA59T human hepatoma cells

Methoxychlor, an organochlorine pesticide, is thought to be an endocrine disrupter that affects Ca²⁺ homeostasis and cell viability in different cell models. This study explored the action of methoxychlor on cytosolic free Ca²⁺ concentrations ([Ca²⁺]i) and apoptosis in HA59T human hepatoma cells. Fura-2, a Ca²⁺-sensitive fluorescent dye, was applied to measure [Ca²⁺]i. Methoxychlor at concentrations of 0.1-1 μM caused a [Ca²⁺]i rise in a concentration-dependent manner. Removal of external Ca²⁺ abolished methoxychlor's effect. Methoxychlor-induced Ca²⁺ influx was confirmed by Mn²⁺-induced quench of fura-2 fluorescence. Methoxychlor-induced Ca²⁺ entry was inhibited by nifedipine, econazole, SK&F96365, and protein kinase C modulators. Methoxychlor killed cells at concentrations of 10-130 μM in a concentration-dependent fashion. Chelation of cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid/AM (BAPTA/AM) did not prevent methoxychlor's cytotoxicity. Methoxychlor (10 and 50 μM) induced apoptosis concentration-dependently as determined by using Annexin V/propidium iodide staining. Together, in HA59T cells, methoxychlor induced a [Ca²⁺]i rise by inducing Ca²⁺ entry via protein kinase C-sensitive Ca²⁺-permeable channels, without causing Ca²⁺ release from stores. Methoxychlor also induced apoptosis that was independent of [Ca²⁺]i rises.

Effect of deoxycholic acid on Ca2+ movement, cell viability and apoptosis in human gastric cancer cells

Deoxycholic acid (DOA) is one of the secondary bile acids used as a mild detergent for the isolation of membrane associated proteins. This study examined whether the secondary bile acid, DOA, altered Ca(2+) movement, cell viability and apoptosis in SCM1 human gastric cancer cells. The Ca(2+)-sensitive fluorescent dye fura-2 was used to measure [Ca(2+)]i. DOA-evoked [Ca(2+)]i rises concentration dependently. The response was reduced by removing extracellular Ca(2+). DOA-evoked Ca(2+) entry was inhibited by store-operated Ca(2+) channel inhibitors (nifedipine, econazole and SKF96365), the protein kinase C (PKC) activator phorbol 12-myristate 13 acetate (PMA) and the PKC inhibitor GF109203X. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) abolished DOA-evoked [Ca(2+)]i rises. Conversely, treatment with DOA abolished TG-evoked [Ca(2+)]i rises. Inhibition of phospholipase C with U73122 abolished DOA-evoked [Ca(2+)]i rises. At 100-500 μM, DOA decreased cell viability, which was not changed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). DOA between 100 and 300 μM also induced apoptosis. Collectively, in SCM1 cells, DOA-induced [Ca(2+)]i rises by evoking phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via store-operated Ca(2+) channels. DOA also caused Ca(2+)-independent apoptosis.

Effect of melamine on [Ca(2+)]i and viability in PC3 human prostate cancer cells

Melamine is thought to be an endocrine disrupter that affects physiology in cells. This study examined the effect of melamine on cytosolic free Ca(2+) concentrations ([Ca(2+)]i) and viability in PC3 human prostate cancer cells. Melamine evoked [Ca(2+)]i rises concentration-dependently. Melamine-evoked Ca(2+) entry was inhibited by nifedipine, econazole, SKF96365, GF109203X and phorbol 12-myristate 13 acetate. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin inhibited melamine-evoked [Ca(2+)]i rise. Conversely, treatment with melamine abolished thapsigargin-evoked [Ca(2+)]i rise. Inhibition of phospholipase C with U73122 did not alter melamine-evoked [Ca(2+)]i rise. Melamine at 500-800μM decreased cell viability, which was not reversed by pretreatment with the Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Collectively, our data suggest that in PC3 cells, melamine induced [Ca(2+)]i rises by evoking phospholipase C-independent Ca(2+) release from the endoplasmic reticulum, and Ca(2+) entry via protein kinase C-regulated store-operated Ca(2+) entry. Melamine also caused Ca(2+)-independent cell death.

The mechanism of honokiol-induced intracellular Ca(2+) rises and apoptosis in human glioblastoma cells

Honokiol, an active constituent of oriental medicinal herb Magnolia officinalis, caused Ca(2+) mobilization and apoptosis in different cancer cells. In vivo, honokiol crossed the blood-brain or -cerebrospinal fluid barrier, suggesting that it may be an effective drug for the treatment of brain tumors, including glioblastoma. This study examined the effect of honokiol on intracellular Ca(2+) concentration ([Ca(2+)]i) and apoptosis in DBTRG-05MG human glioblastoma cells. Honokiol concentration-dependently induced a [Ca(2+)]i rise. The signal was decreased partially by removal of extracellular Ca(2+). Honokiol-triggered [Ca(2+)]i rise was not suppressed by store-operated Ca(2+) channel blockers (nifedipine, econazole, SK&F96365) and the protein kinase C (PKC) activator phorbol 12-myristate 13 acetate (PMA), but was inhibited by the PKC inhibitor GF109203X. GF109203X-induced inhibition was not altered by removal of extracellular Ca(2+). In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) or 2,5-di-tert-butylhydroquinone (BHQ) abolished honokiol-induced [Ca(2+)]i rise. Conversely, incubation with honokiol abolished TG or BHQ-induced [Ca(2+)]i rise. Inhibition of phospholipase C (PLC) with U73122 abolished honokiol-induced [Ca(2+)]i rise. Honokiol (20-80μM) reduced the cell viability, which was not reversed by prechelating cytosolic Ca(2+) with BAPTA-AM (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester). Honokiol (20-60μM) enhanced reactive oxygen species (ROS) production, decreased mitochondrial membrane potential, released cytochrome c, and activated caspase-9/caspase-3. Together, honokiol induced a [Ca(2+)]i rise by inducing PLC-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via PKC-dependent, non store-operated Ca(2+) channels. Moreover, honokiol activated the mitochondrial pathway of apoptosis in DBTRG-05MG human glioblastoma cells.

CCT327 enhances TRAIL-induced apoptosis through the induction of death receptors and downregulation of cell survival proteins in TRAIL-resistant human leukemia cells

Tumor necrosis factor-related apoptosis‑inducing ligand (TRAIL) has potential application in cancer therapy and it has the ability to selectively kill cancer cells without affecting normal cells. However, the development of resistance to TRAIL in cancer cells cannot be avoided. This study investigated the effects of 2-(5-methylselenophen‑2‑yl)‑6,7‑methylenedioxyquinolin‑4-one (CCT327), an analogue of quinolin-4-one, on the sensitization of cancer cells to TRAIL and on TRAIL‑induced apoptosis in TRAIL‑resistance human leukemia cells (HL60‑TR). We found that CCT327 enhanced TRAIL‑induced apoptosis through upregulation of death receptors DR4 and DR5. In addition to upregulating DRs (death receptors), CCT327 suppressed the expression of decoy receptor DcR1 and DcR2. CCT327 significantly downregulated the expression of FLICE inhibitory protein (cFLIP) and other antiapoptotic proteins. We also demonstrated that CCT327 could activate p38 and JNK. Moreover, CCT327-induced induction of DR5 and DR4 was mediated by reactive oxygen species (ROS), and N-acetylcysteine (NAC) blocked the induction of DRs by CCT327. Taken together, these results showed that CCT327 combined with TRAIL treatment may provide an effective therapeutic strategy for cancer.

Design, synthesis, mechanisms of action, and toxicity of novel 20(s)-sulfonylamidine derivatives of camptothecin as potent antitumor agents

Twelve novel 20-sulfonylamidine derivatives (9a-9l) of camptothecin (1) were synthesized via a Cu-catalyzed three-component reaction. They showed similar or superior cytotoxicity compared with that of irinotecan (3) against A-549, DU-145, KB, and multidrug-resistant (MDR) KBvin tumor cell lines. Compound 9a demonstrated better cytotoxicity against MDR cells compared with that of 1 and 3. Mechanistically, 9a induced significant DNA damage by selectively inhibiting Topoisomerase (Topo) I and activating the ATM/Chk related DNA damage-response pathway. In xenograft models, 9a demonstrated significant activity without overt adverse effects at 5 and 10 mg/kg, comparable to 3 at 100 mg/kg. Notably, 9a at 300 mg/kg (i.p.) showed no overt toxicity in contrast to 1 (LD50 56.2 mg/kg, i.p.) and 3 (LD50 177.5 mg/kg, i.p.). Intact 9a inhibited Topo I activity in a cell-free assay in a manner similar to that of 1, confirming that 9a is a new class of Topo I inhibitor. 20-Sulfonylamidine 1-derivative 9a merits development as an anticancer clinical trial candidate.

The mechanism of NPC-14686-induced [Ca²⁺]i rises and non-Ca²⁺-triggered cell death in MG63 human osteosarcoma cells

NPC-14686 has been shown to have anti-inflammatory effect in previous studies, but the mechanisms are unclear. The effect of NPC-14686 on cytosolic Ca²⁺ concentrations ([Ca²⁺]i) and viability in MG63 human osteosarcoma cells was explored. The Ca²⁺-sensitive fluorescent dye fura-2 was applied to measure [Ca²⁺]i. NPC-14686 at concentrations of 100-500 μM induced a [Ca²⁺]i rise in a concentration-dependent manner. The response was reduced by 80% by removing Ca²⁺. NPC-14686 induced Mn²⁺ influx leading to quenching of fura-2 fluorescence. NPC-14686-evoked Ca²⁺ entry was suppressed by nifedipine, econazole, SK&F96365, and protein kinase C inhibitor. Inhibition of phospholipase C with U73122 abolished NPC-14686-induced [Ca²⁺]i rise. At 20-50 μM, NPC-14686 decreased cell viability, which was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl (BAPTA/AM). Annexin V/propidium iodide staining data suggest that NPC-14686 (30-50 μM) induced apoptosis in a concentration-dependent manner. NPC-14686 also increased levels of reactive oxygen species. Together, in human osteosarcoma cells, NPC-14686 induced a [Ca²⁺]i rise by inducing phospholipase C-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ entry via protein kinase C-sensitive store-operated Ca²⁺ channels. NPC-14686 induced cell death that might involve apoptosis via mitochondrial pathways.

The novel pterostilbene derivative ANK-199 induces autophagic cell death through regulating PI3 kinase class III/beclin 1/Atg‑related proteins in cisplatin‑resistant CAR human oral cancer cells

Pterostilbene is an effective chemopreventive agent against multiple types of cancer cells. A novel pterostilbene derivative, ANK-199, was designed and synthesized by our group. Its antitumor activity and mechanism in cisplatin-resistant CAR human oral cancer cells were investigated in this study. Our results show that ANK-199 has an extremely low toxicity in normal oral cell lines. The formation of autophagic vacuoles and acidic vesicular organelles (AVOs) was observed in the ANK-199-treated CAR cells by monodansylcadaverine (MDC) and acridine orange (AO) staining, suggesting that ANK-199 is able to induce autophagic cell death in CAR cells. Neither DNA fragmentation nor DNA condensation was observed, which means that ANK-199-induced cell death is not triggered by apoptosis. In accordance with morphological observation, 3-MA, a specific inhibitor of PI3K kinase class III, can inhibit the autophagic vesicle formation induced by ANK-199. In addition, ANK-199 is also able to enhance the protein levels of autophagic proteins, Atg complex, beclin 1, PI3K class III and LC3-II, and mRNA expression of autophagic genes Atg7, Atg12, beclin 1 and LC3-II in the ANK-199-treated CAR cells. A molecular signaling pathway induced by ANK-199 was therefore summarized. Results presented in this study show that ANK-199 may become a novel therapeutic reagent for the treatment of oral cancer in the near future (patent pending).

The mechanism of bifonazole-induced [Ca(2+)]i rises and non-Ca(2+)-triggered cell death in PC3 human prostate cancer cells

Bifonazole is an antifungal drug widely used for treating skin diseases. The effect of bifonazole on physiology of cancer cells is unclear. The effect of bifonazole on cytosolic free Ca(2+) concentrations ([Ca(2+)]i) and viability in PC3 human prostate cancer cells was explored. The Ca(2+)-sensitive fluorescent dye, fura-2, was applied to measure [Ca(2+)]i. Bifonazole at concentrations of 5-30 µM induced a [Ca(2+)]i rise in a concentration-dependent manner. The response was reduced by 50% by removing extracellular Ca(2+). Bifonazole-evoked [Ca(2+)]i rise was not altered by nifedipine, econazole, SK&F96365 and protein kinase C activator, but was inhibited by 75% by GF109203X, a protein kinase C inhibitor. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) nearly abolished bifonazole-evoked [Ca(2+)]i rise. Conversely, treatment with bifonazole abolished BHQ-evoked [Ca(2+)]i rise. Inhibition of phospholipase C with U73122 abolished bifonazole-induced [Ca(2+)]i rise. At 30-100 µM, bifonazole decreased cell viability concentration-dependently, which was not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N″,N'-tetraacetic acid/acetoxy methyl. Annexin V/propidium iodide staining data suggest that bifonazole (30-100 µM) induced apoptosis concentration-dependently. Together, in PC3 human prostate cancer cells, bifonazole induced [Ca(2+)]i rises by inducing phospholipase C- and protein kinase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx via non-store-operated pathways. Bifonazole induced cell death that might involve apoptosis.

Antifatigue and Antioxidant Activity of Alcoholic Extract from Saussurea involucrata

Fatigue is a noticeable and highly prevalent symptom in tense, industriously, and economically affluent modern society. Therefore, new antifatigue agents to smooth the fatigue feature are an energetic topic. The total ethanol extract (ESI) of Saussurea involucrata Kar et Kir., known as Tian-Shan snow lotus, was evaluated for antifatigue activity in ICR mice with mice forced swimming test and the determination of the contents of blood lactic acid and serum urea nitrogen. ESI (0.05, 0.15, 0.25 g/kg) was administered orally to mice for 4 weeks. The average swimming times to exhaustion of the ESI-treated ICR mice (0.15, 0.25 g/kg) were prolonged by 132% and 180% (p<0.001) with a lessening of fatigue compared with that of the control group. Analysis of biochemical parameters showed that levels of serum urea nitrogen and blood lactic acid of experimental groups were also decreased significantly (p<0.001) compared with that of the control group. The antioxidant activity of ESI was investigated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay and the hydrogen peroxide-induced luminol chemiluminescence assay and the results indicated that ESI exerts DPPH scavenging ability and reducing power. These results provide scientific evidence that S. involucrata may have been potential as an antifatigue agent.

Curcumin-loaded nanoparticles enhance apoptotic cell death of U2OS human osteosarcoma cells through the Akt-Bad signaling pathway

Curcumin has potential anticancer activity and has been shown to be involved in several signaling pathways including differentiation and apoptosis. Our previous study showed that water-soluble PLGA curcumin nanoparticles (Cur-NPs) triggered apoptotic cell death through regulation of the function of MDR1 and the production of reactive oxygen species (ROS) in cisplatin-resistant human oral cancer CAR cells. In this study, we investigated the anti-proliferative effects of Cur-NPs on human osteosarcoma U2OS cells. The morphology of Cur-NPs showed spherical shape by TEM analysis. The encapsulation efficiency of curcumin in Cur-NPs prepared by single emulsion was 90.5 ± 3.0%. Our results demonstrated that the curcumin fragments on the mass spectrum of Cur-NPs and the peaks of curcumin standard could be found on the Cur-NPs spectrum by 1H-NMR spectra analysis. Cur-NPs induced anti-proliferative effects and apoptosis in U2OS cells. Compared to the untreated U2OS cells, more detectable amount of Cur-NPs was found inside the treated U2OS cells. Cur-NPs induced DNA fragmentation and apoptotic bodies in U2OS cells. Both the activity and the expression levels of caspases-3/-7 and caspase-9 were elevated in the treated U2OS cells. Cur-NPs upregulated the protein expression levels of cleaved caspase-3/caspase-9, cytochrome c, Apaf-1 and Bad and downregulated the protein expression level of p-Akt in U2OS cells. These results suggest Cur-NPs are effective in enhancing apoptosis in human osteosarcoma cells and thus could provide potential for cancer therapeutics.

Paroxetine-induced Ca2+ movement and death in OC2 human oral cancer cells

The effect of the antidepressant paroxetine on cytosolic free Ca2+ concentrations ([Ca2+]i) in OC2 human oral cancer cells is unclear. This study explored whether paroxetine changed basal [Ca2+]i levels in suspended OC2 cells by using fura-2 as a Ca2+-sensitive fluorescent dye. Paroxetine at concentrations between 100-1,000 microM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced by 50% by removing extracellular Ca2+. Paroxetine-induced Ca2+ influx was inhibited by the store-operated Ca2+ channel blockers nifedipine, econazole and SK&F96365, and protein kinase C modulators. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished paroxetine-induced [Ca2+]i rise. Inhibition of phospholipase C with U73122 did not alter paroxetine-induced [Ca2+]i rise. Paroxetine at 10-50 microM induced cell death in a concentration-dependent manner. The death was not reversed when cytosolic Ca2+ was chelated with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Propidium iodide staining suggests that apoptosis plays a role in the death. Collectively, in OC2 cells, paroxetine induced [Ca2+]i rise by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via store-operated Ca2+ channels in a manner regulated by protein kinase C and phospholipase A2. Paroxetine (up to 50 microM) induced cell death in a Ca2+-independent manner.

Osthole suppresses hepatocyte growth factor (HGF)-induced epithelial-mesenchymal transition via repression of the c-Met/Akt/mTOR pathway in human breast cancer cells

Substantial activation of the HGF/c-Met signaling pathway is involved in the progression of several types of cancers and associated with increased tumor invasion and metastatic potential. Underlying HGF-induced tumorigenesis, epithelial to mesenchymal transition (EMT) shows a positive correlation with progression in patients. We previously determined that osthole is a potent fatty acid synthase (FASN) inhibitor. FASN is implicated in cancer progression and may regulate lipid raft function. We therefore examined whether osthole could block HGF-induced tumorigenesis by disrupting lipid rafts. Here, we found that osthole could abrogate HGF-induced cell scattering, migration, and invasion in MCF-7 breast cancer cells. Osthole also effectively inhibited the HGF-induced decrease of E-cadherin and increase of vimentin via down-regulation of phosphorylated Akt and mTOR. Interestingly, osthole blocked HGF-induced c-Met phosphorylation and repressed the expression of total c-Met protein in MCF-7 cells. In addition, C75, a pharmacological inhibitor of FASN, repressed the expression of total c-Met protein in MCF-7 cells. Consistent with a role for FASN, loss of c-Met in cells treated with osthole was prevented by the exogenous addition of palmitate. Briefly, our result suggests a connection between FASN activity and c-Met protein expression and that osthole is a potential compound for breast cancer therapy by targeting the major pathway of HGF/c-Met-induced EMT.

Effect of m-3M3FBS on Ca²⁺ movement in PC3 human prostate cancer cells

The effect of 2,4,6-trimethyl-N-(meta-3-trifluoromethyl-phenyl)-benzenesulfonamide (m-3M3FBS), a presumed phospholipase C activator, on cytosolic free Ca²⁺ concentrations ([Ca²⁺]i) in PC3 human prostate cancer cells is unclear. This study explored whether m-3M3FBS changed basal [Ca²⁺]i levels in suspended PC3 cells by using fura-2 as a Ca²⁺-sensitive fluorescent dye. M-3M3FBS at concentrations between 10-50 microM increased [Ca²⁺]i in a concentration-dependent manner. The Ca²⁺ signal was reduced by 60% by removing extracellular Ca²⁺. M-3M3FBS-induced Ca²⁺ influx was inhibited by the store-operated Ca²⁺ channel blockers nifedipine, econazole and SK&F96365, and by the phospholipase A2 inhibitor aristolochic acid. In Ca²⁺-free medium, 30 microM m-3M3FBS pretreatment greatly inhibited the [Ca²⁺]i rise induced by the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or BHQ. Conversely, pretreatment with thapsigargin, BHQ or cyclopiazonic acid reduced the major part of m-3M3FBS-induced [Ca²⁺]i rise. Inhibition of phospholipase C with U73122 did not much alter m-3M3FBS-induced [Ca²⁺]i rise. Collectively, in PC3 cells, m-3M3FBS induced [Ca²⁺]i rises by causing phospholipase C-independent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ influx via store-operated Ca²⁺ channels.

The mechanism of sertraline-induced [Ca2+]i rise in human OC2 oral cancer cells

Effect of sertraline, an antidepressant, on cytosolic free Ca(2+) levels ([Ca(2+)](i)) in human cancer cells is unclear. This study examined if sertraline altered basal [Ca(2+)](i) levels in suspended OC2 human oral cancer by using fura-2 as a Ca(2+)-sensitive fluorescent probe. At concentrations of 10-100 μM, sertraline induced a [Ca(2+)](i) rise in a concentration-dependent fashion. The Ca(2+) signal was reduced partly by removing extracellular Ca(2+) indicating that Ca(2+) entry and release both contributed to the [Ca(2+)](i) rise. Sertraline induced Mn(2+) influx, leading to quench of fura-2 fluorescence suggesting Ca(2+) influx. This Ca(2+) influx was inhibited by suppression of phospholipase A2, inhibition of store-operated Ca(2+) channels or by modulation of protein kinase C activity. In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin or 2,5-di-(t-butyl)-1,4-hydroquinone (BHQ) nearly abolished sertraline-induced Ca(2+) release. Conversely, pretreatment with sertraline greatly reduced the inhibitor-induced [Ca(2+)](i) rise, suggesting that sertraline released Ca(2+) from the endoplasmic reticulum. Inhibition of phospholipase C did not change sertraline-induced [Ca(2+)](i) rise. Together, in human oral cancer cells, sertraline induced [Ca(2+)](i) rises by causing phospholipase C-independent Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx via store-operated Ca(2+) channels.

Effect of diallyl disulfide on Ca2+ movement and viability in PC3 human prostate cancer cells

The effect of diallyl disulfide (DADS) on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in PC3 human prostate cancer cells is unclear. This study explored whether DADS changed [Ca(2+)](i) in PC3 cells by using fura-2. DADS at 50-1000 μM increased [Ca(2+)](i) in a concentration-dependent manner. The signal was reduced by removing Ca(2+). DADS-induced Ca(2+) influx was not inhibited by nifedipine, econazole, SK&F96365, and protein kinase C modulators; but was inhibited by aristolochic acid. In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitors thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) nearly abolished DADS-induced [Ca(2+)](i) rise. Incubation with DADS inhibited thapsigargin or BHQ-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 did not alter DADS-induced [Ca(2+)](i) rise. At 500-1000 μM, DADS killed cells in a concentration-dependent manner. The cytotoxic effect of DADS was partly reversed by prechelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Propidium iodide staining suggests that DADS (500 μM) induced apoptosis in a Ca(2+)-independent manner. Annexin V/PI staining further shows that 10 μM and 500 μM DADS both evoked apoptosis. DADS also increased reactive oxygen species (ROS) production. Collectively, in PC3 cells, DADS induced [Ca(2+)](i) rise probably by causing phospholipase C-independent Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx via phospholipase A(2)-sensitive channels. DADS induced Ca(2+)-dependent cell death, ROS production, and Ca(2+)-independent apoptosis.

Synthesis and structure-activity relationship study of deoxybenzoins on relaxing effects of porcine coronary artery

Deoxybenzoins are potent antioxidants and tyrosinase inhibitors with potential to be developed as food preservatives and cosmetic ingredients. To explore the potential in cardiovascular protection, 25 polyphenolic deoxybenzoins were synthesized and evaluated for inhibitory effects on KCl-induced porcine coronary arterial contraction. The results revealed deoxybenzoins are significant inhibitors of KCl-induced arterial contraction. Among those synthesized, two-thirds of the deoxybenzoins exhibited moderate to good efficacy on relaxing contracted artery including 2,4-dihydroxydeoxybenzoin with EC50=3.30 μM (Emax=100%, n=7) and 2,4-dihydroxy-4'-methoxydeoxybenzoin EC50=3.70 μM (Emax=100%, n=5). Deoxybenzoins displayed an endothelium-dependent relaxing manner on the contracted artery; the contractile responses of neither endothelium denuded nor L-NAME deactivated rings were inhibited. The structure-activity relationships of deoxybenzoin on arterial relaxing effects concluded that the 2,4-dihydroxylated deoxybenzoins presented a potential vascular relaxing pharmacophore, with favoring substitution on ring B in the order of H≥p-OMe>p-OH>o-OMe>m,p-diOMe≥m-OMe.