Antiproliferative effect of pheophorbide a–mediated photodynamic therapy and its synergistic effect with doxorubicin on multiple drug-resistant uterine sarcoma cell MES-SA/Dx5

Abstract

Prolonged cancer chemotherapy is associated with the development of multidrug resistance (MDR), which is a major cause of treatment failure. Photodynamic therapy (PDT) has been applied as anticancer therapy and a means of circumventing MDR. The antiproliferative effect of pheophorbide a–mediated photodynamic therapy (Pa-PDT) has been demonstrated in several human cancer cell lines, including the uterine sarcoma cell line, MES-SA. This study set out to evaluate, first, the therapeutic potential of Pa-PDT on MES-SA/Dx5 uterine sarcoma cells and, subsequently, the effectiveness of combination therapy using Pa-PDT with doxorubicin (Dox). Our results showed that Pa-PDT was able to circumvent MDR in the P-glycoprotein (P-gp) overexpressing human uterine sarcoma cell line, MES-SA/Dx5. Intracellular accumulation of Pa and Pa-PDT-induced cell death was not abrogated by MDR phenotype, when compared to the parental cell line, MES-SA. Combined therapy using Pa-PDT and Dox, a common chemotherapeutic drug, was found to be synergistic in the cell line, MES-SA/Dx5. Both activity and expression of MDR1 and P-gp were reduced by Pa-PDT treatment and such reductions were attenuated by α-tocopherol, the scavenger of reactive oxygen species (ROS), suggesting that the effect of Pa-PDT was mediated by the generation of intracellular ROS. In conclusion, our findings demonstrated the therapeutic potential of Pa-PDT alone or in combination with Dox in combating multidrug-resistant malignancies.     

An examination of the potential effect of lipids on the first‐pass metabolism of the lipophilic drug anethol trithione

In this study, an examination of the potential effect of lipids on the first‐pass metabolism of anethol trithione (ATT) was investigated. ATT is metabolized rapidly and extensively in liver into 4‐hydroxy‐anethole trithione (ATX), which was confirmed using the rat intestinal perfusion with the mesenteric cannulation model. Male Sprague–Dawley rats were orally administered of the lipid‐based formulations (prepared by medium chain triglycerides (MCT)), the cyclodextrin formulation and the suspension formulation, respectively. For 6.75 mg/kg groups, ATX/ATT area under the plasma concentration‐time curve (AUC) ratio decreased by 87% and 76% after administration of the MCT‐based formulations and the cyclodextrin formulation, when compared with the suspension formulation (p < 0.05), respectively; for 2.25 mg/kg groups, it decreased by 53% in the MCT group when compared with the cyclodextrin group (p < 0.05). The saturation of pre‐system metabolism of ATT was observed after administration of the MCT‐based formulations and the cyclodextrin formulation, likely as a result of enhanced absorption and therefore presentation of higher drug concentrations to liver, when compared with the suspension formulation. A trend toward lower systemic metabolite to parent ratios was evident after administration of the lipid formulations, when compared with the cyclodextrin formulation; however, this was not statistically significant. Further studies on the potential for lipids to inhibit hepatic metabolism are therefore warranted. © 2011 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:5048–5058, 2011     

Protective effects of iridoid glycosides on acute colitis via inhibition of the inflammatory response mediated by the STAT3/NF-кB pathway

Morroniside and loganin are iridoid glycosides extracted from Cornus officinalis, a plant species widely used in traditional Chinese medicine. However, the anti-inflammatory effects of morroniside and loganin in colitis are barely understood. The aim of the present study was to explore the effects of morroniside and loganin on the dextran sodium sulfate (DSS)-induced murine model of colitis and an LPS-induced colorectal cancer (CRC) cell inflammation model, and to clarify the underlying mechanisms. We found that morroniside and loganin were able to ameliorate clinical features, including disease activity index (DAI), histological inflammation score and periodic acid-Schiff staining (PAS). In the mouse model, morroniside and loganin treatment increased expression of tight junction proteins (TJs) and decreased pro-inflammatory cytokine production. Moreover, our findings showed that the expression of p-STAT3 and p-p65 were suppressed compared to the disease group. In in vitro experiments, treatment with morroniside and loganin had no obvious effects on proliferative activity in HCT116 cells and HIEC-6 cells. Expression of pro-inflammatory cytokines was inhibited by morroniside and loganin treatment in comparison with the LPS-treated group. Taken together, morroniside and loganin have beneficial effects on colitis in vivo and are anti-inflammatory in vitro. Possible mechanisms of the anti-inflammatory response may include blockade of the STAT3/NF-κB pathway.     

The effect of the uremic toxin cyanate (CNO−) on anaerobic cysteine metabolism and oxidative processes in the rat liver: a protective effect of lipoate

Chronic renal failure (CRF) patients have an increased plasma level of urea, which can be a source of cyanate. This compound can cause protein carbamoylation thereby changing biological activity of proteins. Therefore, in renal failure patients, cyanate can disturb metabolism and functioning of the liver. This work presents studies demonstrating that the treatment of rats with cyanate alone causes the following changes in the liver: (1) inhibition of rhodanese (TST), cystathionase (CST) and 3-mercaptopyruvate sulfotransferase (MPST) activities, (2) decrease in sulfane sulfur level (S*), (3) lowering of nonprotein sulfhydryl groups (NPSH) group level, and (4) enhancement of prooxidant processes (rise in reactive oxygen species (ROS) and malondialdehyde (MDA) level). This indicates that cyanate inhibits anaerobic cysteine metabolism and shows prooxidant action in the liver. Out of the above-mentioned changes, lipoate administered with cyanate jointly was able to correct MDA, ROS and NPSH levels, and TST activity. It had no significant effect on MPST and CST activities. It indicates that lipoate can prevent prooxidant cyanate action and cyanate-induced TST inhibition. These observations can be promising for CRF patients since lipoate can play a dual role in these patients as an efficient antioxidant defense and a protection against cyanate and cyanide toxicity.     

The effect of the uremic toxin cyanate (CNO⁻) on anaerobic cysteine metabolism and oxidative processes in the rat liver: a protective effect of lipoate

Chronic renal failure (CRF) patients have an increased plasma level of urea, which can be a source of cyanate. This compound can cause protein carbamoylation thereby changing biological activity of proteins. Therefore, in renal failure patients, cyanate can disturb metabolism and functioning of the liver. This work presents studies demonstrating that the treatment of rats with cyanate alone causes the following changes in the liver: (1) inhibition of rhodanese (TST), cystathionase (CST) and 3-mercaptopyruvate sulfotransferase (MPST) activities, (2) decrease in sulfane sulfur level (S*), (3) lowering of nonprotein sulfhydryl groups (NPSH) group level, and (4) enhancement of prooxidant processes (rise in reactive oxygen species (ROS) and malondialdehyde (MDA) level). This indicates that cyanate inhibits anaerobic cysteine metabolism and shows prooxidant action in the liver. Out of the above-mentioned changes, lipoate administered with cyanate jointly was able to correct MDA, ROS and NPSH levels, and TST activity. It had no significant effect on MPST and CST activities. It indicates that lipoate can prevent prooxidant cyanate action and cyanate-induced TST inhibition. These observations can be promising for CRF patients since lipoate can play a dual role in these patients as an efficient antioxidant defense and a protection against cyanate and cyanide toxicity.     

Oestrogen inhibits BMP4‐induced BMP4 expression in cardiomyocytes: a potential mechanism of oestrogen‐mediated protection against cardiac hypertrophy

Background and Purpose

Oestrogen inhibits cardiac hypertrophy and bone morphogenetic protein‐4 (BMP4) induces cardiac hypertrophy. Here we have studied the inhibition by oestrogen of BMP4 expression in cardiomyocytes.

Experimental Approach

Cultures of neonatal rat cardiomyocytes were used in in vitro experiments. Bilatαl ovariectomy (OVX) was carried out in female Kunming mice and cardiac hypertrophy was induced by transverse aortic constriction (TAC).

Key Results

Oestrogen inhibited BMP4‐induced cardiomyocyte hypertrophy and BMP4 expression in vitro. The inhibition of BMP4‐induced BMP4 protein expression by oestrogen was prevented by the inhibitor of oestrogen receptor‐β, PHTPP, but not by the inhibitor of oestrogen receptor‐α MPP. BMP4 induced smad1/5/8 activation, which was not affected by oestrogen in cardiomyocytes. BMP4 induced JNK but not ERK1/2 and p38 activation, and activated JNK was inhibited by oestrogen. Treatment with the p38 inhibitor SB203580 or the JNK inhibitor SP600125 inhibited BMP4‐induced BMP4 expression in cardiomyocytes, but the ERK1/2 inhibitor U0126 increased BMP4‐induced BMP4 expression, indicating that JNK, ERK1/2 and p38 MAPKs were all involved, although only JNK activation contributed to the inhibition of BMP4‐induced BMP4 expression by oestrogen. TAC induced significant heart hypertrophy in OVX mice in vivo and oestrogen replacement inhibited TAC‐induced heart hypertrophy in OVX mice. In parallel with the data of heart hypertrophy, oestrogen replacement significantly reduced the increased BMP4 protein expression in TAC‐treated OVX mice.

Conclusions and Implications

Oestrogen treatment inhibited BMP4‐induced BMP4 expression in cardiomyocytes through stimulating oestrogen receptor‐β and inhibiting JNK activation. Our results provide a novel mechanism underlying oestrogen‐mediated protection against cardiac hypertrophy.

Linked Articles

This article is part of a themed section on Chinese Innovation in Cardiovascular Drug Discovery. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-23

Abbreviations

BMP4

bone morphogenetic protein‐4

ER‐α

oestrogen receptor‐α

ER‐β

oestrogen receptor‐β

MPP

1,3‐bis(4‐hydroxyphenyl)‐4‐methyl‐5‐[4‐(2‐piperidinylethoxy)phenol]‐1H‐pyrazole dihydrochloride

OVX

ovariectomy

PHTPP

4‐(2‐phenyl‐5,7‐bis(trifluoromethyl)pyrazolo[1,5‐a]pyrimidin‐3‐yl)phenol

TAC

transverse aortic constriction

Tables of Links

Xenobiotic/medium chain fatty acid: CoA ligase – a critical review on its role in fatty acid metabolism and the detoxification of benzoic acid and aspirin

Introduction: Activation of fatty acids by the acyl-CoA synthetases (ACSs) is the vital first step in fatty acid metabolism. The enzymatic and physiological characterization of the human xenobiotic/medium chain fatty acid: CoA ligases (ACSMs) has been severely neglected even though xenobiotics, such as benzoate and salicylate, are detoxified through this pathway.

Areas covered: This review will focus on the nomenclature and substrate specificity of the human ACSM ligases; the biochemical and enzymatic characterization of ACSM1 and ACSM2B; the high sequence homology of the ACSM2 genes (ACSM2A and ACSM2B) as well as what is currently known regarding disease association studies.

Expert opinion: Several discrepancies exist in the current literature that should be taken note of. For example, the single nucleotide polymorphisms (SNPs) reported to be associated with aspirin metabolism and multiple risk factors of metabolic syndrome are incorrect. Kinetic data on the substrate specificity of the human ACSM ligases are non-existent and currently no data exist on the influence of SNPs on the enzyme activity of these ligases. One of the biggest obstacles currently in the field is that glycine conjugation is continuously studied as a one-step process, which means that key regulatory factors of the two individual steps remain unknown.     

Modification of a cyclo-olefin surface by radio-sterilization: Is there any effect on the interaction with drug solutions?

A cyclo-olefin copolymer was subjected to an e-beam ionizing treatment. Two doses were studied: one corresponding to the recommended dose for the sterilization of pharmaceutical packaging (25 kGy), and a greater one to enhance the modifications caused by the treatment (150 kGy). The surface modifications were studied by X-ray photoelectron spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM). The roughness and the wettability of the surface were enhanced by the treatment. The consequences of the surface modifications on the drug interaction with the polymer were studied.     

Ingenane-type diterpenes with a modulatory effect on IFN-γ production from the roots of Euphorbia kansui

A new ingenane-type diterpene, (3S,5R)5-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-O-deoxyingenol (1), and six known compounds,3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-O-deoxyingenol (2), 20-O-decanoylingenol (3), 20-O-acetylingenol-3-O-(2??E,4??Z) decadienoate (4), kansuiphorin A (5), 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoylingenol (6), and kansuinin F (7) were isolated and evaluated for their effect on IFN-?? production in NK92 cells. Interestingly, subjection to compounds 4 and 6 (10 nM) displayed the most significant response in IFN-?? production, comparable to that produced by the same dose of phorbol 12-myistate 13-acetate (PMA). High doses of compounds 3 (100 nM), 1 (1. 25 ??M) and 5 (5.0 ??M) have also been shown to activate the IFN-?? production.     

Systematic investigation of the effect of lyophilizate collapse on pharmaceutically relevant proteins I: Stability after freeze‐drying

The objective of this work was to investigate the effect of cake collapse during freeze‐drying on the stability of protein lyophilizates containing a monoclonal IgG₁‐antibody or a second pharmaceutically relevant protein, referred to as PA01. In addition, L‐lactic dehydrogenase was investigated because of its well‐documented sensitivity towards freeze‐drying stresses. Collapse was induced by two different means. First, by varying the ratio of the crystalline bulking agent mannitol to the amorphous stabilizer sucrose, different extents of collapsed cakes were generated. Second, formulations were freeze‐dried using an aggressive collapse‐cycle and a conventional freeze‐drying protocol and collapsed and noncollapsed cakes of identical formulation were produced. Lyophilizates were analyzed using a comprehensive set of analytical techniques to monitor protein stability in terms of formation of soluble and insoluble aggregates, the biological activity and the conformational stability. The stability of excipients, namely the glass transition temperature, crystallinity, reconstitution behavior, and the residual moisture content was analyzed as well. In addition, the extent of collapse was quantified using the decrease of the specific surface area (SSA). Collapsed cakes had comparable residual moisture levels to noncollapsed lyophilizates. Reconstitution times were not increased. Protein stability was not relevantly different between collapsed and noncollapsed cakes. © 2009 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2256–2278, 2010     

Influence of sildenafil on copulatory behaviour in sluggish or normal ejaculator male rats: a central dopamine mediated effect?

The present study investigates the effects induced by sildenafil (1 mg/kg, p.o.) and the dopamine agonist, SND 919 (0.1 mg/kg, i.p.) on copulatory behaviour of male rats, categorized, on the basis of seven consecutive mating pre-tests, as sluggish and normal ejaculators (SE and NE, respectively). The data obtained show that sildenafil modifies both sexual arousal and ejaculatory mechanisms of copulation. It appears that, although it induced a facilitatory effect on ejaculation of all rats, similarly to SND 919, the lowering of ejaculatory threshold was achieved by means of a reduction of mount frequency and intromission frequency in SE and NE groups, respectively. Differently from SND 919, sildenafil increased sexual arousal, diminishing post ejaculatory interval in SE animals and inter-intromission interval in both SE and NE rats. As the dopamine antagonist, (-)eticlopride (0.02 mg/kg, s.c.), significantly inhibited sildenafil-induced enhancement of sexual arousal in SE rats, it is suggested that the drug acts both peripherally and centrally.     

The inhibition of HIF-2α on the ATM/Chk-2 pathway is involved in the promotion effect of arsenite on benzo(a)pyrene-induced cell transformation

Both arsenite and benzo(a)pyrene (BaP) are known human carcinogens. Studies on the mode-of-action of arsenite indicate that it can also act as co-carcinogen or as a cancer promoter, and that it can facilitate progression of cancers. Some studies on development of lung cancers have suggested a synergism between arsenite exposure and cigarette smoking. The mechanism of action for such an effect, however, remains obscure. In the present study, we investigated the effects of HIF-2α on arsenite- and BaP-induced cell malignant transformation as well as on signal transduction pathways in human bronchial epithelial (HBE) cells. The results show that arsenite accelerates the neoplastic transformation and migration of cells and enhances chromosomal aberrations induced by BaP. HIF-2α is involved in blocking the effects of arsenite in activating the ATM/Chk-2 pathway and in repair of DNA damage induced by BaP. Moreover, blocking of HIF-2α prevents the effects of arsenite on the neoplastic transformation, cell migration, and chromosomal aberrations caused by BaP. These results indicate that the repressive effect of HIF-2α on the ATM/Chk-2 pathway leads to genomic instability, which is involved in arsenite-accelerated, BaP-induced malignant transformation of HBE cells.     

The effect of uremic toxin cyanate (OCN–) on anaerobic sulfur metabolism and prooxidative processes in the rat kidney: a protective role of lipoate

Cyanate and its active form isocyanate are formed mainly in the process of nonenzymatic urea biodegradation. Cyanate is capable of protein S- and N-carbamoylation, which can affect their activity. The present studies aimed to demonstrate the effect of cyanate on activity of the enzymes implicated in anaerobic cysteine metabolism and cyanide detoxification and on glutathione (GSH) level and peroxidative processes in the kidney. In addition, we examined whether a concomitant treatment with lipoate, a dithiol that may act as a target of S-carbamoylation, can prevent these changes. The studies were conducted in Wistar rats. The animals were assigned to four groups, which received injections of physiological saline, cyanate (200 mg/kg), cyanate (200 mg/kg) + lipoate (100 mg/kg) and lipoate alone (100 mg/kg). The animals were killed 2 h after the first injection, the kidneys were isolated and kept at -80°C until biochemical assays were performed. Cyanate inhibited rhodanese (TST) and mercaptopyruvate sulfotransferase (MPST) activity, decreased GSH level and enhanced peroxidative processes in the kidney. All these changes were abolished by cyanate treatment in combination with lipoate.     

Effect of organic anion transporting polypeptide 1B1 inhibition on the pharmacokinetics of rosuvastatin via HNF1a by ursodeoxycholic acid in vivo

AIM： The inhibition of organic anion transporting polypeptide 1B1 （OATP1B1） on the pharmacokinetics of rosuvastatin is unknown. Hence, the effect of ursodeoxycholic acid （UDCA） on the kinetics of rosuvastatin in healthy volunteers is to be investigated. METHODS： The inhibition effect of long term use of UDCA on rosuvastatin kinetics was studied in 12 subjects in a randomized, crossover study. Each subject received 500 mg UDCA once daily continuously for 14 days. A single oral dose of 20 mg rosuvastatin was given on study day 15 and 34 separated by 2 weeks. Plasma concentrations of rosuvastatin were above the limits of quantitation for up to 72 h after dosing. RESULTS： UDCA significantly increased AUC0-72 and AUC0-∞ of rosuvastatin to 146% ± 55% （P = 0.008） and 167% ± 73% （ P = 0.004） compared with those of the control group and CL/F decreased 75% ± 19% （P = 0. 003）. The results confirmed the in vitro study that UDCA inhibited OATP1B1 activity via hepatic nuclear factor 1a （HNF1a）.[第一段]     

Raising high-density lipoprotein cholesterol with reduction of cardiovascular risk: the role of nicotinic acid – a position paper developed by the European Consensus Panel on HDL-C*

SUMMARY

Reduction of low-density lipoprotein cholesterol (LDL-C) is presently the primary focus of lipid-lowering therapy for prevention and treatment of coronary heart disease (CHD). However, the high level of residual risk among statin-treated patients in recent coronary prevention studies indicates the need for modification of other major components of the atherogenic lipid profile. There is overwhelming evidence that a low plasma level of high-density lipoprotein cholesterol (HDL-C) is an important independent risk factor for CHD. Moreover, a substantial proportion of patients with or at risk of developing premature CHD typically exhibit distinct lipid abnormalities, including low HDL-C levels. Thus, therapeutic intervention aimed at raising HDL-C, within the context of reducing global cardiovascular risk, would benefit such patients, a viewpoint increasingly adopted by international treatment guidelines.     

Chronic treatment with desipramine facilitates its effect on extracellular noradrenaline in the rat hippocampus: studies on the role of presynaptic α2-adrenoceptors

Adaptive phenomena such as desensitization of autoreceptors are considered an important factor in the achievement of therapeutic efficacy of antidepressant drugs after chronic treatment. We have studied whether a chronic treatment with desipramine had a greater effect than a single dose on the extracellular concentrations of noradrenaline in the dorsal hippocampus. Administration of 10 mg/kg i.p. desipramine once daily for 14 days significantly raised the basal extracellular noradrenaline in the dorsal hippocampus 24 h but not 48 h after the last drug injection. A challenge dose of desipramine increased extracellular noradrenaline in rats treated chronically with vehicle and desipramine. The effect was significantly higher in rats treated chronically with desipramine 48 h but not 24 h after the last injection. An intraperitoneal administration of the alpha2-adrenoceptor agonist clonidine at the dose of 10 microg/kg significantly reduced extracellular noradrenaline in the control group but not in animals chronically treated with desipramine whereas 30 microg/kg clonidine produced a similar decrease in both groups. Three concentrations of clonidine (0.05, 0.5 and 1 microM) infused into the hippocampus significantly reduced extracellular noradrenaline to a similar extent in rats chronically treated with saline or desipramine. Fourty-eight hours after the last injection of the chronic treatment, [3H]RX-821002 binding to alpha2-adrenoceptors in the rat locus coeruleus measured by autoradiography was not significantly modified. A slight (17%) but significant decrease of neuronal uptake of [3H]noradrenaline was found in synaptosome preparations from dorsal hippocampus of rats chronically treated with desipramine, but this was likely due to a decrease in affinity. The results suggest that a repeated treatment with desipramine (10 mg/kg i.p. once daily for 14 days) facilitates its effect on extracellular noradrenaline in the dorsal hippocampus and induces adaptive changes probably involving desensitization of alpha2-adrenoceptors, with no changes in their density, on noradrenergic neurons in the locus coeruleus.     

Irreversible inhibition of glucose-6-phosphate dehydrogenase by the coenzyme A conjugate of ketoprofen: a key to oxidative stress induced by non-steroidal anti-inflammatory drugs?

Oxidative damage by non-steroidal anti-inflammatory drugs (NSAIDs) has been considered relevant to the occurrence of gastro-intestinal side-effects. In the case of chiral arylpropionate derivatives like ketoprofen (KPF), this mechanism has been evidenced for the R-enantiomer, especially when chiral inversion was observed, and lets us suppose the involvement of CoA conjugates. Glucose-6-phosphate dehydrogenase (G6PD) is the crucial enzyme to regenerate the GSH pool and maintain the intracellular redox potential. This enzyme is known to be down-regulated by palmitoyl-CoA thioester. We hypothesised then that G6PD is the target of carboxylic NSAIDs, via their CoA metabolites. We used molecular docking to localise a putative site in the human G6PD then we chose the Yeast orthologue, as the most suitable species to study experimentally the precise molecular interaction. KPF-CoA was effectively shown to bind covalently to the unique cysteine residue of the yeast enzyme. Binding was found to occur in the same site as palmitoyl-CoA. It was decreased in the presence of an allosteric inhibitor of G6PD, phospho(enol)pyruvate, and was not detected with G6PD of Leuconostoc mesenteroides, which does not possess the allosteric site. This site is distinct from the catalytic site, and probably allosteric, explaining the observed non-competitive inhibition of its activity by KPF-CoA. KPF-CoA was shown to induce the production of reactive oxygen species in Caco-2 cells, where its inhibition of G6PD activity was observed.