scholarly journals α-Conotoxins Enhance both the In Vivo Suppression of Ehrlich carcinoma Growth and In Vitro Reduction in Cell Viability Elicited by Cyclooxygenase and Lipoxygenase Inhibitors

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 193
Author(s):  
Alexey V. Osipov ◽  
Tatiana I. Terpinskaya ◽  
Tatsiana Yanchanka ◽  
Tatjana Balashevich ◽  
Maxim N. Zhmak ◽  
...  

Several biochemical mechanisms, including the arachidonic acid cascade and activation of nicotinic acetylcholine receptors (nAChRs), are involved in increased tumor survival. Combined application of inhibitors acting on these two pathways may result in a more pronounced antitumor effect. Here, we show that baicalein (selective 12-lipoxygenase inhibitor), nordihydroguaiaretic acid (non-selective lipoxygenase inhibitor), and indomethacin (non-selective cyclooxygenase inhibitor) are cytotoxic to Ehrlich carcinoma cells in vitro. Marine snail α-conotoxins PnIA, RgIA and ArIB11L16D, blockers of α3β2/α6β2, α9α10 and α7 nAChR subtypes, respectively, as well as α-cobratoxin, a blocker of α7 and muscle subtype nAChRs, exhibit low cytotoxicity, but enhance the antitumor effect of baicalein 1.4-fold after 24 h and that of nordihydroguaiaretic acid 1.8–3.9-fold after 48 h of cell cultivation. α-Conotoxin MII, a blocker of α6-containing and α3β2 nAChR subtypes, increases the cytotoxic effect of indomethacin 1.9-fold after 48 h of cultivation. In vivo, baicalein, α-conotoxins MII and PnIA inhibit Ehrlich carcinoma growth and increase mouse survival; these effects are greatly enhanced by the combined application of α-conotoxin MII with indomethacin or conotoxin PnIA with baicalein. Thus, we show, for the first time, antitumor synergism of α-conotoxins and arachidonic acid cascade inhibitors.

1991 ◽  
Vol 130 (1) ◽  
pp. 21-32 ◽  
Author(s):  
A. M. Cowell ◽  
R. J. Flower ◽  
J. C. Buckingham

ABSTRACT Dispersed anterior pituitary cells were used to investigate the possible roles of phospholipid metabolites released by phospholipase A2 (PLA2) in the control of immunoreactive ACTH (ir-ACTH) secretion in vitro. PLA2 (15 600–62 500 U/1), the PLA2 activator melittin (0·5–20 mg/l) and arachidonic acid (1 mmol/l) all produced increases in ir-ACTH release from the cells, whilst platelet-activating factor (PAF), prostaglandin F2α (PGF2α), the prostacyclin analogues iloprost and BW245C, the thromboxane A2 (TXA2) analogue U46619, and the leukotrienes LTB4 and LTC4 were ineffective in this respect. PGF2α (100 nmol/l and 1 μmol/l), iloprost (1 μmol/l) and BW245C (100 nmol/l and 1 μmol/l) depressed corticotrophin-releasing factor-41-induced ir-ACTH secretion, while the PAF antagonist BN52021 (10 and 100 μmol/l) and LTC4 (100 nmol/l and 1 μmol/l) had no discernable effects. The secretory responses of the cells to hypothalamic extracts (0·2 hypothalami/ml) and arachidonic acid (1 mmol/l) were generally unaffected by the cyclooxygenase inhibitors ibuprofen (10 and 100 μmol/l) and indomethacin (10 μmol/l), the TXA2 synthetase inhibitor imidazole (10 μmol/l–1 mmol/l), the lipoxygenase inhibitor nordihydroguaiaretic acid (10 and 100 μmol/l) and the dual cyclo-oxygenase/lipoxygenase inhibitors phenidone (1–100 μmol/l) and BW755C (10 and 100 μmol/l). They were, however, inhibited by the dual cyclo-oxygenase/lipoxygenase inhibitor eicosatetraynoic acid (10 and 100 μmol/l), which also blocks epoxygenase and PLA2 activity and by the cytochrome P450 inhibitor SKF-525A (1 mmol/l). The results suggest that the stimulatory effects of PLA2 and arachidonic acid on ir-ACTH secretion are not effected by products generated by the cyclo-oxygenase or lipoxygenase pathways but may be mediated by metabolites generated by the cytochrome P450 pathway. Journal of Endocrinology (1991) 130, 21–32


Author(s):  
А.А. Раецкая ◽  
С.В. Калиш ◽  
С.В. Лямина ◽  
Е.В. Малышева ◽  
О.П. Буданова ◽  
...  

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.


1990 ◽  
Vol 64 (2) ◽  
pp. 457-464 ◽  
Author(s):  
R. H. Cohen ◽  
E. R. Perl

1. The role of presumed chemical mediators of inflammation in the heat-induced sensitization of cutaneous C-polymodal nociceptors (CPNs) was examined in a rabbit ear preparation maintained in vitro by intra-arterial perfusion with a solution free of protein and cellular elements. 2. In this preparation, CPNs consistently showed enhanced responsiveness after repeated exposure of their receptive fields to noxious levels of heat. The average magnitude of sensitization was quantitatively similar to that observed in vivo, suggesting that blood-born factors are not essential for development of sensitization. 3. Sensitization in one-half of randomly selected CPNs was blocked or reduced when the perfusate contained a cyclooxygenase inhibitor, indomethacin or dipyrone, or the dual cyclooxygenase/lipoxygenase inhibitor, BW755C, even though initial responsiveness to heat and pressure was unaltered. These observations suggest that arachidonic acid breakdown products, possibly prostaglandins, are intermediaries in the sensitization of some, but not all, C-fiber nociceptors of the skin. In addition, heat-induced sensitization for some C-fiber cutaneous nociceptors is the result of processes that are at least partially independent of those involved in excitation. 4. Substance P (SP) or the putative SP antagonists, [D-Pro2, D-Trp7.9]-SP or [D-Pro2, D-Phe7, D-Trip9]-SP, produced no significant effect on heat-responsiveness or sensitization, although ongoing activity may have marginally increased over control levels after repeated heat stimulations. We conclude that SP in an in vitro preparation is not involved in the enhancement of cutaneous C-fiber nociceptor responsiveness after repeated thermal insults.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Andrea Iorga ◽  
Gabriel Wong ◽  
Denise Mai ◽  
Jingyuan Li ◽  
Salil Sharma ◽  
...  

Pulmonary hypertension (PH) is a chronic lung disease characterized by progressively elevated pulmonary arterial pressures and severe pulmonary vascular remodeling resulting from interactions between oxidized lipoprotein deposition and increased endothelial proliferation. Previously we have shown increased plasma levels of biological oxidation products such as hydroxyoctadecadienoic acids (HODEs) and hydroxyeicosatetraenoic acids (HETEs) in the rat monocrotaline model of PH. Here we investigated the role of HETEs and HODEs in the development of PH and whether their inhibition with the lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) attenuates the progression of PH. Mice were placed in a hypoxic chamber with O2 concentrations of ≤10% for 21 days and either left untreated to develop PH (n=7) or treated with NDGA daily (10mg/kg/day, i.p., n=4) from day 1. Direct RV catheterization was terminally performed to record RV pressure (RVP). Pulmonary arteriolar thickening and oxidized lipid deposition were assessed by staining lung sections with Masson’s Trichrome or with α-smooth muscle actin and E-06 (marker for oxidized low-density lipoproteins). In vitro, human pulmonary artery smooth muscle cell (hPASMC) proliferation was assessed by MTT assays in the absence or presence of 12-HETE (100ng/ml), 9-HODE (1µg/ml) and 13-HODE (1µg/ml) alone or together with NDGA (10, 25 and 50µM). In-vitro, HETE/HODE treatment increased hPASMC proliferation ~ 2-fold when compared to untreated cells and NDGA significantly inhibited the proliferative effects of all three oxidized lipids. In-vivo, NDGA treatment prevented the development of PH. RVP was lower in the NDGA-treated group vs. the PH group (24.01±1.39mmHg vs. 36.91±5.74mmHg, p<0.05) and was comparable to control normoxic mice (20.93±2.52mmHg). RV hypertrophy index was significantly elevated in the PH mice versus control mice (0.38±0.03 vs. 0.28±0.02 (p<0.001), while NDGA treatment completely prevented the development of RV hypertrophy (0.28±0.04). Lung sections demonstrated arteriolar thickening and E-06 positive deposits in the PH group, which was prevented by NDGA therapy. We conclude that oxidized fatty acid deposition and accumulation might play a role in the development of PH.


1993 ◽  
Vol 264 (4) ◽  
pp. C912-C917 ◽  
Author(s):  
M. Kuno ◽  
J. Kawawaki ◽  
T. Shibata ◽  
H. Gotani

Effects of inhibitors of the arachidonic acid cascade on Ca2+ release from intracellular stores and Ca2+ influx through the plasma membrane during stimulus-secretion coupling were examined using rat peritoneal mast cells loaded with fura-2. Compound 48/80 (48/80) was used as a secretagogue. A phospholipase inhibitor, p-bromophenacyl bromide (PBPB), or a lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA), inhibited the 48/80 (1 microgram/ml)-induced release of histamine, Ca2+, and Mn2+ influxes, but the cyclooxygenase inhibitor, indomethacin (approximately 50 microM), inhibited neither Ca2+ nor Mn2+ influxes. The Ca2+ release induced by 1 microgram/ml of 48/80 was little inhibited by PBPB, NDGA, or indomethacin. The Ca2+ release was activated and saturated with lower concentrations of 48/80 than was the Ca2+ influx. The percent inhibition of the Ca2+ release by 25 microM PBPB was increased by lowering the concentration of 48/80, but NDGA (10 microM) did not inhibit the Ca2+ release induced by low concentrations of 48/80 (0.03-0.1 microgram/ml). These results suggest that activation of the Ca2+ release and the Ca2+ influx were differently regulated and that full activation of Ca2+ influx needs the arachidonic acid cascade produced by higher concentrations of 48/80 than does the Ca2+ release. Lipoxygenase metabolites of arachidonic acid are potential modulators of the Ca2+ influx.


2003 ◽  
Vol 90 (5) ◽  
pp. 3213-3223 ◽  
Author(s):  
E. Tanaka ◽  
S. Niiyama ◽  
S. Sato ◽  
A. Yamada ◽  
H. Higashi

Intracellular recordings were made from hippocampal CA1 neurons in rat slice preparations. Superfusion with oxygen- and glucose-deprived medium (in vitro ischemia) produced a rapid depolarization ∼5 min after the onset of the superfusion. Even when oxygen and glucose were reintroduced immediately after rapid depolarization, the membrane depolarized further (persistent depolarization) and reached 0 mV (irreversible depolarization) after 5 min from the reintroduction. The pretreatment of the slice preparation with a phospholipase A2 (PLA2) inhibitor, para-bromophenacyl bromide, or a cytochrome P-450 inhibitor, 17-octadecynoic acid, significantly restored the membrane to the preexposure potential level after the reintroduction of oxygen and glucose. The administration of 14,15-epoxyeicosatrienoic acid or 20-hydroxyeicosatetraenoic acid did not change the latency of the rapid depolarization and did not allow the membrane potential to recover after the ischemic exposure. In contrast, after pretreatment with cyclooxygenase or lipoxygenase inhibitors, such as indomethacin, resveratrol, Dup-697, nordihydroguaiaretic acid, and 3,4-dihydrophenyl ethanol, a minority of neurons tested showed postischemic recovery from the persistent depolarization. Improved recovery was also seen after treatment with the free radical scavengers, edaravone and α-tocopherol. These results suggest that the activation of the arachidonic acid cascade via PLA2 and the free radicals produced by arachidonic acid metabolism contribute to the irreversible depolarization produced by in vitro ischemia.


2000 ◽  
Vol 279 (3) ◽  
pp. E593-E600 ◽  
Author(s):  
Maya S. Gowri ◽  
Rakia K. Azhar ◽  
Fredric B. Kraemer ◽  
Gerald M. Reaven ◽  
Salman Azhar

Masoprocol (nordihydroguaiaretic acid), a lipoxygenase inhibitor isolated from the creosote bush, has been shown to decrease adipose tissue lipolytic activity both in vivo and in vitro. The present study was initiated to test the hypothesis that the decrease in lipolytic activity by masoprocol resulted from modulation of adipose tissue hormone-sensitive lipase (HSL) activity. The results indicate that oral administration of masoprocol to rats with fructose-induced hypertriglyceridemia significantly decreased their serum free fatty acid (FFA; P < 0.05), triglyceride (TG; P < 0.001), and insulin ( P < 0.05) concentrations. In addition, isoproterenol-induced lipolytic rate and HSL activity were significantly lower ( P < 0.001) in adipocytes isolated from masoprocol compared with vehicle-treated rats and was associated with a decrease in HSL protein. Incubation of masoprocol with adipocytes from chow-fed rats significantly inhibited isoproterenol-induced lipolytic activity and HSL activity, associated with a decrease in the ability of isoproterenol to phosphorylate HSL. Masoprocol had no apparent effect on adipose tissue phosphatidylinositol 3-kinase activity, but okadaic acid, a serine/threonine phosphatase inhibitor, blocked the antilipolytic effect of masoprocol. The results of these in vitro and in vivo experiments suggest that the antilipolytic activity of masoprocol is secondary to its ability to inhibit HSL phosphorylation, possibly by increasing phosphatase activity. As a consequence, masoprocol administration results in lower serum FFA and TG concentrations in hypertriglyceridemic rodents.


Author(s):  
С.В. Калиш ◽  
С.В. Лямина ◽  
А.А. Раецкая ◽  
И.Ю. Малышев

Цель исследования. Репрограммирование М1 фенотипа макрофагов с ингибированными факторами транскрипции М2 фенотипа STAT3, STAТ6 и SMAD и оценка их влияния на развитие карциномы Эрлиха (КЭ) in vitro и in vivo. Методика. Рост опухоли иницировали in vitro путем добавления клеток КЭ в среду культивирования RPMI-1640 и in vivo путем внутрибрюшинной инъекции клеток КЭ мышам. Результаты. Установлено, что M1макрофаги и in vitro, и in vivo оказывают выраженный противоопухолевый эффект, который превосходит антиопухолевые эффекты М1, M1, M1 макрофагов и цисплатина. Заключение. М1 макрофаги с ингибированными STAT3, STAT6 и/или SMAD3 эффективно ограничивают рост опухоли. Полученные данные обосновывают разработку новой технологии противоопухолевой клеточной терапии. Objective. Reprogramming of M1 macrophage phenotype with inhibited M2 phenotype transcription factors, such as STAT3, STAT6 and SMAD and assess their impact on the development of Ehrlich carcinoma (EC) in vitro and in vivo . Methods. Tumor growth in vitro was initiated by addition of EC cells in RPMI-1640 culture medium and in vivo by intraperitoneal of EC cell injection into mice. Results. It was found that M1 macrophages have a pronounced anti-tumor effect in vitro , and in vivo , which was greater than anti-tumor effects of M1, M1, M1 macrophages and cisplatin. Conclusion. M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 effectively restrict tumor growth. The findings justify the development of new anti-tumor cell therapy technology.


2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.


2018 ◽  
Vol 21 (3) ◽  
pp. 215-221
Author(s):  
Haroon Khan ◽  
Muhammad Zafar ◽  
Helena Den-Haan ◽  
Horacio Perez-Sanchez ◽  
Mohammad Amjad Kamal

Aim and Objective: Lipoxygenase (LOX) enzymes play an important role in the pathophysiology of several inflammatory and allergic diseases including bronchial asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, rheumatoid arthritis and chronic obstructive pulmonary disease. Inhibitors of the LOX are believed to be an ideal approach in the treatment of diseases caused by its over-expression. In this regard, several synthetic and natural agents are under investigation worldwide. Alkaloids are the most thoroughly investigated class of natural compounds with outstanding past in clinically useful drugs. In this article, we have discussed various alkaloids of plant origin that have already shown lipoxygenase inhibition in-vitro with possible correlation in in silico studies. Materials and Methods: Molecular docking studies were performed using MOE (Molecular Operating Environment) software. Among the ten reported LOX alkaloids inhibitors, derived from plant, compounds 4, 2, 3 and 1 showed excellent docking scores and receptor sensitivity. Result and Conclusion: These compounds already exhibited in vitro lipoxygenase inhibition and the MOE results strongly correlated with the experimental results. On the basis of these in vitro assays and computer aided results, we suggest that these compounds need further detail in vivo studies and clinical trial for the discovery of new more effective and safe lipoxygenase inhibitors. In conclusion, these results might be useful in the design of new and potential lipoxygenase (LOX) inhibitors.


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