scholarly journals Antiplasmodial Activity of [(Aryl)arylsulfanylmethyl]Pyridine

2007 ◽  
Vol 52 (2) ◽  
pp. 705-715 ◽  
Author(s):  
Sanjay Kumar ◽  
Sajal Kumar Das ◽  
Sumanta Dey ◽  
Pallab Maity ◽  
Mithu Guha ◽  
...  

ABSTRACT A series of [(aryl)arylsufanylmethyl]pyridines (AASMP) have been synthesized. These compounds inhibited hemozoin formation, formed complexes (KD = 12 to 20 μM) with free heme (ferriprotoporphyrin IX) at a pH close to the pH of the parasite food vacuole, and exhibited antimalarial activity in vitro. The inhibition of hemozoin formation may develop oxidative stress in Plasmodium falciparum due to the accumulation of free heme. Interestingly, AASMP developed oxidative stress in the parasite, as evident from the decreased level of glutathione and increased formation of lipid peroxide, H2O2, and hydroxyl radical (·OH) in P. falciparum. AASMP also caused mitochondrial dysfunction by decreasing mitochondrial potential (ΔΨm) in malaria parasite, as measured by both flow cytometry and fluorescence microscopy. Furthermore, the generation of ·OH may be mainly responsible for the antimalarial effect of AASMP since ·OH scavengers such as mannitol, as well as spin trap α-phenyl-n-tertbutylnitrone, significantly protected P. falciparum from AASMP-mediated growth inhibition. Cytotoxicity testing of the active compounds showed selective activity against malaria parasite with selectivity indices greater than 100. AASMP also exhibited profound antimalarial activity in vivo against chloroquine resistant P. yoelii. Thus, AASMP represents a novel class of antimalarial.

2020 ◽  
Author(s):  
Shweta Sinha ◽  
B.D. Radotra ◽  
Bikash Medhi ◽  
Daniela Batovska ◽  
Nadezhda Markova ◽  
...  

Abstract Objective Chalcones (1, 3-diaryl-2-propen-1-ones) and its derivatives are widely explored from the past decade for its antimalarial activity. To elucidate their mechanism of action on the malaria parasite, the ultrastructural changes with the action of these derivatives in different organelles of the parasite were studied in vitro. Infected RBCs (CQ sensitive (MRC-2) and CQ resistant (RKL-9) Plasmodium strain) were treated with three chalcone derivatives 2, 6 and 7 and standard drugs, i.e., CQ and artemisinin at twice their respective IC50 values for 24 h and then harvested, washed, fixed, embedded and stained to visualize ultra-structure changes before and after intervention of treatment under in vitro condition through transmission electron microscope.Results The ultrastructural changes demonstrate the significant disturbance of all parasite membranes, including those of the nucleus, mitochondria and food vacuole, in association with a marked reduction of ribosomes in the trophozoites and cessation of developing schizonts which suggest multiple mechanisms of action by which chalcone derivatives act on the malaria parasite. The present study opens up perspectives for further exploration of these derivatives in vivo malaria model to discover more about its effect and mechanism of action.


2011 ◽  
Vol 7 (3) ◽  
pp. 1385-1394 ◽  
Author(s):  
Mozammel Haque ◽  
Jahirul Islam ◽  
Asiqur Rahaman ◽  
Fowzia Akter Selina ◽  
Mohammad Azizur Rahman ◽  
...  

Objective: Raphanus sativus is a hugely used edible root vegetable. We investigated whether the feeding of the Raphanus sativus hot water extract (RSE) ameliorates atherogenic lipid profile and oxidative stress in hypercholesterolemia. Methods: After feeding of the RSE to hypercholesterolemic rats for 6 weeks, the levels of plasma and hepatic total cholesterol (TC), triglyceride (TG), and plasma high density lipoprotein-cholesterol (HDL-C) and fecal TC levels were studied. The effects of RSE on the hepatic enzymes, namely alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), the levels of lipid peroxide (LPO) and liver histology were also evaluated. Results: Hypercholesterolemia increased the levels of TC and TG in the plasma and livers. The levels of ALT, AST and ALP in plasma and LPO in the liver also increased. The dietary RSE, however, significantly ameliorated the above atherogenic lipids and liver enzymes. The RSE significantly reduced the levels of LPO in the liver, suggesting an in vivo protection against of oxidative stress. The RSE also inhibited the in vitro Fenton’s reagent-induced oxidative stress, thus corroborating the in vivo anti-LPO actions of RSE. The levels of hepatic LPO were positively correlated with plasma AST (r=0.76; P <0.05) and ALT (r=0.43; P<0.05) levels. Histologically, the livers of the RSE-fed hypercholesterolemic rats exhibited lesser fatty droplets and reduced inflammatory cells. Conclusion: Finally, R. sativus extract lowers the cardiovascular disease risk factors under hypercholesterolemic situation by increasing the plasma/hepatic clearance of cholesterol and improving the hypercholesterolemia-induced oxidative damage of hepatic tissues.


2021 ◽  
Author(s):  
Manami Suzuki-Karasaki ◽  
Takashi Ando ◽  
Yushi Ochiai ◽  
Kenta Kawahara ◽  
Miki Suzuki-Karasaki ◽  
...  

Intractable cancers such as osteosarcoma (OS) and oral cancer (OC) are highly refractory, recurrent, and metastatic once developed, and their prognosis is still disappointing. Tumor-targeted therapy eliminating cancers effectively and safely is the current clinical choice. Since aggressive tumors have inherent or acquired resistance to multidisciplinary therapies targeting apoptosis, tumor-specific induction of another cell death modality is a promising avenue to meet the goal. Here, we report that a cold atmospheric air plasma-activated medium (APAM) can induce cell death in OS and OC via a unique mitochondrial clustering. This event was named monopolar perinuclear mitochondrial clustering (MPMC) because of the characteristic unipolar mitochondrial perinuclear aggregation. APAM had potent antitumor activity both in vitro and in vivo. APAM caused apoptosis, necrotic cell death, and autophagy. APAM contained hydrogen peroxide and increased mitochondrial ROS (mROS), while the antioxidant N-acetylcysteine (NAC) prevented cell death. MPMC occurred following mitochondrial fragmentation coinciding with nuclear damages. MPMC was accompanied by the tubulin network remodeling and mitochondrial lipid peroxide (mLPO) accumulation and prevented by NAC and the microtubule inhibitor, Nocodazole. Increased Cardiolipin (CL) oxidation was also seen, and NAC and the peroxy radical scavenger Ferrostatin-1 prevented it. In contrast, in fibroblasts, APAM induced minimal cell death, mROS generation, mLPO accumulation, CL oxidation, and MPMC. These results suggest that MPMC is a tumor-specific cause of cell death via mitochondrial oxidative stress and microtubule-driven mitochondrial motility. MPMC might serve as a promising target for exerting tumor-specific cytotoxicity.


2000 ◽  
Vol 44 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Thomas Akompong ◽  
Nafisa Ghori ◽  
Kasturi Haldar

ABSTRACT The human malaria parasite Plasmodium falciparumdigests hemoglobin and polymerizes the released free heme into hemozoin. This activity occurs in an acidic organelle called the food vacuole and is essential for survival of the parasite in erythrocytes. Since acidic conditions are known to enhance the auto-oxidation of hemoglobin, we investigated whether hemoglobin ingested by the parasite was oxidized and whether the oxidation process could be a target for chemotherapy against malaria. We released parasites from their host cells and separately analyzed hemoglobin ingested by the parasites from that remaining in the erythrocytes. Isolated parasites contained elevated amounts (38.5% ± 3.5%) of oxidized hemoglobin (methemoglobin) compared to levels (0.8% ± 0.2%) found in normal, uninfected erythrocytes. Further, treatment of infected cells with the reducing agent riboflavin for 24 h decreased the parasite methemoglobin level by 55%. It also inhibited hemozoin production by 50% and decreased the average size of the food vacuole by 47%. Administration of riboflavin for 48 h resulted in a 65% decrease in food vacuole size and inhibited asexual parasite growth in cultures. High doses of riboflavin are used clinically to treat congenital methemoglobinemia without any adverse side effects. This activity, in conjunction with its impressive antimalarial activity, makes riboflavin attractive as a safe and inexpensive drug for treating malaria caused by P. falciparum.


2009 ◽  
Vol 53 (5) ◽  
pp. 1727-1734 ◽  
Author(s):  
S. Agbor-Enoh ◽  
C. Seudieu ◽  
E. Davidson ◽  
A. Dritschilo ◽  
M. Jung

ABSTRACT Histone deacetylases (HDAC) are potential targets for the development of new antimalarial drugs. The growth of Plasmodium falciparum and other apicomplexans can be suppressed in the presence of potent HDAC inhibitors in vitro and in vivo; however, in vivo parasite suppression is generally incomplete or reversible after the discontinuation of drug treatment. Furthermore, most established HDAC inhibitors concurrently show broad toxicities against parasites and human cells and high drug concentrations are required for effective antimalarial activity. Here, we report on HDAC inhibitors that are potent against P. falciparum at subnanomolar concentrations and that have high selectivities; the lead compounds have mean 50% inhibitory concentrations for the killing of the malaria parasite up to 950 times lower than those for the killing of mammalian cells. These potential drugs improved survival and completely and irreversibly suppressed parasitemia in P. berghei-infected mice.


2020 ◽  
Vol 26 (22) ◽  
pp. 2610-2619 ◽  
Author(s):  
Tarique Hussain ◽  
Ghulam Murtaza ◽  
Huansheng Yang ◽  
Muhammad S. Kalhoro ◽  
Dildar H. Kalhoro

Background: Inflammation is a complex response of the host defense system to different internal and external stimuli. It is believed that persistent inflammation may lead to chronic inflammatory diseases such as, inflammatory bowel disease, neurological and cardiovascular diseases. Oxidative stress is the main factor responsible for the augmentation of inflammation via various molecular pathways. Therefore, alleviating oxidative stress is effective a therapeutic option against chronic inflammatory diseases. Methods: This review article extends the knowledge of the regulatory mechanisms of flavonoids targeting inflammatory pathways in chronic diseases, which would be the best approach for the development of suitable therapeutic agents against chronic diseases. Results: Since the inflammatory response is initiated by numerous signaling molecules like NF-κB, MAPK, and Arachidonic acid pathways, their encountering function can be evaluated with the activation of Nrf2 pathway, a promising approach to inhibit/prevent chronic inflammatory diseases by flavonoids. Over the last few decades, flavonoids drew much attention as a potent alternative therapeutic agent. Recent clinical evidence has shown significant impacts of flavonoids on chronic diseases in different in-vivo and in-vitro models. Conclusion: Flavonoid compounds can interact with chronic inflammatory diseases at the cellular level and modulate the response of protein pathways. A promising approach is needed to overlook suitable alternative compounds providing more therapeutic efficacy and exerting fewer side effects than commercially available antiinflammatory drugs.


2019 ◽  
Vol 24 (39) ◽  
pp. 4626-4638 ◽  
Author(s):  
Reyhaneh Moradi-Marjaneh ◽  
Seyed M. Hassanian ◽  
Farzad Rahmani ◽  
Seyed H. Aghaee-Bakhtiari ◽  
Amir Avan ◽  
...  

Background: Colorectal cancer (CRC) is one of the most common causes of cancer-associated mortality in the world. Anti-tumor effect of curcumin has been shown in different cancers; however, the therapeutic potential of novel phytosomal curcumin, as well as the underlying molecular mechanism in CRC, has not yet been explored. Methods: The anti-proliferative, anti-migratory and apoptotic activity of phytosomal curcumin in CT26 cells was assessed by MTT assay, wound healing assay and Flow cytometry, respectively. Phytosomal curcumin was also tested for its in-vivo activity in a xenograft mouse model of CRC. In addition, oxidant/antioxidant activity was examined by DCFH-DA assay in vitro, measurement of malondialdehyde (MDA), Thiol and superoxidedismutase (SOD) and catalase (CAT) activity and also evaluation of expression levels of Nrf2 and GCLM by qRT-PCR in tumor tissues. In addition, the effect of phytosomal curcumin on angiogenesis was assessed by the measurement of VEGF-A and VEGFR-1 and VEGF signaling regulatory microRNAs (miRNAs) in tumor tissue. Results: Phytosomal curcumin exerts anti-proliferative, anti-migratory and apoptotic activity in-vitro. It also decreases tumor growth and augmented 5-fluorouracil (5-FU) anti-tumor effect in-vivo. In addition, our data showed that induction of oxidative stress and inhibition of angiogenesis through modulation of VEGF signaling regulatory miRNAs might be underlying mechanisms by which phytosomal curcumin exerted its antitumor effect. Conclusion: Our data confirmed this notion that phytosomal curcumin administrates anticancer effects and can be used as a complementary treatment in clinical settings.


2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Barbara D'Orio ◽  
Anna Fracassi ◽  
Maria Paola Cerù ◽  
Sandra Moreno

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.


2020 ◽  
Vol 16 ◽  
Author(s):  
Haicheng Liu ◽  
Yushi Futamura ◽  
Honghai Wu ◽  
Aki Ishiyama ◽  
Taotao Zhang ◽  
...  

Background: Malaria is one of the most devastating parasitic diseases, yet the discovery of antimalarial agents remains profoundly challenging. Very few new antimalarials have been developed in the past 50 years, while the emergence of drug-resistance continues to appear. Objective: This study focuses on the discovery, design, synthesis, and antimalarial evaluation of 3-cinnamamido-N-substituted benzamides. Method: In this study, a screening of our compound library was carried out against the multidrug-sensitive Plasmodium falciparum 3D7 strain. Derivatives of the hit were designed, synthesized and tested against P. falciparum 3D7 and the in vivo antimalarial activity of the most active compounds was evaluated using the method of Peters’ 4-day suppressive test. Results: The retrieved hit compound 1 containing a 3-cinnamamido-N-substituted benzamide skeleton showed moderate antimalarial activity (IC50 = 1.20 µM) for the first time. A series of derivatives were then synthesized through a simple four-step workflow, and half of them exhibited slightly better antimalarial effect than the precursor 1 during the subsequent in vitro assays. Additionally, compounds 11, 23, 30 and 31 displayed potent activity with IC50 values of approximately 0.1 µM, and weak cytotoxicity against mammalian cells. However, in vivo antimalarial activity is not effective which might be ascribed to the poor solubility of these compounds. Conclusion: In this study, phenotypic screen of our compound library resulted in the first report of 3-cinnamamide framework with antimalarial activity and 40 derivatives were then designed and synthesized. Subsequent structure-activity studies showed that compounds 11, 23, 30 and 31 exhibited the most potent and selective activity against P. falciparum 3D7 strain with IC50 values around 0.1 µM. Our work herein sets another example of phenotypic screen-based drug discovery, leading to potentially promising candidates of novel antimalarial agents once given further optimization.


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