Search results for " synergism"

Complex interactions between phytochemicals. The multi-target therapeutic concept of phytotherapy.

2010

Drugs derived from natural resources represent a significant segment of the pharmaceutical market as compared to randomly synthesized compounds. It is a goal of drug development programs to design selective ligands that act on single disease targets to obtain highly effective and safe drugs with low side effects. Although this strategy was successful for many new therapies, there is a marked decline in the number of new drugs introduced into clinical practice over the past decades. One reason for this failure may be due to the fact that the pathogenesis of many diseases is rather multi-factorial in nature and not due to a single cause. Phytotherapy, whose therapeutic efficacy is based on th…

Evaluation of anti-androgenic activity of di-(2-ethylhexyl)phthalate

2005

International audience; DEHP is a widely used platiciser in the manufacture of PVC-based materials. It is known to disrupt the reproductive tract development in male rats. We have performed the Hershberger assay with DEHP on an immature castrated rat model to check if DEHP antagonise the testosterone propionate androgenic effect on the accessory sex organs development. DEHP significantly decreased the BC/LA muscles, the prostate, and the seminal vesicles relative weights from 100, 200, and 400 mg/kg bw/day, respectively. DEHP increased the liver relative weight from 100 mg/kg bw/day. A study was also performed on MDA-MB453 cell line stably transfected with pMMTVneo-Luc with DEHP and its maj…

Effects of cyclooxygenase-1/cyclooxygenase-2 inhibition on leukocyte/endothelial cell interactions in the rat mesentery.

2002

Nonsteroidal anti-inflammatory drugs (NSAID) inhibit cyclooxygenase activity and cause gastrointestinal damage in part by promoting leukocyte accumulation in the mucosa. Our aim was to evaluate the effects of selective blockade of the isoenzymes cyclooxygenase-1 and cyclooxygenase-2 on leukocyte adhesion in vivo. Leukocyte/endothelial cell interactions were examined in rat mesenteric venules before and after treatment with indomethacin, SC-560 (5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole, cyclooxygenase-1 inhibitor), DFP (5,5-dimethyl-3-(2-propoxy)-4-(4-methanesulfonyl)-2(5H)-furanone, cyclooxygenase-2 inhibitor), or SC-560 plus DFP (20 mg/kg, i.v. each). Indomethacin i…

Paclitaxel and beta-lapachone synergistically induce apoptosis in human retinoblastoma Y79 cells by downregulating the levels of phospho-Akt.

2009

Paclitaxel (PTX) and beta-lapachone (LPC) are naturally occurring compounds that have shown a large spectrum of anticancer activity. In this article we show for the first time that PTX/LPC combination induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells. Combination of suboptimal doses of PTX (0.3 nM) and LPC (1.5 microM) caused biochemical and morphological signs of apoptosis at 48 h of treatment. These effects were accompanied by potent lowering in inhibitor of apoptosis proteins and by activation of Bid and caspases 3 and 6 with lamin B and PARP breakdown. PTX/LPC combination acted by favoring p53 stabilization through a lowering in p-Akt levels and in ps166-MDM…

Telitromicina, un posible nuevo potenciador del acenocumarol

2006

Synergistic Interactions between Vitamin A and Vitamin E against Lipid Peroxidation in Phosphatidylcholine Liposomes

1996

Interactions between alpha-tocopherol and all-trans retinol in suppressing lipid peroxidation were studied in a unilamellar liposomal system of phosphatidylcholine from either egg or soybean, in which peroxidation was initiated by the water-soluble azo initiator 2,2-azobis(2-amidino-propane)hydrochloride and peroxidation was measured as production of conjugated diene hydroperoxides. While all-trans retinol alone was poorly effective, the combination of all-trans retinol with alpha-tocopherol caused an inhibition period far beyond the sum of the inhibition periods observed with individual antioxidants, providing evidence of synergistic interactions. Furthermore, the inhibition rate calculate…

Drug Synergism: Studies of Combination of RK-52 and Curcumin against Rhodesain of Trypanosoma brucei rhodesiense

2020

Rhodesain is an enzyme essential for the life of Trypanosoma brucei rhodesiense, a parasite causing a rapid-onset form of Human African Trypanosomiasis. RK-52 is a synthetic inhibitor of rhodesain,...

Cytotoxicity of the Urokinase-Plasminogen Activator Inhibitor Carbamimidothioic Acid (4-Boronophenyl) Methyl Ester Hydrobromide (BC-11) on Triple-Neg…

2015

BC-11 is an easily synthesized simple thiouronium-substituted phenylboronic acid, which has been shown to be cytotoxic on triple negative MDA-MB231 breast cancer cells by inducing a perturbation of cell cycle when administered at a concentration equal to its ED50 at 72 h (117 μM). Exposure of cells to BC-11, either pre-absorbed with a soluble preparation of the N-terminal fragment of urokinase-plasminogen activator (uPa), or in co-treatment with two different EGFR inhibitors, indicated that: (i) BC-11 acts via binding to the N-terminus of the enzyme where uPa- and EGF receptor-recognizing sites are present, thereby abrogating the growth-sustaining effect resulting from receptor binding

Cytotoxic effects of individual and combined sterigmatocystin and nivalenol on liver hepatocellular carcinoma cells

2020

Abstract Since humans are exposed to different mycotoxins through daily intake, there is increasing concern about the adverse effects of the interactions between them. Cytotoxicity of sterigmatocystin (STE) and nivalenol (NIV) alone and in combination in human hepatocarcinoma (HepG2) cells was evaluated by MTT assay. Furthermore, ROS production and alteration of ΔΨm as mechanisms of action were assessed. Cells were treated with concentrations ranging from 0.15 to 5 μM for NIV and from 0.78 to 50 μM for STE individually and in binary combinations. The combination ratio between the mixture STE + NIV was 10:1. The IC50 values of NIV ranged from 0.96 to 0.66 μM, whereas no IC50 values were obta…

A synergic nanoantioxidant based on covalently modified halloysite–trolox nanotubes with intra-lumen loaded quercetin

2016

We describe the preparation and properties of the first example of a synergic nanoantioxidant, obtained by different functionalizations of the external surface and the inner lumen of halloysite nanotubes (HNTs). Trolox, a mimic of natural α-tocopherol, was selectively grafted on the HNT external surface; while quercetin, a natural polyphenolic antioxidant, was loaded into the inner lumen to afford a bi-functional nanoantioxidant, HNT–Trolox/Que, which was investigated for its reactivity with transient peroxyl radicals and a persistent 1,1-diphenyl-2-picrylhydrazyl (DPPH˙) radical in comparison with the corresponding mono-functional analogues HNT–Trolox and HNT/Que. Both HNT–Trolox and HNT/Q…