Search results for "alkaloids"
showing 10 items of 182 documents
Indomethacin blocks the increased conditioned rewarding effects of cocaine induced by repeated social defeat
2018
It is well established that repeated social defeat stress can induce negative long-term consequences such as increased anxiety-like behavior and enhances the reinforcing effect of psychostimulants in rodents. In the current study, we evaluated how the immune system may play a role in these long-term effects of stress. A total of 148 OF1 mice were divided into different experimental groups according to stress condition (exploration or social defeat) and pre-treatment (saline, 5 or 10 mg/kg of the anti-inflammatory indomethacin) before each social defeat or exploration episode. Three weeks after the last social defeat, anxiety was evaluated using an elevated plus maze paradigm. After this tes…
Phytochemicals as inhibitors of NF-κB for treatment of Alzheimer's disease.
2017
Alzheimer's disease (AD) is the most prevalent form of dementia. The exact pathophysiology of this disease remains incompletely understood and safe and effective therapies are required. AD is highly correlated with neuroinflammation and oxidative stress in brain causing neuronal loss. Nuclear factor of activated B-cells (NF-κB) is involved in physiological inflammatory processes and thus representing a promising target for inflammation-based AD therapy. Phytochemicals are able to interfere with the NF-κB pathway. They inhibit the phosphorylation or the ubiquitination of signaling molecules, and thus, inhibit the degradation of IκB. The translocation of NF-κB to the nucleus and subsequent tr…
An overview on anti-tubulin agents for the treatment of lymphoma patients
2020
Anti-tubulin agents constitute a large class of compounds with broad activity both in solid tumors and hematologic malignancies, due to the interference with microtubule dynamics. Since microtubules play crucial roles in the regulation of the mitotic spindles, the interference with their function usually leads to a block in cell division with arrest at the metaphase/anaphase junction of mitosis, followed to apoptosis. This explains the reason why tubulin-binding agents (TBAs) proved to be extremely active in patients with cancer. Several anti-tubulin agents are indicated in the treatment of patients with lymphomas both alone and in combination chemotherapy regimens. The article reviews the …
New Thiazole Nortopsentin Analogues Inhibit Bacterial Biofilm Formation.
2018
New thiazole nortopsentin analogues were conveniently synthesized and evaluated for their activity as inhibitors of biofilm formation of relevant Gram-positive and Gram-negative pathogens. All compounds were able to interfere with the first step of biofilm formation in a dose-dependent manner, showing a selectivity against the staphylococcal strains. The most active derivatives elicited IC50 values against Staphylococcus aureus ATCC 25923, ranging from 0.40&ndash
Marine Indole Alkaloids.
2015
Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed.
Human ABCB1 confers cells resistance to cytotoxic guanidine alkaloids from Pterogyne nitens.
2015
Multidrug resistance (MDR) caused by human ABCB1 (P-glycoprotein/MDR1) is one of the major obstacles in chemotherapy. To understand the mechanism of MDR by ABCB1 and circumvent the MDR, in the present study, we established human ABCB1-expressing cells (Flp-In-293/ABCB1 cells) and examined the cytotoxic effects of four guanidine alkaloids from Pterogyne nitens (galegine, nitensidine A, pterogynidine and pterogynine) using Flp-In-293/Mock and Flp-In-293/ABCB1 cells. The activity of ABCB1 in Flp-In-293/ABCB1 cells were confirmed by typical substrates for ABCB1 (taxol and vinblastine) in MTT assay. Flp-In-293/ABCB1 cells were also resistant to the four guanidine alkaloids as well as taxol and v…
Effects of yohimbine on sexual experiences and nocturnal penile tumescence and rigidity in erectile dysfunction.
1996
The therapeutic effect of the alpha 2-antagonist yohimbine in erectile dysfunction was studied in a double-blind placebo-controlled design. Thirty-one male patients underwent extensive clinical, urological, and psychiatric diagnosis and were dichotomically classified into an organic and a nonorganic subgroup. Following a 1-week placebo run-in period, patients were randomly assigned to a placebo or a verum group (yohimbine 15 mg daily) for a treatment period of 7 weeks. The Clinical Global Impression (CGI) scale was used as the primary efficacy parameter. Additionally, nocturnal penile tumescence and rigidity (NPTR) were measured. Global assessment of erectile function applying the CGI scale…
Familial adenomatosis polyposis-related desmoid tumours treated with low-dose chemotherapy: Results from an international, multi-institutional, retro…
2019
[Introduction] Desmoid tumour (DT) is a locally aggressive fibroblastic proliferative disease representing the most common extraintestinal manifestation of familial adenomatosis polyposis (FAP). As data on the activity of chemotherapy in these patients are limited, we examined the outcomes of patients treated with low-dose methotrexate (MTX)+vinca alkaloids (vinorelbine or vinblastine).
The 5-HT and alpha-adrenoceptor antagonist effect of four benzylisoquinoline alkaloids on rat aorta.
1998
Abstract The action of four benzylisoquinoline alkaloids (two aporphines—glaucine and apomorphine, a benzylisoquinoline—papaverine and a bisbenzyltetrahydroisoquinoline—antioquine) on 5-HT-induced contraction in rat thoracic aorta has been examined and compared with that of the control drugs: ketanserin, nifedipine, prazosin and phentolamine. The relaxant action on 5-HT-induced contraction was contrasted with that on the contraction induced by noradrenaline and KCl. The results obtained with control drugs show that ketanserin has clear selectivity for 5-HT receptors, whereas prazosin and phentolamine have high selectivity for the α1-adrenoceptor and nifedipine seems to have a more potent ef…
Bis(oxazoline) Lewis Acid Catalyzed Aldol Reactions of PyridineN-Oxide Aldehydes—Synthesis of Optically Active 2-(1-Hydroxyalkyl)pyridine Derivatives…
2006
A new, short, and simplified procedure for the synthesis of optically active pyridine derivatives from pro-chiral pyridine-N-oxides is presented. The catalytic and asymmetric Mukaiyama aldol reaction between ketene silyl acetals and 1-oxypyridine-2-carbaldehyde derivatives catalyzed by chiral copper(II)-bis(oxazoline) complexes gave optically active 2-(hydroxyalkyl)- and 2-(anti-1,2-dihydroxyalkyl)pyridine derivatives in good yields and diastereoselectivities, and in excellent enantioselectivities-up to 99 % enantiomeric excess. As a synthetic application of the developed method, a full account for the asymmetric total synthesis of a nonnatural indolizine alkaloid is provided.