Vascular injury and inflammation during percutaneous coronary intervention (PCI) are associated with increased risk of post-PCI adverse outcomes. Colchicine decreases neutrophil recruitment to sites of vascular injury. The anti-inflammatory effects of acute colchicine administration before PCI on subsequent myocardial injury are unknown.

In the randomized, placebo-controlled Colchicine Cardiovascular Outcomes Trial (COLCOT) of 4745 patients enrolled within 30 days after myocardial infarction (MI), low-dose colchicine (0.5 mg once daily) reduced the incidence of the primary composite endpoint of cardiovascular death, resuscitated cardiac arrest, MI, stroke, or urgent hospitalization for angina leading to coronary revascularization. To assess the in-trial period and lifetime cost-effectiveness of low-dose colchicine therapy compared to placebo in post-MI patients on standard-of-care therapy.

Colchicine poisoning is commonly lethal. Colchicine-specific Fab fragments increase rat urinary colchicine clearance and have been associated with a good outcome in one patient. We aimed to develop a porcine model of colchicine toxicity to study the pharmacokinetics and efficacy of ovine Fab.

Colchicine has been used historically as an anti-inflammatory agent for a wide range of diseases. Little is known regarding the relationship between colchicine use and infectious disease outcomes. The objective of this study was to systematically examine infectious adverse events associated with colchicine usage and the clinical use of colchicine for infectious diseases.

To evaluate the treatment response to compressed colchicine tablets in familial Mediterranean fever (FMF) patients with resistance or intolerance to coated colchicine. The secondary aim was to determine the demographic and clinical characteristics of responders to compressed colchicine.

Polyploidy in Rhododendron fortunei has great potential to improve its horticultural and commercial value, and to also meet market demands. In this study, a feasible method for polyploid induction in R. fortunei via colchicine treatment was established, and the obtained polyploid plants were identified and characterized. As a result, the stem bases of tissue-cultured plantlets treated with 0.1% colchicine for 24 h showed the highest polyploid induction with a rate of 36.67%. By flow cytometric analysis, 69 tetraploids and 29 octoploids were identified in the regenerated plants that were examined. Phenotypic analysis indicated that the leaves of tetraploid and octoploid plants were smaller, rounder and thicker with more abundant and longer epidermal hairs than those of diploids. Furthermore, the stomata of polyploids were larger and sparser than those of diploids. An increase in chlorophyll content was also detected in polyploids, which resulted in darker green leaves. In conclusion, our study established an effective method to induce polyploidy in R. fortunei, which could be used to develop new genetic resources for breeding R. fortunei and other Rhododendron species in the future.

Few complete pathways have been established for the biosynthesis of medicinal compounds from plants. Accordingly, many plant-derived therapeutics are isolated directly from medicinal plants or plant cell culture1. A lead example is colchicine, a US Food and Drug Administration (FDA)-approved treatment for inflammatory disorders that is sourced from Colchicum and Gloriosa species2-5. Here we use a combination of transcriptomics, metabolic logic and pathway reconstitution to elucidate a near-complete biosynthetic pathway to colchicine without prior knowledge of biosynthetic genes, a sequenced genome or genetic tools in the native host. We uncovered eight genes from Gloriosa superba for the biosynthesis of N-formyldemecolcine, a colchicine precursor that contains the characteristic tropolone ring and pharmacophore of colchicine6. Notably, we identified a non-canonical cytochrome P450 that catalyses the remarkable ring expansion reaction that is required to produce the distinct carbon scaffold of colchicine. We further used the newly identified genes to engineer a biosynthetic pathway (comprising 16 enzymes in total) to N-formyldemecolcine in Nicotiana benthamiana starting from the amino acids phenylalanine and tyrosine. This study establishes a metabolic route to tropolone-containing colchicine alkaloids and provides insights into the unique chemistry that plants use to generate complex, bioactive metabolites from simple amino acids.

The microtubule-disrupting agent colchicine is known to be particular toxic for certain types of neurons, including the granule cells of the dentate gyrus. In this study we investigated whether colchicine could induce such neuron-specific degeneration in developing (1 week in vitro) and mature (3 weeks in vitro) organotypic hippocampal slice cultures and whether the induced cell death was apoptotic and/or necrotic. When applied to 1-week-old cultures for 48 h, colchicine induced primarily apoptotic, but also a minor degree of necrotic cell death in the dentate granule cells, as investigated by cellular uptake of the fluorescent dye propidium iodide (PI), immunostaining for active caspase 3 and c-Jun/AP-1 (N) and fragmentation of nuclei as seen in Hoechst 33342 staining. All four markers appeared after 12 h of colchicine exposure. Two of them, active caspase 3 and c-Jun/AP-1 (N) displayed a similar time course and reached a maximum after 24 h of exposure, 24 h ahead of both PI uptake and Hoechst 33342 staining, which together displayed similar time profiles and a close correlation. In 3-week-old cultures, colchicine did not induce apoptotic or necrotic cell death. Attempts to interfere with the colchicine-induced apoptosis in 1-week-old cultures showed that colchicine-induced PI uptake and formation of apoptotic nuclei were temporarily prevented by coapplication of the protein synthesis inhibitor cycloheximide. Application of the pancaspase inhibitor z-VAD-fmk almost completely abolished the formation of active caspase 3 protein and apoptotic nuclei induced by colchicine, but the formation of necrotic nuclei increased correspondingly and the PI uptake was unaffected. We conclude that colchicine induces caspase 3-dependent apoptotic cell death of dentate granule cells in hippocampal brain slice cultures, but the apoptotic cell death is highly dependent on the developmental stage of the cultures.

Background and Objective. 5-Fluorouracil is one of the most common chemotherapeutic agents used in the treatment of solid tumors. 5-Fluorouracil-associated cardiotoxicity is the second cause of cardiotoxicity induced by chemotherapeutic drugs after anthracyclines. Colchicine is a strong anti-inflammatory drug used to prevent and treat acute gout and treat familial Mediterranean fever. And also, its protective effects on cardiovascular disease have been reported in various studies. The current study is aimed at appraising the effect of colchicine on 5-fluorouracil-induced cardiotoxicity in rats. Methods. Twenty male Wistar rats were divided into four groups as follows: control, 5-fluorouracil, colchicine (5 mg/kg), and 5-fluorouracil+5 mg/kg colchicine. Cardiotoxicity was induced with an intraperitoneal injection of a single dose of 5-fluorouracil (100 mg/kg). The control group received normal saline, and the treatment groups received colchicine with an intraperitoneal injection for 14 days. Findings. 5-Fluorouracil resulted in significant cardiotoxicity represented by an increase in cardiac enzymes, malondialdehyde levels, cyclooxygenase-2 and tumor necrosis factor-alpha expression, cardiac enzymes, and histopathological degenerations. 5-Fluorouracil treatment also decreased body weight, total antioxidant capacity and catalase values, blood cells, and hemoglobin levels. In addition, 5-fluorouracil disrupted electrocardiographic parameters, including increased elevation in the ST segment and increased QRS duration. Treatment with colchicine reduced oxidative stress, cardiac enzymes, histopathological degenerations, and cyclooxygenase-2 expression in cardiac tissue, improved electrocardiographic disorders, and enhanced the number of blood cells and total antioxidant capacity levels. Moreover, body weight loss was hampered after treatment with colchicine. Our results demonstrated that treatment with colchicine significantly improved cardiotoxicity induced by 5-fluorouracil in rats.

Several colchicine analogues in which the N-acetyl residue has been replaced by aliphatic, straight-chain acyl moieties, have been synthesized. These compounds show high cytotoxic activity at the nanomolar level against the tumoral cell lines HT-29, MCF-7 and A549. Some of them exhibit activities in the picomolar range against the HT-29 line and are thus two to three orders of magnitude more cytotoxic than colchicine. In this specific cell line, the activities were found to be closely related to the length of the acyl carbon chain, an increase in the latter giving rise to an increase in the cytotoxicity with a maximum in the range of 10-12 carbon atoms, followed by a decrease in activity with still longer chains. Some of the compounds inhibit microtubule assembly and induce the formation of abnormal polymers and present in most cases better apparent affinity constants than colchicine. In addition, at IC50 concentrations the analogues block the cell cycle of A549 cells in the G2/M phase. Molecular docking studies suggest that, while interactions of the colchicine analogues with the colchicine binding site at β-tubulin are still present, the increase in the acyl chain length leads to the progressive development of new interactions, not present in colchicine itself, with the neighboring α-tubulin subunit. Indeed, sufficiently long acyl chains span the intradimer interface and contact with a hydrophobic groove in α-tubulin. It is worth noting that some of the compounds show cytotoxicity at concentrations three orders of magnitude lower than colchicine. Their pharmacological use in cancer therapy could possibly be performed with lower dosages and be thus endowed with less acute toxicity problems than in the case of colchicine.

Colchicine has the potential in reducing patient morbidity and mortality in COVID-19 infection owing to its anti-inflammatory properties. This study aims to determine the efficacy of colchicine in optimizing inflammatory hematological biomarker levels among COVID-19 patients.

No abstract available

Colchicine is a microtubule depolymerizing agent used extensively in the study of cytoskeleton-dependent cell functions. In studying the possible functional interaction between the GABA(A) receptor and the cytoskeleton, we found that colchicine inhibits GABA(A) receptor function by mechanisms independent of microtubule depolymerization. Human GABA(A) receptor alpha1beta2gamma2L subunits were co-expressed in Xenopus oocytes and the effects of colchicine on GABA(A) receptor function was assessed using the two-electrode voltage-clamp technique. Co-application of GABA (10 microM) with colchicine (100 microM) resulted in a 59.9% inhibition of GABA-gated chloride currents. This effect was instantaneous in onset with no pre-incubation required and reversed within seconds. Other depolymerizing agents, such as nocodazole (20 microM) and vinblastine (200 microM), did not affect GABA(A) receptor function using the same co-application protocol used with colchicine. The polymerizing agent taxol (10-50 microM) did not affect colchicine inhibition of the GABA responses and did not itself alter GABA-gated chloride currents. The inhibitory effect of colchicine was present under conditions in which the oocyte microtubules had been depolymerized by cold temperature. These results indicate that colchicine inhibits the GABA(A) receptor via mechanisms unrelated to microtubule depolymerization. To further examine the inhibitory effect of colchicine on the GABA response, GABA (10-3000 microM) concentration-response curves were performed in the absence or presence of various concentrations of colchicine (30-300 microM). In the presence of colchicine, the GABA concentration-response curve was shifted to the right in a parallel fashion. A Schild plot of this data yielded a linear slope indicating that colchicine acts as a competitive antagonist at the GABA binding site. We conclude that colchicine is a competitive antagonist at the GABA(A) receptor and that studies using colchicine to examine the functional interaction between GABA(A) receptors and microtubules should be interpreted with caution.

Colchicine has been reported to destroy ganglion cells (GCs) in the retina of hatchling chicks. We tested whether colchicine influences normal ocular growth and form-deprivation myopia, and whether it affects cells other than GCs. Colchicine greatly increased axial length, equatorial diameter, eye weight, and myopic refractive error, while reducing corneal curvature. Colchicine caused DNA fragmentation in many GCs and some amacrine cells and photoreceptors, ultimately leading to the destruction of most GCs and particular sub-sets of amacrine cells. Colchicine-induced ocular growth may result from the destruction of amacrine cells that normally suppress ocular growth, and corneal flattening may result from the destruction of GCs whose central pathway normally plays a role in shaping the cornea.

The randomized, placebo-controlled COLCOT (Colchicine Cardiovascular Outcomes Trial) has shown the benefits of colchicine 0.5 mg daily to lower the rate of ischemic cardiovascular events in patients with a recent myocardial infarction. Here, we conducted a post hoc pharmacogenomic study of COLCOT with the aim to identify genetic predictors of the efficacy and safety of treatment with colchicine.

Abdominal aortic aneurysm (AAA) is characterized by at least 1.5-fold enlargement of the infrarenal aorta, a ruptured AAA is life-threatening. Colchicine is a medicine used to treat gout and familial Mediterranean fever, and recently, it was approved to reduce the risk of cardiovascular events in adult patients with established atherosclerotic disease. With an AAA mice model created by treatment with porcine pancreatic elastase (PPE) and β-aminopropionitrile (BAPN), this work was designed to explore whether colchicine could protect against the development of AAA. Here, we showed that colchicine could limit AAA formation, as evidenced by the decreased total aortic weight per body weight, AAA incidence, maximal abdominal aortic diameter and collagen deposition. We also found that colchicine could prevent the phenotypic switching of vascular smooth muscle cells from a contractile to synthetic state during AAA. In addition, it was demonstrated that colchicine was able to reduce vascular inflammation, oxidative stress, cell pyroptosis and immune cells infiltration to the aortic wall in the AAA mice model. Finally, it was proved that the protective action of colchicine against AAA formation was mainly mediated by preventing immune cells infiltration to the aortic wall. In summary, our findings demonstrated that colchicine could protect against the development of experimental AAA, providing a potential therapeutic strategy for AAA intervention in the clinic.

The acute respiratory distress syndrome (ARDS) is characterized by intense dysregulated inflammation leading to acute lung injury (ALI) and respiratory failure. There are no effective pharmacologic therapies for ARDS. Colchicine is a low-cost, widely available drug, effective in the treatment of inflammatory conditions. We studied the effects of colchicine pre-treatment on oleic acid-induced ARDS in rats. Rats were treated with colchicine (1 mg/kg) or placebo for three days prior to intravenous oleic acid-induced ALI (150 mg/kg). Four hours later they were studied and compared to a sham group. Colchicine reduced the area of histological lung injury by 61%, reduced lung edema, and markedly improved oxygenation by increasing PaO2/FiO2 from 66 ± 13 mmHg (mean ± SEM) to 246 ± 45 mmHg compared to 380 ± 18 mmHg in sham animals. Colchicine also reduced PaCO2 and respiratory acidosis. Lung neutrophil recruitment, assessed by myeloperoxidase immunostaining, was greatly increased after injury from 1.16 ± 0.19% to 8.86 ± 0.66% and significantly reduced by colchicine to 5.95 ± 1.13%. Increased lung NETosis was also reduced by therapy. Circulating leukocytosis after ALI was not reduced by colchicine therapy, but neutrophils reactivity and CD4 and CD8 cell surface expression on lymphocyte populations were restored. Colchicine reduces ALI and respiratory failure in experimental ARDS in relation with reduced lung neutrophil recruitment and reduced circulating leukocyte activation. This study supports the clinical development of colchicine for the prevention of ARDS in conditions causing ALI.

Inflammation strongly contributes to atherosclerosis initiation and progression. Consequently, recent clinical trials pharmacologically targeted vascular inflammation to decrease the incidence of atherosclerosis-related complications. Colchicine, a microtubule inhibitor with anti-inflammatory properties, reduced cardiovascular events in patients with recent acute coronary syndrome and chronic coronary disease. However, the biological basis of these observations remains elusive. We sought to explore the mechanism by which colchicine beneficially alters the course of atherosclerosis.

No abstract available

Our previous study demonstrated that colchicine-induced dentate granule cell death is caused by blocking axonal flow and the accumulation of intracellular zinc. Zinc is concentrated in the synaptic vesicles via zinc transporter 3 (ZnT3), which facilitates zinc transport from the cytosol into the synaptic vesicles. The aim of the present study was to identify the role of ZnT3 gene deletion on colchicine-induced dentate granule cell death. The present study used young (3-5 months) mice of the wild-type (WT) or the ZnT3-/- genotype. Colchicine (10 µg/kg) was injected into the hippocampus, and then brain sections were evaluated 12 or 24 h later. Cell death was evaluated by Fluoro-Jade B; oxidative stress was analyzed by 4-hydroxy-2-nonenal; and dendritic damage was detected by microtubule-associated protein 2. Zinc accumulation was detected by N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide (TSQ) staining. Here, we found that ZnT3-/- reduced the number of degenerating cells after colchicine injection. The ZnT3-/--mediated inhibition of cell death was accompanied by suppression of oxidative injury, dendritic damage and zinc accumulation. In addition, ZnT3-/- mice showed more glutathione content than WT mice and inhibited neuronal glutathione depletion by colchicine. These findings suggest that increased neuronal glutathione by ZnT3 gene deletion prevents colchicine-induced dentate granule cell death.