Synthetic Tetraploid of Oncidium crispum Lodd. (Orchidaceae).

In ornamental plants, artificial polyploidization has enabled the creation of new cultivars. Due to their high commercial value in the international flower market and their ornamental characteristics, such as the shape, size, color, and durability of their flower, orchids have received great attention in studies of artificial polyploidization. Here we described the protocol used for polyploid induction in Oncidium crispum, an epiphyte species native of southeastern Brazil, of great ornamental interest and widely sold in flower shops. The species stands out for having inflorescence with large flowers, brown in color with yellow spots. In addition, O. crispum has great potential for use in genetic improvement programs since the species is widely used in interspecific crosses. Closed capsules containing mature O. crispum seeds were subjected to running sterilized water for 10 min and then to a 1.5% sodium hypochlorite solution for 10 min. Small portions of seeds were introduced into 50 mL of water-soluble fertilizer with macro- and micronutrients (B>M) plus 0.7% agar. Explants originating from seeds previously in vitro germinated were submitted to 0.05% and 0.1% of colchicine for 4 days and 8 days. Flow cytometry and chromosome counts confirmed that the protocol successfully produced synthetic polyploid plants.

Gout: A Rapid Review of Presentation, Diagnosis and Management.

Gout is inflammatory arthritis caused by monosodium urate crystal deposition in articular and non-articular structures. Acute gout flares are often monoarticular/polyarticular involving lower extremity joints characteristically involving 1st metatarsophalangeal joint. However, gout flares can also be polyarticular, involving upper extremity joints, especially in patients with multiple comorbidities and contraindications to urate-lowering therapies (ULT). Risk factors exacerbating gout flares include obesity, high alcohol and purine-rich food consumption, and the use of diuretics. Diagnosis requires synovial fluid analysis with direct visualization of monosodium urate crystals. Acute flares are managed with steroids, non-steroidal anti-inflammatory drugs, or colchicine. Long-term management includes lifestyle modifications including a heavy emphasis on weight loss, avoidance of alcohol, purine-rich foods, and diuretics. ULT is indicated in patients with 2 or more gout flares/year, tophi, or radiographic evidence of gouty arthropathy. Although allopurinol is the first-line ULT agent, it does carry a risk of inducing severe cutaneous adverse reactions, especially in patients with chronic kidney disease and patients harboring the HLA-B*5801 allele. Other ULT agents include febuxostat and probenecid. ULT is usually titrated to achieve goal serum uric acid (SUA) levels below 6 mg/dL. However, in patients with tophi, a lower SUA target of less than 5 mg/dL should be implemented for prompt urate crystal dissolution.

Are the metal identity and stoichiometry of metal complexes important for colchicine site binding and inhibition of tubulin polymerization?

Quite recently we discovered that copper(II) complexes with isomeric morpholine-thiosemicarbazone hybrid ligands show good cytotoxicity in cancer cells and that the molecular target responsible for this activity might be tubulin. In order to obtain better lead drug candidates, we opted to exploit the power of coordination chemistry to (i) assemble structures with globular shape to better fit the colchicine pocket and (ii) vary the metal ion. We report the synthesis and full characterization of bis-ligand cobalt(III) and iron(III) complexes with 6-morpholinomethyl-2-formylpyridine 4N-(4-hydroxy-3,5-dimethylphenyl)-3-thiosemicarbazone (HL1), 6-morpholinomethyl-2-acetylpyridine 4N-(4-hydroxy-3,5-dimethylphenyl)-3-thiosemicarbazone (HL2), and 6-morpholinomethyl-2-formylpyridine 4N-phenyl-3-thiosemicarbazone (HL3), and mono-ligand nickel(II), zinc(II) and palladium(II) complexes with HL1, namely [CoIII(HL1)(L1)](NO3)2 (1), [CoIII(HL2)(L2)](NO3)2 (2), [CoIII(HL3)(L3)](NO3)2 (3), [FeIII(L2)2]NO3 (4), [FeIII(HL3)(L3)](NO3)2 (5), [NiII(L1)]Cl (6), [Zn(L1)Cl] (7) and [PdII(HL1)Cl]Cl (8). We discuss the effect of the metal identity and metal complex stoichiometry on in vitro cytotoxicity and antitubulin activity. The high antiproliferative activity of complex 4 correlated well with inhibition of tubulin polymerization. Insights into the mechanism of antiproliferative activity were supported by experimental results and molecular docking calculations.

Colchicine in patients with acute ischaemic stroke or transient ischaemic attack (CHANCE-3): multicentre, double blind, randomised, placebo controlled trial.

OBJECTIVES: To assess the efficacy and safety of colchicine versus placebo on reducing the risk of subsequent stroke after high risk non-cardioembolic ischaemic stroke or transient ischaemic attack within the first three months of symptom onset (CHANCE-3). DESIGN: Multicentre, double blind, randomised, placebo controlled trial. SETTING: 244 hospitals in China between 11 August 2022 and 13 April 2023. PARTICIPANTS: 8343 patients aged 40 years of age or older with a minor-to-moderate ischaemic stroke or transient ischaemic attack and a high sensitivity C-reactive protein ≥2 mg/L were enrolled. INTERVENTIONS: Patients were randomly assigned 1:1 within 24 h of symptom onset to receive colchicine (0.5 mg twice daily on days 1-3, followed by 0.5 mg daily thereafter) or placebo for 90 days. MAIN OUTCOME MEASURES: The primary efficacy outcome was any new stroke within 90 days after randomisation. The primary safety outcome was any serious adverse event during the treatment period. All efficacy and safety analyses were by intention to treat. RESULTS: 4176 patients were assigned to the colchicine group and 4167 were assigned to the placebo group. Stroke occurred within 90 days in 264 patients (6.3%) in the colchicine group and 270 patients (6.5%) in the placebo group (hazard ratio 0.98 (95% confidence interval 0.83 to 1.16); P=0.79). Any serious adverse event was observed in 91 (2.2%) patients in the colchicine group and 88 (2.1%) in the placebo group (P=0.83). CONCLUSIONS: The study did not provide evidence that low-dose colchicine could reduce the risk of subsequent stroke within 90 days as compared with placebo among patients with acute non-cardioembolic minor-to-moderate ischaemic stroke or transient ischaemic attack and a high sensitivity C-reactive protein ≥2 mg/L. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05439356.

Colchicine to reduce coronavirus disease-19-related inflammation and cardiovascular complications in high-risk patients post-acute infection with SARS-COV-2-a study protocol for a randomized controlled trial.

BACKGROUND: There is no known effective pharmacological therapy for long COVID, which is characterized by wide-ranging, multisystemic, fluctuating, or relapsing symptoms in a large proportion of survivors of acute COVID. This randomized controlled trial aims to assess the safety and efficacy of an anti-inflammatory agent colchicine, to reduce symptoms among those at high risk of developing long COVID. METHODS: This multi-centre, parallel arm, 1:1 individual randomized, placebo-controlled, double-blind superiority trial will enrol 350 individuals with persistent post-COVID symptoms. Participants will be randomized to either colchicine 0.5 mg once daily (< 70 kg) or twice daily (≥ 70 kg) or matched placebo for 26 weeks and will be followed up until 52 weeks after randomization. The primary trial objective is to demonstrate the superiority of colchicine over a placebo in improving distance walked in 6 min at 52 weeks from baseline. The secondary objectives are to assess the efficacy of colchicine compared to placebo with respect to lung function, inflammatory markers, constitutional symptoms, and mental health state. In a sub-sample of 100 participants, cardiac biomarkers of myocardial injury and myocardial oedema using MRI will be compared. DISCUSSION: Persistent inflammatory response following SARS-CoV-19 is one of the postulated pathophysiological mechanisms of long COVID. Colchicine, a low-cost anti-inflammatory agent, acts via multiple inflammatory pathways and has an established safety profile. This trial will generate evidence for an important health priority that can rapidly translate into practice. TRIAL REGISTRATION: This clinical trial has been registered prospectively on www. CLINICALTRIALS: gov with registration CTRI/2021/11/038234 dated November 24, 2021.

Dual-target inhibitors of colchicine binding site for cancer treatment.

Colchicine binding site inhibitors (CBSIs) have attracted much attention due to their antitumor efficacies and the advantages of inhibiting angiogenesis and overcoming multidrug resistance. However, no CBSI has been currently approved for cancer treatment due to the insufficient efficacies, serious toxicities and poor pharmacokinetic properties. Design of dual-target inhibitors is becoming a potential strategy for cancer treatment to improve anticancer efficacy, decrease adverse events and overcome drug resistance. Therefore, we reviewed dual-target inhibitors of colchicine binding site (CBS), summarized the design strategies and the biological activities of these dual-target inhibitors, expecting to provide inspiration for developing novel dual inhibitors based on CBS.

The alleviatory effects of koumine on MSU-induced gouty arthritis via the TLR4/NF-κB/NLRP3 pathway.

The aim of this study was to validate the preventive effects of koumine (KM), a monoterpene indole alkaloid, on gouty arthritis (GA) and to explore its possible mechanisms. C57BL/6 mice were intraperitoneally administered KM (0.8, 2.4 or 7.2 mg/kg), colchicine (3.0 mg/kg) or sterile saline. One hour later, a monosodium urate (MSU) suspension was injected into the right hind paws of the mice to establish an acute gout model. Inflammation symptoms were evaluated at 0, 3, 6, 12 and 24 h, and the mechanical withdrawal threshold was evaluated at 0, 6 and 24 h. After 24 h, the mice were euthanized, and the joint tissue, kidney and blood were collected for subsequent experiments. Histological examination and antioxidant enzyme, kidney index and serum uric acid (UA) measurements were taken. The expression levels of the signalling pathway components were determined. KM effectively alleviated the symptoms of redness, swelling and pain; counteracted inflammatory cell infiltration; and increased antioxidant enzyme levels, reduced kidney index and serum UA levels through regulating UA excretion in MSU-induced mice. The expression of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB)/nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) signalling pathway proteins and mRNA were reduced in the KM group. These results suggest that KM may be effective in alleviating GA through the TLR4/NF-κB/NLRP3 pathway.

Long-term colchicine for the prevention of vascular recurrent events in non-cardioembolic stroke (CONVINCE): a randomised controlled trial.

BACKGROUND: Anti-inflammatory therapy with long-term colchicine prevented vascular recurrence in coronary disease. Unlike coronary disease, which is typically caused by atherosclerosis, ischaemic stroke is caused by diverse mechanisms including atherosclerosis and small vessel disease or is frequently due to an unknown cause. We aimed to investigate the hypothesis that long-term colchicine would reduce recurrent events after ischaemic stroke. METHODS: We did a randomised, parallel-group, open-label, blinded endpoint assessed trial comparing long-term colchicine (0·5 mg orally per day) plus guideline-based usual care with usual care only. Hospital-based patients with non-severe, non-cardioembolic ischaemic stroke or high-risk transient ischaemic attack were eligible. The primary endpoint was a composite of first fatal or non-fatal recurrent ischaemic stroke, myocardial infarction, cardiac arrest, or hospitalisation (defined as an admission to an inpatient unit or a visit to an emergency department that resulted in at least a 24 h stay [or a change in calendar date if the hospital admission or discharge times were not available]) for unstable angina. The p value for significance was 0·048 to adjust for two prespecified interim analyses conducted by the data monitoring committee, for which the steering committee and trial investigators remained blinded. The trial was registered at ClinicalTrials.gov (NCT02898610) and is completed. FINDINGS: 3154 patients were randomly assigned between Dec 19, 2016, and Nov 21, 2022, with the last follow-up on Jan 31, 2024. The trial finished before the anticipated number of outcomes was accrued (367 outcomes planned) due to budget constraints attributable to the COVID-19 pandemic. Ten patients withdrew consent for analysis of their data, leaving 3144 patients in the intention-to-treat analysis: 1569 (colchicine and usual care) and 1575 (usual care alone). A primary endpoint occurred in 338 patients, 153 (9·8%) of 1569 patients allocated to colchicine and usual care and 185 (11·7%) of 1575 patients allocated to usual care alone (incidence rates 3·32 vs 3·92 per 100 person-years, hazard ratio 0·84; 95% CI 0·68-1·05, p=0·12). Although no between-group difference in C-reactive protein (CRP) was observed at baseline, patients treated with colchicine had lower CRP at 28 days and at 1, 2, and 3 years (p<0·05 for all timepoints). The rates of serious adverse events were similar in both groups. INTERPRETATION: Although no statistically significant benefit was observed on the primary intention-to-treat analysis, the findings provide new evidence supporting the rationale for anti-inflammatory therapy in further randomised trials. FUNDING: Health Research Board Ireland, Deutsche Forschungsgemeinschaft (German Research Foundation), and Fonds Wetenschappelijk Onderzoek Vlaanderen (Research Foundation Flanders), Belgium.

The cytotoxic natural compound erianin binds to colchicine site of ß-tubulin and overcomes taxane resistance.

Erianin, a natural compound derived from Dendrobium, has shown significant anticancer properties against a wide range of cancer cells. Despite the identification of multiple mechanisms of action for erianin, none of these mechanisms fully account for its broad-spectrum effect. In this study, we aimed to identify the cellular target and underlying mechanism responsible for the broad-spectrum antitumor effects of erianin. We found that erianin effectively inhibited tubulin polymerization in cancer cells and purified tubulin. Through competition binding assays and X-ray crystallography, it was revealed that erianin bound to the colchicine site of ß-tubulin. Importantly, the X-ray crystal structure of the tubulin-erianin complex was solved, providing clear insight into the orientation and position of erianin in the colchicine-binding site. Erianin showed activity against paclitaxel-resistant cells, evidenced by G2/M cell cycle arrest, apoptosis-related PARP and Caspase-3 cleavage, and in vivo xenograft studies. The study concluded that erianin bound reversibly to the colchicine site of ß-tubulin, inhibited tubulin polymerization, and displayed anticancer activity against paclitaxel-resistant cells, offering valuable insights for further exploration as potential anticancer agents.

Discovery of colchicine aryne cycloadduct as a potent molecule for the abrogation of epithelial to mesenchymal transition via modulating cell cycle regulatory CDK-2 and CDK-4 kinases in breast cancer cells.

In this study, we synthesized a new-generation library of colchicine derivatives via cycloaddition of colchicine utilizing position C-8 and C-12 diene system regioselectivity with aryne precursor to generate a small, focused library of derivatives. We assessed their anticancer activity against various cancer cell lines like MCF-7, MDA-MB-231, MDA-MB-453, and PC-3. Normal human embryonic kidney cell line HEK-293 was used to determine the toxicity. Among these derivatives, silicon-tethered compound B-4a demonstrated the highest potency against breast cancer cells. Subsequent mechanistic studies revealed that B-4a effectively modulates cell cycle regulatory kinases (CDK-2 and CDK-4) and their associated cyclins (cyclin-B1, cyclin-D1), inducing apoptosis. Additionally, B-4a displayed a noteworthy impact on tubulin polymerization, compared to positive control flavopiridol hydrochloride in a dose-dependent manner, and significantly disrupted the vimentin cytoskeleton, contributing to G1 arrest in breast cancer cells. Moreover, B-4a exhibited substantial anti-metastatic properties by inhibiting breast cancer cell migration and invasion. These effects are attributed to the down-regulation of major epithelial to mesenchymal transition (EMT) factors, including vimentin and Twist-1, and the upregulation of the epithelial marker E-cadherin in an apoptosis-dependent manner.

Low-Dose Colchicine Ameliorates Doxorubicin Cardiotoxicity Via Promoting Autolysosome Degradation.

BACKGROUND: The only clinically approved drug that reduces doxorubicin cardiotoxicity is dexrazoxane, but its application is limited due to the risk of secondary malignancies. So, exploring alternative effective molecules to attenuate its cardiotoxicity is crucial. Colchicine is a safe and well-tolerated drug that helps reduce the production of reactive oxygen species. High doses of colchicine have been reported to block the fusion of autophagosomes and lysosomes in cancer cells. However, the impact of colchicine on the autophagy activity within cardiomyocytes remains inadequately elucidated. Recent studies have highlighted the beneficial effects of colchicine on patients with pericarditis, postprocedural atrial fibrillation, and coronary artery disease. It remains ambiguous how colchicine regulates autophagic flux in doxorubicin-induced heart failure. METHODS AND RESULTS: Doxorubicin was administered to establish models of heart failure both in vivo and in vitro. Prior studies have reported that doxorubicin impeded the breakdown of autophagic vacuoles, resulting in damaged mitochondria and the accumulation of reactive oxygen species. Following the administration of a low dose of colchicine (0.1 mg/kg, daily), significant improvements were observed in heart function (left ventricular ejection fraction: doxorubicin group versus treatment group=43.75%±3.614% versus 57.07%±2.968%, P=0.0373). In terms of mechanism, a low dose of colchicine facilitated the degradation of autolysosomes, thereby mitigating doxorubicin-induced cardiotoxicity. CONCLUSIONS: Our research has shown that a low dose of colchicine is pivotal in restoring the autophagy activity, thereby attenuating the cardiotoxicity induced by doxorubicin. Consequently, colchicine emerges as a promising therapeutic candidate to improve doxorubicin cardiotoxicity.

In patients with type 2 diabetes and recent MI, colchicine reduced a composite CV outcome at 23 mo.

SOURCE CITATION: Roubille F, Bouabdallaoui N, Kouz S, et al. Low-dose colchicine in patients with type 2 diabetes and recent myocardial infarction in the COLchicine Cardiovascular Outcomes Trial (COLCOT). Diabetes Care. 2024;47:467-470. 38181203.

Acute Pericarditis: Rapid Evidence Review.

Acute pericarditis is defined as inflammation of the pericardium and occurs in approximately 4.4% of patients who present to the emergency department for nonischemic chest pain, with a higher prevalence in men. Although there are numerous etiologies of pericarditis, most episodes are idiopathic and the cause is presumed to be viral. Diagnosis of pericarditis requires at least two of the following criteria: new or worsening pericardial effusion, characteristic pleuritic chest pain, pericardial friction rub, or electrocardiographic changes, including new, widespread ST elevations or PR depressions. Pericardial friction rubs are highly specific but transient, and they have been reported in 18% to 84% of patients with acute pericarditis. Classic electrocardiographic findings include PR-segment depressions; diffuse, concave, upward ST-segment elevations without reciprocal changes; and T-wave inversions. Transthoracic echocardiography should be performed in all patients with acute pericarditis to characterize the size of effusions and evaluate for complications. Nonsteroidal anti-inflammatory drugs are the first-line treatment option. Glucocorticoids should be reserved for patients with contraindications to first-line therapy and those who are pregnant beyond 20 weeks' gestation or have other systemic inflammatory conditions. Colchicine should be used in combination with first- or second-line treatments to reduce the risk of recurrence. Patients with a higher risk of complications should be admitted to the hospital for further workup and treatment.

In vitro induction of tetraploids and their phenotypic and transcriptome analysis in Glehnia littoralis.

BACKGROUND: Glehnia littoralis is a medicinal and edible plant species having commercial value and has several hundred years of cultivation history. Polyploid breeding is one of the most important and fastest ways to generate novel varieties. To obtain tetraploids of G. littoralis in vitro, colchicine treatment was given to the seeds and then were screened based on morphology, flow cytometry, and root tip pressing assays. Furthermore, transcriptome analysis was performed to identity the differentially expressed genes associated with phenotypic changes in tetraploid G. littoralis. RESULTS: The results showed that 0.05% (w/v) colchicine treatment for 48 h was effective in inducing tetraploids in G. littoralis. The tetraploid G. littoralis (2n = 4x = 44) was superior in leaf area, leaf thickness, petiole diameter, SPAD value (Chl SPAD), stomatal size, epidermal tissues thickness, palisade tissues thickness, and spongy tissues thickness to the diploid ones, while the stomatal density of tetraploids was significantly lower. Transcriptome sequencing revealed, a total of 1336 differentially expressed genes (DEGs) between tetraploids and diploids. Chromosome doubling may lead to DNA content change and gene dosage effect, which directly affects changes in quantitative traits, with changes such as increased chlorophyll content, larger stomata and thicker tissue of leaves. Several up-regulated DEGs were found related to growth and development in tetraploid G. littoralis such as CKI, PPDK, hisD and MDP1. KEGG pathway enrichment analyses showed that most of DEGs were enriched in metabolic pathways. CONCLUSIONS: This is the first report of the successful induction of tetraploids in G. littoralis. The information presented in this study facilitate breeding programs and molecular breeding of G. littoralis varieties.