Effects of Colchicine in a Rat Model of Diet-Induced Hyperlipidemia

A toxicological review of alkaloids

Alkaloids are naturally occurring compounds with complex structures found in natural plants. To further improve the understanding of plant alkaloids, this review focuses on the classification, toxicity and mechanisms of action, providing insight into the occurrence of alkaloid-poisoning events and guiding the safe use of alkaloids in food, supplements and clinical applications. Based on their chemical structure, alkaloids can be divided into organic amines, diterpenoids, pyridines, isoquinolines, indoles, pyrrolidines, steroids, imidazoles and purines. The mechanisms of toxicity of alkaloids, including neurotoxicity, hepatoxicity, nephrotoxicity, cardiotoxicity and cytotoxicity, have also been reviewed. Some cases of alkaloid poisoning have been introduced when used as food or clinically, including accidental food poisoning, excessive consumption, and poisoning caused by the improper use of alkaloids in a clinical setting, and the importance of safety evaluation was illustrated. This review summarizes the toxicity and mechanism of action of alkaloids and provides evidence for the need for the safe use of alkaloids in food, supplements and clinical applications.

Colchicine Protects against Ethanol-Induced Senescence and Senescence-Associated Secretory Phenotype in Endothelial Cells

Inflammaging is a potential risk factor for cardiovascular diseases. It results in the development of thrombosis and atherosclerosis. The accumulation of senescent cells in vessels causes vascular inflammaging and contributes to plaque formation and rupture. In addition to being an acquired risk factor for cardiovascular diseases, ethanol can induce inflammation and senescence, both of which have been implicated in cardiovascular diseases. In the current study, we used colchicine to abate the cellular damaging effects of ethanol on endothelial cells. Colchicine prevented senescence and averted oxidative stress in endothelial cells exposed to ethanol. It lowered the relative protein expression of aging and senescence marker P21 and restored expression of the DNA repair proteins KU70/KU80. Colchicine inhibited the activation of nuclear factor kappa B (NFκ-B) and mitogen activated protein kinases (MAPKs) in ethanol-treated endothelial cells. It reduced ethanol-induced senescence-associated secretory phenotype. In summary, we show that colchicine ameliorated the ethanol-caused molecular events, resulting in attenuated senescence and senescence-associated secretory phenotype in endothelial cells.

Targeting the reduction of inflammatory risk associated with cardiovascular disease by treating periodontitis either alone or in combination with a systemic anti-inflammatory agent: protocol for a pilot, parallel group, randomised controlled trial

INTRODUCTION

Cardiovascular disease (CVD) is associated with systemic inflammation. Colchicine, an anti-inflammatory drug, reduces the incidence of CVD events. Periodontitis, a chronic localised inflammatory disease of the tissues supporting the teeth, triggers systemic inflammation and contributes to inflammatory risk. Treatment for periodontitis reduces markers of inflammation, however, there is no evidence on whether an anti-inflammatory medication in combination with periodontal treatment can reduce the inflammatory risk. The aim of this trial is to investigate the effect of periodontal treatment either alone or in combination with an anti-inflammatory agent on inflammation in patients with periodontitis and CVD at 8 weeks.

METHODS AND ANALYSIS

60 participants with moderate-to-severe periodontitis, coronary artery disease and an increased inflammatory risk (>2 mg/L high sensitivity C reactive protein (hsCRP) levels) will be recruited from a tertiary referral hospital in Australia in a parallel design, single blind, randomised controlled trial. Baseline hsCRP levels, lipid profile and periodontal assessment will be completed for each participant before they are randomised in a 1:1:1:1 ratio to one of 4 arms as follows: (group A) periodontal treatment and colchicine; (group B) periodontal treatment only; (group C) colchicine only or (group D) control/delayed periodontal treatment. Periodontal treatment will be provided over three treatment visits, 0.5 mg of colchicine will be provided as a daily tablet. Participants will be followed up at 8 weeks to measure primary and secondary outcomes and complete a follow-up questionnaire. The primary outcome is the difference in hsCRP levels, the secondary outcomes are differences in lipid levels and periodontal parameters and the feasibility measures of recruitment conversion rate, completion rate and the safety and tolerability of the trial.

ETHICS AND DISSEMINATION

The study has been approved by the Western Sydney Local Health District Human Ethics Committee (protocol number 2019/ETH00200). Results will be published in peer-reviewed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

ACTRN12619001573145.

Amino Acid Conjugates of 2-Mercaptobenzimidazole Ameliorates High-Fat Diet-Induced Hyperlipidemia in Rats via Attenuation of HMGCR, APOB, and PCSK9

PURPOSE

This study was designed to explore the antihyperlipidemic effects of amino acid derivatives of 2-mercaptobenzimidazole (4J and 4K) in high-fat diet (HFD)-fed rats.

METHODS

Male Sprague-Dawley rats were divided into nine groups which received either standard diet or HFD for 28 days. Blood samples were taken on 27th day from HFD-fed rats to ensure hyperlipidemia. HFD-induced hyperlipidemic rats later received daily dosing of either vehicle or simvastatin (SIM; 20 mg/kg) or 4J/4K compounds (10, 20, and 30 mg/kg) for 12 consecutive days. On 40th day, animals were sacrificed, and blood samples were collected for the determination of serum lipid profile and liver function parameters. Liver samples were harvested for histopathological, antioxidant, and qPCR analyses. Molecular docking of tested compounds with HMGCR was also performed to assess the binding affinities.

RESULTS

4J and 4K dose dependently decreased serum total cholesterol, triglycerides, low-density lipoprotein, very low-density lipoproteins, alanine transaminase (ALT), and aspartate aminotransferase (AST) levels while significantly alleviated high-density lipoproteins. However, SIM failed to reduce AST and ALT levels. Moreover, tested compounds displayed antioxidant effects by inducing superoxide dismutase and glutathione levels. Histopathology data also displayed protective effects of 4J and 4K against HFD-induced fatty changes and hepatic damage. In addition, 4J and 4K downregulated transcript levels of HMGCR, APOB, PCSK9, and VCAM1, and molecular docking analysis also supported the experimental data.

CONCLUSION

It is conceivable from this study that 4J and 4K exert their antihyperlipidemic effects by modulating multiple targets regulating lipid levels.

Histological, ultrastructural and immunohistochemical studies on the ameliorative role of Cinnamon zeylanicum against high cholesterol diet-induced hypercholesterolemia in the kidney of adult male albino rats

Cholesterol is an important type of lipid as it is involved in the structure of cell membrane, synthesis of steroid hormones, bile acid and vitamin D. Many diseases affect various mammalian organs, including the kidney, as a result of high cholesterol levels (hypercholesterolemia). Cinnamon zeylanicum (C. zeylanicum) proves its efficiency as it has anti-inflammatory and antioxidant prosperities. This study aimed to investigate the possible ameliorative role of C. zeylanicum on hypercholesterolemia-induced the renal toxicity in albino rats. Forty adult male albino rats were equally divided into four groups. The first group served as the control one. The second group was supplemented with C. zeylanicum powder (15% w/w) with the standard diet. The third group was fed high cholesterol diet (HCD) to induce acute hypercholesterolemia. The fourth group was fed HCD provided with C. zeylanicum powder (15% w/w). At the end of the experiment (8^th weeks), kidneys were removed and prepared for histological, immunohistochemical and ultrastructure studies. Rats-fed HCD showed degenerated glomeruli and tubular cells with vacuolated or coagulated cytoplasm and pyknotic nuclei. Moreover, the renal cortex ultrastructural examination showed degenerated podocytes, parietal and mesangial cells, as well as the proximal and distal tubular cells appeared with rarified cytoplasm, degenerated mitochondria, large fat vacuoles and complete damaged microvilli. The same group showed a significant increase in the expression of desmin and inducible nitric oxide synthase. On the other hand, animals fed HCD provided with C. zeylanicum showed an obvious improvement in the observed histological, ultrastructural and immunohistochemical changes. The architecture of the renal cortex appeared mostly similar to the control one. This study concluded that C. zeylanicum has a promising role in treating the nephron-toxicity of HCD due to its natural constituent that is responsible for its pharmaceutical effects.

Association between Clinical Use of Colchicine and Risk of Type 2 Diabetes Mellitus among Gouty Patients: A Nationwide Cohort Study

Background: Gout is the most common form of inflammatory arthritis in adults. Even though a link between gouty arthritis and type 2 diabetes mellitus (T2DM) has been reported, there is a limited understanding of the association between the anti-inflammatory agent colchicine and the risk of T2DM. This aim of this study was to assess the association between the use of colchicine and the risk of T2DM in an Asian cohort. Methods: A retrospective cohort study was conducted using the National Health Insurance Research Database (NHIRD) in Taiwan from 2000 to 2013. The study cohorts comprised 3841 gouty patients using colchicine (the exposed cohort) and 7682 gouty patients not using colchicine (the unexposed -cohort). The primary outcome was incident DM. The hazard ratios (HRs) and 95% confidence intervals (CIs) derived from a Cox proportional regression model were used to assess the association between colchicine use and the risk of diabetes. Results: The cumulative incidence of T2DM was significantly lower in the exposed cohort (18.8%) than in the unexposed cohort (25.0%). The risk of T2DM was significantly lower in colchicine users than in non-users (adjusted HR, 0.74; 95% CI, 0.36–0.87). The inverse relationship between colchicine use and diabetes risk remained consistent across sex and age groups. Conclusions: This cohort study provides longitudinal evidence that the use of colchicine is associated with a reduced risk of T2DM. This conclusion, however, needs to be interpreted cautiously given the lack of body mass index data in the NHIRD. Further studies are needed to determine the clinical implications of this study.