Effects of echinochrome on ventricular repolarization in acute ischemia

Multi-omic analysis reveals genes and proteins integral to bioactivity of Echinochrome A isolated from the waste stream of the sea urchin industry in Aotearoa New Zealand

Evechinus chloroticus (commonly known as kina) is a sea urchin species endemic to New Zealand. Its roe is a culinary delicacy to the indigenous Māori and a globally exported food product. Echinochrome A (Ech A) is a bioactive compound isolated from the waste product of kina shells and spines; however, the molecular mechanisms of Ech A bioactivity are not well understood, partly due to Ech A never being studied using unbiased genome-wide analysis. To explore the high-value pharmaceutical potential of kina food waste, we obtained unbiased functional genomic and proteomic profiles of yeast cells treated with Echinochrome A. Abundance was measured for 4100 proteins every 30 min for four hours using fluorescent microscopy, resulting in the identification of 92 proteins with significant alterations in protein abundance caused by Ech A treatment that were over-represented with specific changes in DNA replication, repair and RNA binding after 30 min, followed by specific changes in the metabolism of metal ions (specifically iron and copper) from 60-240 min. Further analysis indicated that Ech A chelated iron, and that iron supplementation negated the growth inhibition caused by Ech A. Via a growth-based genome-wide analysis of 4800 gene deletion strains, 20 gene deletion strains were sensitive to Ech A in an iron-dependent manner. These genes were over-represented in the cellular response to oxidative stress, suggesting that Ech A suppressed growth inhibition caused by oxidative stress. Unexpectedly, genes integral to cardiolipin and inositol phosphate biosynthesis were required for Ech A bioactivity. Overall, these results identify genes, proteins, and cellular processes mediating the bioactivity of Ech A. Moreover, we demonstrate unbiased genomic and proteomic methodology that will be useful for characterizing bioactive compounds in food and food waste.

Immunomodulatory Compounds from the Sea: From the Origins to a Modern Marine Pharmacopoeia

From sea shores to the abysses of the deep ocean, marine ecosystems have provided humanity with valuable medicinal resources. The use of marine organisms is discussed in ancient pharmacopoeias of different times and geographic regions and is still deeply rooted in traditional medicine. Thanks to present-day, large-scale bioprospecting and rigorous screening for bioactive metabolites, the ocean is coming back as an untapped resource of natural compounds with therapeutic potential. This renewed interest in marine drugs is propelled by a burgeoning research field investigating the molecular mechanisms by which newly identified compounds intervene in the pathophysiology of human diseases. Of great clinical relevance are molecules endowed with anti-inflammatory and immunomodulatory properties with emerging applications in the management of chronic inflammatory disorders, autoimmune diseases, and cancer. Here, we review the historical development of marine pharmacology in the Eastern and Western worlds and describe the status of marine drug discovery. Finally, we discuss the importance of conducting sustainable exploitation of marine resources through biotechnology.

Marine Natural Products from the Russian Pacific as Sources of Drugs for Neurodegenerative Diseases

Neurodegenerative diseases are growing to become one of humanity's biggest health problems, given the number of individuals affected by them. They cause enough mortalities and severe economic impact to rival cancers and infections. With the current diversity of pathophysiological mechanisms involved in neurodegenerative diseases, on the one hand, and scarcity of efficient prevention and treatment strategies, on the other, all possible sources for novel drug discovery must be employed. Marine pharmacology represents a relatively uncharted territory to seek promising compounds, despite the enormous chemodiversity it offers. The current work discusses one vast marine region-the Northwestern or Russian Pacific-as the treasure chest for marine-based drug discovery targeting neurodegenerative diseases. We overview the natural products of neurological properties already discovered from its waters and survey the existing molecular and cellular targets for pharmacological modulation of the disease. We further provide a general assessment of the drug discovery potential of the Russian Pacific in case of its systematic development to tackle neurodegenerative diseases.

Multifaceted Clinical Effects of Echinochrome

The marine drug histochrome is a special natural antioxidant. The active substance of the drug is echinochrome A (Ech A, 7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone), the most abundant quinonoid pigment in sea urchins. The medicine is clinically used in cardiology and ophthalmology based on the unique properties of Ech A, which simultaneously block various links of free radical reactions. In the last decade, numerous studies have demonstrated the effectiveness of histochrome in various disease models without adverse effects. Here, we review the data on the various clinical effects and modes of action of Ech A in ophthalmic, cardiovascular, cerebrovascular, inflammatory, metabolic, and malignant diseases.

Echinochrome A Treatment Alleviates Fibrosis and Inflammation in Bleomycin-Induced Scleroderma

Scleroderma is an autoimmune disease caused by the abnormal regulation of extracellular matrix synthesis and is activated by non-regulated inflammatory cells and cytokines. Echinochrome A (EchA), a natural pigment isolated from sea urchins, has been demonstrated to have antioxidant activities and beneficial effects in various disease models. The present study demonstrates for the first time that EchA treatment alleviates bleomycin-induced scleroderma by normalizing dermal thickness and suppressing collagen deposition in vivo. EchA treatment reduces the number of activated myofibroblasts expressing α-SMA, vimentin, and phosphorylated Smad3 in bleomycin-induced scleroderma. In addition, it decreased the number of macrophages, including M1 and M2 types in the affected skin, suggesting the induction of an anti-inflammatory effect. Furthermore, EchA treatment markedly attenuated serum levels of inflammatory cytokines, such as tumor necrosis factor-α and interferon-γ, in a murine scleroderma model. Taken together, these results suggest that EchA is highly useful for the treatment of scleroderma, exerting anti-fibrosis and anti-inflammatory effects.

Association Between Antiarrhythmic, Electrophysiological, and Antioxidative Effects of Melatonin in Ischemia/Reperfusion

Melatonin is assumed to confer cardioprotective action via antioxidative properties. We evaluated the association between ventricular tachycardia and/or ventricular fibrillation (VT/VF) incidence, oxidative stress, and myocardial electrophysiological parameters in experimental ischemia/reperfusion under melatonin treatment. Melatonin was given to 28 rats (10 mg/kg/day, orally, for 7 days) and 13 animals received placebo. In the anesthetized animals, coronary occlusion was induced for 5 min followed by reperfusion with recording of unipolar electrograms from ventricular epicardium with a 64-lead array. Effects of melatonin on transmembrane potentials were studied in ventricular preparations of 7 rats in normal and “ischemic” conditions. Melatonin treatment was associated with lower VT/VF incidence at reperfusion, shorter baseline activation times (ATs), and activation-repolarization intervals and more complete recovery of repolarization times (RTs) at reperfusion (less baseline-reperfusion difference, ΔRT) (p < 0.05). Superoxide dismutase (SOD) activity was higher in the treated animals and associated with ΔRT (p = 0.001), whereas VT/VF incidence was associated with baseline ATs (p = 0.020). In vitro, melatonin led to a more complete restoration of action potential durations and resting membrane potentials at reoxygenation (p < 0.05). Thus, the antioxidative properties of melatonin were associated with its influence on repolarization duration, whereas the melatonin-related antiarrhythmic effect was associated with its oxidative stress-independent action on ventricular activation.

Animal-derived medicinal products in Russia: Current nomenclature and specific aspects of quality control

ETHNOPHARMACOLOGICAL RELEVANCE

Animal-derived medicinal products (ADMP) had been extensively used in Russia and became a part of officinal medicine in 1778.

AIM OF THE STUDY

The aim of the current review was to analyse the ADMPs authorised in the Russian Federation and to identify specific aspects of quality evaluation of these medicinal products.

MATERIALS AND METHODS

Information of ADMPs was extracted from the online State Register of Medicinal Products of the Russian Federation. At the next stage, we systematically searched library catalogues, E-library.ru, Medline/PubMed, Scopus, Web of Science and Google Scholar databases to find data related to ADMP quality evaluation, clinically proven efficacy and safety.

RESULTS

For classification of ADMP, we propose an approach based on the raw material used: ADMPs derived from marine organisms, ADMPs from cattle and pigs and ADMPs from other terrestrial animals. The majority of ADMPs authorised in Russia are produced by local manufacturers. ADMPs are available in dosage forms of solution for parenteral administration (35% of all products) and lyophilisates for parenteral use (19%), tablets and capsules (17% and 11%, respectively), ointments (5%) and powders (3%). ADMPs belong to the following pharmacotherapeutic groups: medicines for tissue regeneration and repair stimulators (30%), digestive enzyme products (22%), anticoagulants (17%), proteolytic agents (6%) and medicines for the treatment of chronic prostatitis (5%). The most important approaches to standardisation of ADMPs are implementation of modern requirements for registration dossiers, development of risk-oriented approaches for evaluation of impurities, elaboration of advanced instrumental and in vitro test methods capable of replacing in vivo methods and harmonisation of the potency units used for standardisation.

CONCLUSIONS

The key features of ADMPs that help them retain their leading position in the pharmaceutical market are as follows: (i) their unique composition usually represented by a complex of biologically active substances; (ii) a high degree of affinity of the active ingredient of an ADMP to the human body and (iii) proved safety and clinical efficiency. Variability in the quality of raw ingredients, epidemiological situation and other conditions pose additional challenges for the development of ADMPs and for the standardisation.

Therapeutic Cell Protective Role of Histochrome under Oxidative Stress in Human Cardiac Progenitor Cells

Cardiac progenitor cells (CPCs) are resident stem cells present in a small portion of ischemic hearts and function in repairing the damaged heart tissue. Intense oxidative stress impairs cell metabolism thereby decreasing cell viability. Protecting CPCs from undergoing cellular apoptosis during oxidative stress is crucial in optimizing CPC-based therapy. Histochrome (sodium salt of echinochrome A—a common sea urchin pigment) is an antioxidant drug that has been clinically used as a pharmacologic agent for ischemia/reperfusion injury in Russia. However, the mechanistic effect of histochrome on CPCs has never been reported. We investigated the protective effect of histochrome pretreatment on human CPCs (hCPCs) against hydrogen peroxide (H₂O₂)-induced oxidative stress. Annexin V/7-aminoactinomycin D (7-AAD) assay revealed that histochrome-treated CPCs showed significant protective effects against H₂O₂-induced cell death. The anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and Bcl-xL were significantly upregulated, whereas the pro-apoptotic proteins BCL2-associated X (Bax), H₂O₂-induced cleaved caspase-3, and the DNA damage marker, phosphorylated histone (γH2A.X) foci, were significantly downregulated upon histochrome treatment of hCPCs in vitro. Further, prolonged incubation with histochrome alleviated the replicative cellular senescence of hCPCs. In conclusion, we report the protective effect of histochrome against oxidative stress and present the use of a potent and bio-safe cell priming agent as a potential therapeutic strategy in patient-derived hCPCs to treat heart disease.

Effect of Water-Soluble Echinochrome Analog on Arrhythmia Severity in Experimental Model of Acute Myocardial Ischemia

The effects of therapeutic or preventive-therapeutic administration of water-soluble echinochrome analog U-441 on arrhythmia severity assessed by a set of myocardial spatio-temporal depolarization and repolarization parameters were examined on the model of acute myocardial ischemia in cats. Coronary occlusion increased activation time and decreased repolarization time in the ischemic zone; in addition, it increased both global and borderline (local) dispersions of repolarization. The linear regression model showed that only activation time values measured at the initial state and at termination of occlusion were associated with total arrhythmia score during ischemia (regression coefficient β=0.338, 95%CI=0.074-0.602, p=0.015 and β=0.720, 95%CI=0.323-1.117, p=0.001, respectively). The study revealed no association between administration of echinochrome analog U-441 and arrhythmia severity.

Mechanism of electrocardiographic T-wave flattening in diabetes mellitus: experimental and simulation study

In the present study we investigated the contribution of ventricular repolarization time (RT) dispersion (the maximal difference in RT) and RT gradients (the differences in RT in apicobasal, anteroposterior and interventricular directions) to T-wave flattening in a setting of experimental diabetes mellitus. In 9 healthy and 11 diabetic (alloxan model) open-chest rabbits, we measured RT in ventricular epicardial electrograms. To specify the contributions of apicobasal, interventricular and anteroposterior RT gradients and RT dispersion to the body surface potentials we determined T-wave voltage differences between modified upper- and lower-chest precordial leads (T-wave amplitude dispersions, TWAD). Expression of RT gradients and RT dispersion in the correspondent TWAD parameters was studied by computer simulations. Diabetic rabbits demonstrated flattened T-waves in precordial leads associated with increased anteroposterior and decreased apicobasal RT gradients (P<0.05) due to RT prolongation at the apex. For diabetics, simulations predicted the preserved T-vector length and altered sagittal and longitudinal TWAD proven by experimental measurements. T-wave flattening in the diabetic rabbits was not due to changes in RT dispersion, but reflected the redistributed ventricular repolarization pattern with prolonged apical repolarization resulting in increased anteroposterior and decreased apicobasal RT gradients.