Natriuretic peptide based therapeutics for heart failure: Cenderitide: A novel first-in-class designer natriuretic peptide

C-type natriuretic peptide (CNP): The cardiovascular system and beyond

C-type natriuretic peptide (CNP) represents the 'local' member of the natriuretic peptide family, functioning in an autocrine or paracrine capacity to modulate a hugely diverse portfolio of physiological processes. Whilst the best-characterised of these regulatory roles are in the cardiovascular system, akin to its predominantly endocrine siblings atrial (ANP) and brain (BNP) natriuretic peptides, CNP governs many additional, unrelated mechanisms including bone growth, gamete maturation, auditory processing, and neuronal integrity. Furthermore, there is currently great interest in mimicking the biological activity of CNP for therapeutic gain in many of these disparate organ systems. Herein, we provide an overview of the physiology, pathophysiology and pharmacology of CNP in both cardiovascular and non-cardiovascular settings.

Pharmacological potential of cyclic nucleotide signaling in immunity

Cyclic nucleotides are important signaling molecules that play many critical physiological roles including controlling cell fate and development, regulation of metabolic processes, and responding to changes in the environment. Cyclic nucleotides are also pivotal regulators in immune signaling, orchestrating intricate processes that maintain homeostasis and defend against pathogenic threats. This review provides a comprehensive examination of the pharmacological potential of cyclic nucleotide signaling pathways within the realm of immunity. Beginning with an overview of the fundamental roles of cAMP and cGMP as ubiquitous second messengers, this review delves into the complexities of their involvement in immune responses. Special attention is given to the challenges associated with modulating these signaling pathways for therapeutic purposes, emphasizing the necessity for achieving cell-type specificity to avert unintended consequences. A major focus of the review is on the recent paradigm-shifting discoveries regarding specialized cyclic nucleotide signals in the innate immune system, notably the cGAS-STING pathway. The significance of cyclic dinucleotides, exemplified by 2'3'-cGAMP, in controlling immune responses against pathogens and cancer, is explored. The evolutionarily conserved nature of cyclic dinucleotides as antiviral agents, spanning across diverse organisms, underscores their potential as targets for innovative immunotherapies. Findings from the last several years have revealed a striking diversity of novel bacterial cyclic nucleotide second messengers which are involved in antiviral responses. Knowledge of the existence and precise identity of these molecules coupled with accurate descriptions of their associated immune defense pathways will be essential to the future development of novel antibacterial therapeutic strategies. The insights presented herein may help researchers navigate the evolving landscape of immunopharmacology as it pertains to cyclic nucleotides and point toward new avenues or lines of thinking about development of therapeutics against the pathways they regulate.

Therapeutic peptides for coronary artery diseases: in silico methods and current perspectives

Many drug formulations containing small active molecules are used for the treatment of coronary artery disease, which affects a significant part of the world's population. However, the inadequate profile of these molecules in terms of therapeutic efficacy has led to the therapeutic use of protein and peptide-based biomolecules with superior properties, such as target-specific affinity and low immunogenicity, in critical diseases. Protein‒protein interactions, as a consequence of advances in molecular techniques with strategies involving the combined use of in silico methods, have enabled the design of therapeutic peptides to reach an advanced dimension. In particular, with the advantages provided by protein/peptide structural modeling, molecular docking for the study of their interactions, molecular dynamics simulations for their interactions under physiological conditions and machine learning techniques that can work in combination with all these, significant progress has been made in approaches to developing therapeutic peptides that can modulate the development and progression of coronary artery diseases. In this scope, this review discusses in silico methods for the development of peptide therapeutics for the treatment of coronary artery disease and strategies for identifying the molecular mechanisms that can be modulated by these designs and provides a comprehensive perspective for future studies.

Biosensors for natriuretic peptides in cardiovascular diseases. A review

Heart failure (HF) is a complex clinical syndrome associated with high rates of morbidity and mortality. Over the years, it has been crucial to find accurate biomarkers capable of doing a precise monitor of HF and provide an early diagnosis. Of these, it has been established an important role of natriuretic peptides in HF assessment. Moreover, the development of biosensors has been garnering interest as new diagnostic medical tools. In this review we first provide a general overview of HF, its pathogenesis, and diagnostic features. We then discuss the role of natriuretic peptides in heart failure by characterizing them and point out their potential as biomarkers. Finally, we adress the evolution of biosensors development and the available natriuretic peptides biosensors for disease monitoring.

A Review of Rattlesnake Venoms

Venom components are invaluable in biomedical research owing to their specificity and potency. Many of these components exist in two genera of rattlesnakes, Crotalus and Sistrurus, with high toxicity and proteolytic activity variation. This review focuses on venom components within rattlesnakes, and offers a comparison and itemized list of factors dictating venom composition, as well as presenting their known characteristics, activities, and significant applications in biosciences. There are 64 families and subfamilies of proteins present in Crotalus and Sistrurus venom. Snake venom serine proteases (SVSP), snake venom metalloproteases (SVMP), and phospholipases A2 (PLA2) are the standard components in Crotalus and Sistrurus venom. Through this review, we highlight gaps in the knowledge of rattlesnake venom; there needs to be more information on the venom composition of three Crotalus species and one Sistrurus subspecies. We discuss the activity and importance of both major and minor components in biomedical research and drug development.

Unveiling the potential role of natriuretic peptide receptor a isoforms in fine-tuning the cGMP production and tissue-specific function

Atrial natriuretic peptide (ANP) is a peptide hormone that regulates blood pressure and volume. ANP interacts with natriuretic peptide receptor-A (NPR-A) to lower the blood pressure through vasodilation, diuresis and natriuresis. Previously, we designed two human ANP analogues, one with exclusively diuretic function (DGD-ANP) and the other with exclusively vasodilatory function (DRD-ANP). Although both ANP analogues interact with NPR-A, their ability to produce cGMP was different. Three alternatively spliced isoforms of NPR-A were previously identified in rodents. Here, we evaluated the putative human isoforms for their cGMP production independently and in combination with WT NPR-A in various percentages. All three NPR-A isoforms failed to produce cGMP in the presence of ANP, DGD-ANP, or DRD-ANP. Co-expression of isoforms with WT NPR-A were found to significantly impair cGMP production. Considering the differential tissue expression levels of all three spliced isoforms in rodents have previously been demonstrated, the existence of these non-functional receptor isoforms may act as negative regulator for ANP/NPR-A activation and fine-tune cGMP production by WT NPR-A to different degree in different tissues. Thus, NPR-A isoforms potentially contribute to tissue-specific functions of ANP.

Corin and Left Atrial Cardiomyopathy, Hypertension, Arrhythmia, and Fibrosis

Two siblings presented with cardiomyopathy, hypertension, arrhythmia, and fibrosis of the left atrium. Each had a homozygous null variant in CORIN, the gene encoding atrial natriuretic peptide (ANP)-converting enzyme. A plasma sample obtained from one of the siblings had no detectable levels of corin or N-terminal pro-ANP but had elevated levels of B-type natriuretic peptide (BNP) and one of the two protein markers of fibrosis that we tested. These and other findings support the hypothesis that BNP cannot fully compensate for a lack of activation of the ANP pathway and that corin is critical to normal ANP activity, left atrial function, and cardiovascular homeostasis.

Assessment of amino-terminal C-type natriuretic peptide serum level and its correlation with high-density lipoprotein structure and function in patients with end stage renal disease before and after kidney transplantation

We aimed to investigate serum amino-terminal C-type natriuretic peptide (NT-proCNP) and its relationship with quantitative and qualitative HDL-parameters in patients with end-stage renal disease (ESRD) before, then 1 and 6 months after kidney transplantation (TX). Seventy patients (47 males, 23 females, mean age 51.7 ± 12.4 years) were enrolled in a prospective follow-up study. We examined serum creatinine, C-reactive protein, procalcitonin, fasting glucose and lipid parameters before, then 1 and 6 months after TX. High-density lipoprotein- (HDL)-associated paraoxonase-1 (PON1) paraoxonase and arylesterase activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. NT-proCNP and oxidized low-density lipoprotein (oxLDL) levels were measured by ELISA. Mean NT-proCNP was 45.8 ± 21.9 pmol/L before renal transplantation and decreased markedly 1 month and 6 months after transplantation (5.3 ± 2.5 and 7.7 ± 4.9 pmol/L, respectively, P = 1 × 10-4). During the 6 months' follow-up, PON1 arylesterase, paraoxonase and salt-stimulated paraoxonase activities improved. NT-proCNP positively correlated with procalcitonin and creatinine and negatively with GFR, LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C). There was a negative correlation between serum NT-proCNP and PON1 arylesterase activity. According to the multiple regression analysis, the best predicting variables of NT-proCNP were serum procalcitonin, creatinine and PON1 arylesterase activity. NT-proCNP might be a novel link between HDL dysfunction and impaired vascular function in ESRD, but not after kidney transplantation. Further studies in larger populations are needed to clarify the exact role of NT-proCNP in the risk prediction for cardiovascular comorbidities and complications in ESRD.

Snake Venom Components as Therapeutic Drugs in Ischemic Heart Disease

Ischemic heart disease (IHD), especially myocardial infarction (MI), is a leading cause of death worldwide. Although coronary reperfusion is the most straightforward treatment for limiting the MI size, it has nevertheless been shown to exacerbate ischemic myocardial injury. Therefore, identifying and developing therapeutic strategies to treat IHD is a major medical challenge. Snake venoms contain biologically active proteins and peptides that are of major interest for pharmacological applications in the cardiovascular system (CVS). This has led to their use for the development and design of new drugs, such as the first-in-class angiotensin-converting enzyme inhibitor captopril, developed from a peptide present in Bothrops jararaca snake venom. This review discusses the potential usefulness of snake venom toxins for developing effective treatments against IHD and related diseases such as hypertension and atherosclerosis. It describes their biological effects at the molecular scale, their mechanisms of action according to their different pharmacological properties, as well as their subsequent molecular pathways and therapeutic targets. The molecules reported here have either been approved for human medical use and are currently available on the drug market or are still in the clinical or preclinical developmental stages. The information summarized here may be useful in providing insights into the development of future snake venom-derived drugs.

Natriuretic Peptide Receptors (NPRs) as a Potential Target for the Treatment of Heart Failure

PURPOSE OF REVIEW

Heart failure is defined as a complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood. The natriuretic peptide is known to exert its biological action on the kidney, heart, blood vessels, renin-angiotensin system, autonomous nervous system, and central nervous system. The natriuretic peptide-natriuretic receptor system plays an important role in the regulation of blood pressure and body fluid volume through its pleiotropic effects.

RECENT FINDINGS

The clinical and animal studies suggest that natriuretic peptide-natriuretic receptors are important targets for the treatment of heart failure and other cardiovascular diseases. Even though attempts targeting natriuretic peptide receptors are underway for heart failure treatment, they seem insufficient despite the receptor systems' potential. This review summarizes natriuretic peptide-natriuretic receptor system's physiological actions and potential target for the treatment of heart failure. Natriuretic peptides play multiple roles in different parts of the body, almost all of the activities related to this receptor system appear to have the potential to be harnessed to treat heart failure or symptoms associated with heart failure.

Taipan Natriuretic Peptides Are Potent and Selective Agonists for the Natriuretic Peptide Receptor A

Cardiovascular ailments are a major cause of mortality where over 1.3 billion people suffer from hypertension leading to heart-disease related deaths. Snake venoms possess a broad repertoire of natriuretic peptides with therapeutic potential for treating hypertension, congestive heart failure, and related cardiovascular disease. We now describe several taipan (Oxyuranus microlepidotus) natriuretic peptides TNPa-e which stimulated cGMP production through the natriuretic peptide receptor A (NPR-A) with higher potencies for the rat NPR-A (rNPR-A) over human NPR-A (hNPR-A). TNPc and TNPd were the most potent, demonstrating 100- and 560-fold selectivity for rNPR-A over hNPR-A. In vivo studies found that TNPc decreased diastolic and systolic blood pressure (BP) and increased heart rate (HR) in conscious normotensive rabbits, to a level that was similar to that of human atrial natriuretic peptide (hANP). TNPc also enhanced the bradycardia due to cardiac afferent stimulation (Bezold-Jarisch reflex). This indicated that TNPc possesses the ability to lower blood pressure and facilitate cardiac vagal afferent reflexes but unlike hANP does not produce tachycardia. The 3-dimensional structure of TNPc was well defined within the pharmacophoric disulfide ring, displaying two turn-like regions (RMSD = 1.15 Å). Further, its much greater biological stability together with its selectivity and potency will enhance its usefulness as a biological tool.

From Snake Venoms to Therapeutics: A Focus on Natriuretic Peptides

Snake venom is a cocktail of multifunctional biomolecules that has evolved with the purpose of capturing prey and for defense. These biomolecules are classified into different classes based on their functions. They include three-finger toxins, natriuretic peptides, phospholipases and metalloproteinases. The focus for this review is on the natriuretic peptide (NP), which is an active component that can be isolated from the venoms of vipers and mambas. In these venoms, NPs contribute to the lowering of blood pressure, causing a rapid loss of consciousness in the prey such that its mobility is reduced, paralyzing the prey, and often death follows. Over the past 30 years since the discovery of the first NP in the venom of the green mamba, venom NPs have shown potential in the development of drug therapy for heart failure. Venom NPs have long half-lives, different pharmacological profiles, and may also possess different functions in comparison to the mammalian NPs. Understanding their mechanisms of action provides the strategies needed to develop new NPs for treatment of heart failure. This review summarizes the venom NPs that have been identified over the years and how they can be useful in drug development.

The chemistry of snake venom and its medicinal potential

The fascination and fear of snakes dates back to time immemorial, with the first scientific treatise on snakebite envenoming, the Brooklyn Medical Papyrus, dating from ancient Egypt. Owing to their lethality, snakes have often been associated with images of perfidy, treachery and death. However, snakes did not always have such negative connotations. The curative capacity of venom has been known since antiquity, also making the snake a symbol of pharmacy and medicine. Today, there is renewed interest in pursuing snake-venom-based therapies. This Review focuses on the chemistry of snake venom and the potential for venom to be exploited for medicinal purposes in the development of drugs. The mixture of toxins that constitute snake venom is examined, focusing on the molecular structure, chemical reactivity and target recognition of the most bioactive toxins, from which bioactive drugs might be developed. The design and working mechanisms of snake-venom-derived drugs are illustrated, and the strategies by which toxins are transformed into therapeutics are analysed. Finally, the challenges in realizing the immense curative potential of snake venom are discussed, and chemical strategies by which a plethora of new drugs could be derived from snake venom are proposed.

Therapeutic peptides: current applications and future directions

Peptide drug development has made great progress in the last decade thanks to new production, modification, and analytic technologies. Peptides have been produced and modified using both chemical and biological methods, together with novel design and delivery strategies, which have helped to overcome the inherent drawbacks of peptides and have allowed the continued advancement of this field. A wide variety of natural and modified peptides have been obtained and studied, covering multiple therapeutic areas. This review summarizes the efforts and achievements in peptide drug discovery, production, and modification, and their current applications. We also discuss the value and challenges associated with future developments in therapeutic peptides.

Molecular Signaling Mechanisms and Function of Natriuretic Peptide Receptor-A in the Pathophysiology of Cardiovascular Homeostasis

The discovery of atrial, brain, and C-type natriuretic peptides (ANP, BNP, and CNP) and their cognate receptors has greatly increased our knowledge of the control of hypertension and cardiovascular homeostasis. ANP and BNP are potent endogenous hypotensive hormones that elicit natriuretic, diuretic, vasorelaxant, antihypertrophic, antiproliferative, and antiinflammatory effects, largely directed toward the reduction of blood pressure (BP) and cardiovascular diseases (CVDs). The principal receptor involved in the regulatory actions of ANP and BNP is guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA), which produces the intracellular second messenger cGMP. Cellular, biochemical, molecular, genetic, and clinical studies have facilitated understanding of the functional roles of natriuretic peptides (NPs), as well as the functions of their receptors, and signaling mechanisms in CVDs. Transgenic and gene-targeting (gene-knockout and gene-duplication) strategies have produced genetically altered novel mouse models and have advanced our knowledge of the importance of NPs and their receptors at physiological and pathophysiological levels in both normal and disease states. The current review describes the past and recent research on the cellular, molecular, genetic mechanisms and functional roles of the ANP-BNP/NPRA system in the physiology and pathophysiology of cardiovascular homeostasis as well as clinical and diagnostic markers of cardiac disorders and heart failure. However, the therapeutic potentials of NPs and their receptors for the diagnosis and treatment of cardiovascular diseases, including hypertension, heart failure, and stroke have just begun to be expanded. More in-depth investigations are needed in this field to extend the therapeutic use of NPs and their receptors to treat and prevent CVDs.

Piezo1 Mechanosensitive Ion Channel Mediates Stretch-Induced Nppb Expression in Adult Rat Cardiac Fibroblasts

In response to stretch, cardiac tissue produces natriuretic peptides, which have been suggested to have beneficial effects in heart failure patients. In the present study, we explored the mechanism of stretch-induced brain natriuretic peptide (Nppb) expression in cardiac fibroblasts. Primary adult rat cardiac fibroblasts subjected to 4 h or 24 h of cyclic stretch (10% 1 Hz) showed a 6.6-fold or 3.2-fold (p < 0.05) increased mRNA expression of Nppb, as well as induction of genes related to myofibroblast differentiation. Moreover, BNP protein secretion was upregulated 5.3-fold in stretched cardiac fibroblasts. Recombinant BNP inhibited TGFβ1-induced Acta2 expression. Nppb expression was >20-fold higher in cardiomyocytes than in cardiac fibroblasts, indicating that cardiac fibroblasts were not the main source of Nppb in the healthy heart. Yoda1, an agonist of the Piezo1 mechanosensitive ion channel, increased Nppb expression 2.1-fold (p < 0.05) and significantly induced other extracellular matrix (ECM) remodeling genes. Silencing of Piezo1 reduced the stretch-induced Nppb and Tgfb1 expression in cardiac fibroblasts. In conclusion, our study identifies Piezo1 as mediator of stretch-induced Nppb expression, as well as other remodeling genes, in cardiac fibroblasts.

Cardiovascular Effects of Snake Toxins: Cardiotoxicity and Cardioprotection

Snake venoms, as complex mixtures of peptides and proteins, affect various vital systems of the organism. One of the main targets of the toxic components from snake venoms is the cardiovascular system. Venom proteins and peptides can act in different ways, exhibiting either cardiotoxic or cardioprotective effects. The principal classes of these compounds are cobra cardiotoxins, phospholipases A2, and natriuretic, as well as bradykinin-potentiating peptides. There is another group of proteins capable of enhancing angiogenesis, which include, e.g., vascular endothelial growth factors possessing hypotensive and cardioprotective activities. Venom proteins and peptides exhibiting cardiotropic and vasoactive effects are promising candidates for the design of new drugs capable of preventing or constricting the development of pathological processes in cardiovascular diseases, which are currently the leading cause of death worldwide. For example, a bradykinin-potentiating peptide from Bothrops jararaca snake venom was the first snake venom compound used to create the widely used antihypertensive drugs captopril and enalapril. In this paper, we review the current state of research on snake venom components affecting the cardiovascular system and analyse the mechanisms of physiological action of these toxins and the prospects for their medical application.

Advances in venom peptide drug discovery: where are we at and where are we heading?

Introduction: Animal venoms are a complex mixture of bioactive molecules that have evolved over millions of years for prey capture and defense from predators. Venom consists of many different types of molecules, with disulfide-rich peptides being a major component in most venoms. The study of these potent and highly selective molecules has led to the development of venom-derived drugs for diseases such as type 2 diabetes mellitus and chronic pain. As technologies have improved, more bioactive peptides have been discovered from venomous animals. Many of these molecules may have applications as tools for understanding normal and disease physiology, therapeutics, cosmetics or in agriculture.Areas covered: This article reviews venom-derived drugs approved by the FDA and venom-derived peptides currently in development. It discusses the challenges faced by venom-derived peptide drugs during drug development and the future for venom-derived peptides.Expert opinion: New techniques such as toxin driven discovery are expanding the pipeline of venom-derived peptides. There are many venom-derived peptides currently in preclinical and clinical trials that would have remained undiscovered using traditional approaches. A renewed focus on venoms, with advances in technology, will broaden the diversity of venom-derived peptide therapeutics and expand our knowledge of their molecular targets.

Current trends and future perspectives for heart failure treatment leveraging cGMP modifiers and the practical effector PKG

Cyclic guanosine monophosphate (cGMP), an intracellular second messenger molecule synthesized by guanylated cyclases (GCs), controls various myocardial properties, including cell growth and survival, interstitial fibrosis, endothelial permeability, cardiac contractility, and cardiovascular remodeling. These processes are mediated by the main cGMP effector protein kinase G (PKG) activation of which exerts intrinsic protective responses against the adverse effects of neurohormonal stimulation and pathological cardiac stress. Therapeutic strategies that enhance cGMP levels and PKG activation have been used for heart failure, which can be executed by reducing natriuretic peptide (NP) proteolysis, enhancing cGMP synthesis, or blocking cGMP hydrolysis. Among these, reducing NP clearance with neprilysin inhibitor combined with angiotensin receptor blocker has been shown to greatly improve the prognosis of patients with heart failure with reduced ejection fraction (HFrEF) compared to the prognosis of patients on standard therapy using angiotensin-converting enzyme inhibitors. Moreover, in a recent phase III clinical trial, soluble GC-derived cGMP generation was shown to have potential efficacy in the management of HFrEF. Despite the clinical significance of cGMP/PKG signaling activated by either soluble or particulate GCs in heart failure, the differential signaling events downstream of intracellular cGMP, which are precisely controlled not only by PKG activation but also by the changes in its targeting and compartmentalization depending on the pathophysiology of heart disease, are not yet completely understood. Hitherto, the importance of the latter PKG regulatory mechanisms in developing therapeutic strategies has not been elucidated. Further investigation of redox-based PKG modulation will aid in the successful development of clinical therapies and could also lead to the establishment of improved personalized treatments for patients with heart failure.

Novel therapeutics for the treatment of hypertension and its associated complications: peptide- and nonpeptide-based strategies

The renin-angiotensin-aldosterone system (RAAS) is responsible for maintaining blood pressure and vascular tone. Modulation of the RAAS, therefore, interferes with essential cellular processes and leads to high blood pressure, oxidative stress, inflammation, fibrosis, and hypertrophy. Consequently, these conditions cause fatal cardiovascular and renal complications. Thus, the primary purpose of hypertension treatment is to diminish or inhibit overactivated RAAS. Currently available RAAS inhibitors have proven effective in reducing blood pressure; however, beyond hypertension, they have failed to treat end-target organ injury. In addition, RAAS inhibitors have some intolerable adverse effects, such as hyperkalemia and hypotension. These gaps in the available treatment for hypertension require further investigation of the development of safe and effective therapies. Current research is focused on the combination of existing and novel treatments that neutralize the angiotensin II type I (AT1) receptor-mediated action of the angiotensin II peptide. Preclinical studies of peptide- and nonpeptide-based therapeutic agents demonstrate their conspicuous impact on the treatment of cardiovascular diseases in animal models. In this review, we will discuss novel therapeutic agents being developed as RAAS inhibitors that show prominent effects in both preclinical and clinical studies. In addition, we will also highlight the need for improvement in the efficacy of existing drugs in the absence of new prominent antihypertensive drugs.

Recently Approved and Under Investigation Drugs for Treating Patients with Heart Failure

Heart Failure (HF) represents a leading cause of morbidity and mortality worldwide. Despite the recent advances in the treatment of this condition, patients´ prognosis remains unfavorable in most cases. Sacubitril/valsartan and ivabradine have been recently approved to improve clinical outcomes in patients with HF with reduced ejection fraction. Drugs under investigation for treating patients with HF encompass many novel mechanisms including vasoactive peptides, blocking inflammatory- mediators, natriuretic peptides, selective non-steroidal mineralocorticoid-receptor antagonists, myocardial β3 adrenoreceptor agonists, inhibiting the cytochrome C/cardiolipin peroxidase complex, neuregulin-1/ErbB signaling and inhibiting late inward sodium current. The aim of this manuscript is to review the main drugs under investigation for the treatment of patients with HF and give perspectives for their implementation into clinical practice.

From Animal Poisons and Venoms to Medicines: Achievements, Challenges and Perspectives in Drug Discovery

Animal poisons and venoms are comprised of different classes of molecules displaying wide-ranging pharmacological activities. This review aims to provide an in-depth view of toxin-based compounds from terrestrial and marine organisms used as diagnostic tools, experimental molecules to validate postulated therapeutic targets, drug libraries, prototypes for the design of drugs, cosmeceuticals, and therapeutic agents. However, making these molecules applicable requires extensive preclinical trials, with some applications also demanding clinical trials, in order to validate their molecular target, mechanism of action, effective dose, potential adverse effects, as well as other fundamental parameters. Here we go through the pitfalls for a toxin-based potential therapeutic drug to become eligible for clinical trials and marketing. The manuscript also presents an overview of the current picture for several molecules from different animal venoms and poisons (such as those from amphibians, cone snails, hymenopterans, scorpions, sea anemones, snakes, spiders, tetraodontiformes, bats, and shrews) that have been used in clinical trials. Advances and perspectives on the therapeutic potential of molecules from other underexploited animals, such as caterpillars and ticks, are also reported. The challenges faced during the lengthy and costly preclinical and clinical studies and how to overcome these hindrances are also discussed for that drug candidates going to the bedside. It covers most of the drugs developed using toxins, the molecules that have failed and those that are currently in clinical trials. The article presents a detailed overview of toxins that have been used as therapeutic agents, including their discovery, formulation, dosage, indications, main adverse effects, and pregnancy and breastfeeding prescription warnings. Toxins in diagnosis, as well as cosmeceuticals and atypical therapies (bee venom and leech therapies) are also reported. The level of cumulative and detailed information provided in this review may help pharmacists, physicians, biotechnologists, pharmacologists, and scientists interested in toxinology, drug discovery, and development of toxin-based products.

Cardiac natriuretic peptides

Investigations into the mixed muscle-secretory phenotype of cardiomyocytes from the atrial appendages of the heart led to the discovery that these cells produce, in a regulated manner, two polypeptide hormones - the natriuretic peptides - referred to as atrial natriuretic factor or atrial natriuretic peptide (ANP) and brain or B-type natriuretic peptide (BNP), thereby demonstrating an endocrine function for the heart. Studies on the gene encoding ANP (NPPA) initiated the field of modern research into gene regulation in the cardiovascular system. Additionally, ANP and BNP were found to be the natural ligands for cell membrane-bound guanylyl cyclase receptors that mediate the effects of natriuretic peptides through the generation of intracellular cGMP, which interacts with specific enzymes and ion channels. Natriuretic peptides have many physiological actions and participate in numerous pathophysiological processes. Important clinical entities associated with natriuretic peptide research include heart failure, obesity and systemic hypertension. Plasma levels of natriuretic peptides have proven to be powerful diagnostic and prognostic biomarkers of heart disease. Development of pharmacological agents that are based on natriuretic peptides is an area of active research, with vast potential benefits for the treatment of cardiovascular disease.

Omics Technologies for Profiling Toxin Diversity and Evolution in Snake Venom: Impacts on the Discovery of Therapeutic and Diagnostic Agents

Snake venoms are primarily composed of proteins and peptides, and these toxins have developed high selectivity to their biological targets. This makes venoms interesting for exploration into protein evolution and structure-function relationships. A single venom protein superfamily can exhibit a variety of pharmacological effects; these variations in activity originate from differences in functional sites, domains, posttranslational modifications, and the formations of toxin complexes. In this review, we discuss examples of how the major venom protein superfamilies have diversified, as well as how newer technologies in the omics fields, such as genomics, transcriptomics, and proteomics, can be used to characterize both known and unknown toxins.Because toxins are bioactive molecules with a rich diversity of activities, they can be useful as therapeutic and diagnostic agents, and successful examples of toxin applications in these areas are also reviewed. With the current rapid pace of technology, snake venom research and its applications will only continue to expand.

Antibacterial properties of snake venom components

An increasing problem in the field of health protection is the emergence of drug-resistant and multi-drug-resistant bacterial strains. They cause a number of infections, including hospital infections, which currently available antibiotics are unable to fight. Therefore, many studies are devoted to the search for new therapeutic agents with bactericidal and bacteriostatic properties. One of the latest concepts is to search for this type of substances among toxins produced by venomous animals. In this approach, however, special attention is paid to snake venom because it contains molecules with antibacterial properties. Thorough investigations have shown that the phospholipases A2 (PLA2) and l-amino acids oxidases (LAAO), as well as fragments of these enzymes, are mainly responsible for the bactericidal properties of snake venoms. Some preliminary research studies also suggest that fragments of three-finger toxins (3FTx) are bactericidal. It has also been proven that some snakes produce antibacterial peptides (AMP) homologous to human defensins and cathelicidins. The presence of these proteins and peptides means that snake venoms continue to be an interesting material for researchers and can be perceived as a promising source of antibacterial agents.

Hypotensive Snake Venom Components-A Mini-Review

Hypertension is considered a major public health issue due to its high prevalence and subsequent risk of cardiovascular and kidney diseases. Thus, the search for new antihypertensive compounds remains of great interest. Snake venoms provide an abundant source of lead molecules that affect the cardiovascular system, which makes them prominent from a pharmaceutical perspective. Such snake venom components include bradykinin potentiating peptides (proline-rich oligopeptides), natriuretic peptides, phospholipases A2, serine-proteases and vascular endothelial growth factors. Some heparin binding hypotensive factors, three-finger toxins and 5' nucleotidases can also exert blood pressure lowering activity. Great advances have been made during the last decade regarding the understanding of the mechanism of action of these hypotensive proteins. Bradykinin potentiating peptides exert their action primarily by inhibiting the angiotensin-converting enzyme and increasing the effect of endogenous bradykinin. Snake venom phospholipases A2 are capable of reducing blood pressure through the production of arachidonic acid, a precursor of cyclooxygenase metabolites (prostaglandins or prostacyclin). Other snake venom proteins mimic the effects of endogenous kallikrein, natriuretic peptides or vascular endothelial growth factors. The aim of this work was to review the current state of knowledge regarding snake venom components with potential antihypertensive activity and their mechanisms of action.

C-type Natriuretic Peptide: A Multifaceted Paracrine Regulator in the Heart and Vasculature

C-type natriuretic peptide (CNP) is an autocrine and paracrine mediator released by endothelial cells, cardiomyocytes and fibroblasts that regulates vital physiological functions in the cardiovascular system. These roles are conveyed via two cognate receptors, natriuretic peptide receptor B (NPR-B) and natriuretic peptide receptor C (NPR-C), which activate different signalling pathways that mediate complementary yet distinct cellular responses. Traditionally, CNP has been deemed the endothelial component of the natriuretic peptide system, while its sibling peptides, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), are considered the endocrine guardians of cardiac function and blood volume. However, accumulating evidence indicates that CNP not only modulates vascular tone and blood pressure, but also governs a wide range of cardiovascular effects including the control of inflammation, angiogenesis, smooth muscle and endothelial cell proliferation, atherosclerosis, cardiomyocyte contractility, hypertrophy, fibrosis, and cardiac electrophysiology. This review will focus on the novel physiological functions ascribed to CNP, the receptors/signalling mechanisms involved in mediating its cardioprotective effects, and the development of therapeutics targeting CNP signalling pathways in different disease pathologies.