Role of crotoxin in coagulation: novel insights into anticoagulant mechanisms and impairment of inflammation-induced coagulation

Moutan cortex exerts blood-activating and anti-inflammatory effects by regulating coagulation-inflammation cascades pathway in cells, rats and zebrafish

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine, raw Moutan Cortex (RMC) has been used in clinical practice for thousands of years. However, its blood-cooling and blood-activating medicinal effects as well as the underlying mechanisms have not been preliminarily verified until recent years.

AIM OF THE STUDY

Our group's previous network pharmacological studies suggested that RMC might exert its blood-activating and anti-inflammatory effects by modulating the coagulation-inflammation cascade pathway. Therefore, the present study aimed to further investigate the mechanisms relevant to the blood-activating and anti-inflammatory effects of RMC so as to provide more robust data supporting its clinical application.

MATERIALS AND METHODS

The inflammation and coagulation models of human umbilical vein endothelial cells (HUVECs) were induced by TNF-α; The rat models with blood-heat and blood-stasis syndrome (BHS) were constructed by ice-water bath with a combined use of epinephrine hydrochloride and dried yeast; The thrombus models of zebrafish were induced by arachidonic acid, and the inflammation models were established using LPS and CuSO4. The regulatory effects of RMC on the key targets in the pathway of the coagulation-inflammation cascade were investigated by combining ELISA, RT-PCR, and western blot techniques in an attempt to provide multiple validations concerning RMC's pharmacological efficacy and mechanism associated with cooling blood and activating blood circulation.

RESULT

The findings from the pharmacodynamic research demonstrated that RMC could inhibit the coagulation and inflammation process of HUVECs. Besides, it lowered the anal temperature and whole blood viscosity in BHS rats in addition to a prolongation of their prothrombin time (PT), thrombin time (TT), and activated partial thromboplastin time (APTT). Successfully constrained thrombotic area and reduced inflammatory cell counts were also observed in zebrafish models. Meanwhile, ELISA, RT-PCR and WB showed that RMC were capable of inhibiting the factors related to coagulation-MARK inflammation pathway-FⅡ, TF, FⅦ, FⅧ, FⅩ, and PAI, as well as down-regulating the expression of IL-6, COX-2, iNOS, TNF-α, ERK, JNK and p38.

CONCLUSION

RMC exerts blood-activating and anti-inflammatory effects through regulating the target genes of the coagulation-MARK inflammation cascade pathway.

Pathophysiological and Clinical Significance of Crotalus durissus cascavella Venom-Induced Pulmonary Impairment in a Murine Model

Crotalus venom has broad biological activity, including neurotoxic, myotoxic, hematologic, and cytotoxic compounds that induce severe systemic repercussions. We evaluated the pathophysiological and clinical significance of Crotalus durissus cascavella (Cdc) venom-induced pulmonary impairment in mice. We conducted a randomized experimental study, involving 72 animals intraperitoneally inoculated with saline solution in the control group (CG), as well as venom in the experimental group (EG). The animals were euthanized at predetermined intervals (1 h, 3 h, 6 h, 12 h, 24 h, and 48 h), and lung fragments were collected for H&E and Masson histological analysis. The CG did not present inflammatory alterations in pulmonary parenchyma. In the EG, interstitial and alveolar swelling, necrosis, septal losses followed by alveolar distensions, and areas of atelectasis in the pulmonary parenchyma were observed after three hours. The EG morphometric analysis presented pulmonary inflammatory infiltrates at all time intervals, being more significant at three and six (p = 0.035) and six and 12 h (p = 0.006). The necrosis zones were significant at intervals of one and 24 h (p = 0.001), one and 48 h (p = 0.001), and three and 48 h (p = 0.035). Crotalus durissus cascavella venom induces a diffuse, heterogeneous, and acute inflammatory injury in the pulmonary parenchyma, with potential clinical implications for respiratory mechanics and gas exchange. The early recognition and prompt treatment of this condition are essential to prevent further lung injury and to improve outcomes.

Hemodynamic impairment induced by Crotoxin using in vivo and ex vivo approach in a rat model

Crotalus durissus snakebite represent 10 % of snakebite cases in Brazil, which cardiovascular disorders are associated with severe cases. Considering crotoxin (CTX) as the major venom component, the present study aimed to evaluate the hemodynamic alterations induced by CTX using in vivo and ex vivo approaches in a rat model. In vivo cardiac function parameters were analyzed from anesthetized rats treated with CTX or saline only (Sham), along with serum creatine kinase MB (CK-MB) and lung myeloperoxidase. From the same animals, hearts were isolated and functional parameters evaluated in Langendorff method ex vivo. CTX binding to myoblast cell line in vitro were evaluated using confocal microscopy and flow cytometry. CTX was capable of reducing arterial and diastolic blood pressure, heart rate, along with left ventricle pressure development or decay during systole (LVdP/dt_max and LVdP/dt_min) in vivo, however no differences were found in the ex vivo approach, showing that intrinsic heart function was preserved. In vitro, CTX binding to myoblast cell line was mitigated by hexamethonium, a nicotinic acetylcholine receptor antagonist. The present study has shown that CTX induce hemodynamic failure in rats, which can help improve the clinical management of cardiovascular alterations during Crotalus durissus snakebite.

Integrating pharmacokinetics and network analysis to investigate the mechanism of Moutan Cortex in blood-heat and blood stasis syndrome

BACKGROUND

Raw Moutan Cortex (RMC) has been used in China and other Asian countries for thousands of years. Its medical application is the treatment of cooling blood and promoting blood circulation. However, its therapeutic mechanism is still undefined.

METHODS

In this study, the pharmacokinetics strategy that integrated network analysis was employed to explore the mechanism of RMC in blood-heat and blood stasis syndrome (BHS) model rats. Firstly, Ultra-High performance Liquid Chromatography coupled with Diode Array Detector (UHPLC-DAD) method was developed to determine nine absorbed compounds in rat serum in BHS and normal rats after oral administration of RMC extract respectively. Then the pharmacology network was established based on the relationship between nine compounds absorbed into the blood and BHS targets. Finally, the predicted hub targets were validated experimentally in human umbilical vein endothelial cells (HUVECs).

RESULTS

Pharmacokinetic study showed that the pharmacokinetic parameters of nine absorbed compounds had significant differences between BHS and normal groups (p < 0.05). Network analysis showed that 8 target genes, namely, F2, F10, F7, PLAU, MAPK14, MAPK10, AKT1, and NOS3 may be the primary targets regulated by RMC for the treatment of BHS. Among them, targets (F2, F10, F7 and MAPK14, MAPK10, AKT) and 4 active ingredients (paeonol, paeoniflorin, quercetin and oxypaeoniflorin) were selected for evaluating the reliability in vitro experiments, which revealed that the mechanism of RMC against BHS syndrome may inhibit inflammatory pathways and regulate coagulation cascades pathway for cooling and promoting blood circulation.

CONCLUSION

The proposed pharmacokinetics study integrated network analysis strategy provides a combination method to explore the therapeutic mechanism of RMC on BHS.

Revisiting the potential of South American rattlesnake Crotalus durissus terrificus toxins as therapeutic, theranostic and/or biotechnological agents

The potential biotechnological and biomedical applications of the animal venom components are widely recognized. Indeed, many components have been used either as drugs or as templates/prototypes for the development of innovative pharmaceutical drugs, among which many are still used for the treatment of human diseases. A specific South American rattlesnake, named Crotalus durissus terrificus, shows a venom composition relatively simpler compared to any viper or other snake species belonging to the Crotalus genus, although presenting a set of toxins with high potential for the treatment of several still unmet human therapeutic needs, as reviewed in this work. In addition to the main toxin named crotoxin, which is under clinical trials studies for antitumoral therapy and which has also anti-inflammatory and immunosuppressive activities, other toxins from the C. d. terrificus venom are also being studied, aiming for a wide variety of therapeutic applications, including as antinociceptive, anti-inflammatory, antimicrobial, antifungal, antitumoral or antiparasitic agent, or as modulator of animal metabolism, fibrin sealant (fibrin glue), gene carrier or theranostic agent. Among these rattlesnake toxins, the most relevant, considering the potential clinical applications, are crotamine, crotalphine and gyroxin. In this narrative revision, we propose to organize and present briefly the updates in the accumulated knowledge on potential therapeutic applications of toxins collectively found exclusively in the venom of this specific South American rattlesnake, with the objective of contributing to increase the chances of success in the discovery of drugs based on toxins.

Crotalus Durissus Ruruima: Current Knowledge on Natural History, Medical Importance, and Clinical Toxinology

Crotalus durissus ruruima is a rattlesnake subspecies mainly found in Roraima, the northernmost state of Brazil. Envenomings caused by this subspecies lead to severe clinical manifestations (e.g. respiratory muscle paralysis, rhabdomyolysis, and acute renal failure) that can lead to the victim’s death. In this review, we comprehensively describe C. d. ruruima biology and the challenges this subspecies poses for human health, including morphology, distribution, epidemiology, venom cocktail, clinical envenoming, and the current and future specific treatment of envenomings by this snake. Moreover, this review presents maps of the distribution of the snake subspecies and evidence that this species is responsible for some of the most severe envenomings in the country and causes the highest lethality rates. Finally, we also discuss the efficacy of the Brazilian horse-derived antivenoms to treat C. d. ruruima envenomings in Roraima state.