Defibrinogenating effect of batroxobin (Defibrase®) in rats and inhibition of migration of human vascular smooth muscle cells by the plasma of batroxobin-treated rats in vitro

Use of Batroxobin in Central and Peripheral Ischemic Vascular Diseases: A Systematic Review

Background and Purpose: The mechanism of action of Batroxobin included the decomposition of the fibrinogen to fibrin degradation products (FDPs) and D-dimer and mobilization of endothelial cells to release endogenous nt-PA and to promote thrombolysis. This review aims to summarize current study findings about batroxobin on correcting cerebral arterial, venous, and peripheral vascular diseases, to explore the mechanism of batroxobin on anti-thrombosis process.

Methods: A thorough literature search was conducted utilizing the PubMed Central (PMC) and EMBASE databases to identify studies up to June 2021. Data from clinical studies and animal experiments about batroxobin were extracted, integrated and analyzed based on Cochrane handbook for systematic reviews of interventions approach and the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P), including the condition of subjects, the usage and dosage, research observation index and main findings.

Results: A total of 62 studies were enrolled in this systematic review, including 26 clinical studies and 36 animal experiments. The 26 clinical studies involved 873 patients with arterial ischemic events, 92 cases with cerebral venous thrombosis, 13 cases with cerebral cortical vein thrombosis, and 1,049 cases with peripheral vascular diseases. These patients included 452 males and 392 females aged 65.6 ± 5.53 years. The results revealed that batroxobin had broad effects, including improving clinical prognosis (n = 12), preventing thrombosis (n = 7), promoting thrombolysis (n = 6), and improving vascular cognitive dysfunction (n = 1). The effects of batroxobin on reducing neuronal apoptosis (n = 8),relieving cellular edema (n = 4), improving spatial memory (n = 3), and promoting thrombolysis (n = 13) were concluded in animal experiments. The predominant mechanisms explored in animal experiments involved promoting depolymerization of fibrinogen polymers (n = 6), regulating the expression of related molecules (n = 9); such as intercellular adhesion molecule, heat shock proteins, tumor necrosis factor), reducing oxidative stress (n = 5), and reducing inflammation response (n = 4).

Conclusion: Batroxobin can correct both arterial and venous ischemic diseases by promoting depolymerization of fibrinogen polymers, regulating the expression of related molecules, reducing oxidative stress, and reducing the inflammation response.

Insights into the antiviral activity of phospholipases A2 (PLA2s) from snake venoms

Viruses are associated with several human diseases that infect a large number of individuals, hence directly affecting global health and economy. Owing to the lack of efficient vaccines, antiviral therapy and emerging resistance strains, many viruses are considered as a potential threat to public health. Therefore, researches have been developed to identify new drug candidates for future treatments. Among them, antiviral research based on natural molecules is a promising approach. Phospholipases A₂ (PLA₂s) isolated from snake venom have shown significant antiviral activity against some viruses such as Dengue virus, Human Immunodeficiency virus, Hepatitis C virus and Yellow fever virus, and have emerged as an attractive alternative strategy for the development of novel antiviral therapy. Thus, this review provides an overview of remarkable findings involving PLA₂s from snake venom that possess antiviral activity, and discusses the mechanisms of action mediated by PLA₂s against different stages of virus replication cycle. Additionally, molecular docking simulations were performed by interacting between phospholipids from Dengue virus envelope and PLA₂s from Bothrops asper snake venom. Studies on snake venom PLA₂s highlight the potential use of these proteins for the development of broad-spectrum antiviral drugs.

Batroxobin accelerated tissue repair via neutrophil extracellular trap regulation and defibrinogenation in a murine ischemic hindlimb model

Batroxobin, isolated from Bothrops moojeni, is a defibrinogenating agent used as a thrombin-like serine protease against fibrinogen for improving microcirculation. Here, we investigated whether, and if so, how batroxobin restores ischemic tissue injury in terms of anti-inflammatory effects. In an in vitro flow cytometry assay for human neutrophil extracellular traps (NETs), batroxobin (DF-521; Defibrase) inhibited human NETs induced by tumor necrosis factor-α (TNF-α) in the presence of human fibrinogen. Next, the effect of batroxobin was investigated by immunohistochemistry of the anterior tibial muscle (ATM) in an ischemic hindlimb model using C57BL/6J mice intraperitoneally injected with DF-521 versus the saline control. NETs and fibrinogen deposition in the ischemic ATM decreased in DF-521-treated mice on day 2 after ischemia. Meanwhile, reverse transcription-quantitative PCR assay of the ischemic ATM unveiled continuous downregulation in the expression of the genes; Tnf-α and nitric oxide synthase2 (Nos2) with hypoxia-inducible factor-1α (Hif-1α) and vascular endothelial growth factor-a (Vegf-a) from day 3 to day 7, but the upregulation of arginase-1 (Arg-1) and placental growth factor (Plgf) with myogenin (Myog) on day 7. Daily intraperitoneal DF-521 injection for the initial 7 days into mice with ischemic hindlimbs promoted angiogenesis and arteriogenesis on day 14. Moreover, DF-521 injection accelerated myofiber maturation after day 14. Laser doppler imaging analysis revealed that blood perfusion in DF-521-injected mice significantly improved on day 14 versus the saline control. Thus, DF-521 improves microcirculation by protecting NETs with tissue defibrinogenation, thereby protecting against severe ischemic tissue injury and accelerating vascular and skeletal muscular regeneration. To our knowledge, batroxobin might be the first clinically applicable NET inhibitor against ischemic diseases.

Role of fibrinogen in cerebrovascular dysfunction after traumatic brain injury

Traumatic brain injury (TBI) has been associated with various neurological disorders. However, the role of cerebrovascular dysfunction and its mechanisms associated with TBI are still not well understood. Inflammation is the main cause of vascular dysfunction. It affects properties of blood components and the vascular wall leading to changes in blood flow and in interaction of blood components and vascular endothelium exacerbating microcirculatory complications during inflammatory diseases. One of the markers of inflammation is a plasma adhesion protein, fibrinogen (Fg). At elevated levels, Fg can also cause inflammatory responses. One of the manifestations of inflammatory responses is an increase in microvascular permeability leading to accumulation of plasma proteins in the subendothelial matrix and causing vascular remodelling. This has a most devastating effect on cerebral circulation after TBI that is accompanied with an elevation of plasma level of Fg and with an increased cerebrovascular permeability in injury penumbra impairing the normal healing process. This study reviews cerebrovascular alterations after TBI, considers the consequences of increased blood-brain barrier permeability, defines the role of elevated level of Fg and discusses the potential mechanisms of its action leading to vascular dysfunction, which subsequently can cause impairment in neuronal function. Thus, possible mechanisms of vasculo-neuronal dysfunction after TBI are considered.

Are batroxobin agents effective for perioperative hemorrhage in thoracic surgery? A systematic review of randomized controlled trials

The objective of the present study was to evaluate the effect of batroxobin agents on perioperative hemorrhage in thoracic surgery.We systematically searched Cochrane Library, Pubmed, EMBASE and the China Biological Medicine CD-ROM Databases up to August 2007. Reference lists of all included studies and of reviews related to the topic of the present systematic review were manually searched. Two reviewers independently identified the eligible studies, assessed their methodological quality and extracted data. Results of relevant outcomes were pooled together whenever possible, using RevMan software.Five randomized controlled trials involving 678 patients were included. Three trials were for pneumonectomy and two for cardiac surgery with cardiopulmonary bypass. The quality of the identified studies was generally poor. All the trials claimed randomized allocation, but allocation concealment was unclear. Blinding was not mentioned. Two trials found that batroxobin agents decreased intraoperative blood loss for pneumonectomy. Mean differences between the batroxobin agents group and the no-treatment group were -182.20 ml [95% confidence interval (CI), -207.48 to -156.92] and -131.32 ml (95% CI, -142.95 to -119.69), respectively, for these two trials. All included trials reported less drainage volume favoring the batroxobin agents group. Mean differences at different time points after operation ranged from -15 ml (95% CI, -31.77 to 1.77) to -150.60 ml (95% CI, -179.26 to -121.94). Although most of the differences between the batroxobin agents group and the no treatment group were statistically significant, clinical value was limited.There is not enough evidence supporting any benefit of batroxobin agents for hemorrhage during thoracic surgery.

Batroxobin mobilizes circulating endothelial progenitor cells in patients with deep vein thrombosis

Batroxobin, a thrombin-like enzyme from Bothrops atrox moojeni venom, is associated with the reduction of fibrinogen levels in plasma and the enhancement of anticoagulation and fibrinolysis. In this study, 15 patients with deep vein thrombosis (DVT) achieved successful limb salvage after the administration of batroxobin. We found that the levels of CD34+, CD31+, CD34+/CD31+, and vascular endothelial cadherin (VE-cadherin+) cells had increased in the peripheral blood of patients at 7 days and 14 days after treatment. At 0 day, 7 days, and 14 days, the percentages of CD34+ cells, which are assumed to be hematopoietic stem cells, are 0.39% ± 0.43%, 0.71% ± 0.50%, and 1.11% ± 0.66%, respectively. The levels of CD34+ cells at 14 days are significantly higher than the levels on the first day (P = .004). The levels of CD31+ cells and VE-cadherin+ cells, which represent mature endothelial cells, at 7 days (34.15% ± 11.32%, P = .013; 1.25% ± 1.39%, P = .014) and 14 days (35.21% ± 7.66%, P = .071; 1.85% ± 2.60%, P = .117) were slightly elevated compared with those at 0 day (27.55% ± 8.65%; 0.25 ± 0.39%). The double positive of CD34 and CD31 cells are assumed to be endothelial progenitor cells (EPCs). The levels of CD34+/CD31+ cells at 7 days (0.69% ± 0.50%, P = .001) and 14 days (1.07% ± 0.66%, P = .006) are significantly higher than that on the initial day (0.28% ± 0.30%). The number of CD34+/CD31+ cells significantly increased, indicating that in addition to its role in anticoagulation and fibrinolysis, treatment with batroxobin might simultaneously activate circulating EPCs that might promote the recanalization of the damaged vessel wall.

CNS and anticonvulsant activity of a non-protein toxin (KC-MMTx) isolated from King Cobra (Ophiophagus hannah) venom

In the present study, King Cobra (Ophiophagus hannah) venom was subjected to TLC followed by column chromatography/HPLC to isolate and purify a non-protein toxin designated as KC-MMTx. (1)H NMR, IR and EIMS studies showed KC-MMTx likely to be a 282 D unsaturated aliphatic acid having molecular formula C18H34O2. The minimum lethal dose of KC-MMTx was 200 microg/kg (i.v.) and 350 microg/kg (i.p.) in Swiss albino male mice. It significantly increased pentobarbitone induced sleeping time and significantly decreased the body temperature of male albino mice. It provided protection against amphetamine aggregate toxicity in mice but failed to protect amphetamine stereotypy in male albino rats. KC-MMTx provided significant protection against drug (strychnine, pentylenetetrazole, yohimbine) induced convulsions in male albino mice. It increased serum Na+ and decreased serum Ca2+ significantly in male mice. MAO activity and brain neurotransmitter levels in male mice were altered significantly. Further detailed study is warranted on the CNS, anticonvulsant potential of KC-MMTx, which may lead to the development of newer therapeutic tools in the near future.