Natural Products Towards the Discovery of Potential Future Antithrombotic Drugs

Anti-hemostatic, antithrombotic, and chemical profiles of a curly-leaf variety of Petroselinum crispum (Apiaceae), a food and medicinal aromatic herb

Thrombosis is currently among the major causes of morbidity and mortality in the World. New prevention and therapy alternatives have been increasingly sought in medicinal plants. In this context, we have been investigating parsley, Petroselinum crispum (Mill.) Nym, an aromatic herb with two leaf varieties. We report here the in vitro, in vivo, and ex vivo anti-hemostatic and antithrombotic activities of a parsley curly-leaf variety. Aqueous extracts of aerial parts (PCC-AP), stems (PCC-S), and leaves (PCC-L) showed significant in vitro antiplatelet activity. PCC-AP extract exhibited the highest activity (IC50 2.92 mg/mL) when using ADP and collagen as agonists. All extracts also presented in vitro anticoagulant activity (APTT and PT) and anti-thrombogenic activity. PCC-S was the most active, with more significant interference in the factors of the intrinsic coagulation pathway. The oral administration of PCC-AP extract in rats caused a greater inhibitory activity in the deep vein thrombi (50%; 65 mg/kg) than in arterial thrombi formation (50%; 200 mg/kg), without cumulative effect after consecutive five-day administration. PCC-AP extract was safe in the induced bleeding time test. Its anti-aggregating profile was similar in ex vivo and in vitro conditions but was more effective in the extrinsic pathway when compared to in vitro results. Apiin and coumaric acid derivatives are the main compounds in PCC-AP according to the HPLC-DAD-ESI-MS/MS profile. We demonstrated for the first time that extracts from different parts of curly parsley have significant antiplatelet, anticoagulant, and antithrombotic activity without inducing hemorrhage, proving its potential as a source of antithrombotic compounds.

Antithrombotic and antihemolytic effects of Lagerstroemia speciosa (Lythraceae) aqueous extract

Introduction: Aqueous extract of Lagerstroemia speciosa (EALS) (Lythraceae) is widely used to treat diabetes. This plant has been shown an in vitro thrombolytic activity that indicates its potential to prevent the formation of blood clots in vivo. Thus, this study was undertaken to evaluate the antithrombotic and antihemolytic effects of EALS. Methods: Rats of both sexes (200 ± 5 g) were divided into five groups of six animals. Each group received orally distilled water, EALS (250, 500, 1000 mg/kg), and acetylsalicylic acid (100 mg/kg) for five days. After treatment, the FeCl3-induced arterial thrombus formation method was used to determine occlusion time. A coagulometer was used to detect activated partial thromboplastin time (aPTT) and prothrombin time (PT). Rabbit blood was used to determine clot lysis activity in vitro and antihemolytic activity using the 2,2-azobis hydrochloride (2-methylpropionamidine) (AAPH) method. Results: EALS increased the occlusion time in a dose-dependent manner. At the dose of 1000 mg/kg, EALS increased the occlusion time significantly, from 4.59 ± 2.45 minutes to 15.52 ± 2.38 minutes (P<0.01). At high concentrations (1-4 mg/mL), EALS showed a significant increase in aPPT and PT (P<0.05). Streptokinase and EALS (4 mg/mL) induced significant clot lysis with percentage values of 78.48 ± 2.2 % and 49.5 ± 1.53 %, respectively (P<0.001). EALS inhibited AAPH-induced hemolysis. Conclusion: EALS exhibited antithrombotic and antihemolytic activities. The antithrombotic property of the plant could be attributed to its anticoagulant and thrombolytic activities. Regular consumption of L. speciosa leaves may prevent or treat thrombotic diseases.

Potential clinical applications of phytopharmaceuticals for the in-patient management of coagulopathies in COVID-19

Thrombotic complications occur in many cardiovascular pathologies and have been demonstrated in COVID‐19. The currently used antithrombotic drugs are not free of adverse reactions, and COVID‐19 patients in particular, when treated with a therapeutic dose of an anticoagulant do not receive mortality benefits. The clinical management of COVID‐19 is one of the most difficult tasks for clinicians, and the search for safe, potent, and effective antithrombotic drugs may benefit from exploring naturally bioactive molecules from plant sources. This review describes recent advances in understanding the antithrombotic potential of herbal drug prototypes and points to their future clinical use as potent antithrombotic drugs. Although natural products are perceived to be safe, their clinical and therapeutic applications are not always apparent or accepted. More in‐depth studies are necessary to demonstrate the clinical usefulness of plant‐derived, bioactive compounds. In addition, holistic approaches in systematic investigations and the identification of antithrombotic mechanisms of the herbal bioactive molecule(s) need to be conducted in pre‐clinical studies. Moreover, rigorous studies are needed to compare the potency of herbal drugs to that of competitor chemical antithrombotic drugs, and to examine their interactions with Western antithrombotic medicines. We have also proposed a road map to improve the commercialization of phytopharmaceuticals.

Mechanisms and interactions in concomitant use of herbs and warfarin therapy: An updated review

This review is an updated and expanded version published in this journal in 2016. Warfarin pharmacotherapy is extremely complex, since in addition to being a low therapeutic index drug, it does not follow the dose-response pattern and has characteristics that predispose the occurrence of interactions, such as high binding rate to plasma proteins, metabolization by cytochrome P450 enzymes, further to acting in the complex process of blood coagulation, platelet activation, and inflammation. For these reasons, warfarin has great potential for interaction with drugs, foods, and herbal medicines. Herb-warfarin interactions, however, are still not very well studied; thus, the objective of this update is to present new information on the subject aiming to provide a scientific basis to help health professionals in the clinical management of these interactions. A literature review was performed from May to June 2021 in multiple databases and articles published in 2016 to 2021 were included. A total of 59 articles describing 114 herbal medicines were reported to interact with warfarin. Of the plants mentioned, 84% had the potential to increase warfarin effect and the risk of bleeding. Targets possibly involved in these interactions include the processes of blood coagulation, platelet activation, and inflammation, in addition to the pharmacokinetics and pharmacodynamics of warfarin. Despite these alarming numbers, however, the clinical management of interactions is known to be effective. Thus, it is important that the use of these herbal medicines be done with caution in anticoagulated patients and that studies of herb-drug interactions be encouraged in order to generate information to support the clinical management of patients.

The antithrombotic activity of natural and synthetic coumarins

Thrombosis, which seriously endangers human health and life, is the leading cause of morbidity and mortality globally. Antithrombotic drugs can interfere with the occurrence and development of thrombotic diseases and play an important role in the treatment of thrombotic diseases. However, unsatisfactory efficacy and serious adverse effects of existing antithrombotic drugs increase the research for new, efficient and safer drugs. Natural and synthetic coumarins have been shown to possess antithrombotic activity, namely, anticoagulation and antiplatelet aggregation. Especially, coumarin-based warfarin, phenprocoumon and cloricromen have long been used in clinical treatment of thrombosis. Coumarin with low toxicity is the privileged structure for developing novel antithrombotic drugs with multiple mechanisms of action. The present review aims to compile current research on the development of coumarins against thrombosis, emphasizing the relationship between their chemical structures and therapeutic effectiveness. It is intended to provide promising ideas for the discovery of novel coumarin derivatives with high antithrombotic activity.

The Ethanolic Extract of Caesalpinia sappan Heartwood Inhibits Cerebral Ischemia/Reperfusion Injury in a Rat Model Through a Multi-Targeted Pharmacological Mechanism

Background: Caesalpinia sappan L. (C. sappan) is a traditional Chinese medicinal plant. The dried heartwood of C. sappan (also known as Sappan wood) has been widely used for the folkloric medical treatment of ischemic cerebral stroke in China. However, the detailed underlying pharmacological mechanism still remains largely unexplored. Methods: In this study, a middle cerebral artery occlusion (MCAO) rat model was employed to elucidate the mechanism of the anti-cerebral ischemic effects of C. sappan ethanolic extract (CEE). Moreover, systemic multi-target identification coupled with gene ontology biological process (GO BP) and reactome pathway analysis was used to investigate the potential neuroprotective mechanism. Furthermore, the presumed mechanism was confirmed through biological analysis by determining the effects of CEE on the identified signaling pathways in PC12 cells model-induced by oxygen-glucose deprivation/reperfusion (OGD/R). Results: Our study demonstrates that CEE (both through in vivo administration at a dosage of 300 mg/kg and through in vitro incubation at a dosage of 2.4 μg/mL) is a neuroprotective agent that can effectively inhibit neuronal damage, promote synaptic generation, and suppress the activation of neutrophils, microglia, and astrocytes. Moreover, the neuroprotective mechanism of CEE is mediated via regulating 150 potential target proteins, which are associated with 6 biological processes and 10 pathways, including JAK-STAT, HSP90 and DNA damage/telomere stress. Conclusion: CEE can exert neuroprotective effect through multi-target pharmacological mechanisms to prevent ischemia/reperfusion-induced cerebral injury.

The Ovotransferrin-Derived Peptide IRW Attenuates Lipopolysaccharide-Induced Inflammatory Responses

IRW (Ile-Arg-Trp), a bioactive peptide isolated from egg ovotransferrin, has been shown to exert anti-inflammatory effects. In this study, the effects of IRW on inflammatory cytokines and microbiota were explored in human umbilical vein endothelial cells (HUVECs) and a lipopolysaccharide (LPS)-induced rat model of inflammatory peritonitis. Rats were injected intraperitoneally with LPS to establish peritonitis. HUVECs were exposed to IRW for 12 h before introducing LPS. Notably, IRW exerted beneficial effects against LPS-induced peritonitis, specifically, by reducing the serum levels of tumour necrosis factor (TNF)-α and interleukin (IL)-6 and myeloperoxidase (MPO) activity (P<0.05). A faecal microbiota analysis revealed that IRW significantly increased the Shannon and decreased the Simpson indices (P<0.05). Furthermore, IRW treatment significantly inhibited the LPS-induced enhancement of TNF-α, IL-8, intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) expression in HUVECs (P<0.05). In conclusion, IRW supplementation inhibited the inflammatory mediator synthesis and LPS-induced inflammatory responses and influenced the gut microbiota.

The evolution of recombinant thrombolytics: Current status and future directions

Cardiovascular disorders are on the rise worldwide due to alcohol abuse, obesity, hypertension, raised blood lipids, diabetes and age-related risks. The use of classical antiplatelet and anticoagulant therapies combined with surgical intervention helped to clear blood clots during the inceptive years. However, the discovery of streptokinase and urokinase ushered the way of using these enzymes as thrombolytic agents to degrade the fibrin network with an issue of systemic hemorrhage. The development of second generation plasminogen activators like anistreplase and tissue plasminogen activator partially controlled this problem. The third generation molecules, majorly t-PA variants, showed desirable properties of improved stability, safety and efficacy with enhanced fibrin specificity. Plasmin variants are produced as direct fibrinolytic agents as a futuristic approach with targeted delivery of these drugs using liposome technlogy. The novel molecules from microbial, plant and animal origin present the future of direct thrombolytics due to their safety and ease of administration.

Dietary Phytochemicals: Natural Swords Combating Inflammation and Oxidation-Mediated Degenerative Diseases

Cumulatively, degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the sufferers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis (RA), diabetes mellitus (DM), and cardiovascular disease (CVD). Although a number of synthetic medications are used to treat these diseases, none of the current regimens are completely safe. Phytochemicals (polyphenols, carotenoids, anthocyanins, alkaloids, glycosides, saponins, and terpenes) from natural products such as dietary fruits, vegetables, and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases. Based on in vitro, in vivo, and clinical trials, some of these active compounds have shown good promise for development into novel agents for treating RA, DM, and CVD by targeting oxidative stress and inflammation. In this review, phytochemicals from natural products with the potential of ameliorating degenerative disease involving the bone, metabolism, and the heart are described.