Antithrombotic potential of Lippia alba: A mechanistic approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Lippia alba (Mill.) N.E.Br. ex Britton & P. Wilson is traditionally used in Brazil as an adjunct in the relief of mild anxiety, as an antispasmodic, and as an antidyspeptic. This medicinal species was included in the Phytotherapeutic Form of the Brazilian Pharmacopeia 2nd edition (2021) and has already been described as the most used medicinal plant in a study with patients from an Anticoagulation Clinic in Brazil. Meanwhile, no studies were found that support the safety of the use of L. alba in patients using anticoagulants, a drug with several safety limitations. AIM OF THE STUDY: Provide scientific evidence to ensure the safety of the concomitant use of L. alba and warfarin and support the management of these patients by evaluating its in vitro anticoagulant effect and chemical composition. And, as a timely complementation, evaluate the potential of this medicinal species in the development of new antithrombotics. METHODS: The chemical profile of L. alba derivatives was analyzed by chromatographic methods such as Ultra-Performance Liquid Chromatography (UPLC) coupled with electrospray ionization mass spectrometry (ESI-MS), qualitative UPLC using Diode-Array Detection, and Thin Layer Chromatography. The anticoagulant activity was evaluated by the innovative Thrombin Generation Assay by Calibrated Automated Thrombogram method and using traditional coagulometric tests: prothrombin time, activated partial thromboplastin time, and plasma fibrinogen measurement. RESULTS: Extracts and fractions prolonged the coagulation time in all the tests and reduced thrombin formation in thrombin generation assay. Coagulation times with the addition of ethanloic extract (2.26 mg/mL) was 17.78s, 46.43s and 14.25s respectively in prothrombin time, activated partial thromboplastin time and fibrinogren plasma measurement. In thrombin generation test, this same extract showed ETP as 323 nM/min compared to control (815 nM/min) with high tissue factor and 582 nM/min compared to control (1147 nM/min) using low tissue factor. Presence of flavonoids, phenylpropanoids, and triterpenes were confirmed by chromatographic methods and 13 compounds were identified by UPLC-ESI-MS. Based on these results and on the scientific literature, it is possible to propose that phenylpropanoids and flavonoids are related to the anticoagulant activity observed. CONCLUSION: The results demonstrate the in vitro anticoagulant activity of L. alba, probably due to the activation of intrinsic and extrinsic pathways. It is concluded, then, that there is a potential for interaction, which needs to be further studied, between L. alba and warfarin. Also, this medicinal species shows a great potential for use in the development of new antithrombotics.

Anti-inflammatory, ulcerogenic and platelet activation evaluation of novel 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids.

This study reports the synthesis of novel neolignans-celecoxib hybrids and the evaluation of their biological activity. Analogs8-13(L13-L18) exhibited anti-inflammatory activity, inhibited glycoprotein expression (P-selectin) related to platelet activation, and were considered non- ulcerogenic in the animal model, even with the administration of 10 times higher than the dose used in reference therapy. In silico drug-likeness showed that the analogs are compliant with Lipinski's rule of five. A molecular docking study showed that the hybrids8-13(L13-L18) fitted similarly with celecoxib in the COX-2 active site. According to this data, it is possible to infer that extra hydrophobic interactions and the hydrogen interactions with the triazole core may improve the selectivity towards the COX-2 active site. Furthermore, the molecular docking study with P-selectin showed the binding affinity of the analogs in the active site, performing important interactions with amino acid residues such as Tyr 48. Whereas the P-selectin is a promising target to the design of new anti-inflammatory drugs with antithrombotic properties, a distinct butterfly-like structure of 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids synthesized in this work may be a safer alternative to the traditional COX-2 inhibitors.

Thrombin Generation Assay and Hemostatic Profile for Elucidating Hypercoagulability in Endogenous Canine Hyperadrenocorticism.

Canine hyperadrenocorticism is a common endocrine disorder caused by chronic secretion of glucocorticoid, often associated with hypercoagulability and secondary thrombosis. The thrombin generation assay (TGA) evaluates hemostasis globally by measuring endogenous thrombin potential. We aimed to determine whether TGA is suitable for assessing hypercoagulability in dogs with endogenous hyperadrenocorticism (HAC), and to correlate TGA with coagulation markers including fibrinogen, antithrombin (AT), D-dimer, prothrombin time (PT) and activated partial thromboplastin time (aPTT), and with routine laboratory tests for elucidating prothrombotic mechanisms and evaluating their utility as hypercoagulability screening tests. Thrombin generation performed with high activator concentration showed significantly higher endogenous thrombin potential (ETP) (P = .0239) and peak thrombin (P = .0281) in Cushing patients. Fibrinogen (P = <.0001) and AT (P = .0444) activities were significantly higher in the HAC group, while those of PT (P = .0046) and aPTT (P = .0002) were lower. Basal cortisol levels correlated positively with fibrinogen (r = 0.4503; P = .0355) and negatively with AT activity (r = -0.4580; P = .0280). Fibrinogen and hematocrit values were inversely correlated (r = -0.4853; P = .0076). Our study confirmed the presence of higher thrombin generation in dogs with HAC. However, TGA performed with lower activator concentrations was unsuitable for detecting hypercoagulability. Higher AT and fibrinogen levels and lower aPTT activity were identified in dogs with HAC relative to controls suggesting a potential role for the combined use of these assays when assessing hypercoagulability in canine hyperadrenocorticism.

Hemostatic evaluation of rabbits envenomed with Bothrops alternatus treated with anti-bothropic serum, desmopressin and tranexamin acid / Avaliação hemostática de coelhos envenenados com Bothrops alternatus e tratados com soro antibotrópico, desmopressina e ácido tranexâmico

In Brazil, snakes from the Bothrops genus are responsible for thousands of accidents, and their venoms are mainly composed of proteolytic enzymes. Although the antibothropic serum produced by the Brazilian Institutes is remarkably efficient, more studies are necessary, especially in veterinary medicine. The venom contain enzymes and non-enzymatic proteins that interfere with hemostasis leading to hemorrhage or even thrombosis. Possible treatment associations with known bothropic antivenom were the reason for the development of the present study. The aim of this study was to evaluate hemostasis alterations caused by Bothrops alternatus venom in rabbits followed by treatments with anti-bothropic serum, tranexamic acid and desmopressin. Twenty New Zealand rabbits were distributed into five groups (n=4) that were experimentally envenomed with 150mcg/kg of B. alternatus venom via intramuscular injection and treated as follow: Group 1 (G1) was the positive control and received venom and PBS/BSA; Group 2 (G2) was treated with tranexamic acid; Group 3 (G3) with desmopressin; Group 4 (G4) with tranexamic acid and anti-bothropic serum; and Group 5 (G5) with anti-bothropic serum and desmopressin. Blood samples were collected before venom administration, and one, four, eight and 12 hours after, for Partial activated partial thromboplastin time, Prothrombin Time, Thrombin Time and fibrinogen evaluation. Thrombin generation (TG) test was carried out with a pool of samples from final times (8 and 12h). At the end of 12h, all animals were euthanized and necropsy was conducted. Samples from muscle tissue, heart, lungs and kidney were analyzed. Classic coagulation tests showed no significant differences amongst groups and times. However, TG indicated that the venom causes a hypocoagulability state, which was not reversed by proposed treatments. Histology showed muscle inflammation, hemorrhage and necrosis, as well as hemorrhage in other tissues with no differences amongst groups. B. alternatus envenomation causes hypocoagulability detected by TG assay, but not through classical coagulation tests. The use of tranexamic acid and desmopressin for hemostasis stabilization after inoculation of the venom did not show advantage in coagulation restoration.(AU)

No Brasil, as serpentes do gênero Bothrops são responsáveis por milhares de acidentes, e seus venenos são compostos principalmente de enzimas proteolíticas. Embora o soro antiofídico produzido pelos institutos brasileiros seja notavelmente eficiente, mais estudos são necessários, especialmente na medicina veterinária. O veneno contem enzimas e proteínas não-enzimáticas que interferem com a hemostasia levando a hemorragias ou trombose. A associação de outros tratamentos ao soro antibotrópico foi a razão para o desenvolvimento do presente estudo. O objetivo deste estudo foi avaliar as alterações da hemostasia causadas pelo veneno de Bothrops alternatus em coelhos, após tratamento com soro antibotrópico, ácido tranexâmico e desmopressina. Vinte coelhos da Nova Zelândia foram distribuídos em cinco grupos (n = 4) que foram submetidos a experimentos com 150mcg/kg de veneno de B. alternatus por injeção intramuscular. O Grupo 1 (G1) foi o controle positivo e recebeu veneno e PBS / BSA, enquanto o Grupo 2 (G2) foi tratado com ácido tranexâmico, o Grupo 3 (G3) com desmopressina, o Grupo 4 (G4) com ácido tranexâmico e soro antibotrópico, e o Grupo 5 (G5) com soro antibotrópico e desmopressina. As amostras de sangue foram coletadas antes da administração do veneno, e uma, quatro, oito e 12 horas após os tratamentos para realização de tempo de tromboplastina parcial ativada parcial (TTPa), tempo de protrombina (TP), tempo de trombina (TT) e mensuração de fibrinogênio. Para o ensaio de geração de trombina (TG) foi realizado com um pool de amostras nos tempos finais (8 e 12h). Ao final das 12h, todos os animais foram sacrificados e a necropsia foi realizada. Amostras de tecido muscular, coração, pulmões e rins foram analisadas. Os testes TTPa, TP, TT e fibrinogênio não mostraram diferenças significativas entre os grupos e os tempos. No entanto, o TG indicou que o veneno causa um estado de hipocoagulabilidade, que não foi revertido pelos tratamentos propostos. Na histologia, foram observadas inflamação muscular, hemorragia e necrose, além de hemorragia em outros tecidos, sem diferenças entre os grupos. O envenenamento por B. alternatus causa hipocoagulabilidade detectada mais precocemente pelo teste de geração de trombina. O uso de ácido tranexâmico e desmopressina para estabilização da hemostasia após a inoculação do veneno não mostrou vantagem na restauração da coagulação.(AU)

Thrombin generation test with the calibrated automated thrombogram and anticoagulant activity of Mentha crispa.

: Evaluate the in-vitro effect of Mentha crispa extract on blood coagulation, compare the conventional coagulometric tests with thrombin generation test (TGT), and study the qualitative micromolecular composition of M. crispa. Extract of M. crispa was incubated with plasma and used in the coagulometric tests: prothrombin and activated partial thromboplastin times, fibrinogen, and TGT. A phytochemical prospection was performed to evaluate the chemical composition of this extract. The extract was efficient in prolonging prothrombin time and activated partial thromboplastin time, and reducing fibrinogen levels and TGT parameters, indicating that the extract of M. crispa inhibited the intrinsic and extrinsic pathways of blood coagulation. The results obtained in TGT are in agreement with the results of conventional coagulometric tests and the in-vitro anticoagulant activity of M. crispa suggests that its use by patients using oral anticoagulants deserves caution.

Haptoglobin levels, but not Hp1-Hp2 polymorphism, are associated with polycystic ovary syndrome.

PURPOSE: Proteomic studies suggest an association between haptoglobin (Hp) and polycystic ovary syndrome (PCOS). Hp is a classic inflammatory marker and binds to the intravascular hemoglobin, avoiding the oxidative damages that can be caused by free hemoglobin. Inflammation and oxidative stress are important in the pathogenesis of the PCOS, one of the most frequent metabolic diseases in women. METHODS: To validate these proteomic studies, we developed a controlled cross-sectional study that aimed to evaluate the Hp levels and allelic and genotypic frequencies of Hp1-Hp2 polymorphism in Brazilian women with PCOS. We also investigated the correlation between Hp levels and several important parameters in PCOS as follows: body mass index (BMI), waist circumference (WC), fasting glucose, post-prandial glucose, homeostatic model assessment (HOMA), lipid accumulation product (LAP), C-reactive protein (CRP), and metabolization test of tetrazolium salts (MTTs-serum antioxidant capacity). RESULTS: Plasma Hp levels were higher in the PCOS group than in controls [8.20 (4.04) g/L; 7.98 (3.31) g/L; p = 0.018]. No significant difference was observed in the frequency of Hp1-Hp2 genotypes under additive, recessive, or dominant model of inheritance between the PCOS and the control groups. Plasma Hp levels did not differ according to the genotype. However, plasma Hp showed a negative correlation with MTT (r = - 0.383; p = 0.028), as well as a positive correlation with CRP (r = 0.361; p = 0.014) in the PCOS group. CONCLUSION: Hp1-Hp2 polymorphism is not associated with PCOS but plasma Hp could be a potential biomarker for PCOS and its complications.

Cytokines profile and its correlation with endothelial damage and oxidative stress in patients with type 1 diabetes mellitus and nephropathy.

The aim of the present study was to investigate the association between the presence of albuminuria and cytokines profile with biomarkers of endothelial damage and oxidative stress in patients with type 1 diabetes mellitus (DM1). The sample was composed by 35 healthy individuals, 63 DM1 patients with normoalbuminuria (<30 mg of albumin/g of creatinine) and 62 DM1 patients with micro- and macroalbuminuria (≥30 mg of albumin/g of creatinine). Plasma and urinary cytokines (TNF-α, IL-6 and IL-10) and thrombomodulin levels were determined by ELISA. Oxidative status was evaluated using the TBARS and MTT assays. Diabetic patients were characterized by elevated levels of urinary cytokines TNF-α, IL-6 and IL-10. Those with macroalbuminuria presented significantly higher TNF-α and IL-10 urinary levels when compared to other groups. Urinary and plasmatic levels of TNF-α were positively correlated with plasma levels of cystatin C, creatinine, urea and albuminuria, while they were negatively correlated with estimated glomerular filtration rate. Urinary IL-10 levels proved positive correlation with fasting glucose, HbA1c, thrombomodulin and TBARS, while IL-6 plasma levels were positively correlated with HbA1c and albuminuria. Only urinary TNF-α levels were associated with the presence and severity of macroalbuminuria, after logistic regression analysis. This finding suggests that measurement of urinary TNF-α level may be helpful to evaluate progression to nephropathy in DM1 patients.

Effect of acetylsalicylic acid on platelet activation and oxidative profile in a set of Brazilian patients with type 2 diabetes mellitus.

Type 2 diabetes mellitus (DM2) is a metabolic disorder associated with hyperactivation of platelets, increased formation of platelet microparticles (PMPs) and oxidative stress that are related to cardiovascular complications. Acetylsalicylic acid (ASA) is an antiplatelet agent used in the prevention of atherothrombosis. The aim of this study was to evaluate the effect of ASA by means of platelet activation and oxidative profile. We collected blood samples of 81 patients with DM2 before and during ASA treatment. These samples were analyzed to determine the levels of 2,3-dinor thromboxane-B2 (2,3-dinor-TXB2), PMPs, thiobarbituric acid reactive species (TBARS) and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT). Moreover, the relationship between the levels of 2,3-dinor-TXB2 with some clinical and laboratory variables such as glycated hemoglobin, platelet count, D dimer, low-density lipoprotein cholesterol and glycoprotein IIb/IIIa and cyclooxygenase-1 polymorphisms was evaluated. ASA intake did not change the levels of PMP, TBARS and MTT. Although a significant decrease in the levels of 2,3 dinorTXB2 (P < 0.001) in patients under ASA has been observed, an equal and satisfactory response to this drug was not found. However, the presence of PIA2 allele in GPIIIa gene may be associated with a better response to ASA intake in these patients, whereas other clinical and laboratory variables showed no association with this drug use. These findings are consistent with previous reports in the literature that patients with DM2 do not benefit in an equal way from the use of ASA for primary prevention of atherothrombotic events.