Antiproliferative activity of marine stingray Dasyatis sephenvenom on human cervical carcinoma cell line

Background Venoms comprise mixtures of numerous bioactive compounds that have a wide range of pharmacologic actions. Toxins from venomous animals have attracted the attention of researchers because of their affinity for primary sites responsible for lethality and their efficacy at extremely low concentrations. The venoms of marine stingrays have not been extensively studied and limited data is available on them. The present study aims to evaluate the antiproliferative and biochemical properties of the venom obtained from a species of marine stingray (Dasyatis sephen) on human cervical cancer cell line HeLa.MethodsThe antiproliferative effect of D. sephen venom was determined by MTT assay, and the oxidative stress was determined by lipid peroxidation method along with assessment of changes in the enzymatic and non-enzymatic antioxidant status. We observed intracellular reactive oxygen species (ROS) levels by DCFH-DA method, mitochondrial membrane potential alterations by rhodamine 123 staining and apoptotic morphological changes by acridine orange/ethidium bromide dual staining method.ResultsD. sephen venom enhances lipid peroxidative markers such as thiobarbituric acid reactive substance, conjugated diene, and lipid hydroperoxide in HeLa cell lines. Stingray venom enhances the ROS levels, which is evidenced by the increased 27-diacetyl dichlorofluorescein fluorescence. Further, D. sephen venom treatment altered the mitochondrial membrane potential in HeLa cells. Additionally, we observed increased apoptotic morphological changes in D. sephen venom-treated groups. ConclusionsDasyatis sephen venom exhibits potent antiproliferative effect on HeLa cell line and upon further purification it could be a promising antiproliferative agent.

Exenatide improves type 2 diabetes concomitant with non-alcoholic fatty liver disease / Exenatide melhora o diabetes tipo 2 de ocorrência concomitante com doença hepática gordurosa não alcoólica

OBJECTIVE: To investigate the effects of exenatide on blood glucose, body weight and hepatic enzymes in patients with type 2 diabetes mellitus (T2DM) and concomitant non-alcoholic fatty liver disease (NAFLD). SUBJECTS AND METHODS: One hundred and seventeen patients with T2DM and NAFLD were randomly divided into exenatide group and metformin group. Patients were treated with exenatide and metformin, respectively, for 12 weeks. RESULTS: After 12 weeks of treatment, body weight, body mass index (BMI), waist-to-hip ratio, HbA1c, FPG, 2-h PPG, ALT, AST, γ-GT, and hs-CRP were significantly reduced, and the AST/ALT ratio and adiponectin were markedly increased in both groups. BMI, waist-to-hip ratio, 2-h PPG, ALT, AST, γ-GT, and hs-CRP were markedly lower, and AST/ALT ratio and adiponectin in the exenatide group were dramatically higher than in the metformin group. CONCLUSION: Compared with metformin, exenatide is better to control blood glucose, reduces body weight and improves hepatic enzymes, attenuating NAFLD in patients with T2DM concomitant with NAFLD.

OBJETIVO: Investigar os efeitos do exenatide sobre a glicose sérica, peso corporal e enzimas hepáticas em pacientes com diabetes melito tipo 2 (T2DM) e doença hepática gordurosa não alcoólica (DHGNA). SUJEITOS E MÉTODOS: Um total de 117 pacientes com T2DM e DHGNA foi aleatoriamente separado em dois grupos, um tratado com exenatide e um tratado com metformina. Os pacientes foram tratados por 12 semanas. RESULTADOS: Após 12 semanas de tratamento, o peso corporal, índice de massa corporal (IMC), relação cintura-quadril, HbA1c, FPG, glicose pós-prandial, ALT, AST, γ-GT e proteína C-reativa foram significativamente reduzidos, e a relação AST/ALT e a adiponectina aumentaram marcadamente nos dois grupos. O IMC, relação cintura-quadril, glicose pós-prandial, ALT, AST, γ-GT e proteína C-reativa foram marcadamente menores, e a relação AST/ALT e a adiponectina foram dramaticamente mais altas no grupo tratado com exenatide do que no grupo tratado com metformina. CONCLUSÃO: Comparado com a metformina, o exenatide controla melhor a glicose sérica, reduz o peso corporal e melhora as enzimas hepáticas, atenuando a DHGNA em pacientes com T2DM de ocorrência concomitante com a DHGNA.

Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macrophage populations with higher lipid content and lower phagocytic activity were observed. Exendin-4 lowered high lipid levels and enhanced phagocytosis in macrophages from db/db mice infected with L. monocytogenes. Exendin-4 also ameliorated obesity and hyperglycemia, and improved ex vivo bacteria clearance by macrophages in the animals. Liver histology examined during L. monocytogenes infection indicated that abscess formation was much milder in exendin-4-treated db/db mice than in the control animals. Moreover, mechanistic studies demonstrated that expression of ATP binding cassette transporter 1, a sterol transporter, was higher in macrophages isolated from the exendin-4-treated db/db mice. Overall, our results suggest that exendin-4 decreases the risk of infection in diabetic animals by modifying the interaction between intracellular lipids and phagocytic macrophages.

Ensayos clínicos de exenatida y su rol en el tratamiento de la diabetes tipo 2 / Exenatide trials for the treatment of type 2 diabetes

La diabetes mellitus tipo 2 es una enfermedad metabólica crónica, frecuente y progresiva, responsable del 90% de los casos de diabetes a nivel mundial. Aproximadamente el 60% de los individuos que padecen este desorden no alcanzan niveles óptimos de hemoglobina glicosilada, a pesar de la disponibilidad de numerosas alternativas terapéuticas. Los dos objetivos más importantes a cumplir en el manejo actual de la diabetes tipo 2 son la capacidad de los agentes antidiabéticos de exhibir eficacia prolongada y la capacidad de preservar la función de las células beta pancreáticas. El efecto incretina se encuentra reducido en pacientes con diabetes tipo 2. Exenatida pertenece a un nuevo grupo de drogas antidiabéticas que mejoran el control de la glucemia en estos pacientes a través de mecanismos fisiológicos glucorregulatorios que mejoran el efecto incretina. Los ensayos clínicos fase III con exenatida demostraron una reducción media de aproximadamente el 1% en los valores de hemoglobina glicosilada. Los datos a largo plazo de estudios de extensión no controlados indican una mejoría sostenida en los niveles de hemoglobina glicosilada y una reducción progresiva del peso luego de 3 años de tratamiento con esta droga. La droga es generalmente bien tolerada y los efectos adversos más frecuentes son los gastrointestinales, con una intensidad leve a moderada. El objetivo de esta revisión es analizar la evidencia publicada hasta la fecha sobre la eficacia y tolerabilidad del tratamiento con exenatida y su rol en el tratamiento de la diabetes tipo 2.

Type 2 diabetes mellitus is a common, chronic and progressive metabolic disorder, which accounts for 90% of diabetes cases worldwide. Approximately 60% of individuals with the disease do not achieve target glycosylated hemoglobin levels, despite the availability of many antidiabetic agents. The two most important needs in the present management of diabetes are the ability of antidiabetic agents to exhibit prolonged efficacy in reducing hyperglycemia and to preserve beta-cell function. The incretin effect appears to be reduced in patients with type 2 diabetes. Exenatide is the first in a novel class of antidiabetic drugs that improves glycemic control in patients with type 2 diabetes through several physiological glucoregulatory mechanisms which improve the incretin effect. Overall, mean glycosylated hemoglobin (HbA1c) reductions achieved in the exenatide phase III clinical trials were in the order of 1%. Long-term data from the uncontrolled open-label extension studies indicate that adjunctive exenatide therapy leads to sustained improvements in HbA1c and progressive weight loss for at least 3 years. The drug is generally well tolerated. The most common adverse events were gastrointestinal in nature and mild to moderate in severity. The objective of this review is to discuss the available published evidence on exenatide therapeutic efficacy and tolerability, and the role of this new drug in the treatment of type 2 diabetes.

Incretin mimetics and dipeptidyl peptidase-4 inhibitors: innovative treatment therapies for type 2 diabetes / Incretinomiméticos e inibidores da dipeptidil peptidase-4: terapias inovadoras para o tratamento do diabetes tipo 2

The prevalence of diabetes and impaired glucose tolerance is predicted to dramatically increase over the next two decades. Clinical therapies for type 2 diabetes mellitus (T2DM) have traditionally included lifestyle modification, oral anti-diabetic agents, and ultimately insulin initiation. In this report, we review the clinical trial results of two innovative T2DM treatment therapies that are based on the glucoregulatory effects of incretin hormones. Incretin mimetics are peptide drugs that mimic several of the actions of glucagon-like peptide-1 (GLP-1) and have been shown to lower glycated hemoglobin (A1C) levels in patients with T2DM. Additionally, incretin mimetics lower postprandial and fasting glucose, suppress elevated glucagon release, and are associated with progressive weight reduction. Dipeptidyl peptidase-4 (DPP-4) inhibitors increase endogenous GLP-1 levels by inhibiting the enzymatic degradation of GLP-1. Clinical studies in patients with T2DM have shown that DPP-4 inhibitors reduce elevated A1C, lower postprandial and fasting glucose, suppress glucagon release, and are weight neutral. Collectively, these new drugs, given in combination with other antidiabetic agents, such as metformin, sulfonylureas, and/or thiazolidinediones, can help restore glucose homeostasis in poorly controlled patients with T2DM.

É previsto que a prevalência de diabetes e a intolerância à glicose aumente dramaticamente ao longo das próximas duas décadas. As terapias clínicas para diabetes melito tipo 2 (DM2) têm tradicionalmente incluído modificação do estilo de vida, agentes antidiabéticos orais e, por último, o início da insulina. Neste artigo, revisamos os resultados dos estudos clínicos de duas terapias inovadoras no tratamento do DM2 baseadas nos efeitos glicorregulatórios dos hormônios incretina. Os incretinomiméticos são medicamentos peptídeos que mimetizam várias das ações do peptídeo semelhante ao glucagon-1 (GLP-1) e têm demonstrado reduzir níveis de hemoglobina glicada (A1C) em pacientes com DM2. Adicionalmente, incretinomiméticos reduzem as glicemias pós-prandial e de jejum, suprimem a liberação elevada do glucagon, e são associados com redução de peso. Os inibidores da dipeptidil peptidase-4 (DPP-4) aumentam os níveis de GLP-1 endógeno pela inibição da degradação enzimática do GLP-1. Estudos clínicos em pacientes com DM2 têm demonstrado que inibidores da DPP-4 reduzem A1C elevada, reduzem as glicemias pós-prandial e de jejum, suprimem a liberação elevada do glucagon e são neutros quanto ao peso. Coletivamente, estas novas medicações, administradas em combinação com outros agentes antidiabéticos, como metformina, sulfoniluréias e/ou tiazolidinedionas (TZDs), podem ajudar a recuperar a homeostase glicêmica de pacientes com DM2 não-controlados.

Exenatide: uso en humanos / Exenatide: use in humans

El exenatide es el primer agonista sintético del receptor de GLP-1 (glucagon-like peptide 1) aprobado para el tratamiento de pacientes con diabetes tipo 2. La multiplicidad de efectos que produce sobre el metabolismo de la glucosa, el apetito y el peso corporal, así como su capacidad potencial para mantener la masa de células β, lo convierten en una alternativa terapéutica atractiva. El presente artículo pretende revisar la información existente sobre la farmacocinética, farmacodinamia, efectividad y seguridad del exenatide en humanos, derivada de los primeros estudios de fase I y II y de los ensayos clínicos controlados que condujeron a la aprobación de su uso clínico como terapia de combinación con sulfonilureas y metformina.

Exenatide is the first synthetic agonist of the GLP-1 (glucagon-like peptide 1) receptor approved for clinical use in patients with type 2 diabetes. The multiplicity of its effects over glucose metabolism, appetite, body weight and its potential capacity to preserve the ?cell mass, makes it an attractive therapeutic alternative. This article attempts to review the current literature on pharmacokinetics, pharmacodynamics, efficacy, and safety of exenatide in humans, derived from the early phase I and II studies, and from the clinical controlled trials that led to its approval for clinical use as a combination therapy with sulphonylureas and metformin.