Efeito imunomodulador de hipoglicemiantes orais em cultura de linfócitos de pacientes com diabetes tipo 2 / Immunomodulatory effects of oral antidiabetic drugs in lymphocyte cultures from patients with type 2 diabetes

INTRODUCTION AND OBJECTIVE: It has been suggested that type 2 diabetes is an inflammatory response manifestation. The main drugs used to treat type 2 diabetes are sulphonylureas and biguanides. The aim of this study was to demonstrate the modulatory effects of oral hypoglycemic drugs (chlorpropamide and metformin) on lymphocyte proliferation in vitro and ex vivo. METHODS: Peripheral blood mononuclear cells were isolated from human blood by gradient centrifugation. T-lymphocytes were stimulated by phytohemagglutinin (PHA) and oral hypoglycemic drugs. RESULTS: In both in vitro and ex vivo experiments, there was a reduction in cell proliferation after treatment with oral hypoglycemic drugs. When both drugs were used in combination, a high level of cytotoxicity was observed, which made analysis of immunomodulatory effects unfeasible. DISCUSSION AND CONCLUSION: We demonstrated that diabetes itself may reduce cell proliferation significantly when stimulated by PHA, which may indicate that diabetic patients have difficulties in promoting an efficient inflammatory response. Moreover, the use of oral hypoglycemic drugs may aggravate this situation.

INTRODUÇÃO E OBJETIVOS: Tem sido sugerido que o diabetes mellitus tipo 2 (DM2) é uma manifestação da resposta inflamatória. As principais drogas utilizadas no tratamento do DM2 são as sulfonilureias e as biguanidas. O objetivo deste trabalho é demonstrar os efeitos moduladores na proliferação de linfócitos causada pelos hipoglicemiantes orais (clorpropamida e metformina), in vitro e ex vivo. MÉTODOS: Células mononucleares de sangue periférico foram isoladas de seres humanos por gradiente de centrifugação. Os linfócitos T foram estimulados com fito-hemaglutinina (PHA) e hipoglicemiantes. RESULTADOS: Nos experimentos in vitro e ex vivo, mostramos a redução da proliferação celular quando do tratamento com drogas hipoglicemiantes orais. Quando as drogas foram utilizadas em combinação, foi observado alto grau de citotoxicidade, tornando inviável a análise do efeito imunomodulador. DISCUSSÃO E CONCLUSÃO: Mostramos que o diabetes, por si, pode reduzir significativamente a proliferação celular quando estimulada por PHA, o que pode indicar que o paciente diabético tem dificuldade em promover a eficiente resposta inflamatória e que o uso de hipoglicemiantes pode piorar esta situação.

Adenosine A(2A) receptor agonist (CGS-21680) prevents endotoxin-induced effects on nucleotidase activities in mouse lymphocytes.

Adenosine 5'-triphosphate (ATP) released during inflammation presents proinflammatory properties. Adenosine, produced by catabolism of ATP, is an anti-inflammatory compound. Considering the role of ATP and adenosine in inflammation and the importance of ectonucleotidases in the maintenance of their extracellular levels, we investigated the effect of a selective agonist of the adenosine A(2A) receptor (CGS-21680) on ectonucleotidase activities and gene expression patterns in lymphocytes from mice submitted to an endotoxemia model. Animals were injected intraperitoneally with 12mg/kg Lipopolyssacharide (LPS) and/or 0.5mg/kg CGS-21680 or saline. Nucleotidase activities were determined in lymphocytes from mesenteric lymph nodes and analysis of ectonucleotidase expression was carried out by a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Exposure to endotoxemia promoted an increase in nucleotide hydrolysis. When CGS-21680 was administered concomitantly with LPS, this increase was prevented for ATP, adenosine 5'-monophosphate (AMP), and p-Nitrophenyl thymidine 5'-monophosphate (p-Nph-5'-TMP) hydrolysis. However, when CGS-21680 was administered 24h after LPS injection, the increase was not reversed. The expression pattern of ectonucleotidases was not altered between LPS and LPS plus CGS-21680 groups, indicating that the transcriptional control was not involved on the effect exerted for CGS-21680. These results showed an enhancement of extracellular nucleotide catabolism in lymphocytes after induction of endotoxemia, which was prevented, but not reversed by CGS-21680 administration. These findings suggest that the control of nucleotide and nucleoside levels exerted by CGS-21680 could contribute to the modulation of the inflammatory process promoted by adenosine A(2A) agonists.

Anti-inflammatory and immunomodulatory effects of Ulomoides dermestoides on induced pleurisy in rats and lymphoproliferation in vitro.

The following study aimed to evaluate, in vitro and in vivo, the anti-inflammatory effect of Ulomoides dermestoides, a beetle commonly used as a remedy for a variety of diseases including respiratory disorders and asthma. We used an acute inflammation model of injury, injection of carrageenan into the pleural cavity of rats. The rats were treated intraperitoneally with the aqueous extract of U. dermestoides 8 and 16 mg/kg. The exudate volume, protein concentration, polymorphonuclear leukocytes (PMNs) and total leukocyte were measured. The peripheral blood mononuclear cells (PBMCs) were isolated from the blood of healthy subjects and we investigated the immunomodulatory and cytotoxic effect of aqueous extract of U. dermestoides. In conclusion, in vitro we observed a non-cytotoxic effect and antiproliferative activity on the dose of 12.5 mg/dL. In vivo, this paper clarifies the great clinical relevance of the aqueous extract of U. dermestoides in elucidating its role as an anti-inflammatory agent.

Anti-inflammatory and immunomodulatory effects of Baccharis trimera aqueous extract on induced pleurisy in rats and lymphoproliferation in vitro.

Baccharis trimera is a widespread South American plant known as "carqueja". Medicinal teas prepared from the aerial parts of this plant are used in folk medicine in cases of liver diseases and inflammatory processes. We evaluated the effects of aqueous extract of B. trimera in the experimental inflammatory model of carrageenan-induced pleurisy in rat. The injection of carrageenan into the pleural cavity induces an influx of cells and fluid accumulation with a large number of polymorphonuclear leukocytes and increase of protein levels. The inflammation parameters were attenuated when B. trimera (400 and 800 mg/kg, i.p.) was administrated 30 min before the carrageenan. The immunomodulatory effects were evaluated in vitro on human peripheral blood mononuclear cells. The extract in concentration of 25, 50 and 100 mg/mL presented inhibited the T-lymphocytes proliferation stimulated by phytohemagglutinin, but these extract concentrations also presented cytotoxic effect. These results showed that the aqueous extract of B. trimera has anti-inflammatory effect.