RESUMO
Fresh rhizome of Rehmannia glutinosa Libosch. (Saeng-jihwang in Korean: SJH) has been prescribed for the treatment of diabetes-associated complications. The purpose of the present study is to investigate the underlying mechanisms of the efficacy of SJH in diabetes-related complications. Decoction was obtained after boiling SJH in water and subsequent lyophilization. The cellular toxicity of SJH was determined by MTT assay. The antioxidant activity of SJH was measured by DPPH and DCFH-DA assays. The effects of SJH on inflammatory responses elicited by AGEs were assessed by western blotting and semi-quantitative RT-PCR analyses. The water extract of SJH had a high free radical scavenging activity in vitro and decreased the level of intracellular ROS in THP-1 cells treated with AGEs. SJH suppressed the expression of pro-inflammatory genes, including TNF-α, MCP-1, IP-10, COX-2, and iNOS; the activation of NF-κB; and the expression of RAGE, a receptor for AGEs, where the expressions of which were induced by AGEs. These results suggest the possibility that SJH can be an alternative therapeutics for diabetes-associated diseases.
Assuntos
Anti-Inflamatórios/farmacologia , Complicações do Diabetes/tratamento farmacológico , Produtos Finais de Glicação Avançada/metabolismo , Inflamação/tratamento farmacológico , Extratos Vegetais/farmacologia , Rehmannia , Antioxidantes/farmacologia , Linhagem Celular , Quimiocina CCL2/biossíntese , Quimiocina CXCL10/biossíntese , Ciclo-Oxigenase 2/biossíntese , Diabetes Mellitus , Regulação para Baixo , Sequestradores de Radicais Livres/farmacologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/biossíntese , Espécies Reativas de Oxigênio/metabolismo , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/biossíntese , Rizoma , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The present study was conducted to evaluate the immunomodulatory effect of aqueous-extracted Astragali radix (ARE) in methotrexate (MTX)-treated mouse spleen cells. In spleen cell proliferation assay, ARE enhanced mitogenic activity in the dose-response manner. We also investigated the effect of ARE on the reducing of immune suppression caused by MTX in mouse spleen cells. MTX decreased the spleen cell proliferation (IC(50):800 microg/ml). However, ARE significantly reduced the suppression of cell proliferation by MTX in mouse spleen cells. Immunomodulatory effect of ARE were further investigated using reverse transcription polymerase chain reaction (RT-PCR). In RT-PCR, we examined the expressions of various cytokines such as IL-6, IL-1alpha, IL-1beta, IL-12p40, GM-CSF and TNF. Enhancement of IL-1alpha and IL-12p40 mRNA expressions were shown in mouse spleen cells by ARE. In spite of MTX treatment, the expressions of IL-1alpha and IL-12p40 mRNA sustained in spleen cells. These data indicate that (1) ARE has a protective effect of immune suppression, and (2) the immunomodulatory effects of ARE may be, in part, associated with the expressions of IL-1alpha and IL-12p40 mRNA as well as the mitogenic effect on spleen cells.