Cucurbita ficifolia Bouché (Cucurbitaceae) and D-chiro-inositol modulate the redox state and inflammation in 3T3-L1 adipocytes

Objectives Cucurbita ficifolia (characterised by its D chiro inositol (DCI) content) and of synthetic DCI on the redox state, mRNA expression and secretions of proinflammatory cytokines. Additionally, we evaluated the insulinmimetic action of both treatments by assessing protein kinase B (PKB) activation in 3T3-L1 adipocytes. Methods Adipocytes were treated with C. ficifolia and synthetic DCI. The redox state was determined by spectrophotometry as changes in the reduced glutathione/oxidised glutathione (GSH/GSSG) ratio, glutathione peroxidase and glutathione reductase activities; H2O2 levels were measured by flow cytometry. The mRNA expression and the protein level of cytokines were determinate by realtime reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The activation of PKB activation was detected by Western blot. Key findings C. ficifolia extract and synthetic DCI reduced oxidative stress by decreased H2O2 levels, increased glutathione peroxidase activity and changes in the GSH/GSSG ratio. Furthermore, DCI decreased the mRNA expression and secretion of tumour necrosis factor-α, interleukin 6 (IL-6) and resistin, while C. ficifolia reduced protein levels of resistin and increased IL-6 levels. Only DCI demonstrated insulin-mimetic action. Conclusions The antioxidant and anti-inflammatory effects of C. ficifolia extract can be explained in part by its DCI content, which modulates the GSH/GSSG ratio and contributes to a reduced proinflammatory state. C. ficifolia and DCI treatments may reduce the disturbances caused by oxidative stress. Additionally, DCI may improve insulin sensitivity through its insulin-mimetic effects.