N(ϵ) -Carboxymethyllysine Increases the Expression of miR-103/143 and Enhances Lipid Accumulation in 3T3-L1 Cells.

Advanced glycation endproducts, formed in vivo, but also by the Maillard reaction upon thermal treatment of foods, have been associated with the progression of pathological conditions such as diabetes mellitus. In addition to the accumulation with age, exogenous AGEs are introduced into the circulation from dietary sources. In this study, we investigated the effects of addition of free N(ϵ) -carboxymethyllysine (CML), a well-characterized product of the Maillard reaction, on adipogenesis in 3T3-L1 preadipocytes. Treatment with 5, 50, or 500 µM CML resulted in increased lipid accumulation to similar extents, by 11.5 ± 12.6%, 12.9 ± 8.6%, and 12.8 ± 8.5%, respectively. Long-term treatment with 500 µM CML during adipogenesis resulted in increases in miR-103 and miR-143 levels, two miRNAs described to be involved in impaired glucose homeostasis and increased lipid accumulation. Furthermore, the expression of genes associated with these miRNAs, consisting of Akt1, PI3k, and Cav1 was regulated by CML. Short-term treatment of mature 3T3-L1 adipocytes with CML resulted in decreased basal glucose uptake. These results, indicate that the addition of protein-free CML to 3T3-L1 cells influence parameters associated with adipogenesis and glucose homeostasis at transcriptional, and functional level; this indicates that free CML derived from exogenous sources, in addition to protein-bound CML may be relevant in this context. J. Cell. Biochem. 117: 2413-2422, 2016. © 2016 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.

Characterization of alpha-terpineol as an anti-inflammatory component of orange juice by in vitro studies using oral buccal cells.

Epithelial buccal cells (KB) were exposed to orange juice or orange juice fractions containing either the dry matter (DM), the volatile compounds (aqueous distillate, AD), or individual nonvolatile or volatile components. Intracellular formation of the pro-inflammatory cytokine IL-6 was analyzed by flow cytometry. Exposure to whole orange juice resulted in an increase in IL-6 formation of 23% compared to nontreated control cells, whereas treatment of the cells with either DM or AD resulted in a 22 or 1% increase, respectively. Dose-response experiments revealed that exposure of the cells to a 2- or 4-fold concentrated AD resulted in an increased IL-6 formation, whereas an inhibiting effect was measured after treatment of the cells with an 8-fold concentrated AD. These results indicated the presence of pro- as well as anti-inflammatory compounds in the aqueous distillate. To identify the active principles, volatile compounds present in the AD-treated cells were analyzed by GC-MS. In particular, limonene, linalool, and alpha-terpineol were shown to be present in significant amounts. Subsequent studies on the IL-6 formation revealed that limonene had a stimulating effect and alpha-terpineol had an inhibiting effect, whereas linalool had no effect. This anti-inflammatory effect of alpha-terpineol on IL-6 formation was verified by quantitative real-time reverse transcription Polymerase Chain Reaction experiments in which alpha-terpineol inhibited the gene expression of the IL-6 receptor.