Trans-Resveratrol and hesperetin combination (tRES-HESP) in randomized, double-blind, placebo-controlled crossover study in overweight and obese subjects corrected insulin resistance; healthy aging through functional food study (HATFF, Clinicaltrials.gov identifier NCT02095873). tRES-HESP is an optimized supplement for induction of expression of glyoxalase 1 (Glo1) via activation of transcription factor Nrf2. Increased Glo1 expression decreases reactive metabolite, methylglyoxal (MG), contributing to insulin resistance through glycation-linked unfolded protein formation and activation of the unfolded protein response (UPR). Herein, we report further analysis of study variables and follow-up reverse translational studies. With tRES-HESP treatment, plasma MG correlated negatively with peripheral blood mononuclear cell (PBMC) quinone reductase activity - a marker of Nrf2 activation (r = - 0.68, P<0.01). For change from baseline of PBMC gene expression with tRES-HESP treatment (assessed by the Nanostring method), change in area-under-the-curve plasma glucose (ΔAUGg) during oral glucose tolerance tests correlated negatively with change in Glo1 expression (r = - 0.56, P<0.05) and correlated positively with change in expression of thioredoxin interacting protein (TXNIP) (r = 0.59, P<0.05). In reverse translational studies, we found tRES-HESP decreased TXNIP expression by 39 ± 1% (P<0.001) in human hepatocyte-like HepG2 cells and 14 ± 3% in BJ fibroblasts in vitro (P<0.01). tRES-HESP may decrease TXNIP expression by decreasing the MG-driven UPR and by direct Nrf2-driven down regulation. TXNIP is a mediator of insulin resistance in liver and skeletal muscle and impaired pancreatic beta-cell insulin secretion. tRES-HESP is suitable for further evaluation for prevention and treatment of type 2 diabetes where decreased TXNIP may contribute to the therapeutic response.
M. Xue: None. M. Weickert: None. N. Rabbani: None. P. Thornalley: None.
Qatar Foundation; Qatar University