RETRACTED ARTICLE: Coffee component hydroxyl hydroquinone (HHQ) as a putative ligand for PPAR gamma and implications in breast cancer

Abstract

BackgroundCoffee contains several compounds that have the potential to influence breast cancer risk and survival. However, epidemiologic data on the relation between coffee compounds and breast cancer survival are sparse and inconsistent.ResultsWe show that coffee component HHQ has significant apoptotic effect on MDA-MB-231 and MCF-7 cells in vitro, and that ROS generation, change in mitochondrial membrane permeability, upregulation of Bax and Caspase-8 as well as down regulation of PGK1 and PKM2 expression may be important apoptosis-inducing mechanisms. The results suggest that PPARγ ligands may serve as potential therapeutic agents for breast cancer therapy. HHQ was also validated as a ligand for PPARγ by docking procedure.ConclusionThis is the first report on the anti-breast cancer (in vitro) activity of HHQ.

Probing the intermolecular interactions of PPARγ-LBD with polyunsaturated fatty acids and their anti-inflammatory metabolites to infer most potential binding moieties

“…RsvE1, NPD1 and H-LA formed hydrogen bonds with the arm-I residues Hie449 (H11), Ser289(H3) and Tyr327, which are reported to be important for producing full activity of the compound by direct stabilization of H12 helix and are responsible for the transactivation activity of PPARγ [24, 31, 60, 61]. HLA also formed a hydrogen bond with Tyr473 (H12) located on the arm I that harbours transcription activation function-2(AF-2), which is obligatory for ligand binding and as well as in complimenting PPARγ function [27].…”

“…The ligand interactions with ARM-I side chains of Hie323 (H3), Hie449 (H11), Ser289(H3) and Tyr327 of LBD is reported to play a significant role in enhancing agonistic activity as it is found to indirectly influence the H12 stabilization [24, 31, 60, 61]. Of the 10 docked complexes, 9 bioactive lipids are predicted to act as full agonists for PPARγ by forming an H-bond interaction with the ARM-I hydrophilic cavity residues (Hie 323, Hie 449, Tyr473, Ser289 and Tyr327).…”

Coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone improves postprandial endothelial dysfunction in patients with borderline and stage 1 hypertension

“…The reason for the controversial results remains unclear. Hydroxyhydroquinone inhibits the chlorogenic acid-induced restoration of endothelial function and increases production of reactive oxygen species in a dose-dependent manner [29,30]. To evaluate the effects of hydroxyhydroquinone on endothelial function, we compared the effects of coffees with a high content of chlorogenic acids and different contents of hydroxyhydroquinone in Study 1.…”

“…A previous study showed that hydroxyhydroquinone inhibits the chlorogenic acid-induced restoration of endothelial function in a rat model of hypertension [29]. It has also been shown that hydroxyhydroquinone increased the production of reactive oxygen species in a dose-dependent manner [30]. Some clinical studies have shown that coffee with a high content of chlorogenic acids and a low content of hydroxyhydroquinone is effective for reducing blood pressure [31,32].…”

Benefits of curcumin in brain disorders

“…Peroxisome proliferator‐activated receptor gamma (PPAR‐γ) is a ligand‐activated transcriptional factor that belongs to the nuclear hormone receptor superfamily. PPAR‐γ influences the activity of several intracellular second messengers and their signaling cascade, including regulation of insulin sensitivity, glucose homeostasis, fatty acid oxidation, immune responses, redox balance, cardiovascular integrity, and cell fate . Recent studies have reported that activation of PPAR‐γ reduces the development and progression of neurodegenerative diseases by altering the expression of NF‐κB cascade .…”