Inclusion complex of quercetin with sulfobutylether ß-cyclodextrin: preparation, characterization, antioxidant and antibacterial activities and the inclusion mechanism.

Quercetin (QCT) has a variety of pharmacological effects, such as antioxidant, antibacterial, anticancer, anticardiovascular and antiaging effects. However, its poor water solubility, stability and bioavailability limit its applications. The special structure of cyclodextrins and their derivatives with a hydrophobic inner cavity and hydrophilic outer wall can load a variety of hydrophobic drugs of a suitable size and shape, thereby improving the stability and solubility of these molecules. In this study, an inclusion complex of quercetin and sulfobutylether-ß-cyclodextrin was prepared. It was characterized via FT-IR, UV, 1H NMR, XRD, DSC, and SEM analysis, which revealed the successful formation of the inclusion complex. In vitro biological activity estimations were carried out and the results indicated that the inclusion complex displayed higher antioxidative and antibacterial properties compared with free QCT. In addition, the mechanisms of inclusion were explored using 1H NMR analysis and docking calculations, thus providing a theoretical basis for obtaining an inclusion complex.

Triterpenes from Poria cocos are revealed as potential retinoid X receptor selective agonists based on cell and in silico evidence.

Poria cocos is an edible and medicinal fungus that is widely used in Traditional Chinese Medicines as well as in modern applications. Retinoid X receptor (RXR) occupies a central place in nuclear receptor signaling, and a pharmacological RXR-dependent pathway is involved in myeloid cell function. Here, structural information for 82 triterpenes from P. cocos and 17 known RXR agonists was collected in a compound library and retrieved for a molecular docking study. Three triterpenes, 16α-hydroxytrametenolic acid (HTA), pachymic acid (PA), and polyporenic acid C (PPAC), were identified as novel RXR-specific agonists based on luciferase reporter assays and in silico evidence. Treatment with HTA, PA, and PPAC significantly induced differentiation of the human promyelocytic leukemia cell line HL-60 with EC50 values of 21.0 ± 0.52, 6.7 ± 0.37, and 9.4 ± 0.65 µM, respectively. These effects were partly blocked by the RXR antagonist UVI3003, suggesting that an RXR-dependent pathway may play an important role in their anti-acute promyelocytic leukemia (APL) effects. Taken together, triterpenes from P. cocos are revealed as naturally occurring RXR selective agonists with the potential for anti-cancer activity. These results suggest a novel approach to the treatment or prevention of APL.

16α-Hydroxytrametenolic Acid from Poria cocos Improves Intestinal Barrier Function Through the Glucocorticoid Receptor-Mediated PI3K/Akt/NF-κB Pathway.

This study evaluated the effect of triterpenoids from edible mushroom Poria cocos on intestinal epithelium integrity and revealed the transcriptional regulatory pathways that underpin restorative mechanisms in the gut. Based on computational docking studies, transcriptional activation experiments and glucocorticoid receptor (GR) protein immunofluorescence localization assays in cultured cells, 16α-hydroxytrametenolic acid (HTA) was discovered as a novel GR agonist in this study. HTA ameliorates TNF-α-induced Caco-2 monolayer intestinal epithelial barrier damage and suppressed activation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt), which attenuated downstream IκB and nuclear factor kappa-B (NF-κB) phosphorylation through GR activation. Moreover, HTA prevented NF-κB translocation into the nucleus and binding to its cis-element and suppressed lipopolysaccharide-induced downstream NO production and pro-inflammatory cytokines at both protein and mRNA expression levels. In conclusion, HTA from P. cocos improves intestinal barrier function through a GR-mediated PI3K/Akt/NF-κB signaling pathway and may be potentially exploited as a supportive dietary therapeutic strategy for restoring gut health.