Chemical compositions of chrysanthemum teas and their anti-inflammatory and antioxidant properties.

Seventeen commercial chrysanthemum teas (Chrysanthemum morifolium and Coreopsis tinctoria) were extracted with hot-H2O, and examined and compared to the 75% methanol extracts for their chemical compositions using UPLC/Q-TOF-MS analysis. For the first time, 6, 8-C,C-diglucosylapigenin and eriodicyol-7-O-glucoside were detected in the Snow chrysanthemum, and acetylmarein was detected in HangJu, GongJu and HuaiJu. The extracts were also examined for their radical scavenging and anti-inflammatory activities in vitro. The hot-H2O extract of Kunlunmiju 1 had the greatest total phenolic content, and relative DPPH and oxygen radical absorbance capacity values of 12.72 mg gallic acid equivalents/g, 105.48 and 1222.50 µmol Trolox equivalents/g, respectively. In addition, all the hot-H2O extracts suppressed the lipopolysaccharide-induced interleukin-6, IL-1ß and cyclooxygenase-2 mRNA expressions, and H2O2-induced intracellular reactive oxygen species production in cultured cells. The results from this research may be used to promote the consumption of chrysanthemum as a functional tea.

Gypenosides Reduced the Risk of Overweight and Insulin Resistance in C57BL/6J Mice through Modulating Adipose Thermogenesis and Gut Microbiota.

This study investigated whether and how gypenosides from jiaogulan tea at 100 and 300 mg/kg/day levels could reduce the development of overweight and insulin resistance in C57 BL/6J mice fed a high-fat diet in 12 weeks. The 300 mg/kg/day gypenosides supplement significantly reduced final body weight, plasma total cholesterol, and homeostasis model assessment-estimated insulin resistance (HOMA-IR) index by 19.9%, 40%, and 36%, respectively, compared with the high-fat diet control group. Gypenosides also increased brown adipocyte tissue activity and white adipose tissue browning. The expression of genes involved in mitochondrial activity and fatty acid ß-oxidation were also increased in both brown and white adipocyte tissues. In addition, gypenosides at 100 and 300 mg/kg/day levels decreased the ratio of Firmicutes to Bacteroidetes by 20% and 58.6%, respectively, and increased Akkermansia muciniphila abundance in the gut microbiota.

Inhibitory Effect of Piceatannol on TNF-α-Mediated Inflammation and Insulin Resistance in 3T3-L1 Adipocytes.

Piceatannol, a bioactive component in grape and blueberry, was examined for its potential in decreasing the inflammatory activities in adipocytes using a cocultured adipocyte and macrophage system, and suppressing tumor necrosis factor-α (TNF-α)-mediated inflammation and the related insulin resistance using a 3T3-L1 adipocyte model. Piceatannol at 10 µM significantly reduced the release of inflammatory cytokines of TNF-α and monocyte chemoattractant protein-1 (MCP-1) by 19 and 31% in the cocultured system, respectively. Pretreatment with piceatannol also inhibited TNF-α-induced expression of interleukin-6 (IL-6) and MCP-1 at both mRNA and protein levels in the 3T3-L1 adipocytes. Piceatannol also partially improved the malfunction of insulin-stimulated glucose uptake, which was reduced by TNF-α in 3T3-L1 adipocytes. Furthermore, the inhibitions were mediated by significant blocking of IκBα phosphorylation and nuclear factor-κB (NF-κB) activation through suppressing nuclear translocation of NF-κB p65 along with c-Jun N-terminal kinase (JNK)-mitogen activated protein kinase (MAPK) activation. In addition, the Akt-dependent forkhead box O1 (FoxO1) signaling pathway was involved in the restoration of insulin-stimulated glucose uptake through suppressing the down-regulation of phosphorylation of Akt and FoxO1 expressions. These results suggested the potential of piceatannol in improving chronic inflammatory condition and insulin sensitivity in obese adipose tissues.