High-fat diet feeding and palmitic acid increase CRC growth in ß2AR-dependent manner.

Epidemiology studies indicate that consumption of high-fat diet (HFD) is directly associated with the development of colorectal cancer (CRC). However, the exact component in HFD and the mechanism underlying its effect on CRC growth remained unclear. Our study shows that HFD feeding increases ß2AR expression in the xenograft tissues of CRC-bearing mouse model; the elevated ß2AR expression is reduced when HFD is replaced by control diet, which strongly suggests an association between HFD feeding and ß2AR expression in CRC. HFD feeding increases palmitic acid and stearic acid levels in CRC; however, only palmitic acid increases ß2AR expression, which is dependent upon Sp1. ß2AR plays the dominant role in promoting CRC cell proliferation among all the ß-AR subtypes. More importantly, knockout of ß2AR or knockdown of Sp1 abolishes the palmitic acid increased CRC cell proliferation, suggesting palmitic acid increases CRC cell proliferation in ß2AR-dependent manner. HFD or palmitic acid-rich diet (PAD) also fails to increase the tumor growth in xenograft mouse models bearing ß2AR-knockout CRC cells. ß2AR promotes CRC growth by increasing the phosphorylation of HSL at the residue S552. The phosphorylated and activated HSL (S552) changes the metabolic phenotype of CRC and increases energy production, which promotes CRC growth. Our study has revealed the unique tumorigenic properties of palmitic acid in promoting CRC growth, and have delineated the underlying mechanism of action. We are also the first to report the linkage between HFD feeding and ß-adrenergic signaling pathway in relation to CRC growth.

Signal transducer and activator of transcription-3 drives the high-fat diet-associated prostate cancer growth.

Prostate cancer (PCa) is the second leading cause of cancer death in men. PCa progression can be associated with obesity. Signal transducer and activator of transcription-3 (STAT3) plays a crucial role in PCa growth. However, whether STAT3 plays a role in high-fat diet (HFD)-associated PCa growth is unknown. Our data show that HFD feeding increases tumor size, STAT3 phosphorylation, and palmitic acid (PA) level in the xenograft tissues of the PCa-bearing xenograft mouse model. In vitro studies show that PA increases STAT3 expression and phosphorylation (STAT3-Y705) in PCa. Computational modeling suggests strong and stable binding between PA and unphosphorylated STAT3 at R593 and N538. The binding changes STAT3 structure and activity. Functional studies show that both STAT3 mutants (R583A and N538A) and STAT3 dominant negative significantly reduce PA-enhanced STAT3 phosphorylation, PA-increased PCa cell proliferation, migration, and invasion. In the xenograft mouse models, the HFD-increased tumor growth and STAT3 phosphorylation in tumors are reversed by STAT3 inhibition. Our study not only demonstrates the regulatory role of PA/STAT3 axis in HFD-associated PCa growth but also suggests a novel mechanism of how STAT3 is activated by PA. Our data suggest STAT3 as a therapeutic target for the treatment of HFD-associated PCa.

The Potential Impact of Radix Paeoniae Alba in Embryonic Development of Mice.

Although Radix Paeoniae Alba (RPA) has been ranked as one of the top 6 herbs used frequently to prevent and treat miscarriages clinically, there is no clear evidence regarding its safety in embryonic development. This study aims to evaluate the potential impacts of RPA on embryonic stem cells (ESCs) and pregnant mice. Cytotoxicity assays of the extract were performed in ESCs and 3T3 cells. Pregnant ICR mice were orally treated with RPA extracts at dosages of 0 (G1 group as negative controls), 2, 8 and 32 g/kg/day (G2, G3 and G4 groups) respectively from the gestation day (Gd) 6-15. On Gd 18, there was no significant difference in the IC50 values between ESCs and 3T3 cells (p > 0.05). There was no significant difference in the maternal and fetal evaluations among four groups (p > 0.05). Fetal IL-2, IL-2r, TNF-α, TNF-αr, IL-4, IL-4r, IL-10r, IL-17 and IL-17r of G4 group were significantly lower than G1 group (p < 0.05). In conclusion, RPA at dosage of 32 g/kg/day (16-folds of human daily dosage) did not cause adverse impact in cultured ESCs and pregnant mice. RPA might down-regulate fetal Th1/Th2/Th17 cytokines and receptors maybe beneficial to embryonic survival and development. Copyright © 2017 John Wiley & Sons, Ltd.

Chemical differentiation of two taste variants of Gynostemma pentaphyllum by using UPLC-Q-TOF-MS and HPLC-ELSD.

To differentiate the sweet and bitter taste variants of a Chinese medicinal tea Gynostemma pentaphyllum (GP), a method for the quantitative analysis of ginsenosides Rb(1), Rb(3), Rd, and F(2) in GP by using UPLC-Q-TOF-MS was developed. According to the different contents of the four ginsenosides, chemical differentiation of the two taste variants of GP was achieved by principal component analysis (PCA). A supplementary quantitative analysis method of using HPLC-ELSD for determination of 20(S)-panaxadiol in the hydrolysates of GP was also developed. Similarly, chemical differentiation based on different amounts of 20(S)-panaxadiol was established and the result was well consistent with that based on the analysis of the four ginsenosides. It was found that the amounts of the four ginsenosides and 20(S)-panaxadiol in the sweet taste variant were significantly higher than those in the bitter one. The significant difference between the sweet and bitter taste variants of GP was easily visualized in 3D-PCA score plots. The PCA loading plot also indicated the contributions among the four ginsenosides (Rd > Rb(3) > F(2) > Rb(1)) for distinguishing the two taste variants. This is the first report to describe the use of these two quantitative methods (UPLC-Q-TOF-MS and HPLC-ELSD) for the accurate authentication and quality control of GP.