title: Comparisons of ethanol extracts of chinese propolis (poplar type) and poplar gums based on the antioxidant activities and molecular mechanism.
abstract: The biological activities of propolis are varied from plant sources and the prominent antioxidant effects of Chinese propolis (poplar type) have been extensively reported. Oxidative stress is associated with inflammation and induces many diseases. In the study, to evaluate antioxidant capacities and clarify the underlying molecular mechanisms of ethanol extracts of Chinese propolis (EECP) and ethanol extracts of poplar gums (EEPG), we analyzed their compositions by HPLC, evaluating their free radical scavenging activities and reducing power by chemical analysis methods. Moreover, we studied the roles of EECP and EEPG on the elimination of ROS and expressions of antioxidant genes (HO-1, TrxR1, GCLM, and GCLC) in RAW264.7 cells. We further investigated the effects of MAPKs on the antioxidant genes expression by specific inhibitors. The nucleus translocation effects of Nrf2 were also measured by confocal microscopy analysis. The results indicated that EECP had higher TPC and FDC values but regarding TFC values were not significant. EECP also possessed more contents of 11 compounds than EEPG. Both phytochemical analysis and cell experiment reflected that EECP exerted stronger antioxidant activities than EEPG. EECP and EEPG enhanced endogenous antioxidant defenses by eliminating reactive oxygen species directly and activating Erk-Nrf2-HO1, GCLM, and TrxR1 signal pathways.
authors: College of Animal Science, Zhejiang University, Hangzhou 310058, China.
authors: Jianglin
authors: J
authors: Zhang
authors: College of Animal Science, Zhejiang University, Hangzhou 310058, China.
authors: Xueping
authors: X
authors: Cao
authors: College of Animal Science, Zhejiang University, Hangzhou 310058, China.
authors: Shun
authors: S
authors: Ping
authors: College of Animal Science, Zhejiang University, Hangzhou 310058, China.
authors: Kai
authors: K
authors: Wang
authors: Husbandry and Veterinary Technical Popularization Center of Zhejiang Province, Hangzhou 310020, China.
authors: Jinhu
authors: J
authors: Shi
authors: College of Animal Science, Zhejiang University, Hangzhou 310058, China.
authors: Cuiping
authors: C
authors: Zhang
authors: College of Animal Science, Zhejiang University, Hangzhou 310058, China.
authors: Huoqing
authors: H
authors: Zheng
authors: College of Animal Science, Zhejiang University, Hangzhou 310058, China.
authors: Fuliang
authors: F
authors: Hu