title: Antioxidant activities and molecular mechanisms of the ethanol extracts of Baccharis propolis and Eucalyptus propolis in RAW64.7 cells.
abstract: Context Numerous studies have reported that propolis possesses strong antioxidant activities. However, their antioxidant molecular mechanisms are unclear. Objective We utilize ethanol extracts of Chinese propolis (EECP) as a reference to compare ethanol extracts of Eucalyptus propolis (EEEP) with ethanol extracts of Baccharis propolis (EEBGP) based on their antioxidant capacities and underlying molecular mechanisms. Materials and methods HPLC and chemical analysis are utilized to evaluate compositions and antioxidant activities. ROS-eliminating effects of EEBGP (20-75 μg/mL), EEEP (1.25-3.75 μg/mL) and EECP (1.25-5 μg/mL) are also determined by flow cytometry analysis. Moreover, we compared antioxidant capacities by determining their effects on expressions of antioxidant genes in RAW264.7 cells with qRT-PCR, western blot and confocal microscopy analysis. Results EEBGP mainly contains chlorogenic acid (8.98 ± 0.86 mg/g), kaempferide (11.18 ± 8.31 mg/g) and artepillin C (107.70 ± 10.86 mg/g), but EEEP contains 10 compositions, whereas EECP contains 17 compositions. Meantime, although EEEP shows DPPH (IC50 19.55 ± 1.28), ABTS (IC50 20.0 ± 0.31) and reducing power (2.70 ± 0.08 mmol TE/g) better than EEBGP's DPPH (IC50 43.85 ± 0.54), ABTS (IC50 38.2 ± 0.33) and reducing power (1.53 ± 0.05 mmol TE/g), EEBGP exerts much higher ROS inhibition rate (40%) than EEEP (under 20%). Moreover, EEBGP strengthen antioxidant system by activating p38/p-p38 and Erk/p-Erk kinase via accelerating nucleus translocation of Nrf2. EEEP and EECP improve antioxidant gene expression only via Erk/p-Erk kinase-Nrf2 signalling pathway. Discussion and conclusion EEBGP and EEEP exert antioxidant activities via different molecular mechanisms, which may depend on chemical compositions.
authors.affiliation: a College of Animal Science , Zhejiang University , Hangzhou , P.R. China.
authors.forename: Jianglin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: a College of Animal Science , Zhejiang University , Hangzhou , P.R. China.
authors.forename: Xiaoge
authors.initials: X
authors.lastname: Shen
authors.affiliation: a College of Animal Science , Zhejiang University , Hangzhou , P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: a College of Animal Science , Zhejiang University , Hangzhou , P.R. China.
authors.forename: Xueping
authors.initials: X
authors.lastname: Cao
authors.affiliation: a College of Animal Science , Zhejiang University , Hangzhou , P.R. China.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zhang
authors.affiliation: a College of Animal Science , Zhejiang University , Hangzhou , P.R. China.
authors.forename: Huoqing
authors.initials: H
authors.lastname: Zheng
authors.affiliation: a College of Animal Science , Zhejiang University , Hangzhou , P.R. China.
authors.forename: Fuliang
authors.initials: F
authors.lastname: Hu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D031175:Baccharis; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000737:chemistry*; D005052:Eucalyptus; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects* / Q000235:genetics; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D011429:Propolis / Q000737:chemistry*; D000067996:RAW 264.7 Cells; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D012997:Solvents / Q000737:chemistry*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D000975:Antioxidants; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D010636:Phenols; D017382:Reactive Oxygen Species; D012997:Solvents; D000431:Ethanol; D011429:Propolis; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases
keywords: MAPKs; Nrf2; poplar propolis