1.Dichloromethane extracts of propolis protect cell from oxygen-glucose deprivation-induced oxidative stress via reducing apoptosis.
Sun LP;Xu X;Hwang HH;Wang X;Su KY;Chen YL Food Nutr Res. 2016 Jun 20;60:30081. doi: 10.3402/fnr.v60.30081. eCollection 2016.
BACKGROUND: ;Bee propolis, a mixture of the secretion from bee tongue gland and wax gland, was collected from the tree bud and barked by bees. The components were rich in terpenes, phenolics, and flavonoids, and had anti-cancer, anti-bacterial, anti-inflammatory, hepatoprotective, and neuroprotection abilities. However, the potential anti-oxidative stress of propolis was not well documented. This study aimed to study the protective effect of propolis on high-incident nonfatal diseases, such as stroke and cerebral infarction caused by ischemia.;OBJECTIVE: ;Oxidative stress caused by acute stroke results in inflammation and injury followed by cell damage and apoptosis. Clarification of the anti-oxidative stress effect of propolis may contribute to stroke prevention and damage reduction.;DESIGN: ;Propolis was separated and purified into 70% ethanol and dichloromethane extracts systematically. The fraction three (Fr.3) of dichloromethane was further separated into pinocembrin, pinobanksin, pinobanksin-3-acetate, chrysin, and galangin by chromatography. Compounds extracted from propolis were tested for cell-protection effects in an oxygen-glucose deprivation (OGD) N2a cell model. MTT assay, oxidative stress markers measurement, flow cytometry, and QPCR were used to evaluate cell viability and apoptosis.
2.Main flavonoids, DPPH activity, and metal content allow determination of the geographical origin of propolis from the Province of San Juan (Argentina).
Lima B;Tapia A;Luna L;Fabani MP;Schmeda-Hirschmann G;Podio NS;Wunderlin DA;Feresin GE J Agric Food Chem. 2009 Apr 8;57(7):2691-8. doi: 10.1021/jf803866t.
The chemical characterization as well as the assessment of geographical origin of propolis from several areas of the Provincia de San Juan (Argentina) is reported. Chemical characterization of propolis was performed by measuring total phenolic (TP), total flavonoids (FL), free radical scavenging capacity (DPPH bleaching), and metal content in samples of six different districts. Methanolic propolis extracts (MEP) showed TP ranging from 25.7 to 39.3 g of gallic acid equivalents per 100 g of MEP, whereas flavonoids ranged from 6.6 to 13.3 g of quercetin equivalents per 100 g of MEP. Six main flavonoids were isolated and identified from the propolis samples, comprising the flavanones 7-hydroxy-8-methoxyflavanone (1), pinocembrin (2), and pinobanksin (3), the flavones chrysin (4) and tectochrysin (5), and the flavonol galangin (6). Compounds 1-6 were quantified by HPLC-PDA. Free radical scavenging activity, measured as percent DPPH bleaching, ranged from 46.6 to 89.5 at 10 mug/mL. Moreover, propolis samples presented high contents of Ca, K, Fe, Na, and Mg, but low amounts of Mn and Zn. Linear discriminant analysis affords eight descriptors, galangin, pinocembrin, pinobanksin, chrysin, tectochrysin, DPPH, K, and Na, allowing a clear distinction with 100% accuracy among different origins within the Provincia de San Juan.
3.Chemical characterization and cytotoxic activity evaluation of Lebanese propolis.
Noureddine H;Hage-Sleiman R;Wehbi B;Fayyad-Kazan H;Hayar S;Traboulssi M;Alyamani OA;Faour WH;ElMakhour Y Biomed Pharmacother. 2017 Nov;95:298-307. doi: 10.1016/j.biopha.2017.08.067. Epub 2017 Sep 12.
Chemical composition, anti-proliferative and proapoptotic activity as well as the effect of various fractions of Lebanese propolis on the cell cycle distribution were evaluated on Jurkat leukemic T-cells, glioblastoma U251 cells, and breast adenocarcinoma MDA-MB-231 cells using cytotoxic assays, flow cytometry as well as western blot analysis. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that ferulic acid, chrysin, pinocembrin, galangin are major constituents of the ethanolic crude extract of the Lebanese propolis, while the hexane fraction mostly contains chrysin, pinocembrin, galangin but at similar levels. Furthermore chemical analysis was performed using gas chromatography-mass spectrometry (GC-MS) to identify major compounds in the hexane fraction. Reduction of cell viability was observed in Jurkat cells exposed to the ethanolic crude extract and the hexane fraction, while viability of U251 and MDA-MB-231 cells was only affected upon exposure to the hexane fraction; the other fractions (aqueous phase, methylene chloride, and ethyl acetate) were without effect. Maximum toxic effect was obtained when Jurkat cells were cultivated with 90μg/ml of both the crude extract and hexane faction.