Proteomic analysis identifies differentially expressed proteins after red propolis treatment in Hep-2 cells

Abstract

Here we investigated alterations in the protein profile of Hep-2 treated with red propolis using two-dimensional electrophoresis associated to mass spectrometry and apoptotic rates of cells treated with and without red propolis extracts through TUNEL and Annexin-V assays. A total of 325 spots were manually excised from the two-dimensional gel electrophoresis and 177 proteins were identified using LC-MS-MS. Among all proteins identified that presented differential expression, most were down-regulated in presence of red propolis extract at a concentration of 120 μg/mL (IC50): GRP78, PRDX2, LDHB, VIM and TUBA1A. Only two up-regulated proteins were identified in this study in the non-cytotoxic (6 μg/mL) red propolis treated group: RPLP0 and RAD23B. TUNEL staining assay showed a markedly increase in the mid- to late-stage apoptosis of Hep-2 cells induced by red propolis at concentrations of 60 and 120 μg/mL when compared with non-treated cells. The increase of late apoptosis was confirmed by in situ Annexin-V analysis in which red propolis extract induced late apoptosis in a dose-dependent manner. The differences in tumor cell protein profiles warrant further investigations including isolation of major bioactive compounds of red propolis in different cell lines using proteomics and molecular tests to validate the protein expression here observed.

Brazilian red propolis: phytochemical screening, antioxidant activity and effect against cancer cells

“…Others studies indicated that red propolis induces apoptosis on human tumour cells [ 2 , 12 ] that might be the mechanism behind the high index of cell inhibition induced by EEP at a concentration of 50 μg/mL showed in this study. Similar effect was also demonstrated by Begnini et al [ 22 ] that found the ethanolic extract of red propolis at concentrations of 50 and 100 μg/mL induced high levels of apoptosis in bladder carcinoma cells.…”

“…Propolis has been known since centuries for its healing properties but recently it has captured the attention of scientists due to its wide spectrum activities that can be used in the complementary and alternative medicine [ 6 – 8 ]. Consistently, the number of studies conducted with this substance has exhibited a significant increase in countries without the traditional use of natural medicine [ 2 , 9 – 12 ].…”

Chemical Composition and Biological Activity of Extracts Obtained by Supercritical Extraction and Ethanolic Extraction of Brown, Green and Red Propolis Derived from Different Geographic Regions in Brazil

“…The best anti-proliferative effect showed by the red propolis extract, when compared to other samples of propolis may depend on its differentiated composition, for example, the presence of formononetin, the main isoflavones found in this type of propolis [ 123 – 124 ]. Recently, a polyisoprenylated benzophenone (xanthochymol) was also identified in the red propolis [ 123 ].…”

Ethanol extract of propolis and its constituent caffeic acid phenethyl ester inhibit breast cancer cells proliferation in inflammatory microenvironment by inhibiting TLR4 signal pathway and inducing apoptosis and autophagy

“…Apoptosis was another major cause for Chinese propolis and CAPE to inhibit LPS-stimulated MDA-MB-231 cells survival. We and other researchers all reported that propolis could induce cancer cells apoptosis [ 6 , 31 ]. Here we also found that Chinese propolis and CAPE activated caspase 3- the executor of apoptosis in LPS-stimulated breast cancer cells, which might be induced by activating autophagy and depressing TLR4 signaling pathway.…”