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

In vitro cytotoxic activity on KATO-III cancer cell lines of mangiferolic acid purified from Thai Tetragonula laeviceps propolis

Gastric cancer is a global health concern, but current treatment with chemotherapy and surgery is often inadequate, prompting the exploration of alternative treatments. Propolis is a natural substance collected by bees known for its diverse properties linked to floral sources. The Dichloromethane Partitioned Extract (DPE) from Tetragonula laeviceps propolis, in Bankha district, Thailand was previously shown to possess significant cytotoxicity against KATO-III gastric cancer cells, while showing lower cytotoxicity toward WI-38 normal fibroblast cells. Here, the DPE was further fractionated by column chromatography, identified active fractions, and subjected to structural analysis using nuclear magnetic resonance spectroscopy. Cytotoxicity against KATO-III cells was reevaluated, and programmed cell death was analyzed using flow cytometry. Expression levels of cancer-related genes were measured using quantitative real-time reverse transcriptase PCR. Cardol C15:2 (compound 1) and mangiferolic acid (MF; compound 2) were discovered in the most active fractions following structural analysis. MF exhibited strong cytotoxicity against KATO-III cells (IC50 of 4.78-16.02 μg/mL), although this was less effective than doxorubicin (IC50 of 0.56-1.55 μg/mL). Morphological changes, including decreased cell density and increased debris, were observed in KATO-III cells treated with 30 μg/mL of MF. Significant induction of late-stage apoptosis and necrosis, particularly at 48 and 72 h, suggested potential DNA damage and cell cycle arrest, evidenced by an increased proportion of sub-G1 and S-phase cells. Doxorubicin, the positive control, triggered late apoptosis but caused more necrosis after 72 h. Furthermore, MF at 30 μg/mL significantly increased the expression level of COX2 and NFκB genes linked to inflammation and cell death pathways. This upregulation was consistent at later time points (48 and 72 h) and was accompanied by increased expression of CASP3 and CASP7 genes. These findings suggest MF effectively induces cell death in KATO-III cells through late apoptosis and necrosis, potentially mediated by upregulated inflammation-related genes.

Souto E, Cardoso JC. Red Propolis and Its Dyslipidemic Regulator Formononetin: Evaluation of Antioxidant Activity and Gastroprotective Effects in Rat Model of Gastric Ulcer

Propolis has various pharmacological properties of clinical interest, and is also considered a functional food. In particular, hydroalcoholic extracts of red propolis (HERP), together with its isoflavonoid formononetin, have recognized antioxidant and anti-inflammatory properties, with known added value against dyslipidemia. In this study, we report the gastroprotective effects of HERP (50–500 mg/kg, p.o.) and formononetin (10 mg/kg, p.o.) in ethanol and non-steroidal anti-inflammatory drug-induced models of rat ulcer. The volume, pH, and total acidity were the evaluated gastric secretion parameters using the pylorus ligature model, together with the assessment of gastric mucus contents. The anti-Helicobacter pylori activities of HERP were evaluated using the agar-well diffusion method. In our experiments, HERP (250 and 500 mg/kg) and formononetin (10 mg/kg) reduced (p < 0.001) total lesion areas in the ethanol-induced rat ulcer model, and reduced (p < 0.05) ulcer indices in the indomethacin-induced rat ulcer model. Administration of HERP and formononetin to pylorus ligature models significantly decreased (p < 0.01) gastric secretion volumes and increased (p < 0.05) mucus production. We have also shown the antioxidant and anti-Helicobacter pylori activities of HERP. The obtained results indicate that HERP and formononetin are gastroprotective in acute ulcer models, suggesting a prominent role of formononetin in the effects of HERP.

Encapsulation of Red Propolis in Polymer Nanoparticles for the Destruction of Pathogenic Biofilms

Microbial biofilms, structured communities of microorganisms, have been often associated to the infection and bacterial multiresistance problem. Conventional treatment of infection involves the use of antibiotics, being an alternative approach is the use of red propolis, a natural product, to prepare polymer nanoparticles. The aim of the present study was to encapsulate red propolis extract in poly(lactic-co-glycolic acid) (PLGA) nanoparticles for destruction in vitro of pathogenic biofilms. Poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) containing red propolis hydroethanolic extract (2 mg/mL) were produced by emulsification solvent diffusion method. The extract and developed nanoparticles were analyzed for antimicrobial activity and inhibition of bacterial biofilm formation in vitro against Staphylococcus aureus and Pseudomonas aeruginosa. Transmission electron microscopy images confirmed spherical nanoparticles in the range size from 42.4 nm (PLGA NPs) to 69.2 nm (HERP PLGA NPs), with encapsulation efficiencies of 96.99%. The free extract and encapsulated in polymer nanoparticle presented antimicrobial potential, with a minimum inhibitory concentration from 15.6 to 125 μg mL^-1 and from 100 to 1560 μg mL^-1 to inhibit biofilm formation for the Staphylococcus aureus and Pseudomonas aeruginosa, respectively.

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

Background

Propolis and its major constituent – caffeic acid phenethyl ester (CAPE) have good abilities on antitumor and anti-inflammation. However, little is known about the actions of propolis and CAPE on tumor in inflammatory microenvironment, and inflammatory responses play decisive roles at different stages of tumor development. To understand the effects and mechanisms of ethanol-extracted Chinese propolis (EECP) and its major constituent - CAPE in inflammation-stimulated tumor, we investigated their effects on Toll-like receptor 4 (TLR4) signaling pathway which plays a crucial role in breast cancer MDA-MB-231 cell line.

Methods

80% confluent breast cancer MDA-MB-231 cells were stimulated with 1 μg/mL lipopolysaccaride (LPS). Then the cells were divided for treatment by CAPE (25 μg/mL) and EECP (25, 50 and 100 μg/mL), respectively. Cell viability, nitric oxide (NO) production and cell migration were measured by sulforhodamine B assay, chemical method and scratch assay. The levels of TLR4, MyD88, IRAK4, TRIF, caspase 3, PARP, LC3B and p62 were investigated through western blotting. The expression of TLR4, LC3B and nuclear factor-κB p65 (NF-κB p65) were tested by immunofluorescence microscopy assay.

Results

Treatment of different concentrations of EECP (25, 50 and 100 μg/mL) and CAPE (25 μg/mL) significantly inhibited LPS-stimulated MDA-MB-231 cell line proliferation, migration and NO production. Furthermore, EECP and CAPE activated caspase3 and PARP to induce cell apoptosis, and also upregulated LC3-II and decreased p62 level to induce autophagy during the process. TLR4 signaling pathway molecules such as TLR4, MyD88, IRAK4, TRIF and NF-κB p65 were all down-regulated after EECP and CAPE treatment in LPS-stimulated MDA-MB-231 cells.

Conclusions

These findings indicated that EECP and its major constituent - CAPE inhibited breast cancer MDA-MB-231 cells proliferation in inflammatory microenvironment through activating apoptosis, autophagy and inhibiting TLR4 signaling pathway. EECP and CAPE may hold promising prospects in treating inflammation-induced tumor.

Antitumor activity of Brazilian red propolis fractions against Hep-2 cancer cell line

Continuous increases in the rates of tumor diseases have highlighted the need for identification of novel and inexpensive antitumor agents from natural sources. In this study, we investigated the effects of enriched fraction from hydroalcoholic Brazilian red propolis extract against Hep-2 cancer cell line. Initially 201 fractions were arranged in 12 groups according to their chromatographic characteristics (A-L). After an in vitro cell viability screening, J and L were further selected as promising enriched fractions for this study. The chemical characterization was performed and Biochanin A, Formononetin, and Liquiritigenin compounds were quantified. Through MTT viability assay and morphological changes observed by Giemsa and DAPI staining, the results showed that red propolis inhibited cancer cells growth. Flow cytometry results indicated effects that were partly mediated through programmed cell death as confirmed by externalization of phosphatidylserine, DNA cleaved assay, increase at SUB G1-G0 phase in cell cycle analysis and loss of mitochondrial membrane potential. In conclusion, our results demonstrated that red propolis enriched fractions promoted apoptotic effects in human cancer cells through the mechanisms involving mitochondrial perturbation. Therefore, red propolis fractions contain candidate agents for adjuvant cancer treatment, which further studies should elucidate the comprehensive mechanistic pathways.

A proteomic analysis of acute leukemia cells treated with 9-hydroxyoctadecadienoic acid

BACKGROUND

9s-hydroxy-octadecadienoic acid (9S-HOD), one of the natural products of linoleic acid oxygenation by 15-lipoxygenase (15-LOX), has been found to have anti-tumor properties in vitro and in vivo. The present study therefore investigated whether 9S-HOD affects acute leukemia HL-60 cells.

METHODS

The cytotoxicity of 9S-HOD in HL-60 with or without the presence of fetal bovine serum (FBS) in the culture media was tested using cell viability assays and flow cytometry. To explore the mechanism of its anti-tumor activity by 9S-HOD, we used a proteomic analysis to identify HL-60 cells protein profiles, based on two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) identification.

RESULTS

9S-HOD exerted cytotoxicity efficacy and induced apoptosis in HL-60 cells, and the cytotoxicity was largely attenuated by the presence of FBS in culture media. The proteomic results revealed that 9S-HOD remarkably altered the abundance of 23 proteins that were involved in mRNA metabolic process, protein binding, DNA replication and apoptosis.

CONCLUSIONS

Our results indicated that 9S-HOD exerts cytotoxicity in HL-60 cells by affecting several pathways.

Cellular Stress and p53-Associated Apoptosis by Juniperus communis L. Berry Extract Treatment in the Human SH-SY5Y Neuroblastoma Cells

Plant phenolics have shown to activate apoptotic cell death in different tumourigenic cell lines. In this study, we evaluated the effects of juniper berry extract (Juniperus communis L.) on p53 protein, gene expression and DNA fragmentation in human neuroblastoma SH-SY5Y cells. In addition, we analyzed the phenolic composition of the extract. We found that juniper berry extract activated cellular relocalization of p53 and DNA fragmentation-dependent cell death. Differentially expressed genes between treated and non-treated cells were evaluated with the cDNA-RDA (representational difference analysis) method at the early time point of apoptotic process when p53 started to be activated and no caspase activity was detected. Twenty one overexpressed genes related to cellular stress, protein synthesis, cell survival and death were detected. Interestingly, they included endoplasmic reticulum (ER) stress inducer and sensor HSPA5 and other ER stress-related genes CALM2 and YKT6 indicating that ER stress response was involved in juniper berry extract mediated cell death. In composition analysis, we identified and quantified low concentrations of fifteen phenolic compounds. The main groups of them were flavones, flavonols, phenolic acids, flavanol and biflavonoid including glycosides of quercetin, apigenin, isoscutellarein and hypolaetin. It is suggested that juniper berry extract induced the p53-associated apoptosis through the potentiation and synergism by several phenolic compounds.

Discovery of nutritional biomarkers: future directions based on omics technologies

Understanding the interactions between food and human biology is of utmost importance to facilitate the development of more efficient nutritional interventions that might improve our wellness status and future health outcomes by reducing risk factors for non-transmittable chronic diseases, such as cardiovascular diseases, cancer, obesity and metabolic syndrome. Dissection of the molecular mechanisms that mediate the physiological effects of diets and bioactive compounds is one of the main goals of current nutritional investigation and the food industry as might lead to the discovery of novel biomarkers. It is widely recognized that the availability of robust nutritional biomarkers represents a bottleneck that delays the innovation process of the food industry. In this regard, omics sciences have opened up new avenues of research and opportunities in nutrition. Advances in mass spectrometry, nuclear magnetic resonance, next generation sequencing and microarray technologies allow massive genome, gene expression, proteomic and metabolomic profiling, obtaining a global and in-depth analysis of physiological/pathological scenarios. For this reason, omics platforms are most suitable for the discovery and characterization of novel nutritional markers that will define the nutritional status of both individuals and populations in the near future, and to identify the nutritional bioactive compounds responsible for the health outcomes.

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 variations in the chemical composition, and consequently, on the biological activity of the propolis, are associated with its type and geographic origin. Considering this fact, this study evaluated propolis extracts obtained by supercritical extraction (SCO2) and ethanolic extraction (EtOH), in eight samples of different types of propolis (red, green and brown), collected from different regions in Brazil. The content of phenolic compounds, flavonoids, in vitro antioxidant activity (DPPH and ABTS), Artepillin C, p-coumaric acid and antimicrobial activity against two bacteria were determined for all extracts. For the EtOH extracts, the anti-proliferative activity regarding the cell lines of B16F10, were also evaluated. Amongst the samples evaluated, the red propolis from the Brazilian Northeast (states of Sergipe and Alagoas) showed the higher biological potential, as well as the larger content of antioxidant compounds. The best results were shown for the extracts obtained through the conventional extraction method (EtOH). However, the highest concentrations of Artepillin C and p-coumaric acid were identified in the extracts from SCO2, indicating a higher selectivity for the extraction of these compounds. It was verified that the composition and biological activity of the Brazilian propolis vary significantly, depending on the type of sample and geographical area of collection.

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

BACKGROUND

The implementation of new public healthcare models that stimulate the use of natural products from traditional medicine, as a so-called integrated medicine, refers to an approach that use best of both conventional medicine and traditional medicine. Propolis is a widely used natural product by different ancient cultures and known to exhibit biological activities beneficial for health. The large number of studies conducted with propolis had shown that its chemical composition differs as a function of the climate, plant diversity and bee species and plays an important role on its therapeutic properties. The aim of this study was to analyse the phytochemical profile of the ethanolic extract of red propolis (EEP) and its fractionation, antioxidant action of EEP and its fractions hexane, cloroform and ethyl acetate and cytotoxic activity of EEP on human tumour cell lines SF-295 (glioblastoma), OVCAR-8 (ovary) and HCT-116 (colon).

METHODS

EEP was obtained by maceration with absolute ethanol, then it was concentrated in rotaevaporator up to complete evaporation of the solvent. The crude extract was fractionated with hexane, ethyl acetate, chloroform and methanol and they were subjected to phytochemical screening and total phenolic compounds. Antioxidant activity of EEP and fractions was done by means of the 2,2-diphenyl-1-picryhydrazyl (DPPH) method. Biomarkers of red propolis were identified by LC-Orbitrap-FTMS. To assess cytotoxic activity of the extract, cells were exposed to EEP over 72 h. Cell viability was assessed by means of MTT assay. The percentage of cell growth inhibition (IC50) was analysed by means of non-linear regression, and the absorbance values of the various investigated concentrations were subjected to one-factor analysis of variance (ANOVA) followed by Tukey's or Tamhane's tests (α = 0.05).

RESULTS

The results obtained using phytochemical screening and LC-Orbitrap-FTMS indicated the presence of phlobaphene tannins, catechins, chalcones, aurones, flavonones, flavonols, xanthones, pentacyclic triterpenoids and guttiferones in Brazilian red propolis. EEP and its hexane, chloroform and ethyl acetate fractions obtained by liquid-liquid partitioning exhibited satisfactory antioxidant percentages. EEP (IC50 < 34.27 μg/mL) exhibited high levels of cytotoxicity on all human tumour cell lines tested when compared to negative control.

CONCLUSIONS

C-Orbitrap-FTMS was useful to establish the chemical profile of the red propolis. Brazilian red propolis has antioxidant properties and decreases substantially the percentage of cell survival of human tumour cells; thus, it has potential to serve as an anticancer drug.