Rafał Stojko

Caffeic Acid Phenethyl Ester and Ethanol Extract of Propolis Induce the Complementary Cytotoxic Effect on Triple-Negative Breast Cancer Cell Lines

Chemotherapy of breast cancer could be improved by bioactive natural substances, which may potentially sensitize the carcinoma cells’ susceptibility to drugs. Numerous phytochemicals, including propolis, have been reported to interfere with the viability of carcinoma cells. We evaluated the in vitro cytotoxic activity of ethanol extract of propolis (EEP) and its derivative caffeic acid phenethyl ester (CAPE) towards two triple-negative breast cancer (TNBC) cell lines, MDA-MB-231 and Hs578T, by implementation of the MTT and lactate dehydrogenase (LDH) assays. The morphological changes of breast carcinoma cells were observed following exposure to EEP and CAPE. The IC50 of EEP was 48.35 µg∙mL−1 for MDA-MB-23 cells and 33.68 µg∙mL−1 for Hs578T cells, whereas the CAPE IC50 was 14.08 µM and 8.01 µM for the MDA-MB-231 and Hs578T cell line, respectively. Here, we report that propolis and CAPE inhibited the growth of the MDA-MB-231 and Hs578T lines in a dose-dependent and exposure time-dependent manner. EEP showed less cytotoxic activity against both types of TNBC cells. EEP and, particularly, CAPE may markedly affect the viability of breast cancer cells, suggesting the potential role of bioactive compounds in chemoprevention/chemotherapy by potentiating the action of standard anti-cancer drugs.

Biological Activity of Propolis-Honey Balm in the Treatment of Experimentally-Evoked Burn Wounds

Medicines of biogenic origin with micro-organic, regenerative and analgesic properties are becoming more and more significant in the treatment of burn wounds. These properties are found in apitherapeutics such as propolis and honey—products collected and processed by a honey bee. Their effect on the course of the healing processes is multidirectional. The aim of the study was a histopathological and biochemical analysis of the processes of scar formation in experimentally evoked burn wounds in white pigs treated with the 1% and 3% Sepropol balms containing standardized extracts of propolis and honey. The results were compared with the therapeutic effects obtained with dermazin cream (1% silver sulfadiazine). The level of collagen was determined in the wounds treated with 1% and 3% Sepropol and compared with the collagen level in healthy skin and wounds treated with dermazin. Granulation and regenerated epithelium formation times were compared, with the 3% Sepropol being by far the most effective. The 3% Sepropol also increased the collagen level to 116% with the control sub-groups scoring between 80% and 98%. The results show the healing process of burn wounds in pigs treated with the Sepropol balm starts earlier and has a faster course than the standard dermazin therapy.

Migration Rate Inhibition of Breast Cancer Cells Treated by Caffeic Acid and Caffeic Acid Phenethyl Ester: An In Vitro Comparison Study

One of the deadliest cancers among women is a breast cancer. Research has shown that two natural substances occurring in propolis, caffeic acid (CA) and caffeic acid phenethyl ester (CAPE), have significant anticancer effects. The purpose of our in vitro study was to compare cytotoxic activity and migration rate inhibition using CA and CAPE (doses of 50 and 100 µm) against triple-negative, MDA-MB-231 breast adenocarcinoma line cells, drawn from Caucasian women. Viability was measured by XTT-NR-SRB assay (Tetrazolium hydroxide-Neutral Red-Sulforhodamine B) for 24 h and 48 h periods. Cell migration for wound healing assay was taken for 0 h, 8 h, 16 h, and 24 h periods. CAPE displayed more than two times higher cytotoxicity against MDA-MB-231 cells. IC50 values for the XTT assay were as follows: CA for 24 h and 48 h were 150.94 µM and 108.42 µM, respectively, while CAPE was 68.82 µM for 24 h and 55.79 µM for 48 h. For the NR assay: CA was 135.85 µM at 24 h and 103.23 µM at 48 h, while CAPE was 64.04 µM at 24 h and 53.25 µM at 48 h. For the SRB assay: CA at 24 h was 139.80 µM and at 48 h 103.98 µM, while CAPE was 66.86 µM at 24 h and 47.73 µM at 48 h. Both agents suspended the migration rate; however, CAPE displayed better activity. Notably, for the 100 µM CAPE dose, motility of the tested breast carcinoma cells was halted.

Comparison of Two Components of Propolis: Caffeic Acid (CA) and Caffeic Acid Phenethyl Ester (CAPE) Induce Apoptosis and Cell Cycle Arrest of Breast Cancer Cells MDA-MB-231

Studies show that caffeic acid (CA) and caffeic acid phenethyl ester (CAPE) are compounds with potent chemopreventive effects. Breast cancer is a common form of aggressive cancer among women worldwide. This study shows a comparison of CA and CAPE activity on triple-negative human caucasian breast adenocarcinoma line cells (MDA-MB-231). MDA-MB-231 cells were treated by CA and CAPE with doses of from 10 to 100 µM, for periods of 24 h and 48 h. Cytotoxicity MTT tests, apoptosis by Annexin V, and cell cycle with Dead Cell Assays were performed. Cytotoxic activity was greater for CAPE compared to CA (both incubation times, same dosage). IC50 values for CAPE were 27.84 µM (24 h) and 15.83 µM (48 h) and for CA > 10,000 µM (24 h) and > 1000 µM (48 h). Polyphenols induced apoptosis, while CAPE (dose dependently), induced a higher apoptotic effect. CAPE also induced cell cycle arrest in S phase (time and dose dependently), CA did it only for 50 and 100 µM. A dose dependent decline was seen for the G0/G1 phase (CAPE, 48 h), as well as elimination of phase G2/M by 100 µM of CAPE (only mild effect for CA). Comparing CA and CAPE activity on MDA-MB-231, CAPE clearly showed better activity for the same dosages and experiment times.

Polyphenol content and antioxidant activity of bee pollen extracts from Poland

Our study determined the effect of extraction method of bee pollen on the optimal antioxidant activity of the extract obtained. We determined the content of polyphenols and flavonoids as well as the antioxidant activity of the ethanol extract of pollen loads (EEP), the pepsin extract of pollen loads (PEP), and the pepsin-digested extract of pollen loads (EEPP). The total content of polyphenols was measured using Follin–Ciocalteau reagent. The flavonoid content was measured using aluminum chloride. Phenolic acids and flavonoids were identified and quantified by HPLC. The antioxidant activity was measured by 2,2-diphenyl-picrylhydrazyl radical scavenging activity assays and Trolox equivalents antioxidant capacity. Antioxidant activities were the highest in EEPP and associated with the total content of phenolic and flavonoid compounds. This study indicated that pepsin digestion conducted before ethanol extraction allowed us to obtain more bioactive compounds, as well as the highest antioxidant activity of extract.

Comparison of Signaling Pathways Gene Expression in CD34− Umbilical Cord Blood and Bone Marrow Stem Cells

The aim of the study was to compare the biological activity of the total pool of genes in CD34− umbilical cord blood and bone marrow stem cells and to search for the differences in signaling pathway gene expression responsible for the biological processes. The introductory analysis revealed a big similarity of gene expression among stem cells. When analyzing GO terms for biological processes, we observed an increased activity of JAK-STAT signaling pathway, calcium-mediated, cytokine-mediated, integrin-mediated signaling pathway, and MAPK in a cluster of upregulating genes in CD34− umbilical cord blood stem cells. At the same time, we observed a decreased activity of BMP signaling pathways, TGF-beta pathway, and VEGF receptor signaling pathway in a cluster of downregulating genes in CD34− umbilical cord blood stem cells. In accordance with KEGG classification, the cytokine-cytokine receptor interaction, toll-like receptor signaling pathway, and JAK-STAT signaling pathway are overrepresented in CD34− umbilical cord blood stem cells. A similar gene expression in both CD34− UCB and BM stem cells was characteristic for such biological processes as cell division, cell cycle gene expression, mitosis, telomere maintenance with telomerase, RNA and DNA treatment processes during cell division, and similar genes activity of Notch and Wnt signaling pathways.

The influence of pH and pCO2 levels of umbilical cord blood obtained perinatally on selected parameters of stem cells

OBJECTIVE The aim of the study was to demonstrate a correlation between pH and pCO2 levels in umbilical cord blood and the quality of the harvested material. Additionally the effect of pH and pCO2 on the number of cord blood CD34+ cells and their vitality was analyzed. MATERIAL AND METHODS The study included 50 pregnant women after vaginal delivery at term or elective cesarean section. Umbilical cord blood was collected immediately after birth. The probes were analyzed at the Polish Stem Cell Bank in Warsaw. RESULTS The number of CD34+ cells ranged from 0.1-0.2 in white blood cells count over 12 thousand/ml and pH of > 7.3. If pH ranged between 7.35-7.40, the number of CD34+ was 0.3-0.4. The highest number of CD34+ cells was noted for pH of 7.30-7.35 and amounted to 0.4-0.5. Analysis of stem cell vitality showed that the highest level, over 98%, was obtained when pH was < 7.3 and > or = 7.4. The study revealed the viability of stem cells to drop to 97-98% at pH level of 7.3-7.4. Low values of CD34+ (0.01-0.09) were related to pCO2 of > 40.0 mmHg. For pCO2 < 38 mmHg, the value of CD34+ cells was 0.2-0.3%, which is relatively high. However when pCO2 was > or = 38 mmHg, the number of CD34+ ranged between 0.1-0.2. CONCLUSIONS Viability of the umbilical cord stem cells increases along with the decrease of pH and pCO2 levels. The mode of delivery does not influence the viability of the stem cells.

Comparison of gene expression of mitogenic kinin path in adherent and non-adherent CD 34-stem cells using oligonucleotide microarrays.

One of the more interesting cells present in the umbilical cord blood - as far as their potential clinical use is concerned - are stem cells not presenting the CD34 antigen. These are the pluripotential cells with their biological properties similar to mesenchymal stem cells, with the ability to differentiate into such tissue types as bone, cartilage, nervous (to some extent), glia and muscle. The authors compared the activity of genes coding the proteins in mitogenic signal paths activated by kinin receptors using oligonucleotide microarrays in adherent and non-adherent CD 34- cells derived from umbilical cord blood. In the linear regression model with a 95% prognosis area for differentiating genes outside this area, the following genes were selected: c-jun (present in 3 isoforms) and c-fos. The fos and jun genes create the AP-1 transcriptive factor which regulates the expression of genes taking part in numerous cellular processes, including the cell cycle and mitosis. The obtained results shed some light on the molecular processes behind the MSC proliferation and are a starting point for further studies on the mesenchymal stem cell biology.