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Updated: Jan 23, 2026
Extraction and Analysis of Taiwanese Green Propolis
Published on: January 7, 2019
Antiproliferative Activity of Chemically Characterized Propolis from Turkey and Its Mechanisms of Action
Başak Aru1, Etil Güzelmeric2, Aslı Akgül3
1Department of Immunology, Faculty of Medicine, Yeditepe University, TR-34755, Kayışdağı, İstanbul, Turkey.
Abstract:
The aim of this study was to evaluate the ethanolic extract of propolis originated from northern Turkey for its antiproliferative, apoptotic and cell cycle arrest promoting effects on MCF7, HGC27, A549 cancer cell lines and a healthy cell line (HUVEC) in terms of DNA content, morphological features, expression of cell cycle checkpoint proteins p21, p53, Cyclin D1 and immune checkpoint protein PD-L1. The extract showed moderate antiproliferative activity against all tested cancer cell lines with IC50 values in the range of 58.6-90.7 μg/mL in MTS assay. Further studies indicated that propolis extract exerted apoptotic effect on cancer cell lines, promoted cell cycle arrest through activation of p21 and resulted in accumulation at G0/G1 phase of cancer cells. Propolis treatment caused increased cell size, according to fluorescent imaging except for MCF7. HPTLC analysis revealed that 3-O-methylquercetin, chrysin, caffeic acid, CAPE, galangin and pinocembrin were the main components of the extract. The amounts of caffeic acid and CAPE in the extract were found to be 5.5 and 11.1 mg/g, respectively, by a validated HPLC method. Our study is the first one, revealing effect of propolis on PD-L1 expression on certain cancer cell lines.
Insights
This study shows that Turkish propolis extract has moderate antiproliferative and apoptotic effects on cancer cells, inducing cell cycle arrest. It also uniquely impacts programmed death-ligand 1 (PD-L1) expression in cancer.
Area of Science:
- Natural Products Chemistry
- Cancer Biology
- Immunology
Background:
- Propolis, a natural resinous mixture produced by honeybees, possesses diverse biological activities.
- Cancer remains a leading cause of mortality, necessitating novel therapeutic strategies.
- Immune checkpoint proteins, like PD-L1, are crucial targets in cancer immunotherapy.
Purpose of the Study:
- To investigate the antiproliferative, apoptotic, and cell cycle effects of Turkish propolis extract on human cancer cell lines (MCF7, HGC27, A549) and a healthy cell line (HUVEC).
- To analyze the impact of propolis extract on cell cycle proteins (p21, p53, Cyclin D1) and the immune checkpoint protein PD-L1.
- To identify key chemical constituents of the propolis extract using HPTLC and HPLC.
Main Methods:
- MTS assay for antiproliferative activity assessment.
- Flow cytometry and fluorescent imaging for cell cycle analysis and morphological changes.
- Western blotting to evaluate cell cycle checkpoint proteins (p21, p53, Cyclin D1) and PD-L1 expression.
- High-Performance Thin-Layer Chromatography (HPTLC) and High-Performance Liquid Chromatography (HPLC) for chemical composition analysis.
Main Results:
- Propolis extract exhibited moderate antiproliferative effects (IC50: 58.6-90.7 μg/mL) against tested cancer cell lines.
- The extract induced apoptosis and G0/G1 cell cycle arrest, associated with p21 activation.
- Significant changes in cell size were observed, and notably, propolis influenced PD-L1 expression on cancer cells, a novel finding.
Conclusions:
- Ethanolic propolis extract from Northern Turkey demonstrates significant anticancer potential through antiproliferative and apoptotic mechanisms.
- The extract modulates cell cycle progression and impacts the expression of PD-L1, suggesting a role in immune modulation within the tumor microenvironment.
- This study highlights propolis as a promising source for developing novel cancer therapeutics and provides the first evidence of its effect on PD-L1 expression.
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