Phytochemical characterization and biological activity of apricot kernels’ extract in yeast-cell based tests and hepatocellular and colorectal carcinoma cell lines

Abstract Ethnopharmacological relevance Bitter apricot kernels’ extract contains a broad spectrum of biologically active substances with a lot of attention to amygdalin – cyanogenic glycoside. The extract has been used in the pharmaceutical industry for years as an ingredient of different pharmaceuticals with anti-inflammatory, antimicrobial, or regenerative properties. In traditional medicine, the bitter apricot kernels are known as a remedy for respiratory disorders and skin diseases. The apricot kernels and amygdalin are often prescribed by practitioners for the prevention and treatment of various medical conditions, including colorectal cancer. The present study aims to evaluate the phytochemical composition and the potential antimutagenic, antirecombinogenic, and antitumor effect of apricot kernels’ extract at very low concentrations in yeast cell-based tests and mammalian hepatocellular and colon carcinoma cell lines. Materials and methods Phytochemical analysis was performed by LC-MS profiling. Reverse-phase HPLC and UV detection were applied for the determination of amygdalin quantity in the extract. Biological activity was evaluated by Zimmermann's mutagenicity and Ty1 retrotransposition test. Cytotoxic/antiproliferative activity of apricot kernels' extract was performed on four types of cell lines – HepG2, HT-29, BALB/3T3, clone A31, and BJ using the standard MTT-dye reduction assay. Results Data revealed the presence of more than 1000 compounds and 4 cyanogenic glycosides among them – Amygdalin, Deidaclin, Linamarin and Prulaurasin. The Amygdalin concentration was measured to be 57.8 μg/ml. All extract concentrations demonstrated a strong antigenotoxic, antirecombinogenic, antimutagenic, and anticarcinogenic effect in the yeast cell-based tests. High selectivity of the extract action is established among different mammalian cell lines. Normal cell line BJ is found to be resistant to the extract action. HepG2 was found to be the most sensitive to apricot kernels’ action. Conclusion The present study provides the first phytochemical analysis of Bulgarian bitter apricot kernels. Three new cyanogenic glycosides were reported. Evidence is obtained that the apricot kernels’ extract at low concentrations is not able to induce some of the events related to the initial steps of tumorigenesis. Additionally, a high selectivity of the extract action is established among different cell lines. The most sensitive cell line was found to be HepG2.