Planta Med 2015; 81 - PM_68
DOI: 10.1055/s-0035-1565445

In vitro protection and toxicity assessment of Chios Mastic Gum extracts and isolated triterpenic acids using human hepatocarcinoma cells

V Laskari 1, 2, E Katsanou 2, K Kyriakopoulou 2, A Termentzi 1, 3, AL Skaltsounis 2, N Fokialakis 2, K Machera 1
  • 1Laboratory of Toxicological Control of Pesticides, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 14561, St. Delta 8, Kifissia, Greece
  • 2Laboratory of Pharmacognosy and Natural Products Chemistry, School of Pharmacy, National and Kapodistrian University of Athens, 15771, Panepistimiopolis Zografou, Athens, Greece
  • 3Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 14561, St. Delta 8, Kifissia, Greece

Chios mastic gum (CMG), is the resin obtained from Pistacia lentiscus (L.) var. chia (Duham). The plant is cultivated in Chios Island, Greece, and it is known since ancient times for its pharmacological activities.

In the current work, total mastic extract (a) was fractionated giving the neutral (b) and the acidic fraction (c). The latest was used for the purification of several characteristic mastic triterpenic acids at a Supercritical Fluid Chromatography (SFC) system.

The cytotoxic and potential genotoxic effects of (a), (b), (c) and of the isolated triterpenic acids masticadienonic (d) and isomasticadienonic (e) were investigated in vitro using human hepatocarcinoma (HepG2) cells. Cytotoxicity was determined using the MTT assay at concentrations 0.5 to 200 µg/mL for the extracts (a, b, c) and 10– 12 to 10– 5 M for the pure compounds (d, e) after 24-hr incubation in HepG2 cells. The results showed significant cytotoxic activity of all the extracts at 100 µg/mL. Isolated compounds exhibited no cytotoxic activity at the concentrations tested. For the determination of the genotoxic potential, the single cell gel electrophoresis (Comet assay) was used. Pure compounds were tested at concentrations 10– 8 to 10– 6 M and extracts at concentrations 0.5, 1, 5, 10 and 25 µg/mL for 24 hrs in HepG2 cells. Isolated compounds showed no genotoxic potential for the concentrations tested whilst only total mastic extract with polymer exhibited genotoxic activity (DNA damage) at the highest concentration tested. The protective activity of CMG against hydrogen peroxide-induced DNA damage in HepG2 cells has also been tested with the Comet assay and results obtained show a protective activity of the acidic fraction at concentrations of 0.5 and 1 µg/mL. Genotoxicity and cytotoxicity are also currently tested with the γ-H2AX – In Cell Western assay using the Odyssey CLx Infrared system to corroborate the results of the Comet assay.