An apolar Pistacia lentiscus L. leaf extract: GC-MS metabolic profiling and evaluation of cytotoxicity and apoptosis inducing effects on SH-SY5Y and SK-N-BE(2)C cell lines

Abstract

In the course of a cytotoxicity screening of Mediterranean plants vs. neuroblastoma cells, Pistacia lentiscus was of interest. Pl-C extract, prepared from dried leaves by ultrasound assisted maceration (UAM) in chloroform, was profiled through using GC-MS techniques. To evaluate Pl-C cytotoxicity towards SH-SY5Y and SK-N-BE(2)-C cell lines, MTT, SRB and LDH assays were performed. The caspase-3 activation, DNA fragmentation, as well as micronucleation, were also evaluated. The Pl-C oxidant/antioxidant ability was estimated using different methods. The extract, rich in pentacyclic triterpenes, inhibited mitochondrial redox activity and cell viability of the tested cell lines. LDH assay established that Pl-C did not affect the cell membrane integrity. Indeed, it was able to activate caspase-3 and to cause a ladder pattern of DNA. Western blotting analysis showed that Pl-C processed caspase-3 providing two cleavage products of approximately 20 and 17-kDa, whose densitometric evaluation highlighted that Pl-C was more effective than vinblastine by 3-fold. The pro-apoptotic effect could be related to a disturbance in cell redox balance. In fact, it increased intracellular ROS production, GSSG/GSH ratio and the formation of lipoperoxidation products. The data obtained prompted to further investigate and assess the in vivo efficacy of Pl-C to prevent and/or treat neuroblastoma.

Keywords: Apoptosis-inducing effects; Cytotoxicity; GC-MS; Pentacyclic triterpenes; Pistacia lentiscus L.; Pro-oxidant activity.