Biological properties of carotenoids extracted from Halobacterium halobium isolated from a Tunisian solar saltern
1 Ecole Nationale d’Ingénieurs de Sfax, UR: Etude et Gestion des Environnements Côtier et Urbain, Université de Sfax, B.P. 1173, 3038 Sfax, Tunisia
2 Laboratoire de Génétique Moléculaire des Eucaryotes, Centre de Biotechnologie de Sfax, B.P. 1177, 3038 Sfax, Tunisia
3 Department BIONEC, Section Biochemical Science, Marine Biochemistry Laboratory, University of Palermo, Via Barlotta 4, 91100 (TP), Italy
4 Marine Biology Institute, Consorzio Universitario della Provincia di Trapani, Via Barlotta 4, 91100 (TP), Italy
5 Faculté des Sciences de Sfax, Laboratoire de Biotechnologie Microbienne, B.P. 802, 3018 Sfax, Tunisia
BMC Complementary and Alternative Medicine 2013, 13:255 doi:10.1186/1472-6882-13-255Published: 4 October 2013
Bioactive molecules have received increasing attention due to their nutraceutical attributes and anticancer, antioxidant, antiproliferative and apoptosis-inducing properties. This study aimed to investigate the biological properties of carotenoids extracted from Archaea.
Halophilic Archaea strains were isolated from the brine of a local crystallizer pond (TS7) of a solar saltern at Sfax, Tunisia. The most carotenoid-producing strain (M8) was investigated on heptoma cell line (HepG2), and its viability was assessed by the MTT-test. The cells were incubated with different sub-lethal extract rates, with carotenoid concentrations ranging from 0.2 to 1.5 μM. Antioxidant activity was evaluated through exposing the cells to sub-lethal extract concentrations for 24 hours and then to oxidative stress induced by 60 μM arachidonic acid and 50 μM H2O2.
Compared to non-treated cells, bacterial carotenoid extracts inhibited HepG2 cell viability (50%). A time and dose effect was observed, with cell viability undergoing a significant (P < 0.05) decrease with extract concentration. After exposure to oxidative stress, control cells underwent a significant (P < 0.05) decrease in viability as compared to the non-treated cells.
The bacterial extracts under investigation were noted to exhibit the strongest free radical scavenging activity with high carotenoid concentrations. The carotenoid extract also showed significant antiproliferative activity against HepG2 human cancer cell lines.