In Vitro Antioxidant, Antihemolytic, and Anticancer Activity of the Carotenoids from Halophilic Archaea

Abstract

Halophilic archaea represent a promising natural source of carotenoids. However, little information is available about the biological effects of carotenoids from halophilic archaea. In this study, the carotenoids produced by seven halophilic archaeal strains Halogeometricum rufum, Halogeometricum limi, Haladaptatus litoreus, Haloplanus vescus, Halopelagius inordinatus, Halogranum rubrum, and Haloferax volcanii were identified by ultraviolet/visible spectroscopy, thin-layer chromatography, and high-performance liquid chromatography-tandem mass spectrometry. The C carotenoids bacterioruberin and its derivatives monoanhydrobacterioruberin and bisanhydrobacterioruberin were found to be the predominant carotenoids. The antioxidant capacities of the carotenoids from these strains were significantly higher than β-carotene as determined by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. The antihemolytic activities of these carotenoid extracts against HO-induced hemolysis in mouse erythrocytes were 3.9-6.3 times higher than β-carotene. A dose-dependent in vitro antiproliferative activity against HepG2 cells was observed for the extract from Hgm. limi, while that from Hpn. vescus exhibited a relatively high activity in a dose-independent manner. These results suggested that halophilic archaea could be considered as an alternative source of natural carotenoids with high antioxidant, antihemolytic, and anticancer activity.

Bacterioruberin extracts from a genetically modified hyperpigmented Haloferax volcanii strain: antioxidant activity and bioactive properties on sperm cells

“…). Similar DPHH radical scavenging activity was also reported for the carotenoids extracted from various haloarchaea, including H. volcanii (Hou and Cui ). The higher antioxidant activity observed in the Bctr‐rich extracts from the strain HVLON3 compared to βcar was not surprising and it is consistent with the fact that the ability to scavenge free radicals increases with the conjugated double bonds (Bctr has C 50 and 13 CDB vs C 40 and 9 CDB of βcar) (Saito et al .…”

“…The predominance of Bctr in H. volcanii HVLON3 was consistent with the composition of carotenoids extracted from H. volcanii wt (Fig. 1) (Ronnekleiv 1995;Biswas et al 2016;Hou and Cui 2018), Halobacterium salinarum, Halococcus morruhae, Haloterrigena turkmenica, Halorubrum sp and Haloarcula japonica (see Table S1 for detailed references). HVLON3 Bctr-rich extracts were a more effective antioxidant than bcar (threefold) (Fig.…”

“…) (Ronnekleiv ; Biswas et al . ; Hou and Cui ), Halobacterium salinarum , Halococcus morruhae , Haloterrigena turkmenica , Halorubrum sp and Haloarcula japonica (see Table for detailed references).…”

“…A few examples that show the bioactivity of Bctr include Halobacterium halobium carotenoid extracts with antiproliferative activity against HepG2 human cancer cell lines (Abbes et al . ) and in vitro antihaemolytic and anticancer activities of carotenoids extracted from haloarchaea (Hou and Cui ).…”

“…In contrast to C 40 carotenoids derived from plants and algae, the bioactive properties of Bctr are scarcely known and its biotechnological potential is at present unexploited. A few examples that show the bioactivity of Bctr include Halobacterium halobium carotenoid extracts with antiproliferative activity against HepG2 human cancer cell lines (Abbes et al 2013) and in vitro antihaemolytic and anticancer activities of carotenoids extracted from haloarchaea (Hou and Cui 2018).…”