Open Access Research article

Cytotoxic and apoptotic evaluations of marine bacteria isolated from brine-seawater interface of the Red Sea

Sunil Sagar1*, Luke Esau1, Tyas Hikmawan2, Andre Antunes2, Karie Holtermann2, Ulrich Stingl2, Vladimir B Bajic1 and Mandeep Kaur1

Author Affiliations

1 King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center, Thuwal, 23955-6900, Kingdom of Saudi Arabia

2 King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal, 23955-6900, Kingdom of Saudi Arabia

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BMC Complementary and Alternative Medicine 2013, 13:29  doi:10.1186/1472-6882-13-29

Published: 6 February 2013

Abstract

Background

High salinity and temperature combined with presence of heavy metals and low oxygen renders deep-sea anoxic brines of the Red Sea as one of the most extreme environments on Earth. The ability to adapt and survive in these extreme environments makes inhabiting bacteria interesting candidates for the search of novel bioactive molecules.

Methods

Total 20 i.e. lipophilic (chloroform) and hydrophilic (70% ethanol) extracts of marine bacteria isolated from brine-seawater interface of the Red Sea were tested for cytotoxic and apoptotic activity against three human cancer cell lines, i.e. HeLa (cervical carcinoma), MCF-7 (Breast Adenocarcinoma) and DU145 (Prostate carcinoma).

Results

Among these, twelve extracts were found to be very active after 24 hours of treatment, which were further evaluated for their cytotoxic and apoptotic effects at 48 hr. The extracts from the isolates P1-37B and P3-37A (Halomonas) and P1-17B (Sulfitobacter) have been found to be the most potent against tested cancer cell lines.

Conclusion

Overall, bacterial isolates from the Red Sea displayed promising results and can be explored further to find novel drug-like molecules. The cell line specific activity of the extracts may be attributed to the presence of different polarity compounds or the cancer type i.e. biological differences in cell lines and different mechanisms of action of programmed cell death prevalent in different cancer cell lines.

Keywords:
Marine bacteria; Deep sea brine pools; Extracts; Cytotoxicity; Apoptosis