Rhamnolipids elicit the same cytotoxic sensitivity between cancer cell and normal cell by reducing surface tension of culture medium

• Published in: Applied microbiology and biotechnology Vol. 98; no. 24; pp. 10187 - 10196
• Main Authors: Jiang, Lifang, Shen, Chong, Long, Xuwei, Zhang, Guoliang, Meng, Qin
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.12.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Analysis; antineoplastic agents; Applied Microbial and Cell Physiology; Benzene; Bioengineering; Biomedical and Life Sciences; biosurfactants; Biotechnology; Cancer; Cancer cells; Cancer therapies; Cell Line; Cell proliferation; Cell Survival - drug effects; Cells; Cellular biology; chemical structure; culture media; Culture Media - chemistry; Cytotoxicity; Engineering; fetal bovine serum; Glycolipids - toxicity; human cell lines; Humans; Hydrocarbons; Life Sciences; Lipids; Microbial Genetics and Genomics; Microbiology; Pharmaceuticals; Physiological aspects; polysorbates; Reagents; Sodium; sodium dodecyl sulfate; Studies; Surface active agents; Surface Tension; Surface-Active Agents - toxicity; Surfactants; Toxicity; wastes; China; Cytotoxicity; Surface tension; Mono-rhamnolipids; Di-rhamnolipids
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-014-6065-0

Biosurfactant rhamnolipids have been claimed to show biological activities of inhibiting the proliferation of cancer cells. In this study, the cytotoxicity of rhamnolipids was examined on four cancer cells (HepG2, Caco-2, Hela, MCF-7 cells) and two normal cells (HK-2 cell, primary hepatocyte). Interestingly, both cancer cells and normal cells exhibited similar sensitivities to the addition of rhamnolipids in culture medium, and the cytotoxicity was largely attenuated by the presence of fetal bovine serum (FBS) in culture medium. In correlation of the mono-/di-rhamnolipid cytotoxicity with the surface tension of culture medium, it was found that rhamnolipids triggered cytotoxicity whenever the surface tension of culture medium decreased below 41 mN/m irrespective of the FBS content in culture medium, cell line, or rhamnolipid congener. Similarly, each chemical surfactant (Tween-80, sodium dodecyl sulfate, and sodium dodecyl benzene sulfonate) could cause cytotoxicity on HepG2 cells whenever its addition made the surface tension under 41 mN/m in culture medium with or without the presence of FBS. It seems that rhamnolipids, like chemical surfactants, exhibited cytotoxicity by reducing the surface tension of culture medium rather than by changing its specific molecular structure, which had no selection on tumor cells. This study could offer helps to correct the misleading biological activity of rhamnolipids and to avoid the possible large wastes of time and expenses on developing the applications in antitumor drugs.