Toxicity order of cholanic acids using an immobilised cell biosensor

Area of Science:

• Environmental toxicology
• Biotechnology
• Biochemical analysis

Background:

• Cell-based biosensors are increasingly used for compound toxicity evaluation.
• Toxicity biosensors detect alterations in cell metabolic functions caused by toxic substances.
• A rapid toxicity testing method for aqueous matrices is needed.

Purpose of the Study:

• To develop and utilize a biosensor for rapid toxicity screening of cholanic acid sodium salts.
• To establish a toxicity ranking for free and conjugated cholanic acids.
• To validate the biosensor's performance against existing in vitro toxicity data.

Main Methods:

• Development of a biosensor using immobilized yeast cells (Saccharomyces cerevisiae).
• Quantification of changes in respirometric curves before and after incubation with cholanic acid sodium salts.
• Determination of toxicity ranking based on the slopes of regression lines.

Main Results:

• A toxicity scale was established for free cholanic acids: deoxycholic acid > chenodeoxycholic acid > ursodeoxycholic acid > cholic acid.
• A similar scale was determined for glycocholanic acids: glycodeoxycholic acid > glycochenodeoxycholic acid > glycocholic acid.
• Results showed good agreement with previously published in vitro toxicity data.

Conclusions:

• The immobilized yeast cell biosensor provides a valid method for rapid toxicity assessment of organic compounds.
• This biosensor is suitable for preliminary toxicity evaluation of pharmaceutical compounds in aqueous environments.
• The established toxicity ranking offers valuable insights into the relative hazards of different cholanic acid derivatives.