Estrogenic activity and toxicity screening of Damnacanthal nanospheres and their metabolites assessed using an in vitro bioluminescent yeast assay

Abstract

The root of Morinda citriforia L. (Noni) was used to extract Damnacanthal (Damna), an anthraquinone compound. In this study, Damna was successfully incorporated in N-phthaloylchitosan-grafted poly (ethylene glycol) methyl ether (PhCS-g-mPEG) to form Damna nanospheres (Damna-NS) with the particle size 298 nm and the incorporation efficiency 36.30 %. A bioluminescent yeast-reporter system was used to assess Damna-NS’s estrogenic or toxic effects. The initial screening results revealed that both Damna and Damna-NS themselves showed no estrogenic effect. They showed strong effects when treated with a S9 fraction or liver microsomes, showing that their metabolites are estrogenic. Toxicity tests demonstrated that Damna and Damna-NS are harmful when used alone; however, they showed no toxicity when treated with S9 mix. In conclusion, the findings showed that Damna-NS, when taken as an oral phytoestrogen for hormone replacement treatment, has the potential to endanger human health by producing estrogenic effects and minimizing harmful effects in the liver.

Keywords

• Damnacanthal
• Amphiphilic chitosan nanospheres
• Bioluminescent yeast assay
• Estrogenic activity
• Metabolic activation