Lipid reducing activity and toxicity profiles of a library of polyphenol derivatives

Obesity is an increasing epidemic worldwide and novel treatments are urgently needed. Polyphenols are natural compounds derived from plants, which are known in particular for their antioxidant properties. However, some polyphenols were described to possess anti-obesity activities in vitro and in vivo. In this study, we aimed to screen a library of 85 polyphenol derivatives for their lipid reducing activity and toxicity. Compounds were analyzed at 5 μM with the zebrafish Nile red fluorescence fat metabolism assay and for general toxicity in vivo. To improve the safety profile, compounds were screened at 50 μM in murine preadipocytes in vitro for cytotoxicity. Obtained activity data were used to create a 2D-QSAR (quantitative structure activity relationship) model. 38 polyphenols showed strong lipid reducing activity. Toxicity analysis revealed that 18 of them did not show any toxicity in vitro or in vivo. QSAR analysis revealed the importance of the number of rings, fractional partial positively charged surface area, relative positive charge, relative number of oxygen atoms, and partial negative surface area for lipid-reducing activity. The five most potent compounds with EC50 values in the nanomolar range for lipid reducing activity and without any toxic effects are strong candidates for future research and development into anti-obesity drugs. Molecular profiling for fasn, sirt1, mtp and ppary revealed one compound that reduced significantly fasn mRNA expression.

This article is a result of the project INNOVMAR - Innovation and Sustainability in the Management and Exploitation of Marine Re- sources (reference NORTE-01-0145-FEDER-000035, within the research line NOVELMAR, supported by North Portugal Regional Operational Program (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This research was developed under the project PTDC/MAR-BIO/4694/2014 (reference POCI-01-0145-FEDER- 016790) and PTDC/DTPFTO/1981/2014 (POCl-01-0145-FEDER- 016581) supported through national funds provided by FCT e Foundation for Science and Technology and European Regional Development Fund (ERDF) through the COMPETE - Programa Operacional Factores de Competitividade (POFC) programme. Ralph Urbatzka and M. Correia-da-Silva were supported by FCT grants SFRH/BPD/112287/2015 and SFRH/BPD/81878/2011, respectively