New insights into the effects of formulation type and compositional mixtures on the antioxidant and cytotoxic activities of dietary supplements based-on hepatoprotective plants
Artichoke (A), borututu (B) and milk thistle (M) are included in several supplements to provide beneficial effects. Different formulations (infusions, pills and syrups), as also different proportions of A, B and M (1:1:1, 2:1:1, 1:2:1, 1:1:2) within each formulation were assayed to optimize the desired benefits. The antioxidant activity, anti-hepatocellular carcinoma activity, hepatotoxicity and bioactive compounds contents were evaluated. Syrups tended to be the formulation with highest antioxidant activity and total phenolics and flavonoids content; otherwise, pills were the worst formulation. In what concerns A:B:M ratios, the results did not reveal so pronounced differences. None of the assayed mixtures resulted to be toxic (up to the maximum assayed dose) for liver primary cells (PLP2), but some samples, especially infusions, showed toxicity for the hepatocellular carcinoma cell line (HepG2). With no exception, the mixtures for all formulations gave synergistic effects in antioxidant activity, when compared to the activity of single plants.
The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). J.C.M. Barreira and R.C. Calhelha thank FCT, POPH-QREN and FSE for their grants (SFRH/BPD/68344/2010 and SFRH/BPD/72802/2010, respectively). L. Barros thanks “Compromisso para a Ciência 2008” for her contract.
