Polypodium leucotomos extract: Antioxidant activity and disposition

• Published in: Toxicology in vitro Vol. 20; no. 4; pp. 464 - 471
• Main Authors: Gombau, L., García, F., Lahoz, A., Fabre, Myriam, Roda-Navarro, P., Majano, P., Alonso-Lebrero, J.L., Pivel, J.P., Castell, J.V., Gómez-Lechon, M.J., González, S.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2006
• Subjects: ADME; Animals; Antioxidant photoprotective agent; Antioxidants - chemistry; Antioxidants - pharmacokinetics; Caco cells; Caco-2 Cells; Cell Survival - drug effects; Dose-Response Relationship, Drug; Hepatocytes - drug effects; Hepatocytes - metabolism; Hepatocytes - pathology; Humans; Hydroxybenzoates - analysis; Hydroxybenzoates - pharmacokinetics; Photoprotection; Plant Extracts - chemistry; Plant Extracts - pharmacokinetics; Polypodium - chemistry; Polypodium leucotomos; Rats; Rats, Sprague-Dawley; UVR; ECOD; Polypodium leucotomos; Papp; DMSO; ADME; PDTC; Caco cells; TEER; Antioxidant photoprotective agent; PL; Photoprotection
• ISSN: 0887-2333; 1879-3177
• DOI: 10.1016/j.tiv.2005.09.008

The extract of the fern Polypodium leucotomos (PL, Fernblock ®) is an oral photoprotectant with strong antioxidative properties. Recent studies to determine its chemical composition have shown 4-hydroxycinnamic acid ( p-coumaric), 3 methoxy-4-hydroxycinnamic acid (ferulic), 3,4-dihydroxycinnamic acid (caffeic), 3-methoxy-4-hydroxybenzoic acid (vanillic) and 3-caffeoilquinic acid (chlorogenic) to be among its major phenolic components. No conclusive data are available, however, on the H 2O 2-scavenging capacity of these compounds, or on their absorption and metabolism following their oral intake. In the present work, their antioxidative capacity was assessed by the luminol/H 2O 2 assay, their absorption studied using Caco-2 cells to resemble the intestinal barrier, and their metabolism investigated using cultured primary rat hepatocytes. The antioxidant capacity of PL components increased in a concentration-dependent manner, with ferulic and caffeic acids the most powerful antioxidants. The apparent permeability results correspond to a human post-oral administration absorption of 70–100% for all tested substances. Coumaric, ferulic and vanillic acids were metabolized by CYP450-dependent mono-oxygenases and partially conjugated to glucuronic acid and sulfate. These phenolic compounds may contribute to the health benefits afforded by this oral photoprotectant.