Polypodium leucotomos extract: antioxidant activity and disposition.
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 H2O2-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/H2O2 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.
Gombau
L
L
Advancell, 46009 Valencia, Spain.
García
F
F
Lahoz
A
A
Fabre
Myriam
M
Roda-Navarro
P
P
Majano
P
P
Alonso-Lebrero
J L
JL
Pivel
J P
JP
Castell
J V
JV
Gómez-Lechon
M J
MJ
González
S
S
D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000493:pharmacokinetics*; D018938:Caco-2 Cells; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D062385:Hydroxybenzoates / Q000032:analysis / Q000493:pharmacokinetics*; D010936:Plant Extracts / Q000737:chemistry / Q000493:pharmacokinetics; D032494:Polypodium / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000975:Antioxidants; D062385:Hydroxybenzoates; D010936:Plant Extracts