Original Contribution FERULIC ACID EXCRETION AS A MARKER OF CONSUMPTION OF A FRENCH MARITIME PINE (PINUS MARITIMA) BARK EXTRACT FABIO VIRGILI, ² GEORGE PAGANA, ‡ LOUISE BOURNE, ‡ GERALD RIMBACH,* FAUSTA NATELLA, ² CATHERINE RICE-EVANS, ‡ and LESTER PACKER* *Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA; ² National Institute of Nutrition, Rome, Italy; and ‡ Antioxidant Research Centre, Guy’s, King’s and St Thomas School of Biomedical Sciences, King’s College, London, UK (Received 19 November 1999; Revised 29 February 2000; Accepted 9 March 2000) Abstract—French maritime pine (Pinus maritima) bark extract (PBE) is a polyphenol-rich food supplement patented under the name of Pycnogenol and known to have strong antioxidant activity and different beneficial effects on human health. Although its biological properties have begun to be extensively studied both in vitro, in laboratory animals and more recently in humans, little is known about its bioavailability. The present study investigated the urinary excretion of free and conjugated ferulic acid, present in quantitatively detectable amounts in PBE, after oral PBE administration to human subjects. Eleven healthy adult subjects (4 women and 7men) consumed either a single dose (200 mg PBE) or two doses of PBE (100 and 200 mg, respectively) within a 48-h interval. Two days before the oral administration of PBE and during the urine sample collection period volunteers adhered to a diet low in polyphenols. Aliquots of all urine production were collected over 24 h. Free and conjugated ferulic acid was assessed in urine by HPLC using diode array detection. A close association between the dietary intake of PBE and the urinary excretion of ferulic acid was detected. Moreover, the results indicate that a considerable proportion of ferulic acid is excreted as glucuronide or sulfate after PBE consumption, varying over the range 2 to 20% between individuals. The kinetics of excretion associated with the administration of 100 mg PBE was quite similar to that obtained after 200 mg PBE. A a biphasic trend was evident in a number of subjects. All subjects studied here displayed a significant, although variable level of excretion of ferulic acid after supplementation with PBE, Thus, the data provide evidence that at least a part of the phenolic components of PBE are absorbed, metabolized, and eliminated by humans. © 2000 Elsevier Science Inc. Keywords—Bioavailability, Ferulic acid, Pine (Pinus maritima) bark extract, Free radicals INTRODUCTION A growing interest is seen in the utilization of polyphe- nol-rich plant extracts as dietary food supplements. A wide spectrum of beneficial activity for human health has been advocated for these kind of supplements, at least in part, because of their strong antioxidant activity [1– 4]. More recently, the ability of antioxidant nutrients to effect cell response and gene expression has been re- ported in vitro, providing a novel and different mecha- nistic perspective underlying the biological activity of plant extracts [5–9]. The term “nutraceutical” has, therefore, been estab- lished to describe a food item that significantly and positively affects human health [10]. The standardized extract from the bark of the French maritime pine (pine bark extract [PBE]), which is one of the most utilized food supplements in the Western countries, is patented under the name Pycnogenol (Horphag Research Ltd, Geneva, Switzerland). Its biological properties and ac- tivities have been recently reviewed [11]. PBE is ob- tained by water extraction of the raw bark of the Pinus maritima followed by ethyl acetate washing to eliminate some of the nonwater-soluble substances, as described both in the early work of Masquelier [12] and in the U.S. patent (#4,698,360). Although its chemical composition is still not completely elucidated, the main constituents of PBE are known to be phenolic compounds, broadly divided into monomers (catechin, epicatechin, and taxi- folin) and condensed flavonoids classified as procyani- Address correspondence to: Dr. Lester Packer, 251 Life Science Addition, University of California, Berkeley, CA, 94720-3200, USA; Tel: (510) 642 1872; Fax: (510) 642 8313; E-Mail: packer@socrates.berkeley.edu. Free Radical Biology & Medicine, Vol. 28, No. 8, pp. 1249 –1256, 2000 Copyright © 2000 Elsevier Science Inc. Printed in the USA. All rights reserved 0891-5849/00/$–see front matter PII S0891-5849(00)00244-6 1249