Perilla seed oil, which contains the highest proportion of ALA among vegetable oils, is widely used
in Asian countries for cooking and as a traditional medicine but remains largely unknown in Western
societies. Evidence from animal studies suggests that perilla seed oil has ability to prevent atherosclerosis
[6] and chemically induced cancer [7] and that it also improves immune [8] and mental function [9].
Enteric coated softgel perilla oil capsules (Entrox) have been recently introduced (i) to address unpleasant
gastrointestinal effects (belching, cramping, clinging odor and taste) associated with consumption of
long-chain o-3 fatty acids, (ii) to increase stability and shelf-life of perilla seed oil capsules by providing a
barrier to oxidation and rancidity, (iii) to increase absorption of perilla seed oil components. The enteric
coating polymer was designed to resist gastric acidmediated disintegration for 60 min, thus bypassing the
stomach and allowing slow release of perilla seed oil components in the neutral medium of the small
intestine. The coating has been formulated using a soft gelatin capsule in which the gelatin matrix has been
augmented with the addition of xylose (a polysaccharide). This modification affects the cross-linking of the matrix
resulting in an improved resistance to air permeation and breakdown in an acidic environment. Thus, the
capsules should not break down in the gastric juices in the stomach, but rather in the small intestine where the potential for absorption is greatest. Previous reports showed that in patients with inflammatory bowel
(Crohn’s) disease, chronic administration of fish oil capsules with similar enteric coating increased incorporation
of EPA and DHA in red blood cell phospholipid membranes [10]. The Entrox-coated perilla seed oil
capsules are available on the market but the bioavailability of their constitutive fatty acids has not been
evaluated. The present study was designed to assess the bioavailability of Entrox-coated vs. uncoated perilla
seed oil capsules.