ornamental or potherb; naturalized in central,
eastern, and western Europe; established as a
casual weed in the eastern United States. The
parts used are the nutlets (seeds), leaves, and
flowers.
CHEMICAL COMPOSITION
Seeds, leaves, and flowers contain pyrrolizi-
dine alkaloids (PA);^1 total alkaloid content
of the plant is less than 0.001%;^2 mature seeds
contain about 0.03% crude alkaloids.^3 Leaves
contain small amounts, including lycopsa-
mine, intermedine, their acetyl derivatives,
supinine, supinidine, and amabiline; also cho-
line (WREN); 9.1% fatty acids, including
a-linolenic acid (55%) andg-linolenic acid
(>4%); silicic acid (1.5%–2.2%); potassium,
calcium, potassium nitrate (3%), acetic, lactic,
and malic acids; d-bornesitol, cyanogens;
fresh leaves contain up to 30% mucilage
hydrolyzing to glucose, galactose, arabinose,
and allantoin (especially in seedlings). Seed
oil (28–38% lipids) is of recent interest as
a rich source of g-linolenic acid (GLA;
17–25%).^2 Other seed fatty acids include li-
noleic (38%), oleic (14.5–23%), palmitic
(11%), and stearic (4.7%).3,4Immature seeds
and flowers contain amabiline and the rare
nontoxic, saturated PA, thesinine;^3 in mature
seeds contain a glucoside of thesinine (thesi-
nine-4^0 - O-b-D-glucoside^5 ); thesinine and tox-
ic PA are absent from seed oil;6,7roots contain
minor amounts of PA (supinine, intermedine,
lycopsamine, amabiline, 7-acetyllycopsa-
mine, and 7-acetylintermedine).^7
PHARMACOLOGY AND BIOLOGICAL
ACTIVITIES
Seed oil of interest for GLA content as a
prostaglandin precursor, especially for PGE 1 ;
prostaglandins help regulate metabolic func-
tions. Normal synthesis of GLA from linoleic
acid viad-6-desaturase may be blocked or
diminished in mammalian systems as the re-
sult of aging, diabetes, excessive carbohydrate
intake, or fasting. Seeds ofOenothera biennis
(seeevening primrose), variousRibesspe-
cies, and borage serve as GLA sources for
dietary supplements, borage seed oil having
the highest concentration.^4 GLA is of poten-
tial therapeutic interest in treatments of atopic
eczema, premenstrual syndrome, diabetes, al-
coholism, inflammation, and prevention of
heart disease and stroke.^8
A methanol extract of the leaves exhibited
antioxidant activity using the DPPH free rad-
ical method. The major antioxidant was iden-
tified as rosmarinic acid.^9 Solvent extracts of
the defatted seeds have shownin vitroantiox-
idant activity in a meat model system^10 and the
DPPH free radical method.^11
A double-blind, placebo-controlled trial of
borage seed oil (providing 1.4 g GLA/day)
in patients with active synovitis and rheuma-
toid arthritis found significant symptomatic
improvements in both tender and swollen
joints.^12 Compared to placebo, borage seed
oil also significantly attenuated heart and
blood pressure rates, decreased task perfor-
mance and the increase in skin temperature in
humans in response to acute stress.^13
TOXICOLOGY
The dried herb, tincture, and decoction fed to
guinea pigs for 5 weeks produced no adverse
effects except for fatty liver. The seed oil
administered orally to mice (0.1 mL) was also
without toxic effects and only produced a mild
laxative effect.^6 Toxic PA in borage are ly-
copsamine and intermedicine and their 7-ace-
tyl derivatives and the only slightly toxic
alkaloid amabiline.^2
USES
Medicinal, Pharmaceutical, and Cosmetic.
Borage extract used in skin care products
(NIKITAKIS).
Food. Seldom used in flavoring; fresh flow-
ers with saline, cucumber-like flavor (free of
toxic PA) used in salads.
Borage 111