Evening primrose seed oil

Wright, S. and Burton, J.L., Evening primrose seed oil improves atopic eczema, Lancet, ii, 1120, 1982. 

Gamma-linolenic acid (18 3n-6) is an important unsaturated fatty acid. It is the precursor for biosynthesis of arachidonic acid that is a precursor for prostaglandin formation. Recently, y-linolenic acid has been recognized for its potential health benefits in prevention and treatment of cardiovascular disorders, premenstrual syndrome, atopic eczema, rheumatic arthritis, and alcoholism (13, 14). Seed oils of blackcurrant and other Ribes species, as well as evening primrose seed oils, are rich sources of natural y-linolenic acid. 

Blackcurrant and Evening primrose stand for Blackcurrant and Evening primrose seed oil, respectively. Numbers correspond to the references cited, nd stands for not detected, whereas N/A stands for not applicable. 

C18H30O2 M 278.434 (Z,Z,Z) form [506-26-3] y-Linolenic acid. Gamolenic acid, ban, usan Isol. from evening primrose seed oil. A minor component of many animal lipids. Antihypercholesterolemic drug. Hexabromide Mp 196 dec. 

Evening primrose oil (OEP) is derived from the plant s small, dark seeds (5). China is now the major grower of evening primrose seed in the world, supplying an estimated 90% of the world s crop (3). A total of approx 4001 of seeds are processed each year in the United States and Canada. One major supplier of OEP derives the oil from specially selected and hybridized forms of Oenothera species (6). 

Evening primrose is a North American native biennial plant. With an estimated 90% of global supply, China has actually become the major producer of evening primrose seed worldwide. Evening primrose oil has a long history of use as an alternative medicine and is offered for healthy, active-lifestyle diets. It contains up to 10% of y-linolenic acid (GLA). Formulations of GLA apply for a range of nutritional, cosmetic and pharmaceutical products, including some used in the treatment of rheumatoid arthritis (Table 9.1.7). 

The psychiatric community, the lay press, and ads on the Internet have drawn attention to the role of essential fatty acids (EFAs) on neural development and on the treatment of mental illness. The EFAs are often referred to as omega-3 and omega-6 fatty acids, and include fish oil, flax seed oil, and evening primrose oil supplements. 

Evening primrose oil. This oil is extracted from the seeds of the evening primrose wildflower plant,... 

There are a number of minor oils, all of high value, most of which are marketed mainly either for medical purposes or for their flavour. Olive, evening primrose, borage, fish oils and cocoa butter are described elsewhere. Others include hazelnut, walnut, macadamia, almond, apricot, pumpkin, poppy-seed and rice bran oils. The process of testing for authenticity of these oils should be approached in the same way as for the bulk oils above, i.e. fatty acid profile, sterols, tocopherols and triglyceride composition. However, there is little generally available published material on the ranges of values to be expected... 

Evening primrose (Oenothera biennis L.), a biennial plant belonging to the Ona-graceae family, is considered a weed native to North America. It is cultivated in a number of countries on account of the nutritional and pharmaceutical properties of the oil which is in constant demand (Carter, 1988). The oil extracted, referred to as evening primrose oil (EPO), is a good source of GLA. Unlike commercial oilseeds, evening primrose does not produce a high yield of seeds, but is a preferred source of GLA as it does not contain any ALA. 

The presence of C22 l and C24 l in commercial EPO detected by Gibson et al. (1992) suggested possible adulteration of the oil as these fatty acids were not found in any of the seeds they analysed. However, other studies did report the presence of C22 1 in evening primrose (Muderhwa et al., 1987 Singer et al., 1990). These fatty acids were not detected by Court et al. (1993) in their seed samples, with the exception of one sample which had several peaks that were quite negligible and did not warrant further examination. 

Singer, P., Moritz, V., Wirth, M., Berger, I. and Forster, D. (1990) Blood pressure and serum lipids from SHR after diets supplemented with evening primrose, sunflower seed or fish oil. Prostaglandins Leukotrienes Essential Fatty Acids, 40, 17-20. 

GLA is commercially available in three seed oils blackcurrant, borage, and evening primrose. The production and use of these oils has been reviewed by Clough (80, 81). See also references 82-85 and Section 2.3 (Table 7). 

Of the above discussed sources of GLA, the commercial oils are mainly produced from borage and evening primrose. Black currant oil is limited as a result of availability of seeds for oil production, whereas hemp is still subject to trade restrictions in many countries because of the potential tetrahydrocannabinoid (THC) content. Echium is a new crop and has not been commercialized to any signihcant extent so far. All of these seeds are processed following general methods of oil extraction common in the vegetable oil industry as discussed here. 

An alternative route to EPA and DHA can come from elongation and further desaturation of stearidonic acid (18 4A ). Certain plants, including blackberry, borage, and evening primrose, contain up to 25% of y-linolenic acid (18 3A ) in their seed oil, with considerably smaller amounts of stearidonic acid. The y-linolenate arises from the action of a A6-desaturase on linoleate. Small amounts of co-3-desaturase present in these seeds account for the stearidonate produced. When A6-desaturase from borage was introduced into soy, plants producing up to 29% y-linolenate (precursor to arachidonate), with up to 4% stearidonate in oil, resulted (32). Further desaturation to stearidonate could be promoted with high expression of an co-3-desaturase. 

The seeds of Oenothera biennis (evening primrose, fever plant, king s cure-all, night willow herb, scabish, sundrop, tree primrose) yield evening primrose oil, which contains gamma-linolenic acid and has been used in various disorders, such as atopic eczema, premenstrual syndrome, and benign breast pain, but is probably not efficacious (1,2). 

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