PhytoScience - Article

Evening primrose oil

 

Evening primrose is an indigenous plant to North America. In most species the flowers are yellow; they have a strong, sweet scent, and only bloom at night during the months of June through October; hence the name "Evening Primrose".

Evening primrose has been used for hundreds of years to treat various ailments of the skin and muscular system. Several Native American tribes discovered that the entire plant is edible, and could be used as a painkiller in addition to everyday consumption. The roots have a peppery flavor and can be eaten like a vegetable. The shoots can be eaten as a salad. The whole plant has historically been used to treat various medical conditions.

In Europe; Evening primrose has been used as an effective treatment for PMS. The bark and leaves of evening primrose are said to have astringent and sedative properties. It has also been effective in regards to treatment with gastro-intestinal disorders, asthma and chronic or whooping coughs.

Evening Primrose Oil is extracted from the seeds of the Onagraceae family of plants. The mature seeds contain approximately 7-10% gamma-linolenic acid, (GLA) which is an Omega 6 essential fatty acid. These polyunsaturated fats are good fats, unlike the saturated fats that contribute to heart disease.

Proported Uses

  • Cancer treatment
  • Diabetic neuropathy
  • Eczema
  • GI disorders
  • High cholesterol
  • Mastalgia
  • Menopausal symptoms
  • Premenstrual syndrome
  • Rheumatoid arthritis

Mechanism of Action

Theoretically, GLA can be converted directly to the prostaglandin precursor dihomo-GLA. The administration of the oil might be beneficial to individuals unable to metabolize cis-linolenic acid to GLA and to produce subsequent intermediates of considerable metabolic significance, including prostaglandins.

Adverse Reactions

Reported: Headache, GI upset, nausea, and increased risk of pregnancy complications

Interactions

Anticoagulants / Antiplatelets: May have additive effects and increase risk of bleeding.
Phenothiazines (e.g. fluphenazine): Evening primrose oil may lower the seizure threshold and precipitate seizures in patients taking phenothiazines.primrose

Clinical Summary

Major constituents found in evening primrose: Alanine (0.5%), arginine (1.5%), aspartic acid (1.2%), beta-sitosterol (1.2-2.5%), calcium (1.3-1.8%), cellulose (27%), gamma-linolenic acid (0.5-10%), glutamic acid (2.7%), glycine (1%), fat (15-32%), fiber (43%), histidine (0.4%), isoleucine (0.5%), leucine (1%), lignin (16%), linoleic acid (12-22%), lysine (0.3%), methionine (0.6%), phenylalanine (0.7%), proline (0.6%), protein (15-17%), serine (0.9%) threonine (0.4%), tryptophan (up to 1.6%), tyrosine (0.4%), valine (up to 0.8%) and other lesser constituents.

Oil derived from the plant. Evening primrose oil (EPO) is used for rheumatoid arthritis, premenstrual syndrome, mastalgia, eczema, fatigue and diabetic neuropathy. EPO contains gamma-linolenic acid (GLA), a primary fixed oil that is converted to dihomo-gamma-linolenic-acid, a prostaglandin precursor. Clinical efficacy data are inconsistent, although one study showed GLA to be an effective adjunctive therapy for breast cancer. Adverse reactions include headache and GI disturbances. EPO should not be taken during pregnancy. One study reports a reduced seizure threshold when EPO was combined with phenothiazine antipsychotics. Although EPO does not have intrinsic estrogenic properties, several manufacturers do combine EPO with phytoestrogens, and product labels should be carefully reviewed.

References

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Disclaimer:
These statements have not been evaluated by the FDA. Any product mentioned is not intended to diagnose, treat, cure or prevent any disease.