Introduction

Typically found in the thickets of mountain slopes, high-altitude meadows, river banks, and seashores, sea buckthorn is a deciduous, hardy, thorny shrub.^1,2 It produces yellow-green flowers in the spring followed by yellow and orange fruits that have a passion fruit flavor when sweetened.¹ The dried fruit has a sour and astringent taste. Native to Asia and Europe, sea buckthorn is widely distributed from China, India, Mongolia, and the Russian Federation, to Afghanistan, Kazakhstan, Kyrgyzstan, Pakistan, Tajikistan, Turkmenistan, Uzbekistan, and parts of Europe.³ The material of commerce comes primarily from China and Russia, with increasing production in Kazakhstan, India, and Germany.⁴ Pharmacopeial quality sea buckthorn used in the Chinese system of medicine is collected in autumn and winter when ripe or frozen hard, removed from foreign matter, and sun dried or dried after steaming. It must contain a minimum of 15% ethanol-soluble extractives, minimum 1.5% of total flavonoids (calculated as rutin), and not less than 0.1% of isorhamnetin as determined by High Performance Liquid Chromatography.⁵ The material used in the Tibetan system of medicine is collected from August to October and processed into a medicinal concentrated decoction form. The pith of the stem is also used medicinally.⁶ In the European Anthroposophical system of medicine, the fresh branches with fruit, the fresh fruits, and the fatty oil obtained from the seeds and/or fruit are used medicinally.⁷

History and Cultural Significance

For over a thousand years, preparations made from sea buckthorn have been used medicinally in Mongolia, China, and Tibet.² The first documented benefits of sea buckthorn were recorded in the classic 8th century CE Tibetan medical text rGyud Bzi (The Four Books of Pharmacopeia). Young branches and leaves were used in ancient Greece as horse feed, which resulted in weight gain and a healthy shine to the horses’ coats, and accounts for the genus name, Hippophae (shining horse). Sea buckthorn selection and breeding began in Russia in 1933, and researchers there have investigated active compounds in the plant’s fruits, leaves, and bark since the 1940s.⁸ Russian cosmonauts incorporated the fruit juice into their diet and the fruit pulp oil into a cream to help protect them from solar radiation. An estimated 1.2 million hectares (nearly 3 million acres) of sea buckthorn are found in China, half of which have been cultivated, with about 150 processing plants that produce over 200 industrial and consumer products such as pharmaceuticals and cosmetics.⁹ Sea buckthorn fruit is an official medicine in the Chinese pharmacopeia, indicated for the treatment of cough with profuse expectoration, indigestion, stagnancy of food with abdominal pain, amenorrhea due to blood stagnation, and traumatic swelling and bleeding under the skin (eccymosis).¹⁰

Various medicinal forms of sea buckthorn are prepared for oral and topical administration in Chinese medicine. In addition to the Chinese pharmacopeial standard for the dried fruit (Fructus Hippophae PPRC), which is used in decoctions, there are other “national standards” established for the seed oil, the fruit oil, and for “flavones powder” (powdered extract of fruit pulp and leaves standardized to isorhamnetin). There are non-official industry standards established for the juice, juice concentrate, powdered juice (spray-dried and freeze-dried), and wine.¹¹ Sea buckthorn oil, extracted from the seeds and/or the fruits, is used externally in cosmetics as a natural ultraviolet light filter, in skin-regenerating compositions, and as a natural plasticizer and emulsifier.¹² In Europe, CO2 extracts of the fruit pulp and of the seeds (oily or semi-solid extracts containing CO2-soluble lipohilic components) are produced for pharmaceutical products, cosmetics for skin care, sunburn, and for essential fatty acid food supplements. Sea buckthorn fruit is high in vitamin A and C,^1,12 protein, fatty acids,¹³ carotene,¹⁴ and vitamin E.¹⁵ The fruit is used to make bonbons, marmalades, syrups, fruit-flavored herb teas, liquors, dietary supplements, and medicinal herbal products.

Sea buckthorn also has environmental value. Between 1950 and 1985, 200,000 hectares (just over 494,210 acres) of sea buckthorn were planted in China for erosion control and fuel wood production.¹⁶ It is being used to reclaim wasteland and mined areas in Canada, Germany, Hungary, Romania, and Russia.

Modern Research

Both clinical and animal research has shown that sea buckthorn preparations, especially the oil obtained from the seeds or fruit, taken internally can treat clinical indicators associated with heart disease,^17,18,19 and a powdered extract of the fruit and leaf, standardized to total flavones, was shown to improve heart function in a small randomized, double-blind, placebo-controlled trial.²⁰ A randomized controlled trial investigating the effect of an undefined sea buckthorn dry extract granule (Sichuan Pharmaceutical Co. LTD) concluded that the extract may be useful for prevention and treatment of liver fibrosis.²¹ A small open-label pilot study investigated the treatment of chronic vaginal inflammation with orally administered capsules containing a mixture of oils extracted from sea buckthorn seeds and berries using supercritical CO2 (Omega 7 Sea Buckthorn Oil manufactured by Aromtech Ltd, Finland). Based on improvements seen in the trial, larger clinical trials are justified.²² The same authors carried out a double-blind, placebo-controlled trial using the same sea buckthorn oil preparation in female patients with Sjögren’s syndrome (an immunologic disorder characterized by the progressive destruction of the exocrine [tear, salivary and sweat] glands). Results of the trial suggest beneficial effects of sea buckthorn oil capsule on the overall condition of the mucous membranes of patients with Sjögren’s syndrome.²³

Sea buckthorn oil is very stable and has shown promise for external use as a therapeutic skin cream ingredient.²⁴ Numerous trials suggest its efficacy in wound and burn healing, skin grafts, and reducing tissue inflammation.²⁵ Sea buckthorn pulp and seed oil has also been found to improve cases of radiation-induced dermatitis, wounds, and burns.²⁶ One human clinical trial has shown sea buckthorn oil to be successful in treating skin pigmentation disorders and prematurely aging skin, as well as in removing freckles.²⁷ Both sea buckthorn pulp oil and seed oil internally have been helpful in alleviating dermatitis in humans.²⁸ (Although the chemistry of the 2 oils differs, they are often combined into one product.)

Future Outlook

Sea buckthorn occurs in sizable stands across the Eurasian continent and there is some concern about its being invasive, although there are both natural and conventional agricultural ways of controlling its spread.² Conversely, it is rarely observed in the wild in Hungary and is protected there as an endangered species. Some experts on sea buckthorn think that this protection needs to be extended and that considerable research and development needs to occur to ensure sea buckthorn’s sustainability. Recent awareness of the plant’s nutritional and medicinal value has led to exploitation and destruction of sea buckthorn in its natural habitat.²

Sea buckthorn grows well in certain parts of Canada and was recently promoted there as a cash crop; however, attempts to produce commercially viable sea buckthorn fruits there have been unsuccessful, due to the planting of a non-optimal variety, resulting in losses by growers (C. Kehler email to M. Blumenthal, Mar. 29, 2008). Agriculture and Agri-Food Canada (AAFC) estimated in 2002 that there was a potential annual demand for 10,000 kilograms (about 22,000 pounds) of sea buckthorn oil in North America.¹⁶ To produce this amount of oil,1.5 million kilograms (about 3,307,000 pounds) of raw fruit would be needed. AAFC also reported that there is potential for a long-term sea buckthorn market in Europe of perhaps 75,000 kilograms (165,000 pounds) of fruit.¹⁶

Various types of sea buckthorn preparations have recently been introduced as dietary supplements and cosmetics in the United States and as natural health products in Canada. Given the relatively wide range of use and the growing body of scientific and clinical research on sea buckthorn preparations, it is likely that they will become popular consumer products in the near future.

-Gayle Engels

References

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