The consumption of sea buckthorn, Hippophae rhamnoides, has come to the forefront as a popular supplement in recent years. This popular supplement, derived from the orange-yellow berries of the actinomycetes plant species, can be found in extract pill form, as well as in candies, beverages, jams, and even cosmetics, (Michel, et al, 2012). Beyond its popularity as a supplement, it has proven itself to be beneficial in medicine. In fact, H. rhamnoides has been used in many regions of Europe and Asia in traditional and folk medicines, including in the Tibetian, Mongolian, and Chinese cultures for many decades, (Guliyev, et al, 2004). With sea buckthorn's extensive amounts of nutrients, polyphenals, and a diverse amount of chemical constituents with healing properties, this herb has many potential uses in both complimentary and alternative medicine and preventative medicine alike.
Origins and ethnobotanical background
The deciduous plant itself comes from the Elaeagnaceae family, growing up to six meters in height with a thick main stock and elongated leaves attached to thin, gray branches. Leaves of the plant can grow either in cluster or alternating formation, with a light green color on top of the leaf and a shimmering gray underside. When in bloom, the heterosexual male or female plant pollinates via wind dispersion, and later bears a yellowish-orange berry which is powdered in a silver dust. The berry, when ripe, is sour to the taste with citrus notes (Guliyev, et al, 2004).
There are seven primary species in the genus Hippophae and eight subspecies exist of H rhamnoides L. Hippophae rhamnoides, Hippophae salicifolia, Hippophae tibetana, Hippophae rhamnoides L. are the most commonly known (Suryakumar & Gupta, 2011).
Native to Europe, H. ramnoides is a hardy plant, grown in higher altitudes and frequently survives the bitter cold and long droughts (Suryakumar & Gupta, 2011). This plant can be found in many areas across Europe and Asia, including Italy, Spain, Britain, Russia, India, Turkey, and Tibet.
More recently, it was domesticated in Canada and British Columbia (Guliyev, et al, 2004).
From an ethnobotanist's perspective, H. rhamnoides has been used in traditional and folk medicines in many European and Asian cultures. Sea buckthorn was used in traditional Chinese medicine since the Tang Dynasty; Scandinavians used the plant as an agricultural necessity, providing food, medicine, veterinary care, and domestic tools; in other regions, ancient cultural uses of the plant included fencing, fodder, timber, herbal supplementation, and livestock feed (Suryakumar & Gupta, 2011). In Chinese medicine, sea buckthorn has been used as a cough suppressant, digestion aid, and pain reliever. In other traditional medicines the plants are used in the treatment of colitis, gastrointestinal upset, and diarrhea. The hemostatic actions of the plant made it useful in India and Tibet for aiding in pulmonary, cardiac, blood, and metabolic disorders. Other cultures have used the plant creatively for dermatological disorders and rheumatoid arthritis (Guliyev, et al, 2004).
H. rhamnoides consists of many vitamins, bio-flavanoids, phytosterols, and fatty acids essential for human health. Many of the constituents contained within H. rhamnoides posses therapeutic actions such as immunumodulatory, hepato-protective, and antioxidant properties, (Guliyev, et al, 2004). The tiny berries are considered to be a great source of vitamins A, C, E, and K, as well as vitamin B complex. The fruit also contains adequate amounts of riboflavin, folic acid, zinc, coumarins, triterpenes, essential fatty acids, α-carotene, β-carotene, δ-carotene, lycopene, malic acid, oxalic acid, tocopherols and polyphenolic compounds (Suryakumar & Gupta, 2011). H. rhamnoides contains six cyclitol isomers, neo-inositol, myo-inositol, D-chiro-inositol, L-chiro-inositol, scyllo-inositol, and muco-inositol (Yang, et al, 2011) The phytosterols in sea buckthorn include campesterol, clerosterol, lanosterol, sitosterol, sitostanol,α-amyrin β-amyrin, Δ5- avenasterol, Δ24(28) – stigmastaenol, A stigmastadienol, Δ5,24(25) - stigmastadienol, lupeol + gramisterol, Δ57 - sitosterol, cycloartenol, cycloeucalenol, Δ7- avenasterol, 28 - methylobtusifoliol, 24 – methylenecycloartanol, erythrodiol, citrostadienol, uvaol, and oleanol aldehyde, (Li, et al, 2007). Of the oil found in sea buckthorn, 32.8% is palmitoleic acid, 17.3% is oleic acid, 9.1% is vaccenic acid, 9% is linoleic acid, and 3.4% is α-linolenic acid (Mathew, et al, 2011).
Impacts of geographical variations
Hippophae rhamnoides, as with any plant, may vary in physiological and physiochemical characteristics depending on a multitude of factors such as climate, weather, participation, and local variety of genotypes (Yang, et al, 2011), (Suryakumar & Gupta, 2011) and (Ercisli, et al, 2007). Thorough research is constantly being conducted in order to investigate the composition and phytochemicals of the world's sea buckthorn. The research has focused on primarily the fruits and seeds, such as sterols, phenolic compounds, vitamins, minerals, tocopherols, fatty acids, and carotenoids (Yang, et al, 2011).
Hippophae rhamnoides' pharmacological and medicinal uses
Because of the H. rhamnoides ability to produce large amounts of phenolic compounds, such as flavonoids, phenolic acid, and tannins, the fruit exhibits a high anti-pathogenic properties. The antioxidant properties exhibited in the fruit are also well noted in medicinal literature due to the berries' high amounts of ascorbic acid, carotenoids, flavonoids, proanthocyanidins, (Michel, et al, 2012). The oils from the berries and seeds have been shown to stabilize membrane structures and slow down the overall oxidation process in animal studies. The antioxidative effects of the seed oil decreased malondialdehyde levels and increased sialic acid both in the liver and erythrocyte membranes in rats and guinea pigs, while protecting them from cold-induced tissue damage. The oil also had increased activities of gluthathione peroxidase, Na, K-ATPase, superoxide dismutase, and glucose-6-phosphate dehydrase (Yang & Kallio, 2002).
Studies have also concluded that the phenolic compounds within the fruit pulp inhibit Gram- negative bacteria, prohibit tumor growth and gastric ulcers in rats, plus it has demonstrated health benefits for dermatological disorders, (Guliyev, et al, 2004).
The polyunsaturated fatty acids within the fruit offer immunomodulatory and neuroprotective activity, while the organic acids lower the risk of heart attacks, stroke prevention, anti-ulcer, anti-arthritic, and wound healing properties (Suryakumar & Gupta, 2011). In a double-blind, randomized, controlled study, twelve healthy, normolipidemic males between 20 and 59 years of age were asked to consume 5 grams per day of a random fatty acid blend of consisting of sea buckthorn berry oil and fractionated coconut oil for a period of 4 weeks, then separated by a 4 to 8 week washout. Out of the twelve participants, eleven completed the study. Fasting (12 hour) venous blood samples were drawn both before and after each supplementation equaling four samples per participant. The blood samples were centrifuged and then analyzed. It was concluded at the end of the study that the oil influenced platelet aggregation, especially aggregation induced by adenosine-5'-diphosphates (Johansson, et al, 2000).
Sea buckthorn extracts have shown to provide hepatoprotective activity, including the leaves and seed oil. In studies using CCI4 induced hepatic damage in animals, the constituents in the leaves, such as myricetin and quercetin were shown to significantly protect the liver from further damage from CCI4 induced hepatic damage (Suryakumar & Gupta, 2011).
The tocopherols within the fruit acts as an anti-oxidant, minimizes lipid oxidation, and reduces pain (Suryakumar & Gupta, 2011). The majority of the tocopherols and tocotienols in H. rhamnoides are found in the fruit and seeds, 10 – 150 mg/kg and 100 – 300 mg/kg respectfully (Yang & Kallio, 2002). Other antioxidant compounds, such as carotenoids, also aid in cardiovascular health, decreasing the development of atherosclerosis, and increasing HDL cholesterol levels. In a double-blind, placebo-controlled parallel design study, sea buckthorn juice was administered to thirty non-smoking males with history of cardiovascular disease and either hematological, hepatic, renal, diabetes, or hormonal dysfunction for an 8-week period. Blood samples were obtained from each participant after a 12 hour fast; tests were conducted on the samples, including LDL oxidation analysis, sICAM-1 measurments, and plasma lipid levels. Of the thirty participants, twenty completed the eight-week study. Although there was no observable changes in LDL cholesterol following the trial, there was increases in plasma TAG and HDL-C levels in the group taking the sea buckthorn juice (Eccleston, et al, 2002).
Carotenoids are known for their ability to help with collagen synthesis and epithelialization (Suryakumar & Gupta, 2011). The concentration of carotenoids are found in the fruits, as well as a lesser concentration in the seeds. The amount of β-carotene is highest in pulp oil, 100 – 500 mg/100g; and are the lowest in fresh berries, 1 to 120 mg/100g (Yang & Kallio, 2002).
Phytosterols have shown promising results in lowering serum cholesterol levels and lowering the risk of heart disease (Li, et al, 2007), while improving microcirculation in the epidermis, regulating the inflammatory process, and playing a role in anti-tumor, anti-ulcer and anti-atherogenic activities (Suryakumar & Gupta, 2011). The flavones of the fruit have shown to inhibit platelet aggregation in multiple studies, both in vitro and in mice; demonstrated rapid heart repolarization periods in rat myocardial cells and guinea pig papillary muscle cells; as well as shown to increase lipoprotein-cholesterol and tricyglycerol concentrations within blood plasma in humans (Guliyev, et al, 2004).
In addition to the phytochemicals, the coumarins and triterpenes within H rhamnoides helps with the control of appetite, sleep patterns, memory retention, and learning. Vitamin B complex aids in nerve and cellular regeneration; vitamin C aids in collagen synthesis and cell membrane integrity; vitamin K aids in ulcer prevention (Suryakumar & Gupta, 2011).
H. rhamnoides contains concentrations of D-chiro-inositol, which patients with diabetes mellitus have a reduced dietary intake of. In studies with diabetic and insulin resistant rhesus monkeys, administration of D-chiro-inositol improved their sensitivity to insulin as well as activated muscular glycogen synthase. Similar studies in humans with insulin sensitivity due to polycystic ovary syndrome, saw improvement in ovulatory function and a decrease in androgen levels, blood pressure, and triglyceride levels (Yang, et al, 2011).
Extracts of the seed oil contains essential fatty acids including omega-3 (linolenic acid), and omega-6 (linoleic acid). The oil provides a 1:1 ratio of omega-3:omega-6 fatty acids. The oil also contains a high concentration of omega-7 (palmitoleic acid) and rich in omega-9 (oleic acid), (Suryakumar & Gupta, 2011). Fatty acids contribute to the health of epithelial cells, including repairing epidermal barrier system. In a placebo-controlled, parallel, randomized, double-blind experiment at the University of Turku, Finland, 22 patients with atopic dermatitis were randomly divided into three groups which were either assigned to take sea buckthorn seed oil, sea buckthorn pulp oil, or paraffin oil. Ten oil capsules (5 g) were prescribed to each patient per day and asked to maintain their normal diet and skin care regiment throughout the four-month trial. Of the 16 patients who completed the study, those who took the seed oil shown dramatic results in the production of docosapentaenoic acid, while those who took the pulp oil treatment shown an increase production of stearic acid epidermically (Yang, et al, 2000).
In addition to improving the symptoms of atopic dermatitis with the increased production of docosapentaenoic and stearic acids epidermically, the topical application of H rhamnoides oil has proven effective in healing wounds, burns, and radiation exposure. H. rhamnoides has been shown to possess antimicrobial, tissue-regenerative and anti-inflammatory properties (Yang & Kallio, 2002).
Studies evaluating the antioxidant and α-flucosidase inhibitory activities of sea buckthorn extracts showed promising results in anti-cancer research. Compounds, including 1-feruloyl-β -D-glucopyranoside and kaempferol-3-O-β-D-(6'-O-coumaryl) glycoside, among others, were extracted from the leaves of H. rhamnoides. These specific extracts showed high antioxidant activity and cytoprotection against oxidative stress in lymphocytes; nicotine induced oxidative stress in rat liver and heart; plus H rhamnoides flavones at a concentration levels of 100 μg/ml restricted induced apaptosis in lymphocytes by decreasing calcium levels intracellularly. Furthermore, Hippophae rhamnoides lowered the caspase-3 expression, thus protected against H2O2 induced apaptosis on vascular endothelial cells (Suryakumar & Gupta, 2011).
Hippophae rhamnoides' dietary and nutritional benefits
Since there are over 190 beneficial compounds contained within the plant Hippophae rhamnoides, it is arguably one of the most nutritional herbs ever produced. The fruit of the H. rhamnoides contains high levels of vitamin C, some species of which can contain as much as 12 times the amount of oranges. The fruit also contains high levels of vitamin E, 481 mg/100 g for some of the Chinese species of plants; and the berries are also rich in vitamins B1, B2, K. Mineral elements in the fruit and seed of H rhamnoides include iron, manganese, phosphorus, nitrogen, silicon, aluminum, boron, calcium and potassium (Bal, et al, 2011).
Consumption of myo-inositol, which converts to chiro-inositol, is an essential part of human health. Not only does it play a role in metabolism, but also plays a role in insulin production. In patients with diabetes mellitus, it was noted that their was a physical impairment of myo-inositol conversion to chiro-inositol and an increase of urinary secretion of D-chiro-inositol (Yang, et al, 2011)
H. rhamnoides fresh fruit also contains bioflavonoids as high as 1000 mg.100 g, carotenoids as high as 2139 mg/100 g depending on the species, organic acids as high as 9.1 g/100ml, and carotenolipoprotein complexes which act as a bridge between polar proteins and non-polar carotenoids (Bal, et al, 2011).
The fruit of H rhamnoides contains 18 of the 22 essential amino acids including aspartic acid (426.6 mg/100 g); serine (28.1 mg/100 g); glutamine (19.4 mg/100 g); glycine (16.7 mg/100 g); alanine (21.2 mg/100 g); cysteine (3.3 mg/100 g); valine (21.8 mg/100 g); ammonia (41.8 mg/100 g); tyrosine (13.4 mg/100 g); isoleucine (17.4 mg/100 g); methionine (2.3 mg/100 g); proline (45.2 mg/100 g); phenylalanine (20.0 mg/100 g); histadine (13.7 mg/100 g); lysine (27.2 mg/100 g); threonine (36.8 mg/100 g); and arginine (11.3 mg/100 g). Additional amino acids in the subspecies sinensis includes tryptophan (0.51 mg/100 g); leucine (1.94 mg/100 g) and glycin (0.64 mg/100 g) (Bal, et al, 2011).
The moisture content of the fruit varies from 80% - 87% depending on origin and climate, and even higher for the fruit pulp, 85% - 98% in the Indian varieties of sea buckthorn. The total soluble solids within the fruit pulp range from 8.86 – 22.74 depending on the subspecies and region, however the juice from the berries ranges from 10.7 – 13.2 TSS (Bal, et al, 2011).
The sugar content of H. rhamnoides is comprised of glucose, fructose, and xylose. The Chinese species often show higher concentrations of these sugar compounds than in other species, such as the Russian and Finnish species. The glucose and fructose in the berry usually accounts for 60% - 90% of the sugars within the fruit. Frequently, the percentage of glucose and fructose contents of the berries from a specific plant will change annually, explained by the collecting dates and weather conditions during the growing season. Sugar alcohols, such as mannitol, sorbitol, and xylitol have been seen in the species Hippophae rhamnoides ssp. sinensis, rhamnoides and mongolica (Bal, et al, 2011).
Sea buckthorn, Hippophae rhamnoides, has been an important part of human history. It has been included in almost every culture ranging from Asia to India, Russia to middle Europe, and from Scandinavia to North America. This extraordinary plant has been included in many different traditional and folk medicines, including Chinese, Tibetian, Mongolian, Nordic, and Indian cultures for the treatment of coughs, pain, gastrointestinal disorders, immunosuppressive disorders, wound healing, gynecological conditions, and cardiovascular disorders. Today, H rhamnoides is used for its antioxidant and pharmacological activities. However, with its cytoprotective, hepatoprotective, and immunomodulatory properties, plus its anti-microbial, anti-tumor, and anti-inflammatory benefits, sea buckthorn is a plant which must become a medicinal mainstay in complementary and alternative medicine and preventative medicine.
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