**Abstract**

Sea Buckthorn (*Hippophae rhamnoides*) has a long history of use as food and medicine in Tibet and Northern Asia, where the plant has been associated with a wide range of health benefits. Sea buckthorn (SB) berry, seed and leaf have been reported to contain more than 190 bioactive compounds, including polyphenols (epicatechin, epigallocatechin, gallic acid, proanthocyanidins, chloregenic acid) and flavonoids (quercetin, isorhamnetin, kampferol glycosides, lutoelin, myricetin). SB represents a good source of phenolic compounds and flavonoids acting in synergy with PUFA such as omegas 3, 6, 7 and 9, vitamins (vitamin C), and organic acids. SB exerts antioxidant, anti-inflammatory, cytoprotective, anti-cancer, hepatoprotective properties, associated with improvement in various metabolic markers such as glycemic control and lipid profile. SB polyphenol fraction also demonstrated significant cardioprotective, antihypertensive and neuroprotective actions. SB acts as a natural stem cell mobilizer associated with significant regenerative properties. As a consequence, SB polyphenol consumption stimulates pancreatic regeneration in animal model of insulin-dependent diabetes. In conclusion, SB polyphenols exert a wide range of health benefits in metabolic health including obesity, diabetes and hypertension, as well as liver, kidney and brain health, positioning sea buckthorn berry extract as an interesting and valuable dietary supplement for natural complementary therapy and for antiaging.

**Keywords:** Polyphenols, flavonoids, proanthocyanidins, sea buckthorn, anti-inflammatory, antioxidant, stem cell enhancer, metabolic health, cardiovascular health

## **1. Introduction**

Although it has been used for centuries in many parts of the world, especially in Northern Asia, sea buckthorn berry and its derivatives are relatively novel ingredients in the field of dietary supplements and functional foods. Sea buckthorn (SB) berry and leaf contain a variety of polyphenols, some of them being especially abundant in SB, that have been documented to bring a wide range of health benefits. This review is aimed at describing the composition of SB derivatives and the health benefits associated with their consumption.

## **2. Geographical origin**

Sea Buckthorn is a deciduous, branched, spiny shrub belonging to genus *Hippophae* and family *Elaeagnaceae*. *Hippophae rhamnoides L.* is synonymous with *Elaeagnus rhamnoides* (L.) *A. Nelson*. SB usually forms a shrub or a small tree of 3–4 m in height, though it can reach up to 7 m when growing at low altitude and in moderate climate. The plant originally comes from the Northern Himalayan region where it naturally grows at altitudes ranging between 1600 and 5200 m and can resist to winter temperatures down to −40°C. Sea buckthorn's natural distribution area includes Northern China, Mongolia, India, Nepal, Northern Pakistan, and Russia, though over the centuries it has spread to Europe and North America. Seven species and 11 subspecies have been identified worldwide [1].

### **3. Botanical identity**

Sea buckthorn is dioecious, with separate male and female plants. The male plants produce brownish flowers, which produce wind-distributed pollen and female plants produce an orange berry-like fruit. The leaves are narrow, alternate, lanceolate-linear and obtuse with peltate and stellate scales on the lower surface. The fruits are subglobose, spherical or oblate, succulent, and orange colored with a mean diameter of 5-8 mm. The seeds are solitary, uniquely lobed, light black, and stony. The seed kernel is white and oily, sour and astringent. The pulp of the fruit is oily and soft. The surface of the peel epidermal cells is polygonal with a slightly thicker vertical wall. The parenchyma cells of the pulp contain many orange-red or orange-yellow particles, along with bright yellow oil drops. The content in actives is respectively not less than 1.5% flavonoids, 0.1% isorhamnetin (Identification criteria by Chinese pharmacopeia).

Sea buckthorn has been reported to contain more than 190 bioactive compounds in the seeds, pulp, fruit, and juice. These compounds include fat-soluble vitamins (A, K, E), 22 fatty acids, 42 lipids, organic acids (malic acid, oxalic acid), amino acids, carbohydrates, vitamins C, B1, B2, B6, B12, folic acid, flavonoids (quercetin, isorhamentin, kaempferol glycosides, luteolin, myricetin), polyphenols (epicatechin, epigallocatechin, gallic acid, proanthocyanidins, chlorogenic acid), terpenes, carotenoids (zeaxanthin, beta carotene, lycopene) and tannins [2]. Sea buckthorn berry also contains twenty mineral elements, including Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Zn. It is a rich source of omega 3, 6, 7, and 9. It is the only plant that offers a wide variety of fatty acids and includes a beneficial amount Omega 7 (palmitoleic acid) [3].

### **4. Traditional use of the plant**

The genus name of Sea Buckthorn "Hippophae" originates from the Greek words "Hippo" (horse) and "Phaos" (to shine), meaning essentially "shining horse". It is said that when Alexander the Great headed back from his Asian conquest, he travelled with his troops through a desert region near today's Northern Pakistan, where he had previously abandoned a group of horses wounded in battle. The area was abundant in sea buckthorn trees and the horses had the opportunity to feed on the berries and leaves. At one point they spotted the horses looking vibrant and with a shiny coat, which is a sign of health for horses. From there sea buckthorn was brought to Greece where it was used ever since of as horse feed to keep horses healthy and strong.
