What is borage oil

Borage (Borago officinalis Linn), also known as a star flower, is an annual herb in the flowering plant family Boraginaceae ¹⁾. Borage is a medicinal plant which has different usages in pharmaceutical, industrial and forage fields and is used in production of drinks and salads. This plant is known as high plant in Mediterranean region. The leaves are edible and the plant is grown in gardens for that purpose in some parts of Europe. Vegetable use of borage is common in Germany (as an ingredient in green sauce, made in Frankfurt), Crete and in the Italian region of Liguria (to fill traditional ravioli pasta). Vegetable borage is also very popular in the cuisine of the Spanish regions of Aragon and Navarra (i.e., boiled and sautéed with garlic, served with potatoes). Borage is also used by naturopathic practitioners in the regulation of metabolism and the hormonal system, being considered a good remedy for premenstrual syndrome and menopause symptoms, such as hot flashes ²⁾. In Iran, people make tea (Gol Gav Zaban tea) to relieve colds, flu, bronchitis, rheumatoid arthritis, and kidney inflammation ³⁾.

The plant is also commercially cultivated for borage seed oil extracted from its seeds. cultivated for medicinal although it is commercially cultivated for borage seed oil. Borage seed oil is rich in gamma-linolenic acid (30%-40%) which is used as dietary or food supplement. Gamma-linolenic acid, a omega-6 polyunsaturated fatty acid, is sometimes prescribed as anti-inflammatory drug with this belief that it lacks some of the common side-effects of other anti-inflammatory drugs. Gamma-linolenic acid is also used for the treatment of multiple sclerosis, diabetes, heart diseases, arthritis, eczema, autoimmune disorders, cancer and premenstrual syndrome ⁴⁾. Gamma-linolenic acid is one of the volatile fatty acids which is synthesized just by a few plant varieties and often found in their seeds. The main sources of the gamma-linolenic acid are borage and evening primrose ⁵⁾. But borage is a better resource of the gamma-linolenic acid since its seeds contain 30%-40% oil of which 20%-30% is gamma-linolenic acid. This amount is approximately twice as many as that of in evening primrose. The oil of borage is more constant and its process is simpler than the oil of the evening primrose ⁶⁾.

Borage Leafs

The leaves of borage contains following compounds: a few amount of pyrrolizidine alkaloids, licosamin, intermedin, sopinin, sopindian, yezan, colin; fatty acids including alpha-linolenic acid [ALA] (55%) and gamma-linolenic acid (more than 4%); silicic acid (1.5%-22.0%); potassium, calcium, nitrate potassium (3%), acetic, lactic and malic acid; δ-bornesitol, cianozhens; fresh leaves also contain mucilage hydrolysable to glucose, galactose, arabinose and alantoein up to 30%; leaves of borage in seeding stage contain 2.5-5.0 mg gamma-linolenic acid and 5.7-9.0 mg stearidonic acid ⁷⁾. The most amount of the gama-linolenic fatty acids are seen in May or June and the most amount of that in upper leaves of the stem in August or September ⁸⁾.

Borage Seeds

Borage is important due to high amount of gamma-linolenic acid available in its seed oil. In a comprehensive research, antioxidants properties of borage extracts have been reported ⁹⁾. These antioxidants properties of borage are attributed to phenolic compounds. It has been determined that rosmarinic acid, synergic acid and synaptic acid are main phenolic compounds available in extract of borage seed. These three compounds act as bioactive molecules and exert antioxidant and anti-inflammatory properties ¹⁰⁾. Specially, rosmarinic acid is investigated and employed by the food and pharmaceutical industries ¹¹⁾. Rosmarinic acid is the main component of rosemary extract which is used extensively in food industries.

There is potential for borage antioxidants to be used in food formulations and in skin health products as compounds which absorb UV. It has been suggested that linoleic acid and palmitic acid are dominant fatty acids available in mature seeds of borage ¹²⁾. Borage oil due to high amount of gamma-linolenic acid is investigated by food and pharmaceutical research groups. Oils containing gamma-linolenic acid is used to treat some diseases resulted from lack of gamma-linolenic acid in human ¹³⁾.

Figure 1. Borage flower

Borage Oil Uses

Borage seeds oil is the richest plant source of γ-linolenic acid (gamma-linolenic acid) which is used as dietary supplement for prevention and/or treatment of various degenerative pathologic illnesses ¹⁴⁾, as osteoporosis ¹⁵⁾, diabetes ¹⁶⁾, and cancer ¹⁷⁾. Gamma-linolenic acid has also been reported to suppress tumor growth in vitro ¹⁸⁾, improve oxygenation status ¹⁹⁾, exert anti-inflammatory activity and display beneficial effects in the early stages of sepsis ²⁰⁾. Gamma linolenic acid is thought to exert its therapeutic effect in rheumatologic and dermatologic conditions by inhibiting leukotriene synthesis, resulting in anti-inflammatory and anti-thrombotic effects ²¹⁾.

Table 1. Fatty acids methyl esters composition of borage oil as a percentage concentrations of total fatty acids

[Source ²²⁾]

Today gamma-linolenic acid and stearidonic acid supplements and oils containing these fatty acids are used in diet to meet the shortage of necessary fatty acids and prostaglandin. They are also used in folk medicine in treating thrombosis, inflammation and cancer ²³⁾. Atopic dermatitis is an inherited and regressive disease which is seen in 5%-10% of children and now local corticosteroid is often used to remove inflammatory and itchy rashes seen in patients. However a recent good quality systematic review ²⁴⁾ involving 27 studies, with 1596 adults and children from 12 countries, found no evidence that  orally taken either borage oil or evening primrose oil are effective in treatment of eczema (atopic dermatitis). Both of these products and the placebos used in the studies had similar mild, temporary side-effects, which were mainly headache and upset stomach or diarrhea ²⁵⁾. In conclusion, there is no convincing evidence of the benefit of dietary supplements in eczema, and they cannot be recommended for the public or for clinical practice at present.

In rheumatoid arthritis there is some evidence that oils containing gamma-linolenic acid (evening primrose, borage oil or blackcurrant seed oil) afford some benefit in relieving symptoms for rheumatoid arthritis ²⁶⁾. However. we are uncertain of the effects of other herbal therapies because only single studies were available, or important features of rheumatoid arthritis, such as changes in the number of swollen and tender joints, were not reported. Many trials of herbal therapies are hampered by research design flaws and inadequate reporting. Further investigation of each herbal therapy is warranted, particularly via well designed, fully powered, confirmatory clinical trials that use American College of Rheumatology improvement criteria to measure outcomes.

It has been reported that treatment of aged rats with gamma-linolenic acid restores the hippocampal long-term potentiation and reversed age-related changes in glutamate release ²⁷⁾ and improves both memory and N-methyl-D-aspartic acid receptor function ²⁸⁾, suggesting that at least part of its activity is specifically directed at synaptic plasticity. It is concluded that gamma-linolenic acid and the anti-oxidant alpha-lipoic acid, which is known to improve early deficits in peripheral nerve conduction in diabetic rats, is unable to reverse late deficits in the peripheral and central nervous system of streptozotocin-diabetic rats ²⁹⁾. Treatment with gamma-linolenic acid rich natural oils was previously shown to partially prevent nerve ischemia and associated conduction anomalies and improved long-term potentiation in the hippocampus in rats with experimental diabetes mellitus ³⁰⁾.

Borage oil side effects

Apart from the temporary headache, and upset stomach or diarrhea, borage oil has been reported to cause status epilepticus (continuous seizure activity) ³¹⁾. A case report of a 41 year old previously healthy female, who one week prior to presentation, began taking between 1,500 and 3,000 mg of borage oil a day. She was also regularly taking several other supplements including vitamin B and E complexes, ascorbylpalmitate, coenzyme Q10, and L-carnitine. She did not take any prescription medications and did not drink alcohol or use illicit drugs. Her seizures were controlled with pentobarbital but would reoccur as pentobarbital dosing was reduced. Levetiracetam was instituted. After roughly 10 days in the pentobarbital coma, the pentobarbital was tapered and her neurological status rapidly improved. The patient developed an increase in transaminases and the phenytoin was discontinued. She was transferred to a rehab facility. While at the rehab facility, she developed two brief seizures that resolved spontaneously. Carbamazepine was added and she had no further seizure activity. At 4-months follow-up, she reported no convulsive seizures but was occasionally having simple partial seizures which involved a familiar-sounding tone that can be triggered by loud noises. She also reported short-term memory and word-finding impairment. At that point, she transferred her care to a neurologist closer to her home and was lost to follow-up ³²⁾.

In a literature review of central nervous system (CNS) effects related to gamma-linolenic acid or linolenic acid, found only two reports describing a total of five cases of purported gamma-linolenic acid-induced seizures. Three patients with schizophrenia developed EEG-confirmed temporal lobe epilepsy after starting treatment with evening primrose oil. All patients improved after withdrawal of primrose oil and institution of carbamazepine treatment ³³⁾. Generalized tonic–clonic seizures were described in two further schizophrenic patients after starting treatment with evening primrose oil ³⁴⁾. However, one recent study has called these two earlier case series into question ³⁵⁾. It should be noted that all five cases used evening primrose oil rather than Borage oil, which was used by female patient discussed earlier. Borage oil may have the potential to lower the seizure threshold although some studies report anti-epileptic effects of fatty acids gamma-linolenic acid and linolenic acid ³⁶⁾. Research in this regard is mixed and so no certain conclusions can be drawn. These herbal preparations may best be avoided by epilepsy patients at least until this issue is clarified ³⁷⁾.