Disease relevance of Borago

• In a previous study, we showed that dietary gamma-linolenic acid (GLA), an omega-6 polyunsaturated fatty acid found in borage oil (BOR), attenuates the development of hypertension in young spontaneously hypertensive rats (SHR) [1].
• OBJECTIVES: Because vasoactive eicosanoids derived from arachidonic acid present in immune cell phospholipids promote lung inflammation in critically ill patients, novel experimental diets containing eicosapentaenoic acid from fish oil and gamma-linolenic acid from borage oil have been designed to limit arachidonic acid metabolism [2].
• This study shows no overall efficacy of GLA-containing borage oil in atopic eczema, with steroid use being the primary response parameter, although it suggests that a subgroup of patients may benefit from this well-tolerated treatment [3].
• This study examined the effects of supplementing patients with cystic fibrosis daily for 4 weeks with 1,500 mg borage oil, containing 330 mg gamma-linolenic acid, on the fatty acid composition of serum phospholipids (PL) and cholesteryl esters (CE) [4].
• This study has demonstrated the feasibility of administering simultaneously tamoxifen and GLA using borage oil as vehicle, which warrants further investigation as a novel topical two-component system in relation to or prophylaxis of those perceived at high risk of developing breast cancer [5].

High impact information on Borago

• To enable the production of GLA in conventional oilseeds, we have isolated a cDNA encoding the delta6-fatty acid desaturase from developing seeds of borage and confirmed its function by expression in transgenic tobacco plants [6].
• Diets were supplemented with several dosages of oils containing either gamma-linolenic acid (GLA) (borage oil), eicosapentaenoic acid (EPA) (sardine oil), or a combination of the two in a dose-response protocol [7].
• We administered borage seed oil (9 capsules/day) for 12 weeks to 7 normal controls and to 7 patients with active rheumatoid arthritis [8].
• Histidine-41 of the cytochrome b5 domain of the borage delta6 fatty acid desaturase is essential for enzyme activity [9].
• The borage oil diet increased serum cholesterol levels in WKY rats and hepatic B-hydroxy-3-methylglutaryl coenzyme A reductase in SHR [10].

Biological context of Borago

• The Borago officinalis Delta6 fatty acid desaturase (Boofd6) shares 58% identity in its amino acid sequence with Boofd8, a Delta8 sphingolipid desaturase from the same plant species [11].
• The gamma-linolenic acid content generally varied from 11 to 19% of the total fatty acids, but three genotypes had higher values of 22-24%, levels previously not reported for blackcurrant seed and similar to those for borage seed [12].
• Dietary borage oil rich in gamma-linolenic acid (GLA) has been shown to lower blood pressure in Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR) [13].
• Mutagenesis of the borage Delta(6) fatty acid desaturase [14].
• After diets, the PNE and vasoconstrictor responses to -40 mmHg LBNP, as well as the reflex vasodilation on its cessation, were significantly augmented by borage oil [15].

Anatomical context of Borago

• Alveolar macrophage and liver phospholipid concentrations of arachidonic acid were lower, and the concentrations of eicosapentaenoic acid and docosahexaenic acid were higher, with 20% fish oil, and 5% borage oil, and 20% fish and 20% borage oil, as compared with corn oil [16].
• Macrophages from borage oil-fed mice synthesized the lowest amount of prostacyclin (198.7 nmol 6-keto-prostaglandin F1 alpha/mg protein) compared with corn oil-, primrose oil- and fish-borage oil mixture-fed mice (379.7, 764.8 and 384.2 nmol 6-keto-prostaglandin F1 alpha/mg protein, respectively) [17].
• The oxidation rate of palmitoyl-CoA in the peroxisomes was higher in rats fed a fat mixture rich in 18:3n-3 (3.03 nmol/min/mg protein) and borage oil (2.89 nmol/min/mg protein) than in rats fed palm oil (2.08 nmol/min/mg protein) and a fat mixture rich in 18:2n-6 (2.15 nmol/min/mg protein) [18].
• Fatty acyl desaturation in isolated hepatocytes from Atlantic salmon (Salmo salar): stimulation by dietary borage oil containing gamma-linolenic acid [19].
• An increase in the percentage composition of arachidonic acid (20:4n-6) in both the choline and ethanolamine phospholipids, together with a decrease in linoleic acid in ethanolamine phospholipids, were found in heart membranes after feeding the rats with diets containing borage oil or fungal oil as compared to those fed the stock diet [20].

Associations of Borago with chemical compounds

• The substrate for the delta 6-desaturase in borage was, therefore, the linoleate in the complex microsomal lipid phosphatidylcholine, rather than, as in animals, the acyl-CoA [21].
• The developing seeds of Borago officinalis (common borage) accumulate a triacylglycerol oil that is relatively rich in the uncommon fatty acid gamma-linolenate (octadec-6,9,12-trienoic acid) [21].
• Dietary supplementation with ethyl ester concentrates of fish oil (n-3) and borage oil (n-6) polyunsaturated fatty acids induces epidermal generation of local putative anti-inflammatory metabolites [22].
• Delta 6- and delta 12-desaturase activities and phosphatidic acid formation in microsomal preparations from the developing cotyledons of common borage (Borago officinalis) [23].
• MEASUREMENTS AND MAIN RESULTS: Lung phospholipid concentrations of arachidonic acid were lower and the concentrations of eicosapentaenoic acid and docosahexaenoic acid were higher with fish oil and fish and borage oil as compared with corn oil [24].

Gene context of Borago

• In addition, borage oil-, primrose oil- and fish-borage oil mixture-fed mice had significantly (P less than 0.05) higher levels of dihomo-gamma-linolenic acid [20:3(n-6)] in membrane phospholipids (5.5, 3.5 and 5.7 mol/100 mol, respectively) relative to corn oil-fed mice (2.0 mol/100 mol).(ABSTRACT TRUNCATED AT 250 WORDS)[17]
• Interestingly, despite the lack of DGLA in SPH, this phospholipid exhibited a marked enrichment in nervonic acid (NA, 24:1n-9) from 16.2 to 24.7 mol% upon borage oil consumption [25].
• Weanling GPs were initially fed diets supplemented with olive oil (less than 0.1% EPA; less than 0.1% GLA) for 2 weeks, followed by a crossover by two sets of animals to diets supplemented with fish oil (19% EPA) or borage oil (25% GLA) [26].
• Effects of dietary gamma-linolenic acid-rich borage oil combined with marine fish oils on tissue phospholipid fatty acid composition and production of prostaglandins E and F of the 1-, 2- and 3-series in a marine fish deficient in delta5 fatty acyl desaturase [27].
• The rapid evaluation of antioxidant activity of crude borage (Borago officinalis L.) extract was determined by using DPPH free radical method [28].

Analytical, diagnostic and therapeutic context of Borago

• In contrast to the corn oil group, endotoxin did not significantly increase bronchoalveolar lavage levels of leukotriene B4, leukotriene C4/D4, and thromboxane B2 above those of saline-treated rats with fish oil and fish and borage oil [24].
• Site-directed mutagenesis has been used to probe the functional importance of a number of amino acid residues which comprise the third histidine box of a 'front end' desaturase, the borage Delta6-fatty acid desaturase [29].
• Determination of rosmarinic acid in sage and borage leaves by high-performance liquid chromatography with different detection methods [30].
• Rats were fed a low-fat diet containing 2% safflower oil or 20% fat diets containing either safflower oil rich in linoleic acid, borage oil containing 25% gamma (gamma)-linolenic acid or enzymatically prepared gamma-linolenic acid enriched borage oil containing 47% gamma-linolenic acid for 14 days [31].
• Recent double blind studies have shown some benefit of borage oil in treatment of rheumatoid arthritis [32].

References