linoleic-acid and eleostearic-acid

In this letter to editor, I hypothesize a potential affinity of retinol saturase (RetSat) enzyme towards a conjugated trienoic fatty acid; alpha-eleostearic acid (α-ESA) and subsequent hindrance of the action on its usual substrate; all trans retinol. Hence, RetSat is speculated to be involved in a rapid unusual conversion of α-ESA to conjugated linoleic acid (CLA), giving a less priority to its usual substrate all trans retinol, which would subsequently be converted into "all trans retinoic acid" (atRA). Otherwise, all trans retinol is converted by RetSat into all-trans-13,14-dihydroretinol and eventually forms all-trans-13,14-dihydroretinoic acid, but not the atRA. The atRA controls differentiation, proliferation and apoptosis of cells and it's deficiencies end up as neoplasms. Thus, here it is emphasized that safeguarding atRA would help controlling cell division and growth in a favourable manner. Hence, inhibition of RetSat could be a hot target to control unwarranted cell growths within the body. This hypothesis could be easily tested in a RetSat ablated (RetSat -/-) animal model or using antagonists on RetSat activity or α-ESA.

Topics: Animals; Cell Differentiation; Cell Division; Humans; Linoleic Acid; Linoleic Acids, Conjugated; Linolenic Acids; Lipid Metabolism; Metabolomics; Neoplasms; Tretinoin; Vitamin A

Lipophilic bioactive compounds in oils recovered from the kernels of seven sweet cherry (Prunus avium L.) cultivars, harvested at single location in 2013, were studied. Oil yield in sweet cherry ranged between 30.3-40.3 % (w/w) dw. The main fatty acids were oleic acid (39.62-49.92 %), linoleic acid (31.13-38.81 %), α-eleostearic acid (7.23-10.73 %) and palmitic acid (5.59-7.10 %), all four represented approximately 95 % of the total detected fatty acids. The ranges of total tocochromanols and sterols were between 83.1-111.1 and 233.6-419.4 mg/100 g of oil, respectively. Regardless of the cultivar, the γ-tocopherol and β-sitosterol were the main lipophilic minor bioactive compounds. The content of the carotenoids and squalene were between 0.38-0.62 and 60.9-127.7 mg/100 g of oil, respectively. Three significant correlations were found between oil yield and total contents of sterols (r = -0.852), tocochromanols (r = -0.880) and carotenoids (r = -0.698) in sweet cherry kernel oils. The oil yield, as well as the content of lipophilic bioactive compounds in oil was significantly affected by the cultivar.

Topics: Carotenoids; Linoleic Acid; Linolenic Acids; Phytosterols; Plant Oils; Prunus avium; Seeds; Sitosterols; Squalene; Sterols

Eleostearic acid (alpha-ESA) is a conjugated linolenic acid that makes up approximately 60% of Momordica charantia (bitter melon) seed oil. Prior work found that water extract from bitter melon was able to inhibit breast cancer. Here, we investigated effects of alpha-ESA on both estrogen receptor (ER)-negative MDA-MB-231 (MDA-wt) and ER-positive MDA-ERalpha7 human breast cancer cells. We found that alpha-ESA inhibited proliferation of both MDA-wt and MDA-ERalpha7 cells, whereas conjugated linoleic acid had comparatively weak antiproliferative activity at 20 to 80 micromol/L concentrations. We also found that alpha-ESA (40 micromol/L) treatment led to apoptosis in the range of 70% to 90% for both cell lines, whereas conjugated linoleic acid (40 micromol/L) resulted in only 5% to 10% apoptosis, similar to results for control untreated cells. Addition of alpha-ESA also caused loss of mitochondrial membrane potential and translocation of apoptosis-inducing factor as well as endonuclease G from the mitochondria to the nucleus. Additionally, alpha-ESA caused a G(2)-M block in the cell cycle. We also investigated the potential for lipid peroxidation to play a role in the inhibitory action of alpha-ESA. We found that when the breast cancer cells were treated with alpha-ESA in the presence of the antioxidant alpha-tocotrienol (20 micromol/L), the growth inhibition and apoptosis effects of alpha-ESA were lost. An AMP-activated protein kinase inhibitor (Dorsomorphin) was also able to partially abrogate the effects of alpha-ESA, whereas a caspase inhibitor (BOC-D-FMK) did not. These results illustrate that alpha-ESA can block breast cancer cell proliferation and induce apoptosis through a mechanism that may be oxidation dependent.

Topics: Apoptosis; Breast Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Female; Humans; Linoleic Acid; Linolenic Acids; Membrane Potential, Mitochondrial; Oxidation-Reduction

The formation of hydroxy radicals, hexanal, and 2,4-decadienal was demonstrated from the autocatalytic dimer peroxide which had been reported by us in autoxidizing linoleate (Morita and Tokita in Lipids 41:91-95, 2006). Then, autoxidizing linoleate containing eleostearate was investigated for new autocatalytic substances. The substances obtained were identified as peroxide-linked polymers consisting of both linoleate- and eleostearate-origin units with one hydroperoxy group, and also revealed activity of hydroxy-radical generation. The background of this study is as follows: the above paper reported this autocatalytic dimer peroxide as one of the real radical generators in linoleate autoxidation; this is a peroxide-linked dimer consisting of two linoleate moieties with two hydroperoxy groups, and was much more important than the main-product hydroperoxide in autocatalytic radical supply; its proposed decomposition mechanism has suggested the generation of hydroxy radicals, hexanal, and 2,4-decadienal; on the other hand, analogy to the formation mechanism of this dimer peroxide has predicted the formation of similar polymeric products from conjugated polyene components in lipids. In this study, these two predictions were successfully verified and a discussion is presented in connection with them.

Topics: Aldehydes; Catalysis; Chromatography, High Pressure Liquid; Esters; Gas Chromatography-Mass Spectrometry; Hydroxyl Radical; Linoleic Acid; Linolenic Acids; Molecular Structure; Oxidation-Reduction; Plant Oils

As part of an investigation on the chemical constituents and contaminants of the basidiomycete Pleurocybella porrigens (Japanese name: Sugihiratake), we analyzed the UV-detected constituents of this mushroom using HPLC. One of the major UV peaks detected was isolated and identified as a-eleostearic acid, a long-chain fatty acid with a conjugated triene moiety, based on the results of spectroscopic methods. alpha-Eleostearic acid was concluded to be a characteristic fatty acid of P. porrigens, because it was not detected in eight other edible mushrooms examined. Free long-chain fatty acids in P. porrigens and other edible mushrooms were analyzed by HPLC after derivatization with acidic 2-nitrophenylhydrazine hydrochloride. Oleic acid was the main fatty acid in P. porrigens, and saturated long-chain fatty acids such as linoleic acid, palmitic acid, and stearic acid, together with a-eleostearic acid, were also detected.

Topics: Agaricales; Chromatography, High Pressure Liquid; Food Analysis; Linoleic Acid; Linolenic Acids; Oleic Acid; Palmitic Acid; Spectrophotometry, Ultraviolet; Stearic Acids