Current Insights into the Effects of Dietary α-Linolenic Acid Focusing on Alterations of Polyunsaturated Fatty Acid Profiles in Metabolic Syndrome.

The plant-derived α-linolenic acid (ALA) is an essential n-3 acid highly susceptible to oxidation, present in oils of flaxseeds, walnuts, canola, perilla, soy, and chia. After ingestion, it can be incorporated in to body lipid pools (particularly triglycerides and phospholipid membranes), and then endogenously metabolized through desaturation, elongation, and peroxisome oxidation to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with a very limited efficiency (particularly for DHA), beta-oxidized as an energy source, or directly metabolized to C18-oxilipins. At this moment, data in the literature about the effects of ALA supplementation on metabolic syndrome (MetS) in humans are inconsistent, indicating no effects or some positive effects on all MetS components (abdominal obesity, dyslipidemia, impaired insulin sensitivity and glucoregulation, blood pressure, and liver steatosis). The major effects of ALA on MetS seem to be through its conversion to more potent EPA and DHA, the impact on the n-3/n-6 ratio, and the consecutive effects on the formation of oxylipins and endocannabinoids, inflammation, insulin sensitivity, and insulin secretion, as well as adipocyte and hepatocytes function. It is important to distinguish the direct effects of ALA from the effects of EPA and DHA metabolites. This review summarizes the most recent findings on this topic and discusses the possible mechanisms.

Variability in somatic embryo-forming capacity of spinach.

High variability in somatic embryo (SE)-forming capacity has previously been observed in several spinach cultivars. Such variability frequently accounted for more variation in embryogenic response of the explants than the factor being investigated. Hence, the variability in embryogenic capacity was examined in the present study at both the population and the single-seedling level, using seeds of spinach cultivar Matador obtained from nine European seed companies. Seed population obtained from Slovenia (Sl) was superior to others, with the highest regeneration frequency (100%) and the highest mean SE number (14.4). A total of 82% of these seedlings had 80-100% of regenerating explants, while in populations with intermediate embryogenic capacity approximately 40% of seedlings had 20-60% of regenerating explants. The explants from the majority of seedlings (52-100%) in the least responsive populations were irresponsive. Furthermore, the explants from Sl seedlings regenerated from 10-20 (43.5%) up to > 20 (27.6%) SEs on average, while the explants from the majority of seedlings belonging to other populations regenerated 1-10 SEs. The present study strongly indicates that the variability of plant material must not be overlooked, because choosing more responsive individuals for one treatment and less responsive ones for another may lead to misinterpretation of the data.