Doses Of Linoleic Acid Research Articles

Alterations in niban gene expression as a response to stress conditions in 3T3-L1 adipocytes.

Adipocyte death is important in obesity development. Understanding and prevention of adipocyte deaths may be a molecular approach in the treatment. In the study, we aimed to understand role of Niban gene, which acts as an anti-apoptotic molecule as a response to stress conditions, in adipocytes. 3T3-L1 adipocytes were treated with different doses of linoleic acid, hydrogen peroxide and ethanol; and proliferation of the cells examined with real time monitoring iCELLingence system. Gene expression levels were measured by q-PCR. As a response to 24h 480 µM linoleic acid treatment, Niban gene expression was found to be higher than control group (p = 0.008), whereas 24 h 90 mM ethanol treatment was determined to be lower than control group (p = 0.008). The highest value of Niban gene expression among H2O2 treatment groups was detected in 4h 600µM H2O2 in comparison to control group (p = 0.008). To understand role of Niban in adipogenesis, Niban gene expressions were compared between pre-adipocytes and advanced fat accumulated adipocytes and determined to be significantly different (p = 0.042). Our results suggest that Niban might be involved in stress response process in adipocytes. However, the exact molecular role of Niban needs to be investigated in further studies.

Protective Efficacy of Vitamin F against Acrylamide Induced Toxicity: Studies on Oxidative Stress Biomarkers

Introduction:Vitamin F is also known as Linoleic Acid (LA), is an Essential Fatty Acid (EFA) which is not produced in humans. It can be modified to form essential precursors such as arachidonic acid which is used to make prostaglandins, thromboxanes, and leukotrienes. It is found in abundance in several vegetable oils such as sunflower, poppy seed, safflower and corn oils. LA has shown diverse beneficial effects against diseases such as cancer, skin permeability, insulin resistance, depression and cardiovascular diseases. Acrylamide (AA) is a well known neurotoxic, carcinogenic and genotoxic compound. It is used universally in the industrial process and recently found in various food products which are cooked at a temperature above 120˚C such as potato crisps, bread, cookies and french fries. Over exposure of humans and laboratory animals to monomer AA causes damages to the central and peripheral nervous system.Objective:To investigate the therapeutic effect of linoleic acid against acrylamide toxicity.Methods:AA was given at 38.27 mg/kg dose for 10 days and therapy with different doses of linoleic acid for three days (11-13 days) to female albino rats.Results:Signs and symptoms of acrylamide toxicity occur, they include significant body weight reduction, hair loss, splaying of hindlimbs, dragging of back legs and skin irritation. A significant decline was observed in hemoglobin level and GSH, whereas significant enhancement in LPO was noted, as compared to the control group after AA exposure. The activity of acetylcholinesterase was decreased in the brain after AA administration. AA significantly reduced the superoxide dismutase and catalase activities in liver, kidney and brain but activities of serum transaminases, bilirubin, creatinine, urea and lipid profile increased in serum. Biochemical studies were also strengthened by histopathological observations.Conclusion:Study has shown that linoleic acid promotes defense against AA toxicity.

Supplementation of increasing amounts of linoleic acid to Leymus chinensis decreases methane production and improves fatty acid composition in vitro

The effects of linoleic acid (LA) supplementation on in vitro dry matter disappearance (DMD), gas production, methane and hydrogen gas production, ruminal fermentation characteristics, and fatty acid (FA) profiles in fermentation fluid were investigated in vitro. Rumen fluid was collected from four ruminally cannulated goats, diluted with incubation buffer, and then incubated with 500 mg Leymus chinensis meal supplemented with different amounts of LA (0, 20, 40, and 60 mg for the control, LA20, LA40, and LA60 groups, respectively). In vitro rumen incubation was anaerobically carried out in 130‐mL sealed fermentation bottles at 39°C for 48 h, and samples were collected at three time points (12, 24, and 48 h) for analysis. Supplementation of LA reduced DMD (P<0.05), the cumulative gas production, theoretical maximal gas production and methane production (P<0.05), whilst increased the hydrogen gas production. In addition, LA addition to substrate had no negative effects on ruminal fermentation parameters (pH, NH3, and VFA). The concentration of total polyunsaturated fatty acid (PUFA) and conjugated linoleic acid (CLA) were higher for LA groups than for control during the whole incubation process. These results indicate that LA supplementation in substrate reduces gas and methane production, and increases the amounts of some beneficial fatty acids in fermentation liquid in vitro.Practical applications: Achieving reduction of the production of methane and improving the composition of fatty acids in ruminant products.Information about H2 concentrations in the rumen of ruminents is scarce. This study investigated the effects of increasing amounts of linoleic acid on CH4 and H2 production when Leymus chinensis was fermented as a substrate in vitro. Supplementing different doses of LA to Leymus chinensis decreased the GP and suppressed CH4 emissions in vitro.

Linoleic acid-induced expression of defense genes and enzymes in tobacco

Linoleic acid (LA) is a naturally occurring fatty acid (FA) found to elicit induced systemic resistance (ISR) of tobacco against the bacterial soft rot pathogen, Pectobacterium carotovorum subsp. carotovorum (PCC). In this study, we examined effects of six doses of exogenous LA on the induction of defense genes and enzymes. The optimum ISR activity was observed in plants treated with 0.1mM LA where the effect of LA on membrane permeability was minimal. The application of LA as a root drench enhanced the activity of defense enzymes such as phenylalanine ammonia-lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) and induced the expression of β-glucuronidase (GUS). PAL and POD activities were increased in a concentration dependent manner while the maximum PPO activity was observed after treatment with 0.01mM LA. An RT-PCR analysis of the defense-related genes, Coi1, NPR1, PR-1a and PR-1b, of tobacco plants treated with 0.1mM LA revealed an association of LA with elicitation of ISR in tobacco.

Effect of ruminal pulse dose of polyunsaturated fatty acids on ruminal microbial populations and duodenal flow and milk profiles of fatty acids

The objective of this study was to examine the effect of ruminal pulse dose of free linoleic acid (LA) and free docosahexaenoic acid (DHA) on microbial populations in the rumen, duodenal fatty acid (FA) flow, milk composition, and milk FA profiles of Chinese Holstein dairy cows. Four rumen- and duodenal-fistulated Chinese Holstein cows in mid lactation (138.5±10d in milk) were randomly assigned to 3 treatment groups and 1 control group in a 4×4 Latin square design over 4 periods (3 wk per period). Diets contained either no LA or 2.7% LA and either no DHA or 0.5% DHA in a 2×2 factorial arrangement of treatments. Ruminal pulse dose with DHA increased counts of Megasphaera elsdenii, decreased Fibrobacter succinogenes, but did not affect Butyrivibrio fibrisolvens or Ruminococcus flavefaciens. The pulse dose of LA at 2.7% dry matter had no effect on the population sizes of the 3 major cellulolytic bacterial species or M. elsdenii, and no interaction was observed between LA and DHA. The pulse dose of LA or DHA, either alone or in combination, increased the duodenal flow of vaccenic acid (VA). The milk VA and cis-9,trans-11 conjugated linoleic acid (CLA) contents also increased in response to the fatty acid pulse dose, and the pulse dose of both LA and DHA together had the most profound stimulatory effect. This study indicated that ruminal pulse dose of LA or DHA could be used to increase duodenal flow of VA and the milk contents of potentially health-promoting FA, such as VA and cis-9,trans-11 CLA. These results might be useful in formulating dietary interventions to improve milk cis-9,trans-11 CLA contents.

Allometric scaling of dietary linoleic acid on changes in tissue arachidonic acid using human equivalent diets in mice

BackgroundIt is hypothesized that dietary linoleic acid (LA) promotes chronic and acute diseases in humans by enriching tissues with arachidonic acid (AA), its downstream metabolite, and dietary studies with rodents have been useful for validation. However, levels of LA in research diets of rodents, as published in the literature, are notoriously erratic making interspecies comparisons unreliable. Therefore, the ability to extrapolate the biological effects of dietary LA from experimental rodents to humans necessitates an allometric scaling model that is rooted within a human equivalent context.MethodsTo determine the physiological response of dietary LA on tissue AA, a mathematical model for extrapolating nutrients based on energy was used, as opposed to differences in body weight. C57BL/6J mice were divided into 9 groups fed a background diet equivalent to that of the US diet (% energy) with supplemental doses of LA or AA. Changes in the phospholipid fatty acid compositions were monitored in plasma and erythrocytes and compared to data from humans supplemented with equivalent doses of LA or AA.ResultsIncreasing dietary LA had little effect on tissue AA, while supplementing diets with AA significantly increased tissue AA levels, importantly recapitulating results from human trials.ConclusionsThus, interspecies comparisons for dietary LA between rodents and humans can be achieved when rodents are provided human equivalent doses based on differences in metabolic activity as defined by energy consumption.

Linoleic acid both enhances activation and blocks Kv1.5 and Kv2.1 channels by two separate mechanisms.

Linoleic acid (LA) had two effects on human Kv1.5 and Kv2.1 channels expressed in Chinese hamster ovary cells: an increase in the speed of current activation process (EC(50) = 2.4 and 2.7 microM for Kv1.5 and Kv2.1, respectively) and current inhibition (IC(50) = 6.6 and 7.4 for Kv1.5 and Kv2.1, respectively). LA affected the activation kinetics via two processes: a leftward shift in the instantaneous activation curves and an increase in the rate of current rise. Current inhibition by LA was time dependent but voltage independent. Hill slopes for plots of current inhibition (3.5 and 3.9 for Kv1.5 and Kv2.1, respectively) vs. dose of LA suggested that cooperativity was involved in the mechanism of current inhibition. A similar analysis of the effects of LA on current activation did not reveal cooperative interactions. The effects of LA were mediated from the external side of the channels, since addition of 10 microM LA to the patch pipette solution was without effect. Additionally, the methyl ester of LA was effective at enhancing peak current and promoting channel activation for Kv1.5 and Kv2.1 without inducing significant current inhibition.

Effect of dietary linoleic acid on vitamin E requirement and fatty acid composition of erythrocyte lipids in rats.

In order to investigate the effect of an increasing linoleic acid content of the diet on vitamin E requirement, young male rats were divided into 4 groups receiving respectively 0.27, 0.98, 3.57 and 12.98% linoleic acid (from mixtures of coconut oil and tocopherol-free safflower oil) in their diets. Each group was subdivided into 6 groups, receiving increasing amounts of D-α-tocopheryl acetate (2.5–23.5 mg) in their food. Spontaneous haemolysis <i>in vitro </i>was used as a criterion for vitamin E requirement. The amount of D-α-tocopheryl acetate needed to prevent haemolysis was 13 mg/kg food for the lowest three doses linoleic acid, the highest dose required 18 mg/kg food. The fatty acid composition of erythrocyte lipids was not influenced by the vitamin E content and only moderately by the linoleic acid content of the diet: a higher level of dietary linoleic acid caused an increase in linoleic acid content of erythrocyte lipids, which was mainly compensated by a decrease in oleic acid content. The group with the lowest dose of vitamin E and the highest dose of linoleic acid showed a significant increase in non-electrolyte (= thiourea) haemolysis time.