Effects Of Lipoic Acid Supplementation Research Articles

Effects of lipoic acid supplementation on age- and iron-induced memory impairment, mitochondrial DNA damage and antioxidant responses.

To investigate the effects of lipoic acid (LA) supplementation during adulthood combined with supplementation later in life or LA administration only at old age on age-induced cognitive dysfunction, mitochondrial DNA deletions, caspase 3 and antioxidant response enzymes expression in iron-treated rats. Male rats were submitted to iron treatment (30mg/kgbody wt of Carbonyl iron) from 12 to 14th post-natal days. Iron-treated rats received LA supplementation (50mg/kg, daily) in adulthood and old age or at old age only for 21days. Memory, mitochondrial DNA (mtDNA) complex I deletions, caspase 3 mRNA expression and antioxidant response enzymes mRNA expression were analyzed in the hippocampus. LA administration in adulthood combined with treatment later in life was able to reverse age-induced effects on object recognition and inhibitory avoidance memory, as well as on mtDNA deletions, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression, and antioxidant enzymes disruption induced by iron in aged rats. LA treatment only at old age reversed iron-induced effects to a lesser extent when compared to the combined treatment. The present findings support the view that LA supplementation may be considered as an adjuvant against mitochondrial damage and cognitive decline related to aging and neurodegenerative disorders.

Effect of lipoic acid supplementation on gene expression and activity of glutathione S-transferase enzyme in infertile men

Oxidative stress has become the focus of interest as a potential cause of male infertility. We evaluate effects of lipoic acid (LA) supplementation on glutathione S-transferase (GST) expression. This randomized, triple-blind, placebo-controlled clinical trial was conducted on 44 infertile males with idiopathic asthenozoospermia. Men were randomized to receive 600 mg LA or placebo once daily for 12 weeks and semen samples and venous blood samples were obtained. GST expression, reactive oxygen species (ROS) levels, GST activity and reproductive hormone profiles were also measured. GST expression in the intervention group were significantly higher than the control group. Also, at the end of the study, GST activity increased, and ROS levels decreased significantly compared to the baseline. Additionally, the intervention group showed an increase in testosterone and decrease in serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and prolactin after 12 weeks, but this difference was not significant. We conclude a 12-week treatment with LA leads to improvements in reproductive hormones in serum, and significantly reduces the generation of ROS and increases the gene expression and activity of GST in seminal fluid.

Effects of Lipoic Acid Supplementation on Activities of Cyclooxygenases and Levels of Prostaglandins E2 and F2α Metabolites, in the Offspring of Rats with Streptozotocin-Induced Diabetes.

Background. Our aim was to evaluate the protective effect of lipoic acid (LA) on fetal outcome of diabetic mothers. Methods. Diabetes was induced in female rats using streptozotocin and rats were made pregnant. Pregnant control (group 1; n = 9; and group 2; n = 7) or pregnant diabetic (group 3; n = 10; and group 4; n = 8) rats were treated daily with either LA (groups 2 and 4) or vehicle (groups 1 and 3) between gestational days 0 and 15. On day 15 of gestation, the fetuses, placentas, and membranes were dissected, examined morphologically, and then homogenized, to measure cyclooxygenase (COX) activities and metabolisms of prostaglandin (PG) E2 (PGEM) and PGF2 α (PGFM) levels. The level of total glutathione was measured in the maternal liver and plasma and in all fetuses. Results. Supplementation of diabetic rats with LA was found to significantly (p < 0.05) reduce resorption rates in diabetic rats and led to a significant (p < 0.05) increase in liver, plasma, and fetuses total glutathione from LA-TD rats as compared to those from V-TD. Decreased levels of PGEM and elevated levels of PGFM in the fetuses, placentas, and membranes were characteristic of experimental diabetic gestation associated with malformation. The levels of PGEM in malformed fetuses from LA-TD mothers was significantly (p < 0.05) higher than those in malformed fetuses from V-TD rats. Conclusions. LA treatment did not completely prevent the occurrence of malformations. Thus, other factors may be involved in the pathogenesis of the diabetes-induced congenital malformations.

Effects of lipoic acid supplementation on activities of cyclooxygenases and levels of prostaglandins E2 and F2 alpha metabolites, in the offspring of rats with Streptozotocin-induced diabetes

Effects of lipoic acid supplementation on activities of cyclooxygenases and levels of prostaglandins E2 and F2 alpha metabolites, in the offspring of rats with Streptozotocin-induced diabetes

Modulation of antioxidant and detoxification responses induced by lipoic acid in the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) subjected to hypoxia and re-oxygenation

The effect of lipoic acid supplementation and moderate hypoxia (3 mg/L), followed by re-oxygenation, was analyzed in terms of antioxidant and oxidative damage responses in juvenile shrimp Litopenaeus vannamei. Lipoic acid (LA)-enriched rations (D1: 76.4 ± 6.4; D2: 196.4 ± 70.2; and D3: 397.2 ± 79.97 mg LA/kg) were offered to shrimps. A control group without LA adding was also run. After 45 days, LA-enriched ration increased the activity of the detoxifying enzyme glutathione-S-transferase in gills. Total antioxidant capacity against peroxy radicals was augmented in gills and hepatopancreas at doses D2 and D3. Doses D1 and D2 of LA reduced the levels of oxidative damage (lipid peroxidation) in gills and hepatopancreas. The results showed that certain LA doses (particularly D2) improved not only antioxidant responses but also weight gain. It can be concluded that LA triggered antioxidant and detoxification protection in L. vannamei, allowing the shrimp to cope with environmental stressful factors.

The effects of lipoic acid supplementation on blood glucose and insulin concentrations in pony mares

<h2>ABSTRACT</h2> Lipoic acid has been found to modulate insulin and glucose dynamics in several species; therefore, the objectives of this project were to determine a) blood concentrations of lipoic acid after oral delivery to pony mares and b) whether daily treatments of 10 mg/kg of BW of lipoic acid for 14 d to overweight pony mares would alter insulin and glucose dynamics. In Exp. 1, 3 pony mares were used to determine absorption of lipoic acid into the peripheral blood supply after oral dosing. Jugular catheters were inserted and serial blood samples collected after administration of 10 mg/kg of BW of lipoic acid. Serum concentrations of lipoic acid increased 3,000-fold at 30 min postdosing, providing evidence that orally dosed lipoic acid is absorbed. In Exp. 2, 11 pony mares were blocked by BCS and ovarian status (intact vs. ovariectomized) and randomly assigned to receive daily treatments for 14 d of 10 mg/kg of BW of lipoic acid (LA; n=6) or to the control group (CON; n=5). On d 14, CON and LA ponies were fitted with jugular catheters, and i.v. glucose tolerance tests were performed. Insulin area under the curve was greater (P = 0.05) among CON (7,551 ± 1,136) than among LA (4,046 ± 1,037) treated ponies. No differences (P = 0.68) were found in glucose area under the curve between CON (3,961 ± 269) and LA (4,114 ± 246) treated ponies. These data provide evidence that lipoic acid supplementation for 14 d alters insulin dynamics in pony mares.

Lipoic acid administration prevents nonalcoholic steatosis linked to long-term high-fat feeding by modulating mitochondrial function

Nonalcoholic steatosis is an important hepatic complication of obesity linked to mitochondrial dysfunction and insulin resistance. Furthermore, lipoic acid has been reported to have beneficial effects on mitochondrial function. In this study, we analyzed the potential protective effect of lipoic acid supplementation against the development of nonalcoholic steatosis associated with a long-term high-fat diet feeding and the potential mechanism of this effect. Wistar rats were fed on a standard diet (n=10), a high-fat diet (n=10) and a high-fat diet supplemented with lipoic acid (n=10). A group pair-fed to the latter group (n=6) was also included. Lipoic acid prevented hepatic triglyceride accumulation and liver damage in rats fed a high-fat diet (−68%±11.3% vs. obese group) through the modulation of genes involved in lipogenesis and mitochondrial β-oxidation and by improving insulin sensitivity. Moreover, this molecule showed an inhibitory action on electron transport chain complexes activities (P<.01–P<.001) and adenosine triphosphate synthesis (P<.05), and reduced significantly energy efficiency. By contrast, lipoic acid induced an increase in mitochondrial copy number and in Ucp2 gene expression (P<.001 vs. obese). In summary, this investigation demonstrated the ability of lipoic acid to prevent nonalcoholic steatosis induced by a high-fat intake. Finally, the novelty and importance of this study are the finding of how lipoic acid modulates some of the mitochondrial processes involved in energy homeostasis. The reduction in mitochondrial energy efficiency could also explain, at least in part, the beneficial effects of lipoic acid not only in fatty liver but also in preventing excessive body weight gain.

The effects of lipoic acid supplementation on blood glucose, insulin, and leptin concentrations in pony mares

The effects of lipoic acid supplementation on blood glucose, insulin, and leptin concentrations in pony mares

Effects of lipoic acid supplementation on rat brain tissue: An FTIR spectroscopic and neural network study

The unfortunate increase in exposure to free radicals justifies antioxidant supplementation. Therefore, in the current study, the effect of exogenously administered lipoic acid, a natural amphipathic antioxidant, on rat brain tissue was investigated via Fourier transform infrared spectroscopy in order to understand its interactions with biological molecules. The results suggest that lipoic acid slightly disorders the acyl chains of phospholipids as observed from the frequency of the CH 2 stretching vibrations while it strengthens the hydrogen bonding of the interfacial region of phospholipids as indicated by the C O stretching band. Moreover, lipoic acid seems to cause an increase in the quantity of proteins, without affecting the protein secondary structure revealed by neural network predictions based on FTIR data. These slight variations in the lipid structure and the unaltered protein secondary structure may suggest that lipoic acid is non-toxic and thus support the usage of lipoic acid as an antioxidant supplement.

Effects of Lipoic Acid Supplementation on Finishing Steer Growth Performance, Carcass Merit, Beef Tenderness, and Beef Retail Display Properties

Angus cross steers (n = 84; BW =325 ± 3 kg) were used to evaluate the effects of lipoic acid (LA) supplementation on growth performance, carcass merit, beef tenderness, and beef retail display properties. Treatments were control (no LA), 8mg of LA/kg of BW per d (LA8), and 16mg of LA/kg of BW per d (LA16). Lipoic acid was incorporated into an extruded corn flour pellet and top-dressed onto a finishing diet for 125 d. Steers were subsequently delivered to a commercial abattoir for harvest. Carcass data and left-side longissimus sections (6th to 12th rib) were collected from each carcass at 24h post-mortem. Steaks from each longissimus section were analyzed for Warner-Bratzler shear force (WBSF) and color. Final BW of control steers was greater (P<0.01) than that of LA16 steers; final BW of LA8 steers was intermediate between the two. There were no treatment differences in ADG, DMI, or gain to feed ratio (G:F). Treatment had no effect on carcass weight, marbling score, longissimus area, kidney-pelvic-heart fat, or USDA yield grade. Subcutaneous fat thickness and the percentage of USDA Yield Grade 4 carcasses tended (P≤0.09) to be greater for LA16 steers than for control steers; LA8 carcasses were intermediate between control and LA16 steers in both categories. Mean WBSF values for steaks aged 21 d were less (P<0.01) for LA16 steers than for control and LA8 steers. Lipoic acid supplementation had negligible effects on subjective color scores of steaks aged from 7 to 21 d. Lipoic acid supplementation appeared to increase external fatness of beef carcasses.

Lipoic acid supplementation prevents angiotensin II–induced renal injury

Angiotensin II (Ang II)-induced renal injury is associated with perivascular inflammation, cell proliferation, and increased superoxide production in the vascular wall. We tested whether lipoic acid, an endogenous antioxidant, protects against the Ang II-induced inflammatory response and end-organ damage. Light microscopy, immunohistochemistry, electrophoretic mobility shift assay, Northern blots, and high-pressure liquid chromatography (HPLC) were used in kidneys from double transgenic rats (dTGR) harboring human renin and angiotensinogen genes and normotensive Sprague Dawley (SD) rats. The effects of lipoic acid supplementation for three weeks were examined in dTGR and SD rats. Lipoic acid effectively prevented Ang II-induced glomerular and vascular damage in the kidneys and completely prevented the development of albuminuria. Ang II-induced leukocyte infiltration and cell proliferation in the kidney were attenuated. The redox-sensitive transcription factors nuclear factor (kappa) B (NF-kappa B) and activator protein-1 (AP-1) in the kidneys were increased in dTGR compared with SD, and were effectively reduced. Renal glutathione levels were much higher in dTGR than in SD, while the opposite was true for cysteine levels. These results suggested increased renal glutathione oxidation in dTGR, leading to cysteine shortage. Lipoic acid partly prevented renal cysteine depletion and increased hepatic cysteine and glutathione concentrations. This effect was accompanied by increased hepatic gamma-glutamylcysteine synthetase mRNA expression. Our in vivo results suggest that lipoic acid protects against Ang II-induced renal injury through anti-inflammatory/antioxidative mechanisms. The effects are associated with decreased NF-kappa B and AP-1 activation, as well as improved thiol homeostasis.