Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LIPOIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed2001

Effects of dietary supplementation of alpha-lipoic acid on early glomerular injury in diabetes mellitus.

Antioxidants, in particular vitamin E (VE), have been reported to protect against diabetic renal injury. alpha-Lipoic acid (LA) has been found to attenuate diabetic peripheral neuropathy, but its effects on nephropathy have not been examined. In the present study, parameters of glomerular injury were examined in streptozotocin diabetic rats after 2 mo on unsupplemented diets and in diabetic rats that received the lowest daily dose of dietary LA (30 mg/kg body wt), VE (100 IU/kg body wt), or vitamin C (VC; 1 g/kg body wt), which detectably increased the renal cortical content of each antioxidant. Blood glucose values did not differ among the diabetic groups. At 2 mo, inulin clearance, urinary albumin excretion, fractional albumin clearance, glomerular volume, and glomerular content of immunoreactive transforming growth factor-beta (TGF-beta) and collagen alpha1 (IV) all were significantly increased in unsupplemented D compared with age-matched nondiabetic controls. With the exception of inulin clearance, LA prevented or significantly attenuated the increase in all of these glomerular parameters in D, as well as the increases in renal tubular cell TGF-beta seen in D. At the dose used, VE reduced inulin clearance in D to control levels but failed to alter any of the other indices of glomerular injury or to suppress renal tubular cell TGF-beta in D. VC suppressed urinary albumin excretion, fractional albumin clearance, and glomerular volume but not glomerular or tubular TGF-beta or glomerular collagen alpha1 (IV) content. LA but not VE or VC significantly increased renal cortical glutathione content in D. These data indicate that LA is effective in the prevention of early diabetic glomerular injury and suggest that this agent may have advantages over high doses of either VE or VC.

Animals↗
PubMed2000

Effects of a unique conjugate of alpha-lipoic acid and gamma-linolenic acid on insulin action in obese Zucker rats.

The purpose of this study was to assess the individual and interactive effects of the antioxidant alpha-lipoic acid (LPA) and the n-6 essential fatty acid gamma-linolenic acid (GLA) on insulin action in insulin-resistant obese Zucker rats. LPA, GLA, and a unique conjugate consisting of equimolar parts of LPA and GLA (LPA-GLA) were administered for 14 days at 10, 30, or 50 mg. kg body wt(-1). day(-1). Whereas LPA was without effect at 10 mg/kg, at 30 and 50 mg/kg it elicited 23% reductions (P < 0.05) in the glucose-insulin index (the product of glucose and insulin areas under the curve during an oral glucose tolerance test and an index of peripheral insulin action) that were associated with significant increases in insulin-mediated (2 mU/ml) glucose transport activity in isolated epitrochlearis (63-65%) and soleus (33-41%) muscles. GLA at 10 and 30 mg/kg caused 21-25% reductions in the glucose-insulin index and 23-35% improvements in insulin-mediated glucose transport in epitrochlearis muscle. The beneficial effects of GLA disappeared at 50 mg/kg. At 10 and 30 mg/kg, the LPA-GLA conjugate elicited 29 and 38% reductions in the glucose-insulin index. These LPA-GLA-induced improvements in whole body insulin action were accompanied by 28-63 and 38-57% increases in insulin-mediated glucose transport in epitrochlearis and soleus muscles and resulted from the additive effects of LPA and GLA. At 50 mg/kg, the metabolic improvements due to LPA-GLA were substantially reduced. In summary, these results indicate that the conjugate of the antioxidant LPA and the n-6 essential fatty acid GLA elicits significant dose-dependent improvements in whole body and skeletal muscle insulin action on glucose disposal in insulin-resistant obese Zucker rats. Moreover, these actions of LPA-GLA are due to the additive effects of its individual components.

Animals↗
PubMed2006

Effect of dietary lipoic acid on metabolic hormones and acute-phase proteins during challenge with infectious bovine rhinotracheitis virus in cattle.

OBJECTIVE: To determine the effect of dietary supplemental lipoic acid (LA) on serum concentrations of metabolic hormones and acute-phase proteins of steers challenged with infectious bovine rhinotracheitis virus (IBRV). ANIMALS: 32 steers. PROCEDURES: Steers were randomly assigned to 4 treatments: negative control (NC; no LA, no IBRV challenge), control (CON; no LA, IBRV challenge), 16 mg of LA/kg of body weight (BW)/d plus IBRV challenge (LA16), and 32 mg of LA/kg of BW/d plus IBRV challenge (LA32). Following a 21-day adaptation period, CON, LA16, and LA32 steers received IBRV (2 mL/nostril [day 0]); NC steers received saline (0.9% NaCl) solution. Blood samples, nasal swab specimens, BW, and rectal temperatures were obtained 0, 1, 3, 5, 7, 14, and 21 days after challenge. Serum was analyzed for concentrations of haptoglobin, amyloid-A, leptin, and anti-IBRV antibodies. RESULTS: Steers fed LA32 began gaining BW by day 7, whereas BW of CON and LA16 steers declined. Serum haptoglobin concentration of LA32 steers was lower than that of CON and LA16 steers on day 7. Serum neutralization titers for 30 of 32 steers were negative for anti-IBRV antibodies before challenge; however, all steers (including NCs) had antibodies on day 21. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that LA supplementation augmented certain aspects of the immune response; LA32 steers had a more rapid recovery from IBRV viral challenge than did others.

Acute-Phase Proteins↗
PubMed2005

Alpha-lipoic acid increases insulin sensitivity by activating AMPK in skeletal muscle.

Triglyceride accumulation in skeletal muscle contributes to insulin resistance in obesity. We recently showed that alpha-lipoic acid (ALA) reduces body weight and prevents the development of diabetes in diabetes-prone obese rats by reducing triglyceride accumulation in non-adipose tissues. AMP-activated protein kinase (AMPK) is a major regulator of cellular energy metabolism. We examined whether ALA lowers triglyceride accumulation in skeletal muscle by activating AMPK. Alpha2-AMPK activity was decreased in obese rats compared to control rats. Administration of ALA to obese rats increased insulin-stimulated glucose disposal in whole body and in skeletal muscle. ALA also increased fatty acid oxidation and activated AMPK in skeletal muscle. Adenovirus-mediated administration of dominant negative AMPK into skeletal muscle prevented the ALA-induced increases in fatty acid oxidation and insulin-stimulated glucose uptake. These results suggest that ALA-induced improvement of insulin sensitivity is mediated by activation of AMPK and reduced triglyceride accumulation in skeletal muscle.

AMP-Activated Protein Kinases↗
PubMed1998

Modelling cortical cataractogenesis XX. In vitro effect of alpha-lipoic acid on glutathione concentrations in lens in model diabetic cataractogenesis.

In previous studies stereospecific protection against lens opacity was consistent with specific reduction of R-alpha-lipoic acid(R-alpha-LA) in mitochondria of the vulnerable cells at the lens equator where the first globular degeneration is seen in glucose cataract. In this study two further possible explanations of this effect were investigated: (1) increased glucose uptake by the lens, leading to increased glycolysis and release of lactate into the incubation medium and/or (2) maintenance of glutathione levels by the R-alpha-LA. The data did not support 1, but was consistent with 2, after 24 hr incubation. The concentrations of glutathione in normal lenses or lenses incubated with R- or racemic alpha-LA were not significantly different, but the concentration of glutathione in lenses incubated with S-alpha-LA was significantly lower than the R-alpha-LA-incubated lenses.

Animals↗
PubMed1999

alpha-Lipoic acid treatment decreases serum lactate and pyruvate concentrations and improves glucose effectiveness in lean and obese patients with type 2 diabetes.

OBJECTIVE: We examined the effect of lipoic acid (LA), a cofactor of the pyruvate dehydrogenase complex (PDH), on insulin sensitivity (SI) and glucose effectiveness (SG) and on serum lactate and pyruvate levels after oral glucose tolerance tests (OGTTs) and modified frequently sampled intravenous glucose tolerance tests (FSIGTTs) in lean (n = 10) and obese (n = 10) patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: FSIGTT data were analyzed by minimal modeling technique to determine SI and SG before and after oral treatment (600 mg, twice a day, for 4 weeks). Serum lactate and pyruvate levels of diabetic patients after glucose loading were compared with those of lean (n = 10) and obese (n = 10) healthy control subjects in which SI and SG were also determined from FSIGTT data. RESULTS: Fasting lactate and pyruvate levels were significantly increased in patients with type 2 diabetes. These metabolites did not exceed elevated fasting concentrations after glucose loading in lean patients with type 2 diabetes. However, a twofold increase of lactate and pyruvate levels was measured in obese diabetic patients. LA treatment was associated with increased SG in both diabetic groups (lean 1.28 +/- 0.14 to 1.93 +/- 0.13; obese 1.07 +/- 0.11 to 1.53 +/- 0.08 x 10(-2) min-1, P < 0.05). Higher SI and lower fasting glucose were measured in lean diabetic patients only (P < 0.05). Lactate and pyruvate before and after glucose loading were approximately 45% lower in lean and obese diabetic patients after LA treatment. CONCLUSIONS: Treatment of lean and obese diabetic patients with LA prevents hyperglycemia-induced increments of serum lactate and pyruvate levels and increases SG.

Blood Glucose↗
PubMedDate not supplied

Alpha lipoic acid (ALA) protects proteins against the hydroxyl free radical-induced alterations: rationale for its geriatric topical application.

The well known OH* free radical scavenging properties of alpha-lipoic acid (ALA) cannot be easily utilized for biological experiments, because the compound is practically insoluble in water. We elaborated a simple method of preparing its Na-salt (Na-ALA) which proved to be water soluble. It has been demonstrated by ESR spin trapping experiments with DMPO, using the Fenton reaction as the source of OH* free radicals that Na-ALA maintains its OH* free radical scavenging ability: it reacts nearly an order of magnitude faster with these radicals than the spin trap itself. It was tested in two different systems to determine whether Na-ALA was able to protect bovine serum albumin (BSA) against the OH* free radical-induced polymerization and protein oxidation. (i) OH* free radicals were generated by Fenton reaction in the presence of BSA. This protein is polymerized by these radicals shown by the loss of its water solubility; Na-ALA exerted a considerable protective effect against this type of protein damage. (ii) BSA oxidation was induced by Co-gamma irradiation of 80 krad, resulting in a strong increase in the protein carbonyl content. Na-ALA inhibited this carbonyl formation very efficiently. The data suggest that the interaction of the OH radical with Na-ALA takes place on the disulfide group, yielding thiosulfinate or thiosulfonate. The results indicate that the geriatric topical application of Na-ALA may have an established rationale.

Journal Article↗
PubMed2006

L-dopa- and dopamine-(R)-alpha-lipoic acid conjugates as multifunctional codrugs with antioxidant properties.

A series of multifunctional codrugs (1-4), obtained by joining L-Dopa (LD) and dopamine (DA) with (R)-alpha-lipoic acid (LA), was synthesized and evaluated as potential codrugs with antioxidant and iron-chelating properties. These multifunctional molecules were synthesized to overcome the pro-oxidant effect associated with LD therapy. The physicochemical properties, together with the chemical and enzymatic stabilities of synthesized compounds, were evaluated in order to determine both their stability in aqueous medium and their sensitivity in undergoing enzymatic cleavage by rat and human plasma to regenerate the original drugs. The new compounds were tested for their radical scavenging activities, using a test involving the Fe (II)-H2O2-induced degradation of deoxyribose, and to evaluate peripheral markers of oxidative stress such as plasmatic activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the plasma. Furthermore, we showed the central effects of compounds 1 and 2 on spontaneous locomotor activity of rats in comparison with LD-treated animals. From the results obtained, compounds 1-4 appeared stable at a pH of 1.3 and in 7.4 buffered solution; in 80% human plasma they were turned into DA and LD. Codrugs 1-4 possess good lipophilicity (log P > 2 for all tested compounds). Compounds 1 and 2 seem to protect partially against the oxidative stress deriving from auto-oxidation and MAO-mediated metabolism of DA. This evidence, together with the "in vivo" dopaminergic activity and a sustained release of the parent drug in human plasma, allowed us to point out the potential advantages of using 1 and 2 rather than LD in treating pathologies such as Parkinson's disease, characterized by an evident decrease of DA concentration in the brain.

Animals↗
PubMed2003

Prophylactic action of lipoic acid on oxidative stress and growth performance in broilers at risk of developing ascites syndrome.

The objective of this study was to assess the effects of dietary supplementation with lipoic acid (LA) on broilers maintained at 2235 m above sea level with high risk to develop ascites syndrome (AS). A total of 2040 chicks were fed under commercial conditions with water and specific diets ad libitum during 7 weeks in two consecutive experiments. Mortality and indicators of performance and oxidative stress were compared weekly in broilers fed a basal diet plus 0, 10, 20, or 40 parts/10(6) LA. The effects of LA at 40 parts/10(6) were also studied during the initial 3 weeks or the last 4 weeks of the production cycle. Diets supplemented with 40 parts/10(6) of LA during 7 weeks significantly improved feed conversion, decreased general mortality and mortality attributable to AS, and lowered thiobarbituric acid reactive substances and hydroxyl radicals in liver, and increased total glutathione pool. Smaller doses or shorter periods of exposure to LA were partially effective. In conclusion, LA under our experimental conditions has a prophylactic action in broilers with high risk to develop AS due to oxygen availability limitation.

Animals↗
PubMedDate not supplied

[Evaluation of the actiom of lipoic acid in ischemia and hypertension].

A total of 203 patients, 48 -- with ischemic and 155 -- with hypertensive disease in the 11A and 11B stages, were examined. The effect of lipoic acid (LA) was assessed on the ground of the dynamics in the clinical picture of the patients, some vitamins allowance figures and the activity of a number of enzymes in leucocytes, erythrocytes and in the blood serum. The LA was administered in the form of tablets, in a dose of 75 mg per day, for 10 dyas. As controls served 90 patients with ischemic and hypertensive diseases. Investigations showed the LA to have but a little influence on the clinical picture of the disease, raising somewhat the beta-lipoproteids level in patients with hypertensive and ischemic disease, irrespective of their age, and increasing the level of free fatty acids in patients over 50, forcing it down in those below 50. An age-specific effect of the LA on the blood proteinic spectrum was disclosed, viz. in patients below 55 it increased the proportion of albumins and reduced that of gamma-globulins, whereas in those aged above 55 reverse picture was in evidence. In the young LA had the tendency of bringing down the coagulating activity of the blood; whereas disaggregation of thrombocytes changed not depending upon the age, but on the form of the affection, decreasing in patients with hypertensive disease and remaining unchanged in those with ischemic heart disease. The LA helped normalize the thiamine metabolism in the organism and that of the thiamine-diphosphate containing enzymes with concurrently disturbed utilization of riboflavin in the examined patients.

Adult↗
PubMed2003

ADP- and oligomycin-sensitive redox behavior of F0 b thiol in ATPsynthase depends on neighbored primary structure: investigations using 14-C-labeled alpha lipoic acid.

Purified ATPsynthase of bovine heart mitochondria has been analyzed for its mobility and reactivity of oligomycin-sensitive sulfhydryl regions in presence of the substrate ADP and oligomycin. Labeling of thiol groups at the hydrophobic F_0 region of the ATPsynthase was increased in the enzyme initially treated with SDS, N-ethylmaleimide and dithiothreitol (modified enzyme). After dialysis or gel permeation the ATPsynthase was treated with [14C] alpha lipoic acid at a molar ratio of 35-85/1 (lipoic acid/ATPsynthase) corresponding to 4-8.6 nmol/mg protein. Under these conditions, ATPase activity of the native enzyme was significantly decreased. After preincubation with ADP, PAGE of the native, [14C] labeled enzyme revealed an increase of radioactivity at a region of 25 kDa deduced to Cys 197 of subunit b. In the modified enzyme the increase in radioactivity was found at 10 kDa. In this context, the sequence Lys-Cys-Ile around Cys 197 of subunit b suggests excessive reactivity of this thiol, as well as ready reversibility by -SH-S-S- interchange. Therefore, previously observed reaction by thiol reagents and antioxidants from outside the mitochondrion can be interpreted with Cys 197 of F0 b. It accounts for sulfhydryl unmasked by binding of ADP at F1.

Adenosine Diphosphate↗
PubMed2006

Effect of chronic restraint stress and alpha-lipoic acid on lipid peroxidation and antioxidant enzyme activities in rat peripheral organs.

OBJECTIVES: The aim of this study was to evaluate the effect of chronic restraint stress and alpha-lipoic acid (LA) administration on lipid peroxidation and antioxidant enzyme activities in rat peripheral organs. METHODS: Forty male wistar rats, aged 3 months were randomized to one of the following groups: control, restraint stress, LA treated and restraint stress+LA treated. Chronic restraint stress was applied for 21 days (1h/day) and LA (100 mg/kg/day) was administered intraperitoneally for the same period. RESULTS: Restraint stress had no statistically significant effect on lipid peroxidation, copper/zinc superoxide dismutase (Cu/Zn SOD), catalase (CAT) and glutathione peroxidase (GPx) activity in rat liver and heart, when compared to the control group. Lipid peroxidation, determined by measuring malondialdehyde (MDA) levels, was found to be increased in the kidney of restraint stress treated rats, compared to controls. Restraint stress-induced lipid peroxidation in the kidney was significantly decreased via LA treatment. Administration of LA also enhanced GPx and decreased Cu/Zn SOD activity in rat kidney, liver and heart, compared to the control group. CONCLUSIONS: The presented data shows that LA is a protective agent against restraint stress--the inducer of lipid peroxidation in the kidney. These findings also suggest that LA-induced changes in antioxidant enzyme activities in rat peripheral organs may contribute to their versatile effects observed in vivo.

Animals↗
PubMed2003

Lipoic acid protects efficiently only against a specific form of peroxynitrite-induced damage.

The ability of the sulfur-containing compounds glutathione (GSH), glutathione disulphide (GSSG), S-methylglutathione (GSMe), lipoic acid (LA), and dihydrolipoic acid (DHLA) to protect against hypochlorous acid (HOCl)-mediated damage and peroxynitrite (ONOOH)-induced damage has been compared. Protective activity was assessed in competition assays by monitoring several detectors, i.e. dihydrorhodamine-123 (DHR-123) oxidation, alpha(1)-antiproteinase (alpha(1)-AP) inactivation, and glutathione S-transferase P1-1 (GST-P1-1) inactivation. In addition, nitration of tyrosine was measured to assess protection of the sulfur-containing compounds against ONOOH. For protection against HOCl, the efficacy of the antioxidant was controlled by the ratio of the reaction rates of the antioxidant and the detector molecule with the oxidant. The rank order of the activity of the antioxidants (GSH > DHLA approximately LA approximately GSMe > GSSG) appeared to be independent of the detector used. However, the rank order of the antioxidants against ONOOH-induced damage is strongly dependent on the detector. LA was 40 times less active than GSH in the inhibition of ONOOH-induced DHR-123 oxidation, whereas LA was 20 times more active than GSH in preventing the inhibition of GST-P1-1 by ONOOH. This points to different molecular mechanisms of ONOOH damage to DHR-123 compared with ONOOH damage to GST-P1-1. LA is a poor antioxidant in protecting against the form of ONOOH damage involved in DHR-123 oxidation. In the form of ONOOH toxicity involved in GST-P1-1 inhibition, LA is the most potent sulfur-containing antioxidant in our series. It is proposed that an intermediate product in which both sulfur atoms of LA have reacted is involved in the reaction of ONOOH with LA. The high potency of LA to protect GST-P1-1 against ONOOH might be of therapeutic interest.

Antioxidants↗
PubMed2004

Attenuation of chloroquine-induced renal damage by alpha-lipoic acid: possible antioxidant mechanism.

The toxic effect of chloroquine (CQ) has been attributed to oxidative stress with the consequences of lipid peroxidation. This study investigates the effects of alpha-lipoic acid (LA) on CQ-induced nephrotoxicity in rats. A single oral administration of CQ (970 mg/kg)-induced nephrotoxicity, manifested biochemically by a significant increase in serum creatinine and blood urea nitrogen concentrations. In addition, renal tissue from CQ-treated rats showed a significant increase in lipid peroxides measured as thiobarbituric acid reactive substances and hydroperoxides, along with significant decrease in nonenzymic antioxidants (vitamin C, vitamin E, and reduced glutathione) and enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase) levels. Oral administration of LA (10, 30, or 100 mg/kg) in different doses for 10 days produced a significant protection against nephrotoxicity induced by CQ. Treatment with LA markedly reduced the elevated lipid peroxidation, restored the depleted renal antioxidant defense system. LA at 100 mg/kg was effective when compared with other doses (10 and 30 mg/kg). This was accompanied by the histopathological observations in kidney tissue. The results suggest that LA ameliorate the lipid peroxidation and the loss of cellular antioxidants, thereby protecting the CQ-induced oxidative damage in kidney.

Animals↗
PubMed1999

Involvement of lipoic acid in plasma metabolites, hepatic oxygen consumption, and metabolic response to a beta-agonist in broiler chickens.

The present study was conducted to determine the role of alpha-lipoic acid (LA) in plasma metabolites, hepatic O2 consumption, and beta-adrenergic response in broilers. In Expt 1, 12-d-old female broiler chicks were divided into three dietary groups and fed on diets with or without LA (5 or 50 mg/kg) until 4 or 6 weeks of age, as a 2 x 3 factorial arrangement. The dietary LA had no effect on growth rates (body weight, abdominal fat, breast muscle, and liver). The higher level of LA increased plasma non-esterified fatty acid and decreased plasma triacylglycerol concentrations only at 6 weeks of age. A 42% increase in hepatic respiration was observed in the 4-week-old chickens given 50 mg LA/kg diet. In Expt 2, 3-d-old female broiler chicks were treated with or without dietary LA at 50 mg/kg. At 30 and 31 d old, isoproterenol (2 mg/kg body weight per h) was continuously infused into a wing vein for 2 h, and changes in plasma glucose, triacylglycerol, and non-esterified fatty acid concentrations were analysed. Isoproterenol increased plasma glucose over basal levels maximally at 60 min. Furthermore, the glucose increase in the LA-treated chickens was 35% greater than that of the controls at this time. Plasma non-esterified fatty acid and triacylglycerol concentrations were decreased by the isoproterenol infusion, regardless of LA administration. Therefore, the present study suggests that dietary LA has repartitioning effects on energy metabolism in chickens (although this depends on age-related metabolic state) and is a possible facilitator in the beta-adrenergic response of plasma glucose to a beta-agonist.

Adrenergic beta-Agonists↗
PubMed2000

Nutrients and HIV: part three - N-acetylcysteine, alpha-lipoic acid, L-glutamine, and L-carnitine.

The role of antioxidants in preventing apoptosis and viral activation in HIV is well documented. N-acetylcysteine, glutathione, and alpha-lipoic acid have been shown to interrupt the process of viral activation and CD4 cell death. L-glutamine has been shown to improve glutathione levels and significantly increase lean body mass in HIV infection. The literature on the use of L-carnitine and acetyl-L-carnitine in treating mitochondrial toxicity, both in muscle and nerve pathologies is relevant in nutritional treatment of HIV, given the mitochondrial toxicity of nucleoside analog reverse transcriptase inhibitor therapy. The current use of highly active antiviral therapies, their toxicity, and significant failure rates have created the need for a more conservative reassessment of HIV treatment. The adjunctive use of nutrient therapy in the treatment of HIV is reviewed here.

Acetylcysteine↗
PubMed1984

[Demonstration of hormonal actions on Escherichia coli K 12 by potentiometry in the presence of lipoic acid; correlation with measurements of microbial growth and glucose consumption].

The action of hormones on Escherichia coli K 12 was followed by potential-time measurements in the presence of lipoic acid (LA), photometric determinations of growth and glucose titrations. Bovine growth hormone (5 to 60 IU/1) increased O2 consumption. The (10 IU/1) insulin-facilitated transport of LA was stimulated by glucose. Adrenaline (0.5 to 15 mg/l) increased more glucose and O2 consumption than growth.

Epinephrine↗
PubMed2004

Effects of a medium chain triglyceride oil mixture and alpha-lipoic acid diet on body composition, antioxidant status, and plasma lipid levels in the Golden Syrian hamster.

The objective of this study was to examine the effects of the antioxidant alpha-lipoic acid (ALP) versus a medium chain triglyceride oil mixture (MCTo), which was designed to increase energy expenditure and to improve lipid profiles containing medium chain triglycerides, phytosterols, and omega-3 fatty acids in the form of flaxseed oil. A total of 48 hamsters were fed a) hypercholesterolemic (HC) control, b) HC MCTo, c) HC ALP, or d) HC MCTo/ALP diet for 4 weeks. No differences were observed on food intake, body weight, total body water, lean and fat mass, and tissue thiobarbituric acid reactive substances (TBARS). ALP alone had no effect on total cholesterol (TC); however, MCTo feeding increased TC with (P < 0.03) and without (P < 0.003) ALP when compared with control. ALP increased HDL levels compared with control (P < 0.04) and MCTo/ALP (P < 0.007) groups. MCTo, with (P < 0.0001) or without (P < 0.006) ALP, increased non-HDL cholesterol levels versus control. The non-HDL:HDL cholesterol ratio was decreased by ALP compared with MCTo (45%) and MCTo/ALP (68%) (P < 0.0001), a similar trend was seen when compared with the HC control (22%) group (P < 0.14). Triglyceride levels were not altered by any dietary treatment. Liver and heart tissue reduced glutathione (GSH) was increased (P < 0.05) by all three treatments when compared with control. Both tissues showed an increase (P < 0.05) in oxidized glutathione (GSSG) when fed ALP as compared with other treatments. Hamsters fed ALP had a lower (P < 0.05) GSH/GSSG ratio compared with other treatment groups. In conclusion, MCTo feeding does not elicit beneficial effects on circulating plasma lipids and measures of body composition. In addition, our results do not clearly support an improvement in oxidative status through supplementation of ALP. However, our results do support the existence of beneficial effects of ALP on circulating lipoprotein content in the hamster.

Animals↗