The simple and sensitive measurement of malondialdehyde in selected specimens of biological origin and some feed by reversed phase high performance liquid chromatography

A Cross-Sectional Study Comparing Oxidative Stress in Patients with Epilepsy Treated with Old and New Generation Antiseizure Medications

Background and Objectives: Oxidative stress resulting from a disturbance of the endogenous redox system is suspected in numerous diseases of the central nervous system, including epilepsy. In addition, antiseizure medications (ASMs), especially those of the old generation, may further increase oxidative stress. To evaluate the effects of ASM generation on oxidative stress, we conducted a cross-sectional study in patients with epilepsy treated with old, new, and polytherapy. Materials and Methods: The antioxidant activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, as well as the concentrations of malondialdehyde, protein carbonyl, nitrate, nitrite, and glutathione in reduced and oxidized forms, were measured in 49 patients with epilepsy and 14 healthy controls. In addition, the plasma concentrations of ASMs and metabolites of carbamazepine and valproic acid were measured in the patients. Results: Patients with epilepsy showed increased activities of superoxide dismutase and catalase (p < 0.001), concentrations of glutathione disulfide and markers of nitric oxide metabolism (p < 0.001), and decreased activities of glutathione peroxidase, glutathione reductase, glutathione, and nitrite concentrations (p ≤ 0.005) compared to healthy controls. A comparison of ASM generations revealed increased levels of superoxide dismutase and catalase (p ≤ 0.007) and decreased levels of glutathione peroxidase and glutathione reductase (p ≤ 0.01) in patients treated with old ASMs compared to those treated with new generation ASMs. In addition, an increase in protein carbonyl and nitric oxide metabolites (p ≤ 0.002) was observed in patients treated with old generation ASMs compared to those treated with new generation ASMs. Most oxidative stress parameters in patients receiving polytherapy with ASMs were intermediate between the results of patients treated with the old and new generations of ASMs. Conclusions: An increase in oxidative stress markers and modulation of antioxidant enzyme activities was observed in patients with epilepsy compared to controls. The results of our study showed significantly higher oxidative stress in patients treated with old ASMs compared to those treated with new generation ASMs.

Supplementation of vitamin E as an addition to a commercial renal diet does not prolong survival of cats with chronic kidney disease

BACKGROUND

The aim of this double-blind, placebo-controlled study was to investigate the effect of vitamin E supplementation as an addition to a commercial renal diet on survival time of cats with different stages of chronic kidney disease (CKD). In addition, we were interested whether vitamin E supplementation affects selected oxidative stress and clinical parameters. Thirty-four cats with CKD and 38 healthy cats were included in the study. Cats with CKD were classified according to the IRIS Guidelines; seven in IRIS stage 1, 15 in IRIS stage 2, five in IRIS stage 3 and seven in IRIS stage 4. Cats with CKD were treated according to IRIS Guidelines. Cats with CKD were randomly assigned to receive vitamin E (100 IU/cat/day) or placebo (mineral oil) for 24 weeks in addition to standard therapy. Plasma malondialdehyde (MDA) and protein carbonyl (PC) concentrations, DNA damage of peripheral lymphocytes and plasma vitamin E concentrations were measured at baseline and four, eight, 16 and 24 weeks thereafter. Routine laboratory analyses and assessment of clinical signs were performed at each visit.

RESULTS

Vitamin E supplementation had no effect on the survival time and did not reduce the severity of clinical signs. Before vitamin E supplementation, no significant differences in vitamin E, MDA and PC concentrations were found between healthy and CKD cats. However, plasma MDA concentration was statistically significantly higher (p = 0.043) in cats with early CKD (IRIS stages 1 and 2) than in cats with advanced CKD (IRIS stages 3 and 4). Additionally, DNA damage was statistically significantly higher in healthy cats (p ≤ 0.001) than in CKD cats. Plasma vitamin E concentrations increased statistically significantly in the vitamin E group compared to the placebo group four (p = 0.013) and eight (p = 0.017) weeks after the start of vitamin E supplementation. During the study and after 24 weeks of vitamin E supplementation, plasma MDA and PC concentrations and DNA damage remained similar to pre-supplementation levels in both the placebo and vitamin E groups.

CONCLUSIONS

Vitamin E supplementation as an addition to standard therapy does not prolong survival in feline CKD.

Optimization of high-efficient pre-column sample treatments and C18-UFLC method for selective quantification of selected chemical forms of tocopherol and tocotrienol in diverse foods

The improved pre-column methods followed by gradient elution C18-chromatography (C18-UFLC) with photodiode (DAD) and fluorescence (FLD) detection for analysis of tocotrienols (T3s), tocopherols (Ts), α-tocopheryl acetate and cholesterol in plant, algae and fish oils, milk and animal tissues have been described. C18-chromatography without saponification permitted quantification of T3s and Ts in oils. Quantification of tocols in milk involved saponification followed by C18-chromatography. β-tocol and γ-tocol were unseparated using C18-chromatography. Esterification of hydroxyl group of tocols with trifluoroacetic anhydride allows their satisfactory separation. The combination of esterification of tocols, C18-chromatography and DAD monitoring at 278 and 205 nm provide the suitable analytical tool for quantification of β- and γ-forms of tocols in biological samples. Our original C18-chromatographic methods are satisfactory precise, accurate, repeatable and offer low values of limit of detection (<10 ng/mL) and limit of quantification (<27 ng/mL) for assayed tocols and cholesterol.

Biomarkers of oxidative stress and liver function in early lactation and their relationship with the reproductive efficiency of multiparous grazing dairy cows in Argentina. A retrospective study

This study aimed to analyze the possible relationship between days to conception and different oxidative stress (OS) biomarkers and liver functional parameters in multiparous dairy cows. Besides, a fast reliable method for the accurate measurement of malondialdehyde (MDA) by liquid chromatography-tandem mass spectrometry was developed in several matrices. During lactation, the days to conception of 28 cows were determined for a retrospective study. According to this parameter, cows were divided into two groups: high and low days to conception (HDC and LDC, respectively). Blood, urine and liver biopsies were sampled 21 days before the expected calving date, and 7 and 21 days after calving. The method developed for MDA was validated according to international requirements. The lower limit of quantification was 0.25 µmol/L for plasma and urine and 10.00 µmol/L for liver tissue. No differences between groups were observed in the systemic concentration of non-esterified fatty acids, β-hydroxybutyric acid and liver triacylglycerol content (P > 0.05). Cholesterol concentration was higher in the LDC than in the HDC group (P < 0.05). Plasma 3-nitrotyrosine (3-NT) concentration was lower in the LDC than in the HDC group on day 21 post-calving (P < 0.05). Superoxide dismutase activity was higher in the LDC than in the HDC group (P < 0.05). Particularly, in the liver, 3-NT and MDA concentrations were lower in the LDC than in the HDC group (P < 0.05). These results allow inferring that the amelioration of OS biomarkers in plasma and liver could be related to a better reproductive performance of dairy cows.

Evaluation of antioxidant status and lipid peroxidation in dogs with myxomatous mitral valve degeneration stage B1

Myxomatous mitral valve degeneration (MMVD) is the most common naturally occurring heart disease in dogs. There is a lack of data on antioxidant status and oxidative damage in dogs with MMVD stage B1 according to the American College of Veterinary Internal Medicine (ACVIM B1). The aim of this study was to investigate antioxidant status (plasma vitamin E, lipid-standardized vitamin E (LS-VitE), antioxidant capacity of lipid-(ACL) and water-soluble antioxidants, whole blood glutathione peroxidase and erythrocyte superoxide dismutase), and lipid peroxidation [malondialdehyde (MDA)] in dogs with MMVD ACVIM B1. Serum cholesterol and triglyceride concentrations were measured to calculate LS-VitE. Fourteen dogs with MMVD ACVIM B1 and 12 control dogs were included in the study. Dogs with MMVD had significantly higher vitamin E, ACL, MDA, and cholesterol concentrations and significantly higher LS-VitE values than control dogs. No significant correlations between MDA and antioxidant parameters were determined in either group. In conclusion, oxidative damage to lipids is already present and the antioxidant status is altered but not depleted in dogs with MMVD ACVIM B1. The antioxidant response to increased oxidative damage consists mainly of the activation of fat-soluble antioxidants. Further research is needed to evaluate the efficacy and targets of early antioxidant supplementation to prevent or ameliorate oxidative stress and mitigate disease progression in dogs with early-stage MMVD.

The Effect of Two Acute Bouts of Exercise on Oxidative Stress, Hematological, and Biochemical Parameters, and Rectal Temperature in Trained Canicross Dogs

Canicross is a sport discipline that connects human and canine athletes in running. Changes in physiological, hematological, and biochemical parameters, and exercise-induced oxidative stress have not been thoroughly characterized in canicross dogs. The aim of our study was the assessment of the health status of trained canicross dogs that were subjected to two acute bouts of exercise with their owners during the training season. Health status was assessed by measuring the rectal temperature, hematological and biochemical parameters, as well as blood oxidative stress parameters (plasma malondialdehyde, lipid peroxidation marker; whole blood glutathione peroxidase and erythrocyte superoxide dismutase1, antioxidant enzymes) before and during a two-day canicross training session and after a 24-h rest period. Seven trained canicross dogs (three females/four males) aged 12–120 months were included in the study. Blood samples were collected before and immediately after the first acute bout of exercise (day 1), after the second acute bout of exercise (day 2), and after 24 h of rest (day 3). Rectal temperature was measured at the same time as blood sample collection. The majority of hematological and biochemical parameters remained within reference ranges at all sampling times. Rectal temperature was significantly higher after training on days 1 and 2 compared to resting temperature on day 3. Hematological parameters did not change significantly; however, there were significant differences in urea, creatinine, creatine kinase, and triglycerides between specific sampling times. Despite significant changes, these biochemical parameters remained within reference ranges. Significant changes in biochemical parameters seem to reflect the dogs' physiological response to each acute bout of exercise, considering all biochemical parameters and rectal temperature returned to pre-exercise values after a 24-h rest period (day 3). No significant differences in oxidative stress parameters were found between any sampling times. Relatively high erythrocyte superoxide dismutase1 activity at all sampling times may indicate that the canicross dogs are adapted to training by an increased expression of antioxidant enzymes. Based on our results, we can conclude that the trained canicross dogs included in our study were healthy, in good physical condition, and fit for the two acute bouts of field exercise.

The Improved Method for Determination of Orotic Acid in Milk by Ultra-Fast Liquid Chromatography with Optimized Photodiode Array Detection

Ultra-fast liquid chromatography (UFLC) with a photodiode array detector (DAD) for simple and rapid determination of orotic acid (OAc) in milk of sheep and cows is described. Milk samples are treated with acetonitrile (1:1, v/v) and then centrifuged at 4 °C. To 1 mL of the obtained supernatant 9 mL of ultrapure water was added. Subsequently, 0.5-6 µL of the resulting solution was injected into the UFLC-DAD system. Separation and quantification of OAc in milk samples was achieved using two Kinetex C18 columns (1.7 µm, 150 mm × 2.1 mm, i.d., 100 Å; Phenomenex) fitted with a pre-column of 4 mm × 2 mm, i.d. (Phenomenex) containing C₁₈ packing material. All separations were performed at a column temperature of 35 °C while the ambient temperature was 21-24 °C. Satisfactory separation of OAc from endogenous species of milk can be achieved using the binary gradient elution program and UV detection at wavelengths 278 nm. Our original procedure resulted in suitable separation and quantification of OAc in milk samples; OAc eluted at 6.44 ± 0.03 min. The total run time of OAc analysis (including re-equilibration) was 27 min. As expected, the OAc peak was absent from the blank when the proposed gradient elution program and UV detection at 278 nm was used. The average recoveries of OAc standards added to milk samples were satisfactory (96.7-105.3%). The low inter-and intra-assay coefficient of variation derived from the measurements of OAc in cow and ovine milk samples (i.e., 0.784%, 1.283% and 0.710%, 1.221%, respectively) and in O-Ac standards (i.e., 0.377% and 0.294%, respectively), as well as high recoveries of OAc added to ovine and cows' milk (~100%) and the low detection (0.04 ng) and quantification (0.12 ng) limits point to satisfactory accuracy, precision and sensitivity of the reported method. OAc concentrations in ovine milk samples were within the range from 25 to 36 mg/L, while OAc levels in cows' milk samples was found in the range of 32-36 mg/L. Our original procedure is suitable for routine quantification of OAc in milk of ewes and cows.

Method Validation and Characterization of the Associated Uncertainty for Malondialdehyde Quantification in Exhaled Breath Condensate

There are several methods for quantifying malondialdehyde (MDA), an oxidative stress biomarker, in exhaled breath condensate (EBC). However, due to the very diluted nature of this biological matrix, a high variability is observed at low concentrations. We aimed to optimize a 2,4-dinitrophenylhydrazine-based method using liquid chromatography coupled to tandem mass spectrometry and characterize the uncertainty associated with this method. We investigated the following parameters for the method validation: calibration linearity, limit of detection (LOD), precision, recovery, and matrix effect. The results were used to identify the main sources of uncertainty and calculating the combined uncertainty. The applicability of this method was evaluated in an ongoing epidemiological study by analyzing 164 EBC samples collected from different professional groups in subway environments. The optimized method was sensitive (LOD: 70 pg/mL), precise (inter-day variation < 19%) and accurate (recovery range: 92–106.5%). The calculated analytical uncertainty was the highest at the LOQ level and reached 23%. Although the analytical uncertainty was high at low MDA concentrations, it was significantly lower than that the observed inter-individual variability. Hence, this method performs sufficiently well and can be recommended for future use in epidemiological researches relying on between-subject differences.

Dietary carnosic acid and seleno-compounds change concentrations of fatty acids, cholesterol, tocopherols and malondialdehyde in fat and heart of lambs

The aim of the current study was to evaluate the impact of carnosic acid (CA), selenised yeast (^YSe) and selenate (^VISe) supplemented to diets, including fish oil (FO) and rapeseed oil (RO), on the content of fatty acids, total cholesterol (TCh), tocopherols and malondialdehyde in the fat located between the thigh muscles and the heart in lambs. Twenty-four male Corriedale lambs were divided into 4 groups of 6 animals. Animals were fed a diet with FO and RO (the control diet) or experimental diets containing RO, FO and CA with/without Se (as ^YSe or ^VISe). The experimental diets without/with ^YSe or ^VISe changed concentrations of fatty acids in the fat and heart compared to the control. All experimental diets increased the levels of c11c14C20:2, c5c8c11c14C20:4, c5c8c11c14c17C20:5 and the sums of long-chain polyunsaturated fatty acids (LPUFA) and conjugated linoleic acid isomers in the fat compared to the control. The experimental diet containing ^YSe or ^VISe increased the content of Se, TCh, c11c14C20:2, c8c11c14C20:3, c5c8c11c14C20:4, c5c8c11c14c17C20:5, c7c10c13c16c19C22:5, c4c7c10c13c16c19C22:6 and the concentration sum of n-3LPUFA, n-6LPUFA and tocopherols in the heart in comparison with the control diet and the diet containing only CA. Experimental diets reduced the concentration of malondialdehyde in the fat and heart in comparison with the control diet. Our dietary intervention has great potential for future practical and commercial implementations.

Effects of Vitamin E and Coenzyme Q10 Supplementation on Oxidative Stress Parameters in Untrained Leisure Horses Subjected to Acute Moderate Exercise

The effects of antioxidant supplements on exercise-induced oxidative stress have not been investigated in untrained leisure horses. We investigated the effects of 14-day supplementation with vitamin E (1.8 IU/kg/day), coenzyme Q₁₀ (CoQ₁₀; ubiquinone; 800 mg/day), and a combination of both (the same doses as in mono-supplementation) on the blood levels of CoQ₁₀, vitamin E, and oxidative stress parameters in untrained leisure horses subjected to acute moderate exercise. Correlations between lipid peroxidation and muscle enzyme leakage were also determined. Forty client-owned horses were included in the study, with 10 horses in each of the antioxidant and placebo (paraffin oil) groups. Blood parameters were measured before supplementation, before and immediately after exercise, and after 24 h of rest. The differences in individual parameters between blood collection times and groups were analysed with linear mixed models (p ˂ 0.05). None of the supplemented antioxidants affected vitamin E and CoQ₁₀ concentrations, oxidative stress parameters, or serum muscle enzymes. Lipid peroxidation occurred in horses supplemented with placebo and CoQ₁₀ but not in horses supplemented with vitamin E or the combination of both antioxidants. These results suggest that vitamin E alone or in combination with CoQ₁₀ prevented lipid peroxidation in untrained leisure horses subjected to acute moderate exercise.

Evaluation of Oxidative Stress Parameters in Dogs with Brachycephalic Obstructive Airway Syndrome Before and after Surgery

Introduction

Canine brachycephalic obstructive airway syndrome (BOAS) is a conformation-related respiratory disorder of dog breeds having congenitally flattened facial and skull anatomy. The aim of the study was to determine oxidative stress parameters, the lipid peroxidation product malondialdehyde, and antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase in BOAS patients before and after surgical treatment and in healthy brachycephalic dogs.

Material and Methods

Nine healthy brachycephalic dogs that had not undergone surgery and 39 BOAS patients were included in the study. The BOAS patients were classified as grade 1 (5/34), grade 2 (16/34), and grade 3 (13/34) based on the decrease in the radius of the airway in the larynx. In BOAS patients, oxidative stress parameters were determined before and two weeks after surgery, while in control dogs, blood samples were collected only on inclusion to the study.

Results

All BOAS patients showed various degrees of improvement in clinical signs after surgery. Significantly lower (P < 0.05) SOD activity was found in grade 2 and 3 BOAS patients than in grade 1 patients. Two weeks after surgery, a significant (P < 0.05) increase in SOD activity in grade 2 and 3 patients was observed.

Conclusion

Antioxidant enzyme SOD may play an important role in BOAS and can be used as a biomarker of antioxidant status assessment in BOAS patients.

Effect of housing system and feed restriction on meat quality of medium-growing chickens

The aim of the study was to evaluate the differences in meat quality of 420 Hubbard JA757 cockerels in relation to the housing system (litter and mobile box) and level of mixed feed (ad libitum [AL], reducing the level by 20% [R20] and 30% [R30]). Three groups of chickens were housed in litter boxes for the entire fattening period (stocking density: 0.094 m²/bird). The other 3 groups were housed in litter boxes until 28 d of age and then relocated into mobile boxes (stocking density: 0.154 m²/bird) on pasture until the end of the experiment at 57 d of age. Restricted groups received a reduced diet level from 29th to 57th d of age. Feed mixture restriction increased the pasture vegetation intake of chickens from 2.63 to 3.50 (R20) and 3.94 g of dry matter/bird/d (R30). Restriction adversely affected the dressing percentage (P < 0.001) and breast yield (P < 0.001), while the leg yield (P < 0.001) was increased with increasing restriction levels. Meat of chickens housed in mobile boxes on a pasture showed lower cooking loss (P < 0.001) and higher redness and yellowness values in the skin (P = 0.030 and P = 0.026; respectively) and meat (P = 0.008 and P < 0.001; respectively). The fragile meat after cooking was observed in chickens reared on litter (P = 0.001). As the level of restriction increased, the number of muscle fibres (P = 0.001) increased, and their cross-sectional area (P = 0.001) and diameter (P = 0.002) decreased. The highest contents of lutein (P = 0.002) and zeaxanthin (P = 0.006) in breast muscle were found in chickens housed in mobile boxes and fed 80% and 70% AL. However, the concentrations of α- and γ-tocopherol (P = 0.006 and P = 0.003) were negatively affected by feed restriction. A 30% reduction in feed level in outdoor housed chickens led to a decrease in oxidative stability (P = 0.024). Feed restriction (R20) in chickens housed in mobile boxes significantly increased the n3 fatty acids content (P = 0.002) and h/H index (P = 0.005) and reduced the n6/n3 ratio (P < 0.001) and atherogenic (P < 0.001) and thrombogenic index (P = 0.003), which possess a health benefits for human. In addition, restriction of mixed feed decreased cholesterol content in breast meat (P = 0.042). It might be concluded that, in terms of meat quality, cereal diet restriction of 20% in medium-growing cockerels housed in mobile boxes on a pasture is beneficial. The higher level of restriction does not lead to further improvement in meat quality indicators.

Pomegranate seed oil and bitter melon extract supplemented in diet influence the lipid profile and intensity of peroxidation in livers of SPRD rats exposed to a chemical carcinogen

Despite promising health effects of pomegranate seed oil (PSO) and bitter melon extract (BM) used for centuries as food and traditional medicine, neither mechanism of action nor safety has been fully recognized. This study aimed to evaluate the influence of diet supplementation with PSO and BM on fatty acid, conjugated fatty acid and cholesterol content in rat' livers, since liver is crucial for lipid metabolism. Oxidation indicators (malondialdehyde, oxysterols and tocopherols) were also determined. Lipid profiles did not reveal the presence of punicic acid, while other conjugated dienes and trienes, including rumenic acid, were determined. Both supplementation and exposition to carcinogen significantly increased cholesterol and reduced selected oxysterols levels, simultaneously increasing malondialdehyde content in animals suffering from cancer. Impact of PSO and BM on oxidative status varied depending on carcinogen exposure and coexisting neoplastic process, which is important, due to the growing interest in their use in prevention and therapy of various diseases, including cancer.

Oxysterols and lipidomic profile of myocardium of rats supplemented with pomegranate seed oil and/or bitter melon aqueous extract - Cardio-oncological animal model research

A close link between cardiovascular diseases and cancer results from sharing the same modifiable risk factors (e.g. nutritional) and cardiotoxicity of anti-cancerous therapies. It justifies cardio-oncological preliminary studies on dietary factors, especially on those of possible anti-carcinogenic or cardioprotective properties. The main purpose was to evaluate the effect of pomegranate seed oil (PSO) and/or bitter melon extract (BME) supplementation of the diet of female rats suffering from mammary tumors on lipidomic profile (expressed as fatty acids, conjugated fatty acids (CFA), malondialdehyde (MDA), cholesterol and oxysterols content) of cardiac tissue. Total lipidomic profile and intensity of lipid peroxidation in hearts of DMBA-treated Sprague-Dawley rats and their healthy equivalents, both obtaining diet supplementation, were evaluated with different chromatographic techniques coupled with appropriate detection systems (GC-MS, GC-TOFMS, Ag+-HPLC-DAD, UF-HPLC-DAD). Dietary modifications neither diminished breast cancer incidence nor exerted explicit cardio-protective influence, however, they diminished cholesterol content, i.a. because of inhibition of the endogenous conversion of squalene to cholesterol in cardiac tissue. CFA were incorporated into cardiac tissue to a lesser extent in the cancerous process. PSO and BME anti-oxidant properties in pathological condition were only slightly reflected in MDA levels but not in oxysterols formation. Obtained results indicate considerable changes in dietary supplements' biological activity in pathological conditions and the need for clear distinction of drugs and dietary supplements, which is of utmost importance, especially for cancer survivors.

Osteocalcin prevents insulin resistance, hepatic inflammation, and activates autophagy associated with high-fat diet-induced fatty liver hemorrhagic syndrome in aged laying hens

The aim of this study was to investigate the effects of osteocalcin (OCN) on fatty liver hemorrhagic syndrome (FLHS) in aged laying hens. Thirty 68-week-old White Plymouth laying hens were randomly assigned into conventional single-bird cages, and the cages were randomly allocated into one of 3 treatments (n = 10): normal diet (ND + vehicle, ND + V), high-fat diet (HFD + vehicle, HFD + V), and HFD + OCN (3 μg/bird, 1 time/2 d, i.m.) for 40 d. At day 30, oral glucose tolerance tests (OGTT) and insulin tolerance tests (ITT) were performed. At the end of experiment, the hens were euthanized followed by blood collection. The plasma aspartate transaminase (AST), alkaline phosphatase (ALP), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured using an automatic biochemistry analyzer. Pathological changes in the liver were examined under both light and transmission electron microscopes. The plasma inflammatory factors including interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF-α) were analyzed by ELISA, and the gene expressions of these inflammatory factors in the liver were analyzed by real-time PCR. The level of oxidative stress was evaluated using malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) assay kits, respectively. The results showed that HFD + V hens had more severe liver hemorrhage and fibrosis than ND + V hens (P < 0.05). The ultramicrostructural examination showed that hepatocytes of HFD + V hens exhibited necrotic pyknosis showing great intracellular electron, mitochondrial swelling, shrunk nucleus, and absence of autolysosomes. Osteocalcin mitigated HFD + V-induced pathological changes in aged laying hens. High-fat diet + OCN hens had higher insulin sensitivity; lower liver concentrations of MDA (P = 0.12) but higher GSH-Px (P < 0.05); and lower blood TNF-α concentrations (P < 0.05) and mRNA expressions (P < 0.05) than HFD + V hens. These results suggest OCN functions in preventing the FLHS process in old laying hens through inhibiting excessive energy diet-induced metabolic disorder, oxidative stress, and related pathological damage.

The Effect of Diet Supplementation with Pomegranate and Bitter Melon on Lipidomic Profile of Serum and Cancerous Tissues of Rats with Mammary Tumours

The aim of this study was to present overall lipid profile of organisms with ongoing neoplastic process and applied diet supplementation with pomegranate seed oil (PSO) and bitter melon extract (BME). The following were quantified in serum and cancerous tissues of rats suffering from mammary tumours: fatty acids, conjugated fatty acids and sterols, their oxidised metabolites (malondialdehyde and oxysterols) and lipoxygenase (LOX) metabolites of polyunsaturated fatty acids. The obtained results indicate that abnormalities in lipid metabolism accompany neoplastic process. These differences concern all classes of lipids and most pathways of their transformation, with the special emphasis on lipid peroxidation and LOX-mediated metabolism. Cancer process appears to be so detrimental that it may conceal positive influence of dietary modifications. The lack of anticarcinogenic properties of PSO and BME in this model may be due to their antioxidant properties or elevated levels of conjugated linoleic acids (CLA), which change CLA isomer activity from anti- to pro-tumorigenic. As CLA are the product of conjugated linolenic acids (CLnA) endogenous metabolism, high CLA levels may be explained by applied diet enrichment.

Maternal and Early Postnatal Diet Supplemented with Conjugated Linoleic Acid Isomers Affect Lipid Profile in Hearts of Offspring Rats with Mammary Tumors

Linking the early life environment with later health status is known as "developmental programming". This study aimed to assess whether the introduction of conjugated linoleic acids (CLAs) into the maternal diet affects the content fatty acids (FAs), conjugated FAs (CFAs), cholesterol, oxysterols, malondialdehyde (MDA) and tocopherols in the hearts of their female offspring treated with 7,12-dimethylbenz[a]anthracene and if offspring supplementation enhanced the effect of maternal supplementation. FA, cholesterol and oxysterol contents were determined by gas chromatography-mass spectrometry, while contents of CFAs and MDA were determined by high-performance liquid chromatography (HPLC) with photodiode detection. The supplementation of mothers with CLAs significantly decreased the amount of atherogenic saturated FAs and enhanced the level of eicosapentaenoic FA in the hearts of offspring. Continuous progeny supplementation decreased the content of arachidonic acid in hearts. Supplementation of the maternal diet with CLAs and its continuation during the postnatal period increased the ratio of hypo to hypercholesterolemic FAs. Significantly fewer oxysterols were detected in the hearts of progeny of dams fed with CLAs as compared to the offspring of mothers receiving safflower oil. Both fetal and postnatal CLA intake significantly reduced 7β-hydroxycholesterol accumulation. It can be concluded that CLA supplementation during the fetal and postnatal period may be an effective method of maintaining the cardiac health status of newborns.

Performance and Meat Quality of Dual-Purpose Cockerels of Dominant Genotype Reared on Pasture

Simple Summary

One-day-old laying cockerels are killed after hatching because they do not reach the growth rate of broiler chickens, and their fattening would be economically disadvantageous. A possible variant of the use of these cockerels could be organic or free-range farming, where it is desirable that the animals are fattened for a longer period of time, are more physically active, and graze pasture vegetation. Another possibility is dual-purpose genotype breeding, where hens are used for egg production and cockerels are fattened for meat. In the present study, three genotypes of dual-purpose cockerels Dominant were compared. All three genotypes showed the ability to graze with resulting improvements in meat quality. The Dominant 102 cockerels have the greatest prerequisites for use in extensive fattening, mainly due to higher performance, willingness to graze and vitamin E content, which protects the fat from becoming rancid.

Abstract

The culling of layer cockerels due to economic inefficiency is an ethical problem. Organic or free-range fattening of these cockerels or dual-purpose genotypes breeding is a possible solution to this problem. The aim of the study was to assess the differences in performance and meat quality characteristics in dual-purpose cockerels Dominant of three genotypes (Dominant Sussex D 104, Dominant Brown D 102 and Dominant Tinted D 723, 100 cockerels per genotype) with access to pasture. The cockerels were housed in mobile boxes on the pasture herbage from the 50th to 77th day of age (stocking density: 0.108 m²/bird). The highest body weight on the 77th day of age (p < 0.001) and the nonsignificantly lowest feed conversion was achieved by Dominant Brown D 102 cockerels (1842 g and 2.79, respectively). Non-significantly higher pasture herbage intake on the 70th day of age was recorded in genotype Dominant Brown D 102 (7.41 g dry matter (DM)/bird/day) and Dominant Tinted D 723 (7.52 g DM/bird/day). The pasture herbage contained 56.9 mg/kg DM α-tocopherol, 170.3 mg/kg DM zeaxanthin and 175.0 mg/kg DM lutein and had a favourable n6/n3 ratio (0.26). The boiled meat of cockerels Dominant Tinted D723 showed the highest tenderness based on both the sensory evaluation (p = 0.022) and the value of shear force (p = 0.049). This corresponds with a higher (p < 0.001) cross-sectional area and muscle fibre diameter in these chickens. The highest content of n3 fatty acids (eicosapentaenoic, clupanodonic and docosahexaenoic acids) in breast meat were found in Dominant Sussex D104 chickens (p < 0.001). In contrast, a significantly higher α-tocopherol content (p < 0.001) and higher oxidative stability (p = 0.012) were found in Dominant Brown D102 (4.52 mg/kg and 0.282 mg/kg) and Dominant Tinted D 723 chickens (4.64 mg/kg and 0.273 mg/kg) in comparison with the Dominant Sussex D104 genotype (3.44 mg/kg and 0.313 mg/kg). The values of the atherogenic and thrombogenic indexes were the lowest (p < 0.001) in meat from Dominant Brown D102 chickens. Moreover, a lower cholesterol content (p < 0.001) was recorded from the genotypes Dominant Brown D102 (396 mg/kg) and Dominant Tinted D723 (306 mg/kg) chickens, contrary to the Dominant Sussex D104 cockerels (441 mg/kg). It can be concluded that cockerels Dominant Brown D102 are a suitable genotype for free-range rearing due to higher performance and higher pasture herbage intake, which positively influences meat quality, whereas the meat of Dominant Sussex D104 cockerels shows higher amounts of n3 fatty acids and lower n6/n3 ratios.

Conjugated Linoleic Acid Isomers Affect Profile of Lipid Compounds and Intensity of Their Oxidation in Heart of Rats with Chemically-Induced Mammary Tumors-Preliminary Study

Breast cancer and cardiovascular diseases (CVD) have shared risk factors and mechanisms of pathogenicity, as proven by increased cardiac risk in breast cancer patients receiving anticancerogenic therapies and in cancer survivors. A growing mammary tumor may cause heart injury in cancer patients who have not yet been treated. This study aimed to evaluate the effect of conjugated linoleic acid (CLA) supplementation of female rats with 7,12-dimethylbenz(a)anthracene (DMBA)-induced cancerogenesis on fatty acids (FAs), conjugated FAs (CFAs), malondialdehyde (MDA), cholesterol and oxysterols content in cardiac tissue. FAs, cholesterol and oxysterols contents were determined by gas chromatography coupled with mass spectrometry, while the contents of CFAs and MDA were determined by high performance liquid chromatography with photodiode detection. Our results indicate that both CLA supplementation and the presence of tumors influence the lipid biomarkers of CVD. A significant interaction of both experimental factors was observed in the content of polyunsaturated FAs (PUFAs), n-6 PUFAs and CFAs. CLA supplementation significantly inhibited PUFA oxidation, as evidenced by the lower content of MDA in rats' hearts, while the cancerous process intensified the oxidation of cholesterol, as confirmed by the elevated levels of 7-ketocholesterol in DMBA-treated rats. These results may significantly expand knowledge about CLA properties in terms of the prevention of co-existing non-communicable diseases.

Seleno-compounds and Carnosic Acid Added to Diets with Rapeseed and Fish Oils Affect Concentrations of Selected Elements and Chemical Composition in the Liver, Heart and Muscles of Lambs

The objective of our studies was to investigate effects of carnosic acid (CA), selenized yeast (SeY) and selenate (SeVI) added to the diet including rapeseed oil (RO) and fish oil (FO) on concentrations of elements, fatty acids (FAs), tocopherols, cholesterol, and malondialdehyde in the liver, heart, musculus longissimus dorsi (MLD), and musculus biceps femoris (MBF) of lambs. Lambs were fed diets: group I-the basal diet (BD) with RO; group II-BD with RO and FO; group III-BD with RO, FO, and CA; group IV-BD with RO, FO, CA, and SeY; group V-BD with RO, FO, CA, and SeVI. The diets with Se compounds increased Se concentrations in all tissues compared with other diets. The diet with SeVI increased Cd, Sb, and Pb concentrations in the liver compared to groups I, II, and IV. The diets containing Se compounds increased Sb and Pb concentrations in MBF compared to groups I and II. All diets with CA reduced As, Sb, and Pb concentrations in MLD compared to groups I and II. All diets with FO increased concentrations of FAs and malondialdehyde in the liver compared to group I. All diets with FO decreased FAs concentrations in MBF compared to group I. The diets containing CA with/without Se compounds increased malondialdehyde concentrations in MBF compared to groups I and II. The diet with Se compounds reduced malondialdehyde concentrations in MLD compared to group II. All diets with FO changed concentrations of tocopherols and cholesterol in all tissues compared to group I. Our study showed that the addition of SeY or SeVI to the experimental diet increased the concentration of Se in all assayed tissues of lambs without adversely influencing performance or causing physiological disorders in internal organs. Both, SeY or SeVI added to the experimental diet decreased the oxidative stress and the concentrations of As, Sb, and Pb in MLD compared with the diets containing RO, irrespective of the presence of FO (groups I and II). Our study provides useful knowledge for nutritionists carrying out further investigations aimed at improving farm animal health, performance, and the nutritional quality of animal products for humans.

Evaluation of lipid peroxidation by the analysis of volatile aldehydes in the headspace of synthetic membranes using Selected Ion Flow Tube Mass Spectrometry, SIFT-MS

RATIONALE

Oxidative stress of cell membranes leads to a number of pathological processes associated with some diseases and is accompanied by the release of volatile aldehydes, which, potentially, can be used as biomarkers. Thus, the aim was to investigate peroxidation of defined synthetic membranes by direct quantitative analysis of volatile aldehydes.

METHODS

The concentration spectra of volatile compounds present in the headspace of synthetic membranes under peroxidation stress and following mechanical stress due to sonication were obtained using solid phase microextraction (SPME) in combination with Gas Chromatography Mass Spectrometry (SPME/GC/MS) and Selected Ion Flow Tube Mass Spectrometry (SIFT-MS). The focus was on the direct, real time quantification of volatile aldehydes. In addition, the total aldehydes in the aqueous membrane suspensions were quantified using the TBARS method.

RESULTS

Propanal, butanal, pentanal, hexanal, heptanal and malondialdehyde were detected and quantified in the humid headspace of the media containing the synthetic membranes following peroxidation. The composition and concentration of these saturated aldehydes strongly depend on the unsaturated fatty acids representation in the liposomes. Some protective effect of cholesterol was observed especially for membranes peroxidised by Fenton reagents and after application of a mechanical stress.

CONCLUSIONS

This study demonstrates that peroxidation of model synthetic membranes in vitro can be tracked in real time using direct quantification by SIFT-MS of several specific aldehydes in the headspace of the membrane suspensions. Cholesterol plays an important role in retaining membrane structure and can indirectly protect membranes from lipid peroxidation.

Simultaneous Analysis of Seven Biomarkers of Oxidative Damage to Lipids, Proteins, and DNA in Urine

The determination of oxidative stress biomarkers (OSBs) is useful for the assessment of health status and progress of diseases in humans. Whereas previous methods for the determination of OSBs in urine were focused on a single marker, in this study, we present a method for simultaneous determination of biomarkers of oxidative damage to lipids, proteins, and DNA. 2,4-Dinitrophenylhydrazine (DNPH) derivatization followed by solid phase extraction (SPE) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) allowed the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG), o- o'-dityrosine (diY), malondialdehyde (MDA), and four F₂-isoprostane isomers: 8-iso-prostaglandinF_2α (8-PGF_2α), 11β-prostaglandinF_2α (11-PGF_2α), 15( R)-prostaglandinF_2α (15-PGF_2α), and 8-iso,15( R)-prostaglandinF_2α (8,15-PGF_2α) in urine. Derivatization with DNPH and SPE was optimized to yield greater sensitivity and selectivity for the analysis of target chemicals. The limits of detection of target analytes in urine were below 30 pg mL^-1. The assay intra- and interday variability was below 16% of the relative standard deviation, and the recoveries of target chemicals spiked into synthetic urine were near 100%. The method was applied to the analysis of 21 real urine samples, and the analytes were found at a detection frequency of 85% for 8-PGF_2α and 15-PGF_2α, 71% for 11-PGF_2α, 81% for 8,15-PGF_2α, and 100% for diY, 8-OHdG, and MDA. This method offers simultaneous determination of multiple OSBs of different molecular origin in urine samples selectively with high accuracy and precision.

Analysis of malondialdehyde in human plasma samples through derivatization with 2,4-dinitrophenylhydrazine by ultrasound-assisted dispersive liquid-liquid microextraction-GC-FID approach

A sensitive and reliable ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) procedure was developed and validated for extraction and analysis of malondialdehyde (MDA) as an important lipids-peroxidation biomarker in human plasma. In this methodology, to achieve an applicable extraction procedure, the whole optimization processes were performed in human plasma. To convert MDA into readily extractable species, it was derivatized to hydrazone structure-base by 2,4-dinitrophenylhydrazine (DNPH) at 40 °C within 60 min. Influences of experimental variables on the extraction process including type and volume of extraction and disperser solvents, amount of derivatization agent, temperature, pH, ionic strength, sonication and centrifugation times were evaluated. Under the optimal experimental conditions, the enhancement factor and extraction recovery were 79.8 and 95.8%, respectively. The analytical signal linearly (R² = 0.9988) responded over a concentration range of 5.00-4000 ng mL^-1 with a limit of detection of 0.75 ng mL^-1 (S/N = 3) in the plasma sample. To validate the developed procedure, the recommend guidelines of Food and Drug Administration for bioanalytical analysis have been employed.

Influence of sevoflurane or propofol anaesthesia on oxidative stress parameters in dogs with early-stage myxomatous mitral valve degeneration. A preliminary study

The aim of this study was to investigate the effects of total intravenous anaesthesia with propofol and anaesthesia induced with propofol and maintained with sevoflurane on oxidative stress parameters in dogs with early-stage myxomatous mitral valve degeneration (MMVD). Sixteen client-owned dogs with early stage MMVD that required periodontal treatment were included in the study. After induction with propofol, anaesthesia was maintained with propofol (group P) or sevoflurane (group PS). Blood samples for determination of vitamin E, superoxide dismutase, glutathione peroxidase and malondialdehyde were collected before premedication, 5 and 60 minutes and 6 hours after induction to anaesthesia. There were no significant differences between groups in any of the oxidative stress parameters at each sampling time. Compared to basal values, vitamin E concentration decreased significantly during anaesthesia in both groups and glutathione peroxidase activity increased 60 minutes after induction to anaesthesia in PS group. Anaesthesia with propofol or with propofol and sevoflurane did not have any significant impact on oxidative stress parameters in dogs with early stage MMVD. In terms of oxidative stress, both protocols may be equally safely used in dogs with early stage MMVD.

Intraneuronal Amylin Deposition, Peroxidative Membrane Injury and Increased IL-1β Synthesis in Brains of Alzheimer's Disease Patients with Type-2 Diabetes and in Diabetic HIP Rats

Amylin is a hormone synthesized and co-secreted with insulin by pancreatic β-cells that crosses the blood-brain barrier and regulates satiety. Amylin from humans (but not rodents) has an increased propensity to aggregate into pancreatic islet amyloid deposits that contribute to β-cell mass depletion and development of type-2 diabetes by inducing oxidative stress and inflammation. Recent studies demonstrated that aggregated amylin also accumulates in brains of Alzheimer's disease (AD) patients, preponderantly those with type-2 diabetes. Here, we report that, in addition to amylin plaques and mixed amylin-Aβ deposits, brains of diabetic patients with AD show amylin immunoreactive deposits inside the neurons. Neuronal amylin formed adducts with 4-hydroxynonenal (4-HNE), a marker of peroxidative membrane injury, and increased synthesis of the proinflammatory cytokine interleukin (IL)-1β. These pathological changes were mirrored in rats expressing human amylin in pancreatic islets (HIP rats) and mice intravenously injected with aggregated human amylin, but not in hyperglycemic rats secreting wild-type non-amyloidogenic rat amylin. In cultured primary hippocampal rat neurons, aggregated amylin increased IL-1β synthesis via membrane destabilization and subsequent generation of 4-HNE. These effects were blocked by membrane stabilizers and lipid peroxidation inhibitors. Thus, elevated circulating levels of aggregated amylin negatively affect the neurons causing peroxidative membrane injury and aberrant inflammatory responses independent of other confounding factors of diabetes. The present results are consistent with the pathological role of aggregated amylin in the pancreas, demonstrate a novel contributing mechanism to neurodegeneration, and suggest a direct, potentially treatable link of type-2 diabetes with AD.

Lipid Peroxidation Process in Meat and Meat Products: A Comparison Study of Malondialdehyde Determination between Modified 2-Thiobarbituric Acid Spectrophotometric Method and Reverse-Phase High-Performance Liquid Chromatography

The aim of this work was to compare the methods of malondialdehyde detection, as the main secondary product of the lipid peroxidation process, in meat and meat products. Malondialdehyde measurements were performed by two modified methods, the 2-thiobarbituric acid spectrophotometric method and the reverse-phase high-performance liquid chromatography in raw, mechanically-deboned chicken meat and in manufactured frankfurters. The malondialdehyde concentrations measured by the 2-thiobarbituric acid spectrophotometric method were found to be overestimated by more than 25% in raw meat and more than 27% in frankfurters in comparison to the results of reverse-phase high-performance liquid chromatography (p < 0.05). The achieved results showed that the presented modified reverse-phase high-performance liquid chromatography method was more applicable and more accurate for the quantification of malondialdehyde in samples of meat and meat products.

Hyperamylinemia Increases IL-1β Synthesis in the Heart via Peroxidative Sarcolemmal Injury

Hypersecretion of amylin is common in individuals with prediabetes, causes amylin deposition and proteotoxicity in pancreatic islets, and contributes to the development of type 2 diabetes. Recent studies also identified amylin deposits in failing hearts from patients with obesity or type 2 diabetes and demonstrated that hyperamylinemia accelerates the development of heart dysfunction in rats expressing human amylin in pancreatic β-cells (HIP rats). To further determine the impact of hyperamylinemia on cardiac myocytes, we investigated human myocardium, compared diabetic HIP rats with diabetic rats expressing endogenous (nonamyloidogenic) rat amylin, studied normal mice injected with aggregated human amylin, and developed in vitro cell models. We found that amylin deposition negatively affects cardiac myocytes by inducing sarcolemmal injury, generating reactive aldehydes, forming amylin-based adducts with reactive aldehydes, and increasing synthesis of the proinflammatory cytokine interleukin-1β (IL-1β) independently of hyperglycemia. These results are consistent with the pathological role of amylin deposition in the pancreas, uncover a novel contributing mechanism to cardiac myocyte injury in type 2 diabetes, and suggest a potentially treatable link of type 2 diabetes with diabetic heart disease. Although further studies are necessary, these data also suggest that IL-1β might function as a sensor of myocyte amylin uptake and a potential mediator of myocyte injury.

Dietary carnosic acid, selenized yeast, selenate and fish oil affected the concentration of fatty acids, tocopherols, cholesterol and aldehydes in the brains of lambs

Abstract. The function of the brain is to exert centralized control over the other internal organs and tissues of the body. Thus, the objective of our studies was to evaluate changes in the concentration of fatty acids (FAs), cholesterol (CHOL), cholest-4-en-3-one (CHOL-4-3), tocopherols, malondialdehyde (MDA) and fatty aldehydes in the brains of lambs fed supplemented diets. Thirty male Corriedale lambs with a body weight of 30.5 ± 2.6 kg were allotted to five groups of six lambs and housed individually. After the preliminary period, for 35 days the animals were fed a diet containing 3 % rapeseed oil (RO) (the RO diet), a diet enriched with 2 % RO and 1 % fish oil (FO) (the FO diet) or the diets with combined addition of 2 % RO, 1 % FO, 0.1 % carnosic acid (CA) (the CA diet) and 0.35 ppm Se as the selenized yeast (SeY) (the CASeY diet) or selenate (SeVI) (the CASeVI diet). The CASeVI diet most efficiently increased the accumulation of FAs (including unsaturated FAs), CHOL-4-3 and fatty aldehydes in the lamb brain. This diet most effectively decreased the concentration of CHOL and MDA in the brain. The CASeY diet showed a different impact on the level of FAs, CHOL, CHOL-4-3, tocopherols, MDA and fatty aldehydes in the brain as compared with the CASeVI diet. The CA diet reduced the concentration of CHOL-4-3, the sums of fatty aldehydes, FAs, atherogenic- and thrombogenic-saturated FAs in the brain compared with the CASeVI diet; the CA diet most effectively increased the value of polyunsaturated FA (PUFA) peroxidation index in the brain. The RO diet most efficiently increased the concentration of CHOL and values of the ratios of saturated FAs to PUFAs and long-chain n-6PUFAs to long-chain n-3PUFAs in the brain.The current studies provide new useful information for nutritionists carrying out further investigations aimed at improving farm-animal health, growth performance, reproductive system and the nutritional quality of feed for ruminants.

Toward a biomarker of oxidative stress: a fluorescent probe for exogenous and endogenous malondialdehyde in living cells

Malondialdehyde (MDA) is a significant biomarker of oxidative stress. Variations of MDA level in biological systems often represent pathological changes that are related with many types of diseases. Although a variety of techniques have been developed for MDA detection, the probing of this biomarker in living cells remains unexplored. Herein, we report a turn-on fluorescent probe, MDAP-1, with a synergistic photoinduced electron transfer (PET)-hydrogen bonding mechanism, which for the first time realizes MDA sensing under physiological conditions with excellent sensitivity and specificity. The probe responds to MDA with a fluorescence enhancement factor (FEF) of up to >170-fold and a large Stokes shift (∼180 nm). Further biological evaluations show that MDAP-1 is able to detect both endogenous and exogenous MDA in living cells. It can be used to track the generation of MDA under oxidative stress, as stimulated by H2O2. We believe the results of this work will be helpful to the studies of MDA-related biological events and the elucidation of the underlying pathological mechanism in the future.

Plasma malondialdehyde levels in children on 12-hour cyclic parenteral nutrition: are there health risks?

In children undergoing total parenteral nutrition (PN), lipids provide a key source of calories preventing or correcting energy deficits and improving outcomes. However, some of these lipids may undergo oxidation leading to the formation of malondialdehyde (MDA), a cytotoxic byproduct found in these patients. This paper aims to describe a sensitive method for detecting MDA and discuss its role in certain diseases commonly found in children on regular PN. To quantify MDA levels in children benefitting from long-term cyclic PN, a reliable and sensitive high-performance liquid chromatographic method based on a 1-step derivatization/extraction procedure analysis with ultraviolet determination at 305 nm wavelength was achieved. In control children without PN, MDA levels were on average 3.30 ± 0.08 µM. However, in children nourished intravenously by fat emulsion for a long time, in which liver problems have been identified, the circulating concentrations of MDA ranged widely at both the start and the end of a session, 3- to 10-fold, respectively, in comparison with the levels measured in controls. This finding indicates that PN administrated long term raises plasma MDA levels, indicating chronic exposure and therefore a possible health risk, particularly liver damage. This preliminary study using a limited number of patients and controls showed that children undergoing long-term PN are strongly exposed to MDA, which must be considered as a potent toxic compound rather than a simple marker of lipid peroxidation.

A fast and validated method for the determination of malondialdehyde in fish liver using high-performance liquid chromatography with a photodiode array detector

Malondialdehyde (MDA) is a biomarker of lipid peroxidation and is present in foods and biological samples such as plasma. A high-performance liquid chromatography (HPLC) method was applied to determine MDA in fish liver samples after derivatization with 2,4-dinitrophenylhydrazine (DNPH) using a ODS2 column (10 cm × 4.6 mm, 3 μm) and a photodiode array detector. The mobile phase consisted of 0.2% acetic acid (v/v) in distilled water and acetonitrile (42:58, v/v). The present method was validated in terms of linearity, lower limit of quantification, lower limit of detection, precision, accuracy, recovery, and stability of MDA according to U.S. Food and Drug Administration (FDA) guidelines. The limit of quantification of MDA was 0.39 μmol/L, which is comparable to other methods. The recovery of the spiked MDA liver samples was in the range of 92.4% to 104.2%. This newly modified HPLC method is specific, sensitive, and accurate and allows the analysis of MDA within 4 min in fish liver but also in other tissues and plasma.