Evaluation of a new model system for studying the formation of heterocyclic amines

Heterocyclic amines (HAs) are an important class of food mutagens and carcinogens, which can be found in cooked meat and fish. Increasing heating temperatures and times usually increase mutagenic activity in meat and meat extracts during cooking. We developed a model system, which allows to examine the effects of precursor composition and heating conditions (time and temperature) on the formation of HAs in meat. Homogenized and freeze dried meat samples (beef, pork chops, chicken breast and turkey breast) are heated with diethylene glycol in closed vials under stirring in a thermostated heating block. After an appropriate sample preparation (extraction and clean-up) ten different HAs were measured by HPLC analyses with gradient elution and mass selective detection. The time courses of HA-formation in the different kinds of meat at varying heating temperatures were determined up to heating times of 30 min. 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was the most abundant HA in these experiments and reached the highest concentrations in the beef meat samples, as did the other HAs (MeIQ, AalphaC) at 220 degrees C in the heating block under stirred conditions. Additionally the influence of the antioxidant TBHQ (t-butylhydroquinone) on the formation of HAs in the model system was tested. However TBHQ effected only slight reductions of HA formation in all kinds of meat.     

Docking studies of Vitamin C,Vitamin E,Damnacanthal and Scopoletin with human lens gamma D-crystalline

Vitamin C, Vitamin E, scopoletin and damnacanthal are the major constituents of Noni (Morinda citrifolia). These compounds are known to have good medicinal properties and they are known to act as antioxidants. Loss of vision in elderly is due to opaqueness of the lens proteins such as gamma-D-crystallin during oxidative stress conditions. Therefore, it is of importance to find the potential interaction of Vitamin C, Vitamin E, Scopoletin and Damnacanthal with the lens protein gamma-D-crystallin. Hence, their physical binding to gamma-D crystallin (PDB ID: 2G98) was evaluated using molecular and structural docking procedures. Results show the potential binding of all the above anti-oxidants to gamma-D-crystalline with equal affinity. Thus, the role of cumulative anti-oxidant effect in Noni fruit juice through their potential yet predicted interaction with the lens protein gamma-D-crystallin is implied for cataract treatment.     

The effect of different antioxidants on glutathione turnover in human cell lines and their interaction with hydrogen peroxide

BACKGROUND: Glutathione plays crucial roles in antioxidant defence and glutathione deficiency contributes to oxidative stress and may therefore play a key role in the pathogenesis of many diseases. The objectives of the present study were to evaluate the effects on glutathione turnover of thiol and non-thiol antioxidants in human cell cultures and if any of the antioxidant had a short-term cellular effect against different levels of hydrogen peroxide. METHODS: We have investigated the effect on the total glutathione amount in HeLa and hepatoma cell cultures of thiol antioxidants in comparison with non-thiol antioxidants, such as a copper chelator, Vitamin C, and a flavonoid. Furthermore, we have investigated the short-term (within 24h) interaction of the different antioxidants with hydrogen peroxide. RESULTS AND CONCLUSION: Lipoic acid and quercetin (Quer) were the two antioxidants that showed the highest stimulation of glutathione synthesis in cell cultures as judged by the total glutathione amount. However, no antioxidant protected against hydrogen peroxide present in concentrations that lowered cell protein. This finding may be attributed to the fact that it is necessary to incubate cell cultures with antioxidants or small doses of oxidants for a period before the cultures are exposed to hydrogen peroxide in order to enhance the antioxidant defence. The presence of Quer and Vitamin C lowered cell protein and total glutathione even in cell cultures containing hydrogen peroxide in concentrations that did not lower cell protein. This finding might be attributed to pro-oxidant properties and formation of excess reactive oxygen species in the presence of Quer and Vitamin C.     

No Major Differences Found between the Effects of Microwave-Based and Conventional Heat Treatment Methods on Two Different Liquid Foods

Extension of shelf life and preservation of products are both very important for the food industry. However, just as with other processes, speed and higher manufacturing performance are also beneficial. Although microwave heating is utilized in a number of industrial processes, there are many unanswered questions about its effects on foods. Here we analyze whether the effects of microwave heating with continuous flow are equivalent to those of traditional heat transfer methods. In our study, the effects of heating of liquid foods by conventional and continuous flow microwave heating were studied. Among other properties, we compared the stability of the liquid foods between the two heat treatments. Our goal was to determine whether the continuous flow microwave heating and the conventional heating methods have the same effects on the liquid foods, and, therefore, whether microwave heat treatment can effectively replace conventional heat treatments. We have compared the colour, separation phenomena of the samples treated by different methods. For milk, we also monitored the total viable cell count, for orange juice, vitamin C contents in addition to the taste of the product by sensory analysis. The majority of the results indicate that the circulating coil microwave method used here is equivalent to the conventional heating method based on thermal conduction and convection. However, some results in the analysis of the milk samples show clear differences between heat transfer methods. According to our results, the colour parameters (lightness, red-green and blue-yellow values) of the microwave treated samples differed not only from the untreated control, but also from the traditional heat treated samples. The differences are visually undetectable, however, they become evident through analytical measurement with spectrophotometer. This finding suggests that besides thermal effects, microwave-based food treatment can alter product properties in other ways as well.     

Effect of continuous ohmic heating to inactivate Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes in orange juice and tomato juice

Aims: The purpose of this study was to investigate the efficacy of continuous ohmic heating for reducing Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes in orange juice and tomato juice. Methods and Results: Orange juice and tomato juice were treated with electric field strengths in the range of 25–40 V cm^?1 for different treatment times. The temperature of the samples increased with increasing treatment time and electric field strength. The rate of temperature change for tomato juice was higher than for orange juice at all voltage gradients applied. Higher electric field strength or longer treatment time resulted in a greater reduction of pathogens. Escherichia coli O157:H7 was reduced by more than 5 log after 60‐, 90‐ and 180‐s treatments in orange juice with 40, 35 and 30 V cm^?1 electric field strength, respectively. In tomato juice, treatment with 25 V cm^?1 for 30 s was sufficient to achieve a 5‐log reduction in E. coli O157:H7. Similar results were observed in Salm. Typhimurium and L. monocytogenes. The concentration of vitamin C in continuous ohmic heated juice was significantly higher than in conventionally heated juice (P < 0·05). Conclusions: Continuous ohmic heating can be effective in killing foodborne pathogens on orange juice and tomato juice with lower degradation of quality than conventional heating. Significance and Impact of the Study: These results suggest that continuous ohmic heating might be effectively used to pasteurize fruit and vegetable juices in a short operating time and that the effect of inactivation depends on applied electric field strengths, treatment time and electric conductivity.     

Role of curcumin in the conversion of asparagine into acrylamide during heating

This study aimed to investigate the ability of curcumin to convert asparagine into acrylamide during heating at different temperatures. Binary and ternary model systems of asparagine–curcumin and asparagine–curcumin–fructose were used to determine the role of curcumin on acrylamide formation in competitive and uncompetitive reaction conditions. The results indicated that curcumin could potentially contribute to acrylamide formation under long-term heating conditions as long as asparagine was present in the medium. The amount of acrylamide formed in the ternary system was slightly higher than in the binary system during heating (p < 0.05), because of the higher concentrations of carbonyl compounds initially available. The kinetic trends were similar in both model systems evidencing that fructose reacted with asparagine more rapidly than curcumin. The data reveal that acrylamide formation in the temperature range of 150–200°C obeys Arrhenius law with activation energy of 79.1 kJ/mole. Data of this work showed the possibility that antioxidants having a carbonyl compound can react directly with ASN leading to acrylamide. The addition of antioxidants to foods may increase the formation of acrylamide upon long-term heating if free sugar concentration is low and ASN concentration is relatively high.     

Effect of natural antioxidants on frozen bovine semen preservation

The influence exerted by natural antioxidants (Vitamin E or sodium ascorbate) was studied in various thermal treatments of semen and their effect on respiratory activity and membrane integrity during cryopreservation. Frozen bovine semen samples of diverse quality were employed in the presence and absence of antioxidants. Both in good-quality samples subjected to cold shock and in those of poor-quality standard-cooled, low superoxide dismutase activity was observed concomitantly with high malondialdehyde production; as regards oxygen uptake there was no evidence of mitochondrial coupling. In good-quality samples standard-cooled in the presence of antioxidants, greater superoxide dismutase activity, intact acrosome percentage and mitochondrial coupling were recorded as well as lower malondialdehyde production than in the controls. Natural antioxidants would seem to exert a protective effect on the membrane of the cryopreserved spermatozoon in samples from good-quality semen.     

Effect of antioxidants on preservation of motility,viability and acrosomal integrity of equine spermatozoa during storage at 5 degrees C

Preservation of liquid semen at 5 degrees C is an important technique in the breeding management of horses. Oxidative damage to spermatozoa during storage is a potential cause of the decline in motility and fertility during hypothermic storage of liquid semen. The objective of this study was to evaluate the use of water-soluble and lipid-soluble antioxidants to improve the maintenance of motility of equine spermatozoa at 5 degrees C during storage for 72 to 96 h. In Experiment 1, the effect of addition of catalase on the maintenance of motility, viability and acrosomal integrity was determined. Semen was collected, and these treatments were applied: catalase (0, 100 or 200 U/mL) in nonfat, dried skim milk extender (NFDSM; with or without seminal plasma) or 10% seminal plasma + NFDSM. Motility was determined by computerized semen analysis (CASA) at 0, 24, 48 and 72 h. Viability and acrosomal integrity were determined at 72 h of storage. There was no significant treatment effect on the maintenance of sperm motility during 72 h storage. In Experiment 2, the effect of adding lipid-soluble antioxidants on maintenance of motility was evaluated. Semen was diluted to a final concentration of 25 x 10(6) sperm/mL in NFDSM containing butylated hydroxytoluene (BHT; 2.0, 1.0, or 0.5 mM), Vitamin E (4.0, 2.0, 1.0 mM), or Tempo (2.0, 1.0, or 0.5 mM). Although the addition of BHT significantly reduced (P < 0.05) progressive motility during storage compared to the control, there were no positive treatment effects of either Vitamin E or Tempo on maintenance of motility. In Experiment 3, the effect of adding water-soluble antioxidants on maintenance of motility was evaluated. Semen was diluted in NFDSM containing these treatments: Trolox (2.0 mM), Tempo (1.0 mM), Vitamin C (0.45 mg/mL), BSA (3% w/v), combinations of these antioxidants, or control. Adding these water-soluble antioxidants did not significantly improve the maintenance of motility during cooled storage at 5 degrees C. In conclusion, adding the enzyme scavenger, catalase, or a variety of lipid- and water-soluble antioxidants did not significantly improve the maintenance of motility during liquid semen storage at 5 degrees C.     

Effect of Electropermeabilization by Ohmic Heating for Inactivation of Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium,and Listeria monocytogenes in Buffered Peptone Water and Apple Juice

The effect of electric field-induced ohmic heating for inactivation of Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in buffered peptone water (BPW) (pH 7.2) and apple juice (pH 3.5; 11.8 °Brix) was investigated in this study. BPW and apple juice were treated at different temperatures (55°C, 58°C, and 60°C) and for different times (0, 10, 20, 25, and 30 s) by ohmic heating compared with conventional heating. The electric field strength was fixed at 30 V/cm and 60 V/cm for BPW and apple juice, respectively. Bacterial reduction resulting from ohmic heating was significantly different (P < 0.05) from that resulting from conventional heating at 58°C and 60°C in BPW and at 55°C, 58°C, and 60°C in apple juice for intervals of 0, 10, 20, 25, and 30 s. These results show that electric field-induced ohmic heating led to additional bacterial inactivation at sublethal temperatures. Transmission electron microscopy (TEM) observations and the propidium iodide (PI) uptake test were conducted after treatment at 60°C for 0, 10, 20, 25 and 30 s in BPW to observe the effects on cell permeability due to electroporation-caused cell damage. PI values when ohmic and conventional heating were compared were significantly different (P < 0.05), and these differences increased with increasing levels of inactivation of three food-borne pathogens. These results demonstrate that ohmic heating can more effectively reduce bacterial populations at reduced temperatures and shorter time intervals, especially in acidic fruit juices such as apple juice. Therefore, loss of quality can be minimized in a pasteurization process incorporating ohmic heating.     

Formation and stability of heterocyclic amines in a meat flavour model system. Effect of temperature, time and precursors

A model system based on a commercial meat flavour was used to evaluate the formation of heterocyclic amines, simulating the application of this seasoning in household cooking. The effects of different treatments in both dry and aqueous conditions were studied. The lyophilized meat flavour extract was heated at temperatures ranging between 100 and 200 degrees C for times ranging from 10 min to 2 h. Similarly, an aqueous suspension of the extract was heated at 175 degrees C for 1, 2 and 3 h. Precursors of HAs, such as creatinine, glucose, and the amino acids glycine, alanine and phenylalanine were added to the meat extract and their effect was tested by heating the mixture at 200 degrees C for 30 min, when dry conditions were used, and at 175 degrees C for 2 h in wet systems. All conditions led to the formation of HAs, PhIP being the amine that was detected at the highest level of concentration in most model systems (i.e. 173 ng g(-1) at 200 degrees C, 30 min). Moreover, the addition of creatinine and amino acids to the meat extract flavour produced an important increase in IQ and MeIQx content.     

Vitamin A with L-ascorbic acid sodium salt improves the growth performance,immune function and antioxidant capacity of weaned pigs

Vitamin A is easily degraded by environmental factors. Therefore, it is very important to add antioxidants during Vitamin A production. In the past, ethoxyquin (EQ) was widely used, but recent studies have found that it has potential toxicity. Therefore, in this study, we evaluated the antioxidant activities of 4 antioxidants in vitro: EQ, butylated hydroxytoluene, α-tocopherol and L-ascorbic acid sodium salt (Vitamin C sodium). In vitro experiments showed that Vitamin C sodium had better antioxidant capacity. Then, we explored the effects of different antioxidant types of Vitamin A on the growth performance, immune function and antioxidant capacity of weaned pigs. In total, 288 weaned piglets with an initial mean BW of 8.34 ± 0.02 kg at 30 days old were randomly divided into three groups with four replicates and 24 piglets per replicate for 35 days of feeding. The experimental diets were as follows: i) basal diet without external Vitamin A (NC); ii) basal diet supplemented with 12 000 IU/kg EQ Vitamin A and iii) basal diet supplemented with 12 000 IU/kg Vitamin C sodium Vitamin A. On day 36, two pigs from each replicate were selected to collect serum samples. The in vivo results showed that pigs in the EQ Vitamin A and Vitamin C sodium Vitamin A groups had significantly higher final weight and average daily gain (P < 0.05). During the trial, the levels of IgG and glutathione peroxidase in the EQ Vitamin A and Vitamin C sodium Vitamin A groups were significantly higher than those in the NC group (P < 0.05), and the malondialdehyde content was significantly lower (P < 0.05). On the 36th day, the levels of IgA and total antioxidant capacity in the Vitamin C sodium Vitamin A group were significantly higher than those in the EQ Vitamin A and NC (P < 0.05) groups. Thus, Vitamin C sodium Vitamin A can significantly improve the growth performance, antioxidant capacity and immune function of weaned pigs. Meanwhile, Vitamin C sodium may replace EQ as an antioxidant additive for Vitamin A.     

Impact of In-Situ CO2 Nano-Bubbles Generation on Freezing Parameters of Selected Liquid Foods

The impact of in-situ CO₂ nano-bubbles generation on the freezing properties of soft serve, milk, and apple juice was investigated. Carbonated (0, 1000, and 2000 ppm) liquid foods contained in a tube were submerged and cooled for 90 min in a pre-set ethylene glycol bath (−15 °C). Before the enclosed liquid reached 0 °C, the vibration was discharged through ultrasound in the bath to create nano-bubbles within the carbonated food samples, and the changes in temperature for 90 min of each food were recorded as a freezing curve. The time for onset of nucleation of control soft serve mix was halved in samples with 2000-ppm CO₂ due to the presence of nano-bubbles. Likewise, the nucleation time for milk with and without nano-bubbles at the same CO₂ concentration of 2000 ppm was 7.9 ± 0.1 and 2.8 ± 0.8 min_, respectively. The generation of CO₂ nano-bubbles from 2000-ppm CO₂ level in 10 ^oBx apple juice displayed −9.3 ± 0.3 °C nucleation temperature while the control one had −11.7 ± 0.9 °C.

     

Vegetable juice aids the recovery of heated spores of non-proteolytic Clostridium botulinum

Heating spores of non-proteolytic Clostridium botulinum at 85C for 2 min followed by plating on a standard laboratory medium reduced the count of viable spores by a factor of greater than 10⁴. A similar result was obtained when the plating medium was supplemented with juice from courgette, carrot or mung bean sprout. When plating was on media supplemented with hen egg white lysozyme or juice from turnip, swede, flat bean, cabbage or potato, heating at 85C for 10 min did not reduce the viable count by a factor of 10⁴. Thus these vegetable juices increased the measured heat resistance of spores of non-proteolytic Cl. botulinum . These findings are relevant to the safety of minimally processed (e.g. sous-vide ) foods.     

Chromatographic and related techniques for the determination of aromatic heterocyclic amines in foods

Some 20 years ago, Japanese scientists discovered a new group of highly toxic compounds, classified as heterocyclic aromatic amines, from broiled and grilled meat and fish products. Numerous studies have shown that most HAs are mutagenic and carcinogenic, and the safety of HA-containing foods has become a concern for the public. To date, more than 20 different mutagenic and/or carcinogenic heterocyclic amines have been identified in foods. This paper reviews the analysis of foods for HAs with 145 references. We survey some of the numerous methods available for the chromatographic analysis of heterocyclic amines and highlight the recent advances. We discuss chromatographic and related techniques, including capillary electrophoresis, and their coupling to mass spectrometry for the determination of these contaminants in foods. In addition, the review summarises data on the content of HAs in various cooked foods.     

Antioxidants prevent oxidative DNA damage and cellular transformation elicited by the over-expression of c-MYC

Reactive oxygen species (ROS)-induced genomic damage may have important consequences in the initiation and progression of cancer. Deregulated expression of the proto-oncogene c-MYC is associated with intracellular oxidative stress and increased DNA damage. However, the protective role of antioxidants such as Vitamin C against MYC-induced genomic damage has not been fully investigated. In a variety of cell lines, we show that ectopic MYC over-expression results in the elevation of intracellular ROS levels and a concomitant increase in oxidative DNA damage, as assessed by levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) in the genomic DNA. Loading cells with ascorbic acid (AA) relieved MYC-elicited intracellular oxidative stress and conferred genomic protection. A mitochondrially targeted Vitamin E analog, TPPB, also protected cells from MYC-elicited oxidative DNA damage, suggesting the involvement of mitochondria in increased ROS production. We found that deregulated MYC expression resulted in the attenuation of intracellular glutathione levels, which was reversed by loading cells with Vitamin C. Additionally, cells over-expressing MYC had elevated levels of intracellular superoxide, which was significantly quenched by Vitamin C or the selective superoxide quencher, Tiron. Consequently, Vitamin C and other antioxidants protected cells from MYC-induced cellular transformation. Our studies implicate a role for ROS, and superoxide in particular, in MYC-elicited oxidative DNA damage and cellular transformation, and point to a pharmacological role of antioxidants in cancer chemoprevention.     

Effects of combined selenium and vitamin E administration on DNA in Walker tumor bearing Wistar rat exposed to cytostatic acute treatment

Previous studies have showed that organic Se and Vitamin E have a significant protective effect when administered in combination with cytostatics. This paper reports the investigation on effects of mixed administration Orgasel 50 and Vitamin E in Wistar rat with experimentally induced Walker tumor under acute cytostatic treatment, with emphasis on two aspects: a) the influence of antioxidants upon liver unscheduled DNA biosynthesis under cytostatic (Lomustin) acute aggression; and b) the potential improvement of cytostatic effects by antioxidants treatment in tumor. Two lots of animals were used: lot 1 - Orgasel 50 and Vitamin E administered 7 days before the initiation of tumor induction and lot 2 - the antioxidants were concomitantly administered with tumor cell inoculation. The Walker tumor (an epithelial carcinoma) cells were subcutaneously injected (5 x 10(6) cells/0.5 ml in isotonic saline solution); the first tumor nodules appeared in 4 days; the tumor has reached the appropriate dimensions in 12 days. The unscheduled DNA biosynthesis caused by Lomustin in rat liver as well as the replicative DNA biosynthesis taking place in Walker tumor cells were assessed radioisotopically by measuring the uptake of 3H-Thymidine (200 microCi / 100 g.b.w.). Our observations regarding the role of antioxidant treatment suggest: 1) a benefic effect on DNA alkylant-induced lesions, expressed by a decrease in the level of 3H-Thymidine uptake in liver and, 2) an increase of the inhibitory activity of cytostatic on DNA replication biosynthesis in tumor cells, suggested by lower 3H-Thymidine incorporation in tumor cells. The most significant results were showed in both analyzed tissues, when the Orgasel 50 + Vitamin E administration begins at the same time with the tumor cell inoculation. These findings clearly show the organic Se salts and Vitamin E constitute a valuable adjuvant in anticancer medication, increasing the interest for the application of these antioxidants in cancer therapy and prevention.     

Vitamin C or Vitamin B6 supplementation prevent the oxidative stress and decrease of prostacyclin generation in homocysteinemic rats

We hypothesize that homocysteinemia causes oxidative stress, decreases the aortic ability to generate prostacyclin and that antioxidants have a protective role. Four groups of eight rats each were fed for 8 weeks the control diet (group A), control diet with folic acid omitted and excess methionine (Me) added to drinking water (group B), diet B + 500 mg/kg of Vitamin C (group C) or diet B + 60 mg/kg Vitamin B6 (group D). The three groups of rats fed folic acid deficient (FD) diets (groups B, C and D) were homocysteinemic as indicated by the significant increase in their serum homocysteine (HC) concentration. Rats fed diet B had oxidative stress as indicated by an increase in serum thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein products (AOPP) and urinary isoprostanes and had a decreased ability of their aortas to generate prostacyclin. Homocysteinemic rats fed a FD diet + Vitamin C (group C) or Vitamin B6 (group D) also had high levels of serum homocysteine but the oxidative stress markers and the ability of their aortas to generate prostacyclin returned to normal. This indicates that the homocysteinemic effect is through an oxidative mechanism and that Vitamin C as a free radical scavenger prevents these effects. Serum Vitamin C and liver glutathione concentrations significantly increased in rats fed excess Vitamin B6 compared to the control or FD rats. This may explain why Vitamin B6 has an antioxidative effect.     

Preparation of a beef-extract as a laboratory reference material for the determination of heterocyclic amines

The present paper describes the preparation of a suitable laboratory reference material (LRM) to validate analytical methods for the determination of heterocyclic amines (HAs) in foods. Three different lots of reference material were prepared using a beef extract which was contaminated with a well-known quantity of amines at different levels ranging from 10 to 75 ng/g. These materials were then lyophilised under determined conditions and, after grinding and sieving, homogenised and, finally, bottled and labelled. Homogeneity and stability studies were performed and no statistical differences were observed in the analysis of variances for within- and between-bottle results, thus demonstrating the homogeneity of the material. Stability at different storage temperatures (-18, +4, +25 and +40 degrees C) and times (1, 2, 3 and 6 months) was also tested. Therefore, the material can be considered homogeneous and stable and can be proposed for use in inter-comparison exercises for the determination of HAs.     

Use of antioxidants to minimize the human health risk associated to mutagenic/carcinogenic heterocyclic amines in food

Heterocyclic amines (HAs) are mutagenic/carcinogenic compounds formed in meat during cooking. Several efforts have been made to minimize the risk associated to HA human exposure. Supplementation with antioxidants is considered a promising measure to reduce HA exposure because of their ability as inhibitors of HA formation or as blocking/suppressing agents on HA biotransformation/metabolism. The aim of this review is to present the current knowledge on the capability of synthetic and natural antioxidants to modulate HA-induced mutagenicity/carcinogenicity. Data show a general trend towards a reduction of HA formation both in model systems and in real foods as well as an effective modulation of biotransformation and metabolism. Phenolic compounds, particularly those from tea and olive oil, seem to be the most effective, although a great variability is observed because of the concentration-dependent pro- and antioxidant effects.     

Effect of eugenol and tincture of crataegus (TCR) on in vitro oxidation of LDL + VLDL isolated from plasma of non-insulin dependent diabetic patients

The present study was carried out to study the effect of antioxidants on oxidised LDL + VLDL and found that vitamin E, eugenol and tincture of crataegus (antioxidants) inhibited oxidation of (LDL + VLDL) similar to standard antioxidant (butylated hydroxy toluene). Vitamin C acted as an antioxidant at lower concentration, and prooxidant at higher concentration.