Determination of antioxidant properties of aroma extracts from various beans

Effects of Lard and Vegetable Oils Supplementation Quality and Concentration on Laying Performance, Egg Quality and Liver Antioxidant Genes Expression in Hy-Line Brown

This study examined the effects of various types, quality, and levels of dietary oils on laying performance and the expression patterns of antioxidant-related genes in Hy-line brown laying hens. A total of 720 40-week-old Hy-line brown laying hens were fed the same corn-soybean basal meals but containing 0.5 or 1.5% normal or oxidized soybean oil or lard, a total of 8 treatments. The results showed that laying rate (LR) and fatty acids of raw yolk were significantly correlated dietary type of oil (p < 0.05). With the increasing concentration of normal oil, it significantly increased LR and decreased feed conversion ratio (FCR, feed/egg) and albumen height of laying hens. The oxidized oil significant decreased the production performance of laying hens; and adding 1.5% of oxidized lard into feeds could destroy the integrity of yolk spheres of cooked yolk. mRNA expression of liver antioxidant-related genes increased when dietary oxidized oils were added into feeds. By comparing different qualities oil effect on antioxidant-related genes, the expression of Glutathione S-Transferase Theta 1 (GSTT1), Glutathione S-Transferase Alpha 3 (GSTA3), Glutathione S-Transferase Omega 2 (GSTO2), and Superoxide Dismutase 2 (SOD2) were increased when dietary oils were oxidized, in which change of the GSTO2 expression was the most with 1.5% of oxidized soybean oil. In conclusion, the ideal type of oil for Hy-line brown layer hens is soybean comparing with lard in a corn-soybean diet, avoiding using of oxidized oil.

The Use of Sage Oil Macerates (Salvia officinalis L.) for Oxidative Stabilization of Cod Liver Oil in Bulk Oil Systems

The aim of the study was to investigate the antioxidant properties of sage oil macerates (M) in cod liver oil (CLO) during process oxidation catalyzed by UV radiation. CLO was not only subject to oxidative stabilization but also used as a solvent for active ingredients of sage. Macerates were obtained by combining the sage with CLO, homogenization, maceration, and filtration. The effect of different maceration times (0, 3, 6, 8, 10, 13, and 15 days) and different concentrations of macerate addition (5%, 10%, 25%, and 50%) on the CLO oxidation degree, which was determined by peroxide value (PV), anisidine value (AV), and Totox index, was evaluated. Additionally, the total content of polyphenols in macerates by the Folin-Ciocalteu method, antioxidant activity DPPH, and color was determined. The macerates showed antioxidant properties in CLO. The best effect was shown by the initial macerate (maceration time 0, M0), which in 25% concentration significantly inhibited oxidative processes in CLO. It was also characterized by high content of polyphenols and antioxidant activity of DPPH. Sage macerates can effectively inhibit oxidation of fish oils and prolong their durability.

Enhanced Antioxidant and Cytotoxic Potentials of Lipopolysaccharides-Injected Musca domestica Larvae

The usage of insects as a sustainable and functional natural products resource is a new promise in complementary and alternative medicine. The present study aimed to investigate the ability of Musca domestica (housefly) larval hemolymph (insect blood) to display the enhanced in vitro antioxidant and cytotoxic effects. The oxidative stress (OS) was elicited by inducing lipopolysaccharides (LPS) treatment as an exogenous stressor. Determination of superoxide dismutase 1 (SOD1), glutathione (GSH), malondialdehyde (MDA) and total antioxidant capacity (TAC), and mRNA and protein expressions of SOD1, was investigated as confirmatory markers of oxidative stress induction. Cytotoxicity on cancerous MCF-7 and normal Vero cells were also evaluated using an MTT assay at 24 h post-injection. The injection of LPS induced a significant (p < 0.05) increase in SOD, GSH and TAC, whereas, the MDA was diminished. Hemolymph was collected from normal and treated larvae after 6, 12 and 24 h. The M. domestica superoxide dismutase (MdSOD1) transcripts were significantly (p < 0.05) upregulated 6 and 12 h post-treatment, while a significant downregulation was observed after 24 h. Western blot analysis showed that MdSOD1 was expressed in the hemolymph of the treated larvae with an increase of 1.2 folds at 6 and 12 h and 1.6 folds at 24 h relative to the control group. LPS-treated larval hemolymphs exhibited significant cytotoxicity with respect to the untreated ones against MCF-7 while Vero cells showed no cytotoxicity for both hemolymphs. The DPPH free radical scavenging activity was examined and a significant antioxidant potential potency was observed at 6 h (50% maximal inhibitory concentration (IC50): 63.3 ± 3.51 µg/mL) when compared to the control M. domestica larval hemolymph (IC50: 611.7 ± 10.41 µg/mL). Taken together, M. domestica larval hemolymph exhibited enhanced antioxidant and consequently increased cytotoxic capacities under stressed conditions.

Effects of frying, roasting and boiling on aroma profiles of adzuki beans (Vigna angularis) and potential of adzuki bean and millet flours to improve flavor and sensory characteristics of biscuits

Volatile compounds of raw and cooked adzuki beans under three cooking methods namely frying, roasting, and boiling were extracted and identified. The odorants in raw beans changed from "green" and "grassy" to "roasted" and "nutty" in fried and roasted beans. Roasted adzuki beans had the greatest number of volatile compounds and best flavor properties. Because volatiles improve biscuit flavor profiles, biscuits were prepared in which wheat flour was substituted with adzuki bean flour and/or millet flour. The effects of grain flours on the sensory acceptability and aroma of biscuits were evaluated. Descriptive sensory analysis showed that the adzuki bean-millet biscuit had the best sensory quality. Correlation of volatile compounds, biscuit sensory attributes, and biscuit samples showed that maltol contributed to the "caramel-like" aroma of adzuki bean-millet biscuits. Adzuki bean and millet flours have potential in the development of biscuits that meet flavor and nutritional requirements.

Contribution of aroma compounds to the antioxidant properties of roasted white yam (Dioscorea rotundata)

Background

The aroma chemistry and the contribution of the aroma compounds to the anti-oxidative properties of roasted yam have yet to be characterized. The growing popularity of roasted yam in regions where they are being consumed calls for a concerted effort to elucidate their aroma chemistry as well as their anti-oxidative properties.

Results

The aroma compounds in roasted white yam (Dioscorea rotundata) were isolated and identified using static headspace-gas chromatography-mass spectrometry (SH-GC-MS) and gas chromatography-olfactometry (GC-O). In addition, the anti-oxidative activities of the most abundant volatile heterocyclic compounds (2 pyrroles, 4 furans and 3 pyrazines) were evaluated on their inhibitory effect towards the oxidation of hexanal for a period of 30 days. Twenty-nine aroma-active compounds with a flavour dilution (FD) factor range of 2-256 and an array of odour notes were obtained. Among them, the highest odour activities (FD ≥ 128) factors were determined for 2-acetyl furan and 2-acetylpyrrole. Other compounds with significant FD factors ≥ 32 were; 2-methylpyrazine, ethyl furfural, and 5-hydroxy methyl furfural.

Conclusion

Results of the anti-oxidative activity showed that the pyrroles exhibited the greatest antioxidant activity among all the tested heterocyclic compounds. This was followed by the furans and the pyrazines which had the least antioxidant activity.

Changes in the amino acid profiles and free radical scavenging activities of Tenebrio molitor larvae following enzymatic hydrolysis

Tenebrio molitor (T. molitor) larvae provide food at low environmental cost and contribute positively to livelihoods. In this research, we compared the amino acids compositions and antioxidant activities of various extracts of T. molitor to enhance their quality as food. For the comparison, distilled water extracts, enzymatic hydrolysates, and condensed enzymatic hydrolysates of T. molitor larvae were prepared. Their amino acids (AAs) profiles and antioxidant activities, including ferric-reducing antioxidant power, oxygen radical absorption capacity, and DPPH, hydroxyl radical, and hydrogen peroxide radical scavenging properties assay were analyzed. DW extracts had the lowest AAs contents and antioxidant activity compared with enzymatic extracts. Condensed hydrolysates with a combination of alcalase and flavourzyme (C-A+F) exhibited the highest levels of total free AAs (11.1759 g/100 g). C-A+F produced higher total hydrolyzed AAs (32.5292 g/100 g) compared with the other groups. The C-A+F possessed the strongest antioxidant activity. Notably, the antioxidant activities of the hydrolysates and the total hydrolyzed AAs amount were correlated. Taken together, our findings showed that C-A+F was a promising technique for obtaining extracts of T. molitor larvae with antioxidant activity as potential nutritious functional food.

A novel gas chromatographic method for determination of malondialdehyde from oxidized DNA

Malondialdehyde (MA) is known to form from various lipids upon oxidation as one of secondary oxidation products. Determination of MA formed from lipid peroxidation has been used to examine occurrence of oxidative damages associated with many diseases, such as cancer, Alzheimer's, arthritis, inflammation, diabetes, atherosclerosis, and AIDS as well as aging. Analysis of MA is, however, extremely difficult because it is highly reactive and readily polymerized and forming adducts with biological substances such as proteins, phospholipids, and DNA (Shibamoto, J Pharm Biomed Anal 41:12-25, 2002). Gas chromatographic method using stable derivative, 1-methylpyrazole was advanced and has been successfully used to analyze MA in various lipids and lipid-rich foods. This method was also applied to determine MA formed from DNA and related compounds. The amounts found in oxidized 2'-deoxyribonucleotides were 213.8 nmol/16 mmol in 2'-deoxyguanosine, 130.6 nmol/16 mmol in 2'-deoxycytidine, 85.1 nmol/16 mmol in 2'-deoxyadenosine, and 84.5 nmol/16 mmol in thymidine. When the antioxidant activity of flavonoids and anthocyanins against calf thymus DNA oxidized with Fenton's reagent was examined using this newly developed gas chromatographic method, antioxidant activity of flavonoids and anthocyanins ranged from 48.5% (catechin) to 29.9% (apigenin) and from 45.0% (callistephin) to 10.2% (cyaniding), respectively.

Analysis and Antioxidant Activity of Extracts from Broccoli (Brassica oleracea L.) Sprouts

Samples prepared from fresh broccoli (Brassica oleracea L.) sprouts by water distillation or freeze-drying were examined for antioxidant activity using three assays. All samples exhibited dose-dependent antioxidant activity. The antioxidant activity ranged from 74.48 ± 0.46% (less volatile sample) to 93.2 ± 0.2% (dichloromethane extract sample) at the level of 500 μg/mL. Both dichloromethane extract samples from a water distillate of broccoli sprouts and freeze-dried broccoli sprouts showed potent antioxidant activity, which was comparable to that of BHT. Among the 43 compounds positively identified by gas chromatography-mass spectrometry, 5-methylthiopentylnitrile (31.64 μg/g) was found in the greatest concentration, followed by 4-methylthiobutylisothiocyanate (14.55 μg/g), 4-methylthiobutylnitrile (10.63 μg/g), 3-methylthiopropylisothiocyanate (3.00 μg/g), and 4-methylpentylisothiocyanate (2.48 μg/g). These isothiocyanates are known to possess antioxidant properties. Possible phenolic antioxidants found are 4-(1-methylpropyl)phenol (0.012 μg/g), 4-methylphenol (0.159 μg/g), and 2-methoxy-4-vinylphenol (0.009 μg/g). The present study demonstrates that broccoli sprouts are a good source of natural antioxidants.

Neuroprotective Effect of Maltol Against Oxidative Stress in Brain of Mice Challenged with Kainic Acid

The neuroprotective effect of maltol on oxidative damage in the brain of mice challenged with kainic acid was examined. Male ICR mice, 6-8 weeks of age, were administered orally with maltol (50 or 100 mg/kg) for 5 consecutive days. Thirty minutes after the final administration, the animals were challenged s.c. with kainic acid (50 mg/kg), and neurobehavioral activities were monitored. In addition, biomarkers of oxidative stress and neuronal loss in hippocampus for the biochemical and morphological evaluations were analyzed 2 days after the kainic acid challenge. During 5-day treatment with maltol, the body weight gain was not significantly different from that of vehicle-treated control animals. Administration of kainic acid alone induced severe epileptiform seizures, causing a lethality of approximately 50%, and injuries of pyramidals cells in hippocampus of mice survived the challenge. Kainic acid exposure also resulted in marked decreases in total glutathione level and glutathione peroxidase activity, and an increase in thiobarbituric acid-reactive substances (TBARS) value in brain tissues. In comparison, coadministration with maltol (100 mg/kg) remarkably attenuated the neurobehavioral signs and neuronal loss in hippocampus, leading to a decrease in mortality of animals to 12.5% (p < 0.05), although maltol at a dose of 50 mg/kg failed to show any remarkable protection. In addition, the changes in glutathione and TBARS values and glutathione peroxidase activity induced by kainic acid were restored to control levels by pretreatment with maltol (100 mg/kg). On the basis of these results, maltol is suggested to be a functional agent to prevent the oxidative damage in the brain of mice.

Distribution, antioxidant and characterisation of phenolic compounds in soybeans, flaxseed and olives

The distribution of free and bound phenolic compounds present in soybean, flaxseed and olive were investigated. The phenolic compounds were fractionated on the basis on their solubility characteristics in water, alcohol, dilute base and dilute acid. Reversed phase high pressure liquid chromatography (RP-HPLC) and mass spectrometry (MS) were used for identification of individual components of phenolic compounds. Antioxidant activity (AA%) of free and bound phenolic compounds was measured using the linoleic acid/β-carotene assay. The water-soluble phenolic compound fractions represented 68-81%, 50-72% and 46-56% of the total phenolic compounds measured in full-fat soybean, olive and flaxseed, respectively. Methanolic extraction of free phenolic compounds without heat, solubilised 21-56%, 42-62% and 34-51% of the total phenolic compounds measured in soybean, olive and flaxseed, respectively; methanol extraction of free phenolic compounds with heat solubilised a further 24-34%, 31-37% and 36-37% of phenolic compounds from soybean, olive and flaxseed, respectively. Further dilute alkali and dilute acid solubilised the remaining 10-40%, 1-21% and 12-29% of the total phenolic compounds from soybean, olive and flaxseed, respectively. Results indicated that the full-fat meals of soybean, flaxseed and olive showed higher antioxidant activity compared to defatted meals. RP-HPLC and LC-MS/MS profil1 for soybean, flaxseed and olive indicate two classes of phenolic compounds designated as free and bound phenolic compounds.

Variation and correlation analysis of phenolic compounds in mungbean (Vigna radiata L.) varieties

Phenolic compounds from a wide collection of mungbean [Vigna radiata (L.) Wilczek] germplasm (56 varieties) were characterised to determine the diversity among these phytochemicals and to analyse the relationships among their contents. The profiles of 25 phenolic compounds identified from the grains were subjected to data-mining processes, including principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), Pearson's correlation analysis, and hierarchical clustering analysis (HCA). The IT212105 and IT104818 varieties separated from the others in the first two principal components of PCA. PLS-DA showed significant separation between extracts of mungbean originating from three countries: China, Japan, and Korea. HCA of these phytochemicals resulted in clusters derived from common or closely related biochemical pathways. Significant positive relationships were observed between coumaric acid and resveratrol (r=0.7195, p<0.0001). Catechin content was positively correlated with rutin (r=0.6291, p<0.0001). The IT104818 variety appears to be a good candidate for future breeding programs, as it contains high levels of phenolic compounds. These results demonstrate the use of metabolic profiling combined with chemometrics as a tool for assessing the quality of food.

Housefly larvae hydrolysate: orthogonal optimization of hydrolysis, antioxidant activity, amino acid composition and functional properties

BACKGROUND

Antioxidant, one of the most important food additives, is widely used in food industry. At present, antioxidant is mostly produced by chemical synthesis, which would accumulate to be pathogenic. Therefore, a great interest has been developed to identify and use natural antioxidants. It was showed that there are a lot of antioxidative peptides in protein hydrolysates, possessing strong capacity of inhibiting peroxidation of macro-biomolecular and scavenging free redicals in vivo. Enzymatic hydrolysis used for preparation of antioxidative peptides is a new hot-spot in the field of natural antioxidants. It reacts under mild conditions, with accurate site-specific degradation, good repeatability and few damages to biological activity of protein. Substrates for enzymatic hydrolysis are usually plants and aqua-animals. Insects are also gaining attention because of their rich protein and resource. Antioxidative peptides are potential to be exploited as new natural antioxidant and functional food. There is a huge potential market in medical and cosmetic field as well.

RESULT

Protein hydrolysate with antioxidant activity was prepared from housefly larvae, by a two-step hydrolysis. Through orthogonal optimization of the hydrolysis conditions, the degree of hydrolysis was determined to be approximately 60%. Fractionated hydrolysate at 25 mg/mL, 2.5 mg/mL and 1 mg/mL exhibited approximately 50%, 60% and 50% of scavenging capacity on superoxide radicals, 1, 1-Diphenyl-2-picrylhydrazyl radicals and hydroxyl radicals, respectively. Hydrolysate did not exhibit substantial ion chelation. Using a linoneic peroxidation system, the inhibition activity of hydrolysate at 20 mg/mL was close to that of 20 μg/mL tertiary butylhydroquinone, suggesting a potential application of hydrolysate in the oil industry as an efficient antioxidant. The lyophilized hydrolysate presented almost 100% solubility at pH 3-pH 9, and maintained nearly 100% activity at pH 5-pH 8 at 0°C- 4°C and room temperature during the first 6 months of storage. Essential amino acids in the hydrolysate accounted for 43% of the total amino acids.

CONCLUSIONS

The results suggesting that hydrolysate could be added to food oils as an efficient antioxidant. It might be useful for food additives, diet nutrients and pharmaceutical agents.

Antioxidant activities of Korean rice wine concentrates

The antioxidant activities of six Korean rice wine (KRW) concentrates were measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and lipid/malonaldehyde (MA) assays. In the DPPH assay, the antioxidant activities of the KRW concentrates, including Maesilju (MSJ), Kookhwaju-1 (KHJ-1), Kookhwaju-2 (KHJ-2), Gugijaju (GGJ), Sasamju (SSJ), and Sogokju (SGJ), were 40%, 66%, 64%, 35%, 35%, and 63%, respectively. Furthermore, the concentrates inhibited the formation of MA from cod liver oil by 49%, 83%, 75%, 82%, 89%, and 90%, respectively, according to the lipid/MA assay. The sample wines were also analyzed for pH, titratable acidity, soluble solids (°Bx), and reducing sugars. The antioxidant activities of volatile extracts of the KRWs extracted by a solvent assisted flavor evaporation (SAFE) apparatus were evaluated by aldehyde/carboxylic acid assay. The volatile extracts of MSJ, KHJ-1, KHJ-2, GGJ, SSJ, and SGJ inhibited the oxidation of hexanal by 97%, 99%, 90%, 90%, 50%, and 51%, respectively. Among the nonvolatile extracts of KRWs, KHJ-2 showed the highest inhibitory effect on MA formation.

Regiospecific profiles of fatty acids in triacylglycerols and phospholipids from Adzuki beans (Vigna angularis)

Regiospecific distributions of fatty acids (FA) of triacylglycerols (TAG) and phospholipids (PL) isolated from five cultivars of adzuki beans (Vigna angularis) were investigated. The lipids comprised mainly PL (72.2-73.4 wt-%) and TAG (20.6-21.9 wt-%), whilst other components were detected in minor proportions (0.1-3.4 wt-%). The principal profiles of the FA distribution in the TAG and PL were evident in the beans among the five cultivars: unsaturated FA were predominantly distributed in the sn-2 position, whilst saturated FA primarily occupied the sn-1 or the sn-3 position in the these lipids. The results would be useful information to both producers and consumers for manufacturing traditional adzuki confectionaries such as wagashi in Japan.

Antioxidant assays for plant and food components

Recently, research on natural antioxidants has become increasingly active in various fields. Accordingly, numerous articles on natural antioxidants, including polyphenols, flavonoids, vitamins, and volatile chemicals, have been published. Assays developed to evaluate the antioxidant activity of plants and food constituents vary. Therefore, to investigate the antioxidant activity of chemical(s), choosing an adequate assay based on the chemical(s) of interest is critical. There are two general types of assays widely used for different antioxidant studies. One is an assay associated with lipid peroxidations, including the thiobarbituric acid assay (TBA), malonaldehyde/high-performance liquid chromatography (MA/HPLC) assay, malonaldehyde/gas chromatography (MA/GC) assay, beta-carotene bleaching assay, and conjugated diene assay. Other assays are associated with electron or radical scavenging, including the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, ferric reducing/antioxidant power (FRAP) assay, ferrous oxidation-xylenol orange (FOX) assay, ferric thiocyanate (FTC) assay, and aldehyde/carboxylic acid (ACA) assay. In this review, assays used recently were selected for extended discussion, including discussion of the mechanisms underlying each assay and its application to various plants and foods.

Azuki bean juice lowers serum triglyceride concentrations in healthy young women

Effects of azuki bean juice supplementation, prescribed according to a Kanpo medicine regimen, on serum lipid concentrations were studied. Healthy young Japanese women were recruited and were randomly assigned to one of the three groups using a parallel-group design. Control (n = 10), azuki (n = 11) and Concentrated azuki (CA) (n = 12) juice groups consumed 150 g daily of the isocaloric assigned juice for one menstrual cycle with their usual diet. Triglyceride concentrations were decreased in the azuki juice group (p<0.05) and tended to be decreased in the CA juice group (p = 0.055). Triglyceride concentrations in the azuki and CA juice groups decreased by 0.170 mmol/liter (15.4%) and 0.159 mmol/liter (17.9%), respectively (p<0.05). The azuki and CA juice used in this study inhibited pancreatic lipase activity 29.2% and 56.9%, respectively, in vitro. Lipid peroxide changes, based on ANCOVA with the initial level and alpha-tocopherol changes as covariates, did not differ among the three groups. Serum low density lipoprotein-cholesterol and high density lipoprotein-cholesterol (HDL) cholesterol concentrations did not change. Thus, azuki bean juice intake, as a traditional Kampo prescription, might be beneficial for preventing hypertriglyceridemia.

Genotoxicity induced by Eugenia caryophyllata infusion

Several therapeutic properties have been described for Eugenia caryophyllata (clove). In the present study the infusion of E. caryophyllata was evaluated in a series of bacterial and cell-free assays in order to determine genotoxic potential. Negative results were obtained in the SOS chromotest and in the Salmonella reversion assay using strains TA97a, TA98, TA100, and TA102. However, in a forward mutagenesis assay an increase in mutagenesis and high cytotoxicity was observed with the CC104 mutMmutY strain, suggesting that oxidative DNA damage occurred. The treatment of plasmid with clove infusion showed that DNA strand breaks and sites recognized by formamidopyrimidine-DNA-glycosylase (FPG/MutM) were generated. Data suggest that the occurrence of oxidative DNA damage, with low mutagenic potential, may also be involved in the cytotoxicity attributed to clove infusion.

Protective effect of polyphenol-containing azuki bean (Vigna angularis) seed coats on the renal cortex in streptozotocin-induced diabetic rats

This study was undertaken to investigate the effect of azuki bean (Vigna angularis) seed coats (ABSC), which contain polyphenols, on the infiltration of macrophages and the progression of diabetic nephropathy in streptozotocin (STZ)-induced diabetic rats. The diabetic rats were divided into three groups with 0% (commercial diet), 0.1% and 1.0% ABSC diets. The vehicle-injected controls were given a commercial diet. At 10 weeks, the macrophage kinetics, the degree of fibrosis in glomeruli and mRNA expression for monocyte chemoattractant protein-1 (MCP-1) were examined. There was no difference in plasma glucose levels between diabetic rats treated with and without ABSC. The plasma levels of malondialdehyde (MDA) in the ABSC-treated diabetic rats were significantly lower than those in the untreated diabetic rats. Histopathologically, the percentage of the fibrotic areas stained by Sirius red stain in the glomeruli in the ABSC-treated diabetic rats was lower than in the untreated diabetic rats. ED1-positive macrophages in the glomeruli and tubulointerstitium in the untreated diabetic rats showed a significant increase in number compared with the controls. In contrast, the number of macrophages in the ABSC-treated diabetic rats was smaller than that in untreated diabetic rats. MCP-1 mRNA expression, estimated by real-time quantitative RT-PCR, was increased 2.5-fold in the untreated diabetic rat kidney, while a lower level was observed in the ABSC-treated diabetic rats. In conclusion, our results suggest that ABSC treatments suppress the increased number of infiltrating macrophages and MCP-1 mRNA expression, and attenuated the glomerular expansion in STZ-induced rat diabetic nephropathy.

Inhibitory effects of volatile antioxidants found in various beans on malonaldehyde formation in horse blood plasma

The inhibitory effect of aroma extracts isolated from dried soybeans, mung beans, kidney beans, and azuki beans on malonaldehyde (MA) formation from horse blood plasma oxidized with Fenton's reagent was determined by gas chromatography (GC) coupled with nitrogen-phosphorus detector (NPD). Aroma chemicals such as maltol, eugenol, benzyl alcohol, 1-octen-3-ol, butyrolactone, and 1-methyl-2-pyrrolidone, found in the aroma extracts of beans, were also examined for their inhibitory effect on the same system. Among the four aroma extracts tested, the aroma extract of soybeans exhibited the strongest antioxidant activity. Extracts of soybeans, mung beans, azuki beans, and kidney beans inhibited MA formation by 58%, 47%, 40%, and 23%, respectively, at the level of 400 microg/mL, whereas, alpha-tocopherol and BHT inhibited MA formation by 52% and 70%, respectively, at the same level. Among the tested aroma chemicals, the antioxidant activity decreased in the following order: eugenol>maltol>1-octen-3-ol>benzyl alcohol>butyrolactone>1-methyl-2-pyrrolidone.

Protective effect of dietary azuki bean (Vigna angularis) seed coats against renal interstitial fibrosis of rats induced by cisplatin

OBJECTIVE

We investigated the effects of azuki bean (Vigna angularis) seed coats (ABSCs), which mainly contain proanthocyanidins and dietary fibers, on the infiltration of macrophages and the progression of renal interstitial fibrosis induced by cisplatin (CDDP).

METHODS

Male rats were divided into two groups: controls received intraperitoneal injections of saline and the other rats were injected intraperitoneally with 3 mg of CDDP per kilogram once a week for 5 wk. The CDDP-injected animals received one of four diets: 1) control diet (commercial diet only), 2) 0.5% red ABSC (RABSC) diet, 3) 2.0% RABSC diet, and 4) 2.0% white ABSC (WABSC) diet. The saline-injected animals were given the commercial diet. Five weeks after the final CDDP injection, macrophage kinetics and interstitial fibrotic areas were examined.

RESULTS

The content of polyphenols in the RABSC (76.3 g/kg of plant material) was higher than that in the WABSC (18.1 g/kg). Proanthocyanidins were detected in the RABSC (20.4 g/kg) but not in the WABSC. Histologically, the fibrotic areas consisting of fibroblastic cells and mononuclear cells developed around the dilated or atrophic tubules in the corticomedullary junction in CDDP-treated rat kidney, whereas the extent and magnitude of damage were less in the WABSC- and RABSC-treated rats. In immunohistochemical analysis, ED1-positive macrophages in CDDP-treated rats showed a significant increase in number compared with the control. The number of macrophages in CDDP plus WABSC or RABSC groups was significantly smaller than that in CDDP-treated rats. In addition, the number of macrophages in the RABSC group was significantly smaller than in the WABSC group, indicating that ABSC, especially RABSC, prevented macrophages from infiltrating into areas of interstitial fibrosis.

CONCLUSIONS

These results suggest that ABSC, especially RABSC, suppress the increase of infiltrating macrophages in the damaged kidney and may lead to amelioration of interstitial fibrosis. Based on the composition of ABSC, molecules such as proanthocyanidins and/or dietary fibers may be associated with the amelioration of renal damage.