Cytotoxic and antimitotic effects of N-containing Monascus metabolites studied using immortalized human kidney epithelial cells

Recently the first Monascus metabolites with a pyridine ring were detected, the monascopyridines A and B. They are formally dehydrogenated derivatives of the red rice pigments rubropunctamine and monascorubramine. Because of their structural similarity, the toxicological effects of these secondary metabolites were studied using immortalized human kidney epithelial cells. The cytotoxicity was determined with the following different endpoint detection methods: metabolic activity, trypan blue exclusion, and electronic cell counting. The compounds led to EC(50) values between 11 and 31 micromol/L but the pigments caused a stronger reduction of the cell viability. Also, the apoptotic potential was examined by measuring caspase 3 activity and detecting apoptotic bodies, but none of the tested compounds induced apoptosis. All four substances caused a rise of the mitotic index to about 9% (100 micromol/L monascopyridine A and B) and 20% (25 micromol/L rubropunctamine and monascorubramine). The significant decrease of the ratio of cells in the ana- and telophase to cells in the prometa- and metaphase proved a stop of the mitosis at the meta- to anaphase control point. The compounds caused mitotic arrest and the formation of structural damages like c-mitosis through interaction with the mitotic spindle. These effects point to an aneuploidy inducing potential, which is linked to cancer formation.     

山楂、甾醇酯及功能红曲复配物的降血脂活性

目的:研究山楂、甾醇酯及功能红曲复配物的降血脂效果及机制。方法:将6周龄体重为(100±10)g的SPF级雄性仓鼠随机分为正常组N、模型组C、单纯山楂干预组A,山楂+低剂量甾醇酯组B,山楂+高剂量甾醇酯组D,山楂+甾醇酯+低剂量功能红曲组E,山楂+甾醇酯+高剂量功能红曲组F。每2周称重并检测其血脂指标,8周后处死。测定其血脂指标(总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-c);计算脏器及脂重指数、非高密度脂蛋白(non-HDL-c)含量、动脉硬化指数(AI);观察肝脏及主动脉病理切片,胆固醇代谢调控相关基因的mRNA表达水平。结果:F组与高脂对照组相比,小鼠体重、肝脏指数、脂重指数及TC、TG、non-HDL-c、AI极显著下降(P<0.01),HDL-c显著上升(P<0.05);粪便中胆酸含量极显著上升(P<0.01);肝脏组织脂肪变性程度和主动脉粥样硬化症状有所改善;CYP7A1mRNA表达水平显著上调(P<0.05),LXRα、PPARα及FXR极显著上调(P<0.01),LIMA1、NPC1L1的mRNA表达水平显著下调(P<0.05),HMG-CoA-R、SREBP2极显著下调(P<0.01)。结论:F组降脂效果最佳,即3种天然物质的复配从增加体内胆固醇排出体外、减少机体对胆固醇的吸收以及减少胆固醇的自身合成3个途径有效预防因长期高脂饮食导致的高脂血症。     

Tissue levels of malondialdehyde after passive smoke exposure of rats for a 24-week period.

The present study was to evaluate the effects of chronic cigarette smoke exposure on lipid peroxidation in various organ tissues. Sprague-Dawley rats were exposed to passive smoking 2 hr per day, 6 days per week (Monday-Saturday), for 24 weeks. Malondialdehyde levels, as an index of lipid peroxidation, were measured by the thiobarbituric acid assay. Levels were significantly higher in tissues of passive-smoke-exposed groups (n=10) compared with normal-bred control groups (n=6), for red blood cells (2.17+/-0.22 vs. 1.80+/-0.39 nmol/mg), lung (1.39+/-0.32 vs. 1.03+/-0.35 nmol/mg), and spleen (1.75+/-0.33 vs. 1.42+/-0.15 nmol/mg); p<.05. No differences in malondialdehyde levels were found in plasma, heart, liver, stomach, and renal tissues. The results suggest that chronic environmental tobacco smoke exposure can increase lipid peroxidation in red blood cells and in lung and spleen tissue. This finding brings further investigative attention to the public health issue of the injurious effects of chronic passive smoke exposure.     

Thermal inactivation of Bacillus cereus spores formed at different temperatures

The effects of the sporulation temperature in the range 20-45 degrees C on the D and z values of three isolates of Bacillus cereus (ATCC 4342, 7004 and 9818) were investigated. The strains were found to differ in their response. Higher D100 values (around 10-fold) were obtained with isolates 4342 and 9818 when the sporulation temperature increased from 20 to 45 degrees C. With isolate 7004 (the least heat resistant of the three strains), however, the most thermal tolerant spores were obtained at 35 degrees C. The z values were not significantly modified (P > 0.05) by the sporulation temperature. Mean z values of 7.46+/-0.22 degrees C for isolate 4342, 7.80+/-0.40 degrees C for 7004 and 8.09+/-0.33 degrees C for 9818 were obtained.     

Analysis of phenolic compounds and antioxidant activity with H4IIE cells of three different rice grain varieties

The phenolic content and the antioxidant capacity of ethanolic extract of rice grains were examined using three different rice (Oryza sativa L. var. japonica) varieties, Jakwangchalbyeo (red pericarp glutinous rice), Hwasunchalbyeo (white pericarp glutinous rice), and Ilpumbyeo (white pericarp non-glutinous rice). Quantitative high performance liquid chromatography (HPLC) analyses showed that Jakwangchalbyeo contains the highest amount of total phenolic substances. Radical scavenging activities measured by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) assay were 87.5% (Jakwangchalbyeo), 45.0% (Hwasunchalbyeo), and 50.0% (Ilpumbyeo). The results suggest a positive correlation between the phenolic content and the antioxidation capacity. Antioxidant activity in the ethanolic extract of rice grain was further assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assay and fluorescence-activated cell sorting (FACS) analysis of H4IIE cells treated with hydrogen peroxide (H₂O₂). Hwasunchalbyeo and Ilpumbyeo extracts showed no significant effects on H₂O₂-induced oxidative stress. Jakwangchalbyeo extract increased cell viability by up to 82% and 74% after 5- and 24-h treatments at 100 μg/mL, respectively. Consistent with the results of DPPH and MTT assays, dichlorofluorescein (DCF) fluorescence was further reduced when H₂O₂ was applied with Jakwangchalbyeo extract. In conclusion, red pericarp Jakwangchalbyeo grain extracts exerted significantly higher inhibitory effects on H₂O₂-induced oxidative stress in H4IIE cells than did other white pericarp rice grain extracts.     

Evaluation of antioxidant activities and phenolic subtype contents of ethanolic bran extracts of Thai pigmented rice varieties through chemical and cellular assays

This study revealed that the ethanolic bran extracts of 11 Thai pigmented (red and purple) and 2 nonpigmented rice varieties exerted scavenging activity against DPPH and ABTS radicals and ROS in HL‐60 cells in the following order: red > purple > nonpigmented rice. These rice extracts also showed the same order of phenolic and flavonoid contents, which were strongly correlated with their scavenging activity. Phenolic subtype analysis further indicated that proanthocyanidins as well as anthocyanins and protocatechuic acid contributed directly to antioxidant capacity in red and purple rice bran, respectively. In contrast, these pigmented rice bran extracts possessed moderate chelating activity partly attributed to their contents of phenolics and flavonoids, especially proanthocyanidins in red rice bran. Moreover, rice bran extracts significantly restored SOD and CAT activities in oxidative stress‐induced A549 cells. This study provides new insights on the intracellular potent antioxidant capacity of pigmented rice bran extracts in the cell‐based systems.     

Comparative 3D simulation on water absorption and hygroscopic swelling in japonica rice grains under various isothermal soaking conditions

Cracking in rice grains caused by moisture absorption is a major concern among food processors because it has a detrimental effect on the texture. This paper aimed to simulate moisture diffusion three dimensionally (3D) using Fick's diffusion equation, compare the results with an empirical model (Peleg's equation), and simulate in 3D the hygroscopic swelling in rice during soaking at 25, 35, 45 and 55 °C. This study intends to provide preparatory information in understanding the cracking mechanism during soaking. The concept was based on finite element analysis to evaluate both the moisture diffusion and hygroscopic expansion coefficients of milled rice using the reconstructed 3D model of rice geometry. The proposed model was satisfactory for describing the moisture absorption kinetics with root mean square error (RMSE), that ranged from 0.66 to 2.52% dry basis. The results of the 3D simulation of hygroscopic swelling were found to be adequate in representing the swelling characteristics of rice. Analysis of 3D simulation enabled both quantitative and qualitative assessment of the changes in the amount, distribution of moisture, and expansion in the geometry of rice grains.     

Suspending lettuce type influences recoverability and radiation sensitivity of Escherichia coli O157:H7

An outbreak strain of Escherichia coli O157:H7 was inoculated onto closely related but structurally distinct types of lettuce (Lactuca sativa): Boston (butterhead lettuce), iceberg (crisphead lettuce), and green leaf and red leaf (colored variants of looseleaf lettuce). The E. coli O157:H7 was inoculated either onto the surface of cut leaf pieces or into a homogenized leaf suspension. Samples were gamma irradiated, and the radiation sensitivity of the inoculated bacteria was expressed as a D-value (the amount of ionizing radiation necessary to reduce the bacterial population by 90% [kGy]). The recovery of bacteria from nonirradiated leaf pieces was also measured. When inoculated onto the leaf surface, E. coli O157:H7 had significantly stronger radiation sensitivity on red leaf lettuce (D = 0.119 +/- 0.004 [standard error]) and green leaf lettuce (D = 0.123 +/- 0.003) than on iceberg lettuce (D = 0.136 +/- 0.004) or Boston lettuce (D = 0.140 +/- 0.003). When E. coli O157:H7 was inoculated into a homogenized leaf suspension, its sensitivity was significantly stronger on iceberg lettuce (D = 0.092 +/- 0.002) than on green leaf lettuce (D = 0.326 +/- 0.012), Boston lettuce (D = 0.331 +/- 0.009), or red leaf lettuce (D = 0.339 +/- 0.010), with a threefold difference. Significantly fewer bacteria were recovered from the surface of iceberg lettuce than from the surfaces of the other types of lettuce examined. Following radiation doses of up to 0.5 kGy, the texture (maximum shear strength) of lettuce leaves was measured along the midrib and along the leaf edge for each type of lettuce. There was no meaningful change in texture for any type of lettuce for either leaf section examined at any dose up to 0.5 kGy. These data show (i) that relatively subtle differences between lettuce types can significantly influence the radiation sensitivity of associated pathogenic bacteria and (ii) that doses of up to 0.5 kGy do not soften lettuce leaves.     

Characterization of antioxidant compounds of red and white rice and changes in total antioxidant capacity during processing

Although most rice cultivars have whitish kernel, some varieties have a red testa. Aim of this work was to compare the total antioxidant capacity (TAC) and the antioxidant chemical composition (namely tocols, gamma-oryzanols, and polyphenols) of red and white rices. In addition, the effect of milling and cooking on antioxidants was investigated in both rices. Dehulled red rice showed a TAC more than three times greater than dehulled white rice and its high TAC was essentially characterized by the presence of proanthocyanidins (PA) and associated phenolics. Milling caused a significant loss of TAC, even if red rice maintained a higher TAC. Cooking caused a further loss of antioxidants, but when there was a full uptake of cooking water by the grains ("risotto") this loss was limited. Thus, the consumption of whole or partially milled rice cooked as risotto would be preferred to preserve its nutritional properties.     

Alicyclobacillus acidoterrestris spores as a target for Cupuaçu (Theobroma grandiflorum) nectar thermal processing: kinetic parameters and experimental methods

The kinetic parameters of thermal inactivation of a spore former, Alicyclobacillus acidoterrestris, in a tropical fruit nectar [25% of Cupua?u (Theobroma grandiflorum) pulp and 15% sugar] were determined by the isothermal method (IM), under batch heating, and by the paired equivalent isothermal exposures (PEIE) method, under non-isothermal continuous conditions. The isothermal experiments were repeated three times, every 4 months, with the same spore suspension kept frozen between experiments. The aging of spores, under frozen storage, seemed to produce a notorious increase in the z-value from experiment to experiment: Experiment 1 (z = 7.8 +/- 2.6 degrees C, D(95 degrees C) = 5.29 +/- 0.96 min), Experiment 2 (z = 22 +/- 5 degrees C, D(95 degrees C) = 5.99 +/- 0.63 min), and Experiment 3 (z =29 +/- 10 degrees C, D(95 degrees C) = 3.82 +/- 0.48 min). The evaluation of the kinetic parameters by the PEIE method was carried out in parallel with Experiment 3, with the same aged spores, and the results (z = 31 +/- 6 degrees C, D(95 degrees C) = 5.5 +/- 1.2 min) were close to the ones obtained in this experiment. From this work, it seems that the PEIE method can also be applied to evaluate the reduction parameters of a spore-forming microorganism, and in a more realistic way, since the continuous system eliminates the errors caused by come-up and cool-down times (CUT and CDT) that are unavoidable in isothermal experiments. Therefore, when designing a thermal process for a continuous system, the PEIE method should be used, or the chances are that the process would be underdesigned, risking that the desired level of spore inactivation would not be achieved. An optimization of the thermal processing conditions was next performed for Cupua?u nectar, considering a 5D reduction in A. acidoterrestris spores. If a pasteurization process is considered, the conditions that ensure safety (9 min at 98 degrees C) only allow a 55% retention of ascorbic acid (AA). If sterilization is considered, 8 s at 115 degrees C will ensure a safe product and retain 98.5% of the original ascorbic acid. Therefore, if A. acidoterrestris is considered as the target microorganism, the nectar should undergo an aseptic high temperature short time principle (HTST) process to achieve a 5D reduction in this acidophilus spore former. However, if the hot-fill-and-hold pasteurization process is preferred, the product should be fortified with ascorbic acid.     

Effect of high-temperature fluidized-bed drying on cooking, textural and digestive properties of waxy rice

In this work, changes of the cooking and pasting properties as well as starch digestibility of waxy rice (RD6) during hot air fluidized bed drying were investigated. Re-moistened waxy rice at an initial moisture content of 28% dry basis (d.b.) was dried at 90-150 °C. Semi-dried waxy rice was tempered and dried again by ambient air until the moisture content reached 16% (d.b). It was found that the degree of gelatinization increased with an increase in the drying temperature. At 130 and 150 °C the appearance of some waxy rice kernels changed from opaque to translucent, indicating complete gelatinization. Thermal degradation of amylopectin granules during high-temperature drying caused the starch to be more rapidly digested; this led to lower peak viscosity and setback viscosity. In addition, waxy rice processed at higher drying temperatures (90-150 °C) could adsorb more water and exhibited larger loss of solids during soaking. Such effects subsequently led to samples with lower hardness and higher stickiness. Based on the sensory analysis results, however, waxy rice dried at the above temperatures, when cooked, did not significantly differ in overall acceptability from the reference waxy rice.     

Effect of gamma irradiation on the microbiological quality and antioxidant activity of fresh vegetable juice

A fresh vegetable juice has become a new functional food available for dieting and health. However, it poses a microbiological hazard to the consumer because it is distributed and consumed without any cooking. In this study, we applied the radiation sterilization of fresh vegetable juice, and the effectiveness of gamma irradiation for inactivating Salmonella typhimurium and Escherichia coli in the carrot and kale juice was investigated. D((10)) values of S. typhimurium in the carrot and kale juice were 0.445+/-0.004 and 0.441+/-0.006 kGy, while those of E. coli were 0.301+/-0.005 and 0.299+/-0.006 kGy. The test organisms (inoculated at 10(7) cfu/ml) were eliminated by irradiation at 3 kGy. The total phenol contents of the irradiated juice during 3 days of storage at a cold chain temperature (10 degrees C) increased significantly (P<0.05), while those of the non-irradiated juice decreased (P<0.05). The antioxidant capacity of the irradiated carrot juice was higher than that of the non-irradiated control. Therefore, it was concluded that irradiation treatments of carrot and kale juice improve the microbiological safety with maintaining or even enhancing the antioxidative activity.     

黑糯米和血糯米淀粉结构及物化性质的对比分析

本研究从黑糯米、血糯米中提取淀粉,对其表观结构、球晶结构、支链链长、结晶结构、短程结构、黏度性质、糊化性质、老化性质进行对比分析。结果表明：两种淀粉颗粒形态类似,均具有双折射现象;黑糯米淀粉支链中A链、B2链所占比例较低,B1链、B3链所占比例较高;X衍射结果表明,两种淀粉均属于A型晶体,血糯米淀粉相对结晶度较高;红外结果表明,血糯米淀粉有序程度较高,无序程度较低;黏度结果表明,血糯米淀粉峰值黏度、崩解值较高,回升值、糊化温度较低;热力学结果表明,黑糯米淀粉起始温度、峰值温度、终止温度均较高,且更容易发生老化。两种淀粉在结构特性、物化性质方面存在差异,为指导糯米原材料的选用及其在食品工业中的合理开发利用和深加工提供理论依据。     

古田红曲米抗氧化活性物质的分离纯化

本文对产自不同地区的红曲米进行抑菌、抗氧化活性的测定,结果显示古田红曲米的抗细菌活性稍强于其它地区产的红曲米。采用凝胶柱层析、反相和正相硅胶柱层析等分离纯化方法,结合核磁共振波谱及质谱检测等技术手段对古田红曲的甲醇提取活性物质进行分析和结构鉴定。结果表明不同有机溶剂提取物的抑菌效果有很大差异,同浓度下抑菌效果从大到小依次为枯草芽孢杆菌大肠杆菌黑曲霉塔宾曲霉酿酒酵母菌;抗氧化实验中,古田红曲米抗氧化活性较强,此外,古田红曲乙酸乙酯提取物以及50%水-50%甲醇到0%水-100%甲醇提取物的抗氧化活性也较好。最后,从古田红曲米中分离纯化出2个化合物,鉴定为亚油酸和α-亚麻酸,它们均有一定的抗氧化和抗肿瘤等活性。     

Lipid extracts isolated from heat processed food show a strong agglutinating activity against human red blood cells

In this study we investigated the possibility that the lipid components of foodstuffs and mass market oils undergo oxidative and thermal changes during storage, processing and cooking and so become agglutinins. The hemagglutinating activity of several mass market oils and several lipid mixtures isolated from different food items was evaluated against human red blood cells (RBCs) and against hamster RBCs. The unheated oils and the lipid extract of the unheated foodstuff had a very low agglutination titer but lysed red cells at high concentrations. When the same foodstuff items and oils were heated (100 °C for 24 h) in air, the isolated mixture of lipids as well as the oils show a strong hemagglutinating activity. Thin layer chromatography (TLC) of the lipid mixture, isolated from the processed foodstuff, as well as the heated samples of the oils showed appearance of high molecular weight molecules, possibly dimers and polymers. Light microscopy was used to characterize and visualize the agglutination process. Agglutination without lysis or fusion was observed. Agglutination may be the result of membrane properties alteration due to the oxidation product insertion or by hydrophobic side chain insertion into adjacent RBC membranes. We conclude that oils and foodstuff items when heated in air produce hemagglutinins against human RBCs with unknown and possibly toxic effects on human health.     

Feasibility of detection of infested rice using an electronic nose

Electronic nose (E-nose) technology has a potential to be used for detecting insects in stored rice. It may provide a new method to detect the insect activity by providing smell prints for the headspace volatiles in rice mass. The objective of this research was to study the feasibility of using E-nose to detect infested rice during the storage process. An E-nose instrument (Cyranose 320) consisting of 32 sensors for detecting the volatile components produced in infested rice was used for this study. Storage rice with moisture content of 11.8 ± 0.3% was used for conducting the tests. The rice samples were infested with different numbers of adult insects, including rice weevil (Sitophilus oryzae), lesser grain borer (Rhyzopertha dominica) and red flour beetle (Tribolium castaneum), in containers containing 1 kg of rice. The samples were stored at temperatures of 15 °C and 30 °C for four weeks. Air samples in the containers were taken for measurements every five days. The data were analyzed using the principal component analysis (PCA) method. The results revealed that the E-nose was not able to distinguish the clean rice and infested rice with lesser grain borer. While the E-nose had high response ability to the volatile components produced by rice weevil and red flour beetle after four weeks of storage. Consequently, the E-nose could discriminate the clean and infested rice with above insects after four weeks of storage at temperature of 30 °C. Additionally, under the aforementioned conditions, the E-nose could not distinguish the clean and infested rice during the first, second and third weeks of storage. The classification accuracy of E-nose for clean and infested rice was low at storage temperature of 15 °C for the tested insets. It can be concluded that the E-nose has the capability to detect infested rice after four weeks of storage.     

Thermal resistance parameters for pathogens in white grape juice concentrate

The heat resistance of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes that were in stationary phase, had been exposed to high osmotic pressure, or were acid adapted was evaluated in white grape juice concentrate (58 degrees Brix, pH 3.3). The most heat-resistant cells of all three pathogens were those exposed to high osmotic pressure or in stationary phase. Unlike in single-strength juices, in concentrate the acid-adapted cells for all three pathogens were less heat resistant than were cells in the other physiological states. E. coli O157:H7 had the highest heat resistance for all temperatures tested (e.g., D62 degrees C = 1.8 +/- 0.3 min, with a z-value of 9.9 +/- 0.6 degrees C). L. monocytogenes exposed to high osmotic pressure had the highest z-value (12.3 +/- 1.2 degrees C), although its D-values for all temperatures tested were lower (e.g., D62 degrees C = 0.93 +/- 0.1 min) than those for E. coli O157:H7. Salmonella was the most sensitive of the pathogens under all conditions. Based on the results obtained in this study, one example of a heat treatment that will inactivate 5 log units of all three pathogens in white grape juice concentrate was calculated as 1.5 min at 71.1 degrees C (z = 10.3 degrees C). Validation studies confirmed the predicted D71 degrees C for E. coli O157:H7 exposed to high osmotic pressure.     

富硒红曲米对高脂饮食小鼠脂代谢和肠道菌群的改善作用

该研究旨在探究富硒红曲米对高脂饮食小鼠脂代谢和肠道菌群的影响.选用48只C57BL/6J小鼠随机分为6组(n=8):正常饮食组、高脂饮食组、富硒红曲米的低、中、高剂量组和红曲米组.灌胃8周后,测定血清中总甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)含量,对肝脏组...