Resveratrol upregulates nrf2 expression to attenuate methylglyoxal-induced insulin resistance in hep g2 cells

Oxidative stress can result in insulin resistance, a primary cause of type-2 diabetes. Methylglyoxal (MG), a highly reactive dicarbonyl metabolite generated during glucose metabolism, has also been confirmed to cause pancreatic injury and induce inflammation, thereby resulting in insulin resistance. Recently, resveratrol has been reported to exert antioxidant properties, protecting cells from the generation of reactive oxygen species (ROS). The aim of this study was to evaluate resveratrol activation of nuclear factor erythroid 2-related factor 2 (Nrf2) to attenuate MG-induced insulin resistance in Hep G2 cells. Therefore, the molecular signaling events affecting resveratrol-mediated heme oxygenase-1 (HO-1) and glyoxalase expression levels were further investigated in this study. Our findings indicated that resveratrol activated the extracellular signal-regulated kinase (ERK) pathway but not the p38 or c-Jun N-terminal kinase (JNK) pathways, subsequently leading to Nrf2 nuclear translocation and elevation of HO-1 and glyoxalase expression levels. Moreover, resveratrol significantly elevated glucose uptake and protected against MG-induced insulin resistance in Hep G2 cells. In contrast, depletion of Nrf2 by small interfering RNA (si-RNA) resulted in the abrogation of HO-1 and glyoxalase expression in the MG-treated resveratrol group in Hep G2 cells. Administration of an appropriate chemopreventive agent, such as resveratrol, may be an alternative strategy for protecting against MG-induced diabetes.     

落花生之黄曲毒素防治与其保健植物化合物之探讨

落花生是全球熟悉与普遍消费的作物,其特殊之香气与酥脆质地吸引绝大多数消费者的味口。然而,由于落花生可能被黄曲毒素产生菌污染产毒,导致许多消费者常将落花生与黄曲毒素（系一种天然致癌物质）联想在一起,因而犹豫甚至拒绝进食含落花生之产品。落花生虽然是黄曲毒素产生菌生长之良好基质,但必须遭受其侵入,且得到充分生长才会产毒。田间栽种时有适当灌溉、采收后花生荚果迅速干燥,以及良好仓储条件,是落花生采收前后有效降低黄曲毒素污染的最重要方法。加工时,先将花生仁轻度焙烤,再脱膜并以色差电子自动筛检,则能更进一步将被霉菌污染之花生仁筛除,筛选后之花生仁可加工制作安全无虞之高品质食品。另外,有鉴于黄曲毒素产生菌普遍存在于土壤中,但采收后之健康花生荚或花生仁几乎均无黄曲毒素之污染,经探讨得知,落花生具有生合成二苯乙烯类化合物（包括熟知的白藜芦醇在内之植物防御素）以抵抗微生物入侵之本能。因此,落花生可经由发芽制备花生芽作为机能蔬菜,并促进生合成二苯乙烯类化合物,包括白藜芦醇,Arachidin-1,Arachidin-3及Isopentadienylresveratrol（IPD）等,这些二苯乙烯类化合物目前已知,具有相当值得重视的抗氧化与抗发炎活性,具有进一步开发作为饮食补充或保健产品之潜力。     

Effects of lipoxygenase inhibitors in a model of lens-induced uveitis in dogs

Uveitis was induced in dogs by intracameral injection of canine lens protein. The lipoxygenase inhibitors phenidone and norhydroguaiaretic acid, and dimethyl sulfoxide decreased fibrin production at 0.5 and 1 hour after induction of uveitis. Phenidone and norhydroguaiaretic acid also inhibited the initial increase in intraocular pressure early in the course of inflammation. Leukotriene B4 in the aqueous was measured by use of radioimmunoassay at 1 hour after inflammation. In control dogs, 230 to 1,700 pg of leukotriene B4/ml was measured; in dogs treated with phenidone, leukotriene B4 was not measured.     

杉木优良家系选择及造林效益研究

利用已选育出的２３个优良家系中２２个优良家系进行造林对比试验，结果表明（１）使用良种造林，其增产潜力在２２．６％以上；（２）从评选出的７个优良家系内选择出４６个优良单株，其树高、胸径和材积分别比对照增产５０．５％、８０．５４％和３７３．０７％，具有极大的增产潜力；（３）根据杉木各性状相关分析表明，杉木生长性状早晚相关密切，其遗传比较稳定，６年生时进行选择是可行的，同时表明分枝习性在优树选择中可作为一项重要指标。     

Heat expanded starch-based compositions

A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period.     

Influence of soy aglycon isoflavones on bone-related traits and lens protein characteristics of ovariectomized rats and bioactivity performance of osteoprogenitor cells

Health benefits of soy isoflavones have attracted the concern of the public and the interest of health-care professionals. In this study, two trials were conducted in characterizing bone-related traits and lens proteins as affected by supplementation of soy aglycon isoflavones (SAI). In trial 1, an in vivo study, 20 Sprague-Dawley rats were ovariectomized (OVX) and randomly distributed into OVX and OVX+SAI (135 mg of SAI/kg of feed; 8.33 mg/kg body weight; 2.5 mg/day) groups. Another group containing 10 rats with a sham operation was control (Sham). The experiment period was 3 months, and the rats were subjected to bone-related traits and lens protein characterization. In trial 2, an in vitro study, osteoprogenitor cells (UMR-106) were divided into SAI-supplemented (0.5 mg of SAI/mL of medium) and unsupplemented groups. Results of the in vivo study indicated that daily BW gains in the OVX and OVX+SAI groups were greater than that of the Sham group (p < 0.05). Bone ash and Ca contents of the Sham and OVX+SAI groups were higher than those of the OVX group (p < 0.05), while bone density, strength, and phosphorus contents among groups varied insignificantly (p > 0.05). When the lens proteins were extracted and analyzed with size-exclusion HPLC, the contents of beta- and gamma-crystallins were lowest in the OVX group and the protein solubility decrease could be recovered by dietary SAI supplementation (shown by OVX+SAI group). Based on Raman spectra of the isolated lens proteins, disulfide bonds were observed more in OVX lens than in the Sham and OVX+SAI lens. Results of in vitro study with osteoprogenitor cells revealed that cell viability, alkaline phosphatase activity, osteocalcin, and Ca contents of the SAI-supplemented group were higher than those of the unsupplemented group (p < 0.05). The likely potency to enhance bone and lens health by SAI supplementation is worth pointing out.     

Biosynthesis enhancement and antioxidant and anti-inflammatory activities of peanut (Arachis hypogaea L.) arachidin-1, arachidin-3, and isopentadienylresveratrol

Peanut is a potent plant to be induced to synthesize bioactive stilbenoids. Bioactivities of those stilbenoids except resveratrol have been meagerly investigated. When peanut kernels (Tainan 14, a Spanish cultivar) were imbibed, incubated 3 days for germination, sliced, incubated with artificial aeration, periodically sampled, lyophilized, extracted with methanol, and subjected to reverse-phase HPLC analysis, four major fractionations were detected and identified as trans-resveratrol (Res), trans-arachidin-1 (Ara-1), trans-arachidin-3 (Ara-3), and trans-isopentadienylresveratrol (IPD). During incubation of the peanut slices, contents of Res, Ara-1, and Ara-3 increased tremendously from initially trace or not detectable amounts up to 147.3, 495.7, and 2414.8 microg/g, corresponding to 20, 16, and 24 h of incubation, while IPD contents continued to increase up to 28 h (4474.4 microg/g). When the four stilbenoids and butylated hydroxytoluene (BHT) were subjected to antioxidant characterization by various measures, all have exhibited varied potencies of antioxidant activity. In particular, retardation of absorbance increase at 234 nm as formation of the conjugated diene hydroperoxides in a real pork oil system stored at 60 degrees C, supplement of Ara-1 at 100 microM has shown equivalent or even greater activity than did BHT. When the media were supplemented with Res, Ara-1, Ara-3, and IPD at 15 microM for cultivation of mouse macrophage RAW 264.7 cells activated by lipopolysaccharide (LPS), the LPS-induced extracellular production of prostaglandin E2 (PGE2) and nitric oxide (NO) was significantly inhibited by Ara-1 (p < 0.001), Res (p < 0.001), Ara-3 (p < 0.01), and IPD (p < 0.01). It is noteworthy and of merit that all test stilbenoids have exhibited potent antioxidant and anti-inflammatory activities and varied as affected by number of hydroxyl groups and isopentenyl or isopentadienyl moiety. Keywords: Arachis hypogaea L.; peanut; groundnut; resveratrol; stilbenoids; arachidin; antioxidant; anti-inflammation.     

Apoptosis and oxidative stress of infiltrated neutrophils obtained from mammary glands of goats during various stages of lactation

OBJECTIVE: To examine apoptosis in infiltrated neutrophils during involution of mammary glands and compare them with those obtained during late and peak lactation, and to measure oxidative stress and activities of antioxidant enzymes and determine involvement of free radicals in apoptosis of infiltrated neutrophils. SAMPLE POPULATION: Neutrophils from mammary gland secretions of 8 goats at 4 stages (late and peak lactation and 1 and 2 weeks after end of lactation). PROCEDURE: DNA fragmentation was evaluated to characterize apoptosis. Concentration of thiobarbituric acid reactive substances (TBARS) was used to evaluate oxidative stress. Activities of superoxide dismutase and glutathione peroxidase were determined. RESULTS: Neutrophils from secretions obtained after end of lactation of all goats and from late-lactation milk of some goats underwent prominent apoptosis, whereas neutrophils from peak lactation secretions did not. Higher lipid peroxidation and lower antioxidant enzyme activities in neutrophils during involution were observed, compared with those during late and peak lactation. A significant negative correlation existed between TBARS concentrations and antioxidant enzyme activities during the nonlactating period. CONCLUSIONS AND CLINICAL RELEVANCE: Apoptosis is a feature of infiltrated neutrophils during involution of mammary glands in goats. This feature may allow prompt resorption and clearance of infiltrated neutrophils without damaging surrounding tissues. Increased oxidative stress in infiltrated neutrophils from secretions obtained after end of lactation is probably related to a deficiency in antioxidant enzyme activities. Understanding the relationship between apoptosis and oxidative stress will lead to new strategies for manipulating involution and reducing tissue damage.     

Enhancement of tofu isoflavone recovery by pretreatment of soy milk with koji enzyme extract

Isoflavones are novel nutraceutical constituents of soybeans, but considerable amounts are lost in the whey during conventional tofu manufacturing. In this study, in a small-scale process, 2 mL of koji enzyme extract (soybean koji/deionized water, 1/3, w/v) was combined with 600 mL of soy milk, and 30 mL aliquots were incubated at 35 degrees C for 0, 30, 60, 120, and 300 min, for enzyme pretreatment. After each treatment time, soy milk was heated to 85 degrees C, CaSO4 was added to aggregate protein, and the mixture was centrifuged to separate the solids (tofu) from the whey. The tofu yield and moisture contents from soy milk treated for 30 or 60 min were higher than those from soy milk treated for 0 (control), 120, or 300 min. The protein content of freeze-dried tofu varied in a limited range, and native PAGE and SDS-PAGE patterns revealed slight quantitative and qualitative variations among products. Soy milk daidzein and genistein contents increased while daidzin and genistin contents decreased as the time of enzyme pretreatment of the soy milk increased. After 30 min of pretreatment, daidzin, genistin, daidzein, and genistein contents recovered in tofu products were higher than those of the control. In a pilot-scale process, aliquots (3 L) of soy milk were enzyme-treated for 30 min, aggregated with CaSO4, and hydraulically pressed to remove the whey. As in pretreatments, soy milk daidzein and genistein contents increased while daidzin and genistin contents decreased. In a comparison of the control and enzyme-treated tofu products, the total recoveries of daidzin, genistin, daidzein, and genistein in the tofu products increased from 54.9% to 64.2%. When the tofu products were subjected to a sensory panel test, both products were judged acceptable.