Inhibition of inducible nitric oxide synthase expression by an acetonic extract from Feijoa sellowiana Berg. fruits

Feijoa sellowiana Berg. fruits and especially the acetonic extract have been shown to possess biological activities, although the responsible compounds have never been identified. The present study was designed to evaluate the anti-inflammatory activity of an acetonic extract from F. sellowiana Berg. fruits on the nitric oxide (NO) pathway, which plays an important role in inflammation. To this aim the J774 cell line, which expresses inducible nitric oxide synthase (iNOS) following stimulation with lipopolysaccharide (LPS), has been utilized, and the effects of this extract and its fractions on NO production, iNOS protein expression, and signal pathways involved in its regulation have been evaluated. This study demonstrates that at least some part of the anti-inflammatory activity of the acetonic extract is due to the suppression of NO production by flavone and stearic acid. The mechanism of this inhibition seems to be related to an action on the expression of the enzyme iNOS through the attenuation of nuclear factor kappaB (NF-kappaB) and/or mitogen-activated protein kinase (MAPK) activation.     

Apple and pear peel and pulp and their influence on plasma lipids and antioxidant potentials in rats fed cholesterol-containing diets

The aim of this study was to assess the bioactive compounds of apple and pear peel and pulp in vitro and their influence on plasma lipids and antioxidant potentials in vivo. The antioxidant potentials measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), beta-carotene bleaching (beta-carotene), and nitric oxide inhibition radical scavenging (NO) tests in apple peel and pulp were significantly higher than in pear peel and pulp, respectively. The ethanol extract of apple peels showed the strongest inhibition of lipid peroxidation as a function of its concentration and was comparable to the antioxidant activity of butylated hydroxyanisole. The pear pulp extract had the weakest antioxidant ability, whereas other extracts such as apple pulp and pear peel were nearly equal. The antioxidant activities comprised contributions from polyphenols, phenolic acids, and flavonoids and correlated well with polyphenols and flavonoids. The correlation coefficients between polyphenols and antioxidant activities by DPPH, beta-carotene, and NO were as follows: 0.9207, 0.9350, and 0.9453. Contrarily, the correlation coefficient between the content of dietary fiber and the antioxidant activities test was low. The content of all studied indices in apple and pear peel was significantly higher than in peeled fruits (p < 0.05). Diets supplemented with fruit peels exercised a significantly higher positive influence on plasma lipid levels and on plasma antioxidant capacity of rats than diets with fruit pulps.     

Effect of extraction method on the concentrations of selected bioactive compounds in mandarin juice

A mandarin-type citrus fruit, ponkan (Citrus reticulata), was processed by in-line, chopper pulper, and hand-press extractions to investigate the effect of extraction method on the concentrations of bioactive compounds in processed juice. Concentrations of polymethoxylated flavones (tangeretin, nobiletin, and sinensetin) and beta-cryptoxanthin in juice, and inhibitory activities against arachidonate cyclooxygenase and lipoxygenases of the juice extract were analyzed. The juice processed by hand-press extraction contained the largest amounts of nobiletin (3.56 mg/100 mL), tangeretin (4.10 mg/100 mL), and sinensetin (0.13 mg/100 mL). Concentrations of beta-cryptoxanthin were 0.66, 0.59, 0.55, and 0.50 mg/100 mL in chopper pulper, in-line (5/64 in.), in-line (8/64 in.) and hand-press juices, respectively. Both extracts of in-line juices showed greater inhibitory activity toward platelet 12-lipoxygenase than the others. The inhibitory effect of hand-press juice extract on platelet cyclooxygenase activity was remarkable among juice extracts. All juice extracts effectively inhibited polymorphonuclear 5-lipoxygenase activity at nearly the same rate.     

Evaluation of antioxidant activity and inhibitory effect on nitric oxide production of some common vegetables

The objectives of this study were to study the antioxidant activities and nitric oxide (NO) scavenging effects of vegetables in vitro systems and to study the inhibitory effects of vegetables on the NO production and NO-induced DNA damage in RAW 264.7 macrophage. The results indicated that water extracts from Indian lotus, Jew's ear, shiitake, eggplant, and winter mushroom showed stronger antioxidant activity and free-radical-scavenging ability than that of other vegetable extracts. The scavenging effects of vegetable extracts on NO derived from sodium nitroprusside (SNP) were in decreasing order of water spinach > Indian lotus > eggplant and garland chrysanthemum. In the macrophage model system, the water extracts from fresh daylily flower, sponge gourd, pea sprout, and eggplant exhibited over 80% inhibition on NO generation stimulated by lipopolysaccharide. The extract from fresh daylily flower that expressed the strongest inhibition on NO production was attributed to the ability to reduce the inducible nitric oxide synthase (iNOS) induction. However, the extracts from pea sprout and eggplant suppressed the NO production by scavenging on NO and inactivating toward iNOS enzyme. In addition, the water extracts from fresh daylily flower, sponge gourd, pea sprout, and eggplant also showed over 40% inhibitory effect on DNA damage induced by SNP in RAW 264.7 macrophage. The data also indicated that eggplant and pea sprout extracts contained higher total phenolic compounds, anthocyanins, and ascorbic acids and appeared to be responsible for their antioxidant activities and scavenging effects on NO derived from SNP.     

Liquid chromatography/mass spectrometry and liquid chromatography/nuclear magnetic resonance as complementary analytical techniques for unambiguous identification of polymethoxylated flavones in residues from molecular distillation of orange peel oils (Citrus sinensis)

Liquid chromatography/mass spectrometry and liquid chromatography/nuclear magnetic resonance techniques with ultraviolet/diode array detection were used as complementary analytical tools for the reliable identification of polymethoxylated flavones in residues from molecular distillation of cold-pressed peel oils of Citrus sinensis. After development of a liquid chromatographic separation procedure, the presence of several polymethoxy flavones such as sinensetin, nobiletin, tangeretin, quercetogetin, heptamethoxyflavone, and other derivatives was unambiguously confirmed. In addition, proceranone, an acetylated tetranortriterpenoid with limonoid structure, was identified for the first time in citrus.     

The Composition of Volatile Aroma Components, Flavanones, and Polymethoxylated Flavones in Shiikuwasha (Citrus depressa Hayata) Peels of Different Cultivation Lines

Citrus peels are important sources of various pleasant aroma compounds and valuable bioactive substances. To investigate differences in the composition and content of Shiikuwasha (Citrus depressa Hayata) peels from different cultivation lines, the composition of volatile aroma components, flavanones, and polymethoxylated flavones (PMFs) in four Shiikuwasha cultivation lines was examined. The composition of volatile aroma components in cold-pressed extracts of Shiikuwasha peels was analyzed using gas chromatography-flame ionization detection and gas chromatography-mass spectrophotometry. The extracts contained mainly monoterpene hydrocarbons (93.40-97.25%), including limonene (46.52-68.26%) and γ-terpinene (21.48-30.52%). Differences in the composition of volatile aroma compounds in the Shiikuwasha cultivation lines were revealed using principal component analysis. Additionally, the composition of flavanones and PMFs was determined using high-performance liquid chromatography methods. Neohesperidin (96.58%) was the predominant flavanone in 'Izumi kugani' peel, while the other peels had high hesperidin contents (89.26-98.66%). Moreover, the PMFs of Shiikuwasha peels were composed of nobiletin (56.74-64.77%) and tangeretin (23.17-34.70%).     

Anti-inflammatory activities of 6β-acetoxy-7α-hydroxyroyleanone from Taiwania cryptomerioides Hayata ex vivo and in vivo

Excess production of nitric oxide (NO) by inducible NO synthase (iNOS) in activated macrophages is linked to acute and chronic inflammation. Thus, it would be valuable to develop inhibitors of NO production and/or iNOS for potential therapeutic use. This study investigated the anti-inflammatory effects of 6β-acetoxy-7α-hydroxyroyleanone (AHR), a compound isolated from the bark of Taiwania cryptomerioides Hayata, using lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW 264.7) ex vivo and carrageenan (Carr)-induced mouse paw edema model in vivo. When RAW 264.7 macrophages were treated with different concentrations of AHR (0, 0.31, 0.62, 1.25, and 2.50 μg/mL) together with LPS (100 ng/mL), a significant concentration-dependent inhibition of NO production was detected. Western blotting revealed that AHR blocked protein expression of iNOS and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 macrophages, significantly. In the anti-inflammatory test, AHR (1.25 and 2.50 mg/kg) decreased paw edema at 4 and 5 h after λ-carrageenan (Carr) administration and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the liver tissue. It was also demonstrated that AHR significantly attenuated the malondialdehyde (MDA) level in the edema paw at 5 h after Carr injection. AHR (0.62, 1.25, and 2.50 mg/kg) decreased the NO levels on both edema paw and serum at 5 h after Carr injection. Also, AHR diminished the serum tumor necrosis factor (TNF-α) at 5 h after Carr injection. Western blotting revealed that AHR (2.50 mg/kg) decreased Carr-induced iNOS and COX-2 expressions at 5 h in the edema paw. An intraperitoneal (ip) injection treatment with AHR also diminished neutrophil infiltration into sites of inflammation, as did indomethacin (Indo). The anti-inflammatory activities of AHR might be related to the decrease in the levels of MDA, iNOS, and COX-2 in the edema paw and to the increase in the activities of CAT, SOD, and GPx in the liver through the suppression of TNF-α and NO.     

NO处理对采后映霜红桃果实冷害及呼吸作用的影响

为探究一氧化氮(NO)处理对桃果实冷藏期间冷害及呼吸作用的影响,本研究以映霜红桃果实为试验材料,采用不同浓度NO(0、5、10、15 μL·L^-1)处理,检测桃在4℃贮藏期间冷害症状、冷害指数、硬度、呼吸速率、呼吸途径关键酶的变化。结果表明,10 μL·L^-1NO处理延缓了桃冷害的发生,显著降低了冷害指数、呼吸速率(P<0.05),维持了桃果实的硬度,使果实正常软化后熟。同时,10 μL·L^-1NO处理通过抑制桃果实糖酵解、三羧酸(TCA)循环、细胞色素氧化酶途径关键酶—葡萄糖磷酸异构酶(GPI)、琥珀酸脱氢酶(SDH)和细胞色素氧化酶(COX)的活性(P<0.05),抑制了果实呼吸速率,延缓了果实衰老。10 μL·L^-1 NO处理通过提高磷酸戊糖途径关键酶—葡萄糖-6-磷酸脱氢酶(G-6-PDH)和6-磷酸葡萄糖酸脱氢酶(6-PGDH)的联合活性及抗氰呼吸途径关键酶—交替氧化酶(AOX)的活性,增强了桃果实的抗冷性,减轻了桃果实的冷害。本研究结果为NO在桃果实贮藏保鲜中的应用提供了理论依据。     

DATS reduces LPS-induced iNOS expression, NO production, oxidative stress, and NF-kappaB activation in RAW 264.7 macrophages

Diallyl trisulfide (DATS), diallyl sulfide (DAS), and diallyl disulfide (DADS) are the three major organosulfur compounds (OSCs) in garlic oil. In contrast to DADS and DATS, evidence of an anti-inflammatory effect of DATS is limited. In this study compares the efficacy of DATS with those of DAS and DADS on lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production in RAW 264.7 macrophages. The NO production in LPS-activated RAW 264.7 macrophages was suppressed by both DADS and DATS in a dose-dependent manner. At 100 muM, the nitrite levels of DADS- and DATS-treated cells were 57 and 34%, respectively, of cells treated with LPS alone. DAS, however, had no influence on NO production even at a concentration of 1 mM. Western blot and Northern blot assays showed that DADS and DATS but not DAS dose-dependently suppressed LPS-induced iNOS protein and mRNA expression in a pattern similar to that noted for NO production. LPS-induced cellular peroxide production was significantly inhibited by DADS and DATS (P < 0.05) but not by DAS. Electrophoresis mobility shift assays further indicated that DADS and DATS effectively inhibited the activation of NF-kappaB induced by LPS. Taken together, these results indicate that the differential efficacy of three major OSCs of garlic oil on suppression of iNOS expression and NO production is related to the number of sulfur atoms and is in the order DATS > DADS > DAS. The inhibitory effect of DATS on LPS-induced iNOS expression is likely attributed to its antioxidant potential to inhibit NF-kappaB activation.     

Effect of heat treatment on the antioxidant activity of extracts from citrus peels

The effect of heat treatment on the antioxidant activity of extracts from Citrus unshiu peels was evaluated. Citrus peels (CP) (5 g) were placed in Pyrex Petri dishes (8.0 cm diameter) and heat-treated at 50, 100, or 150 degrees C for 10, 20, 30, 40, 50, and 60 min in an electric muffle furnace. After heat treatment, 70% ethanol extract (EE) and water extract (WE) (0.1 g/10 mL) of CP were prepared, and total phenol contents (TPC), radical scavenging activity (RSA), and reducing power of the extracts were determined. The antioxidant activities of CP extracts increased as heating temperature increased. For example, heat treatment of CP at 150 degrees C for 60 min increased the TPC, RSA, and reducing power of EE from 71.8 to 171.0 microM, from 29.64 to 64.25%, and from 0.45 to 0.82, respectively, compared to non-heat-treated control. In the case of WE from CP heat-treated at the same conditions (150 degrees C for 60 min), the TPC, RSA, and reducing power also increased from 84.4 to 204.9 microM, from 15.81 to 58.26%, and from 0.27 to 0.96, respectively. Several low molecular weight phenolic compounds such as 2,3-diacetyl-1-phenylnaphthalene, ferulic acid, p-hydroxybenzaldoxime, 5-hydroxyvaleric acid, 2,3-diacetyl-1-phenylnaphthalene, and vanillic acid were newly formed in the CP heated at 150 degrees C for 30 min. These results indicated that the antioxidant activity of CP extracts was significantly affected by heating temperature and duration of treatment on CP and that the heating process can be used as a tool for increasing the antioxidant activity of CP.     

Suppression effect of soy isoflavones on nitric oxide production in RAW 264.7 macrophages

Genistein, daidzein, and glycitein, as primary isoflavones in soybeans, are reported to have beneficial effects on atherosclerosis, chronic inflammatory diseases, and cancers that are conducted by nitric oxide (NO) injury. The objectives of this study were to investigate the effects and mechanisms of these soy isoflavones on the inducible nitric oxide synthase (iNOS) system in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Genistein, daidzein, and glycitein dose-dependently suppress NO production (IC(50) = 50 microM) in supernatants of LPS-activated macrophages as measured on the basis of nitrite accumulation. In addition, direct inhibition of iNOS activity, determined by means of the conversion of L-[(3)H]arginine to L-[(3)H]citrulline, and markedly reduced iNOS protein and mRNA levels, evaluated by means of Western blot and RT-PCR, respectively, were found in homogenates of LPS-activated cells treated with each isoflavone. Moreover, genistein was found to have a greater inhibitory effect on NO production but no significant effect on iNOS activity or protein and gene expression to daidzein and glycitein. These observations reveal that the suppression of NO production by genistein, daidzein, and glycitein might be due to the inhibition of both the activity and expression of iNOS in LPS-activated macrophages. The result suggests that soy isoflavones might attenuate excessive NO generation at inflammatory sites.     

Antioxidant and anti-inflammatory activities of selected medicinal plants containing phenolic and flavonoid compounds

The antioxidant, anti-inflammatory, and cytotoxic activities of water and ethanol extracts of 14 Chinese medicinal plants were investigated and also their total phenolics and flavonoid contents measured. The antioxidant activity was evaluated in a biological assay using Saccharomyces cerevisiae , whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolics and flavonoid contents were estimated by Folin-Ciocalteu and aluminum chloride methods, respectively. The anti-inflammatory activities of the plant extracts were determined by measuring the inhibition of production of nitric oxide (NO) and TNF-α in LPS and IFN-γ activated RAW 264.7 macrophages. Their cytotoxic activities against macrophages were determined by Alamar Blue assay. Four plants, namely, Scutellaria baicalensis , Taxillus chinensis , Rheum officinale , and Sophora japonica , showed significant antioxidant activity in both yeast model and also free radical scavenging methods. The ethanol extract of S. japonica showed highest levels of phenolics and flavonoids (91.33 GAE mg/g and 151.86 QE mg/g, respectively). A positive linear correlation between antioxidant activity and the total phenolics and flavonoid contents indicates that these compounds are likely to be the main antioxidants contributing to the observed activities. Five plant extracts (S. baicalensis, T. chinensis, S. japonica, Mahonia fortunei , and Sophora flavescens ) exhibited significant anti-inflammatory activity by in vitro inhibition of the production of NO and TNF-α with low IC(50) values. These findings suggest that some of the medicinal herbs studied in this paper are good sources of antioxidants.     

Anti-inflammatory effects of phenolic compounds isolated from the fruits of Artocarpus heterophyllus

Artocarpus heterophyllus Lam is a large evergreen tree cultivated throughout Southeast Asia for its fruits. Its leaves and roots have been used for medicinal purposes. The aim of this work was to study the in vitro anti-inflammatory effects of phenolic compounds isolated from the ethyl acetate extracts of the fruits of Artocarpus heterophyllus. Three phenolic compounds were characterized as artocarpesin [5,7,2',4'-tetrahydroxy-6-(3-methylbut-3-enyl) flavone] ( 1), norartocarpetin (5,7,2',4'-tetrahydroxyflavone) ( 2), and oxyresveratrol [ trans-2,4,3',5'-tetrahydroxystilbene] ( 3) by spectroscopic methods and through comparison with data reported in the literatures. The anti-inflammatory effects of the isolated compounds ( 1- 3) were evaluated by determining their inhibitory effects on the production of proinflammatory mediators in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophage cells. These three compounds exhibited potent anti-inflammatory activity. The results indicated that artocarpesin ( 1) suppressed the LPS-induced production of nitric oxide (NO) and prostaglandin E 2 (PGE 2) through the down-regulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) protein expressions. Thus, artocarpesin ( 1) may provide a potential therapeutic approach for inflammation-associated disorders.     

宽皮柑橘对辊式剥皮机的设计与试验

为改善目前宽皮柑橘加工业中以手工去皮为主的现状,提高柑橘剥皮效率,该文根据宽皮柑橘果皮包着宽松,易与果肉分离等特点,设计了一种可以实现快速去皮的宽皮柑橘对辊式剥皮机。柑橘进入设备后,在刮板的带动下翻转向前运动,运动过程中不同形式且相向转动的剥皮辊夹持并撕扯翻起的果皮,从而将果皮从柑橘上整体剥离。该样机主要由机架、传动装置、对辊装置、拨动装置和下料装置等部件组成,具有结构紧凑,果皮分离能力强等特点。试验结果表明:样机可以很好地完成剥皮功能,宽皮柑橘果皮去净率高于97.5%,果肉损伤率低于2.68%,生产率达到202.5 kg/h,基本满足生产需求。该研究可为中国柑橘加工业中自动去皮设备研制和发展提供参考。