教師著作
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Item Protective effect of spices against peroxynitrite.(2006-10-28) Po-Jung Tsai, Wan-Ju Lu, Hua-Wen Liang, and Su-Chen HoPeroxynitrite, a potent cytotoxic agent, can damage a variety of biomolecules such as proteins, lipids, and DNA, is considered as the major pathological factor in several disease states. Due to the cells lack a specific enzyme to decompose peroxynitrite, the burden of defense against peroxynitrite relies solely on nonezymatic antioxidants. Therefore, it would appear likely that interception of peroxynitrite by certain food items would serve as a promising indicator for the beneficial "health effects" of such food. Spices, rich in phenolics, are speculated conceivably to act as potential peroxynitrite scavengers. The protective effects of methanol extracts derived from eight culinary spices against peroxynitrite mediated damages on proteins, lipids and DNA were determined. All of the tested spices exerted protective effect against peroxynitrite mediated tyrosine nitration, lipid peroxidation and DNA strand breakage. Cloves displayed the most excellent protection. Moreover, phenolics content of spice was highly correlated with their protective effect against peroxynitrite mediated tyrosine nitration and lipid peroxidation. These results indicated that the protective effects of spices against peroxynitrite mediated bimolecule damages were attributed to the phenolics.Item Evaluation of NO-suppressing Activity of Several Mediterranean Culinary Spices.(ELSEVIER, 2007-05-01) Po-Jung Tsai, Tzung-Hsun Tsai, Chun-Hsien Yu, Su-Chen Ho.,Excess nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is implicated in the development of a number of diseases. Due to the absence of any natural specific enzymatic defense system in vivo, the consumption of certain foods which exhibit selective suppressive ability as regards NO overproduction might boost the host’s protective effects against NO-mediated toxicity. Spices, rich in phenolics, are speculated conceivably to act as potential NO-scavengers or iNOS suppressors. The relative NO-suppressing activity of methanol extracts deriving from nine Mediterranean culinary spices was determined by measuring their inhibitory effect upon NO production for lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. In addition, the specifics of the suppressing mechanism were further explored. All of the spices tested, with the exception of clove, displayed a rather linear dose-dependent NO-suppressing effect without there appearing to exist any effect upon cell viability. Furthermore, the NO-suppressing capacity of certain spices was able to be ranked based upon their IC50 (the concentration of spice extracts is required to cause 50% inhibition of NO production by LPS-activated RAW 264.7 cells), the ranking appearing as: rosemary (0.031%) > tarragon (0.052%) > cinnamon (0.059%) > oregano (0.106%) > basil (0.162%) > marjoram (0.236%) > allspice (0.269%) > and thyme (0.270%). Only cinnamon displayed excellent NO-scavenging ability, whereas all of the other spices demonstrated moderate to poor activities in this regard. Moreover, the inhibitory effect of tested spices upon the iNOS protein level was almost equivalent to their suppressive effect upon NO production. It would appear that inhibition of iNOS expression was the primary mechanism of action of spices as regards their exerting NO-suppressing activity.Item Comparison of NO-scavenging and NO-suppressing Activities of Different Herbal Teas with those of Green Tea.(ELSEVIER, 2007-03-01) Po-Jung Tsai, Tzung-Hsun Tsai, Chun-Hsien Yu, and Su-Chen Ho.,Oxidative stress caused by the production of excess nitric oxide (NO) during infection or inflammation has been implicated in the pathogenesis of several diseases, including cancer, diabetes and renal disease. Accordingly, the scavenging of NO radical or/and suppression of NO production by mitogen-activated cells may be promising indicators in screening healthy food. In this work, the NO-scavenging and NO-suppressing activities of different herbal teas were determined and compared with those of green tea. All of the tested herbal teas revealed NO-scavenging and NO-suppressing activities. The NO-scavenging activity of herbal teas can be ranked by the IC50, the concentration of the tested herbal tea required to quench 50% of NO radicals released by sodium nitroprusside. The activities follow the order: green tea > rosemary, sweet osmanthus, rose and lavender > jasmine, lemongrass and daisy. The NO-suppressing activity was evaluated, based on the suppressing effect of herbal teas on the production of NO by LPS-activated RAW 264.7 macrophages. Experimental results indicated that green tea and rosemary had IC50 values of less than 500 μg/ml, and were proven to be good NO-suppressors, whereas lavender, sweet osmanthus, lemongrass, rose, daisy and jasmine had IC50 values that exceeded 500 μg/ml, and were classified as rather poor NO-suppressors. In conclusion, consumption of herbal teas promotes the NO-scavenging and NO-suppressing activities of the diet, even though their activities are weaker than that of green tea.Item Protective capacities of certain spices against peroxynitrite-mediated biomolecular damage.(ELSEVIER, 2008-03-01) Su-Chen Ho, Tzung-Hsun Tsai, Po-Jung Tsai, and Chih-Cheng Lin.Peroxynitrite, a potent cytotoxic agent, can damage a variety of biomolecules such as proteins, lipids, and DNA, and is considered as one of the major pathological causes of several diseases. Therefore, it would appear likely that interception of peroxynitrite by certain dietary compounds may represent one mechanism by which such foods may exert their beneficial action in vivo. A number of researchers have speculated that certain spices, rich in phenolics, may, conceivably, act as potential protectors against the actions of peroxynitrite. Eight culinary spices including cardamom, cinnamon, cloves, cumin, nutmeg, paprika, rosemary and turmeric were selected for study purposes. Further, the protective effects of methanol extracts of such spices against peroxynitrite-mediated damage to proteins, lipids and DNA were evaluated as determined by these extracts’ ability to attenuate the formation of, respectively, nitrotyrosine in albumin, thiobarbiturate acid-reactive substances (TBARS) in liposome and strand breakages for plasmid DNA. All of the tested spices exerted some level of protective ability against peroxynitrite-mediated biomolecular damage. Amongst them, cloves deserve special attention due to their outstanding protective abilities against two of three forms of peroxynitrite-mediated biomolecular damage. Additionally, the phenolic content of certain spices appears to correlate well with such spices’ protective effect against peroxynitrite-mediated tyrosine nitration and lipid peroxidation. Such an observation indicates that phenolics present in the spices contributed to such spice-elicited protection against peroxynitrite toxicity.Item Physiochemical, antioxidant and whitening properties of extract from root cortices of mulberry as affected by membrane(Elsevier, 2007-06-01) Yu, Z.-R., Hung, C.-C., Weng, Y.-M., Su, C.-L., and Wang, B.-J.,Extract from root cortices of mulberry (Morus alba, L.) was separated into permeate and retentate fractions using a membrane system equipped with either a microfiltration membrane or one of four molecular weight cut-off ultrafiltration membranes. The effects of membrane process at volume concentration ratio (VCR)=4 on the physiochemical characteristics, the contents of active compounds, antioxidant ability, and whitening capability (tyrosinase inhibitory activity) in permeate and retentate were evaluated. The clarification degree, antioxidant effects, and whitening capability of the permeates increased as compared to those of feed. In addition, permeate treated with a 0.45 μm microfiltration membrane exhibited less fouling layer and specific resistance (αpCB=622.8 m−2×10−6) and thus had a higher permeate flux than treated with other ultrafiltration membranes (αpCB=786.1–1025.3 m−2×10−6). A higher content of active compounds, such as chlorogenoic acid and p-hydroxybenzoic acid may explain higher antioxidant and whitening capabilities in permeate of extracts from root cortices of mulberry.