The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Malcolm I Whitecross - One of the best experts on this subject based on the ideXlab platform.
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Isovitexin 2 o β 6 o e p coumaroylglucopyranoside from uv b irradiated leaves of rice oryza sativa l inhibits fertility of helicoverpa armigera
Photochemistry and Photobiology, 2007Co-Authors: Merdelyn T Caasilit, Gregory J Tanner, Murali Nayudu, Malcolm I WhitecrossAbstract:: UV-B irradiated rice leaves (Oryza sativa L.) contained four closely related flavonoids, with either an isoorientin or Isovitexin aglycone. These flavonoids have previously been purified and characterized, and were added to artificial diets of the African bollworm (Helicoverpa armigera Hubner) at 0.1x concentration found in irradiated rice leaves. Consumption of different diets had relatively small effects on laval, pupal and adult duration, weight and survival, indicating the insects lived near normal life cycles on all diets. However, one of the compounds, flavonoid IIa, Isovitexin-2''-O-beta-[6-O-E-p-coumaroylglucopyranoside], dramatically reduced the number of fertile eggs laid to 7% of control insects (P<0.001) when added to insect diets at 18 nmol gFW(-1) (14 ppm). A similar antifertility effect was observed when only the male partner consumed diet containing flavonoid IIa, indicating that the reduced fertility may be male specific. In contrast, the fecundity and fertility of insects eating diets containing the closely related flavonoids, isoorientin-2''-O-beta-[6-O-E-p-coumaroylglucopyranoside] or isoorientin-2''-O-beta-[6-O-E-p-feruloylglucopyranoside], were not significantly different to control diets.
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Isovitexin‐2″‐O‐β‐[6‐O‐E‐p‐coumaroylglucopyranoside] from UV‐B irradiated Leaves of Rice, Oryza sativa L. Inhibits Fertility of Helicoverpa armigera
Photochemistry and Photobiology, 2007Co-Authors: Merdelyn T. Caasi-lit, Gregory J Tanner, Murali Nayudu, Malcolm I WhitecrossAbstract:UV-B irradiated rice leaves (Oryza sativa L.) contained four closely related flavonoids, with either an isoorientin or Isovitexin aglycone. These flavonoids have previously been purified and characterized, and were added to artificial diets of the African bollworm (Helicoverpa armigera Hiibner) at 0.1x concentration found in irradiated rice leaves. Consumption of different diets had relatively small effects on laval, pupal and adult duration, weight and survival, indicating the insects lived near normal life cycles on all diets. However, one of the compounds, flavonoid IIa, Isovitexin-2'-O-β-[6-O-E-p-coumaroylglucopyranoside], dramatically reduced the number of fertile eggs laid to 7% of control insects (P < 0.001) when added to insect diets at 18 nmol gFW -1 (14 ppm). A similar antifertility effect was observed when only the male partner consumed diet containing flavonoid IIa, indicating that the reduced fertility may be male specific. In contrast, the fecundity and fertility of insects eating diets containing the closely related flavonoids, isoorientin-2'-O-β-[6-O-E-p-coumaroylglucopyranoside] or isoorientin-2'-O-β-[6-O-E-p-feruloylglucopyranoside], were not significantly different to control diets.
Jan Brederode - One of the best experts on this subject based on the ideXlab platform.
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inhibition of mitochondrial respiration by the flavone aglycone Isovitexin causes aberrant petal and leaf morphology in silene latifolia
Plant Cell Reports, 1996Co-Authors: Anneke M Wagner, Jan BrederodeAbstract:The morphological mutant “Isovitexin” in Silene latifolia (the white campion) has small and up-curled petals and leaves. In this mutant the aglycone Isovitexin is the only flavone present in the vacuole. In the present study it is shown that Isovitexin has a strong toxic effect on mitochondria that is to a large extent abolished by glycosylation. This effect can be used to explain the aberrant morphology. Isovitexin acts at the level of the ubiquinone pool; cytochrome c — cytochrome aa3 oxidase activity was unaffected, and with either reduced nicotinamide adenine dinucleotide or succinate as a respiratory substrate, effects on respiration were found in Silene leaves-, potato (Solanum tuberosum) tuber- and sweet potato (Ipomoea batata L.) tuber mitochondria. Since in sweet potato electron transport via the cyanide insensitive pathway was also inhibited, with the ubiquinone pool as the only component (besides the dehydrogenases) shared by these two pathways, the site of inhibition must be at this level.
Tin Wui Wong - One of the best experts on this subject based on the ideXlab platform.
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vitexin and Isovitexin from the leaves of ficus deltoidea with in vivo α glucosidase inhibition
Journal of Ethnopharmacology, 2012Co-Authors: Chee Yan Choo, N Y Sulong, Tin Wui WongAbstract:Ethnopharmacological relevance The leaves of Ficus deltoidea are used as a traditional medicine by diabetes patients in Malaysia. Aim of the study The objective of the study is to identify and evaluate bioactive constituents with in vivo α-glucosidase inhibition. Materials and Methods The partitioned extracts, subfractions and pure bioactive constituents were subjected to α-glucosidase inhibition assay. The identified bioactive constituents were administered orally to sucrose loaded normoglycemic mice and induced diabetic rats. The postprandial blood glucose levels were monitored at 30 min interval. Acute toxicity was evaluated in both normoglycemic mice and induced diabetic rats. Results Bioactivity guided fractionation led to the isolation of both vitexin (1) and Isovitexin (2). Oral administration of 1 mg/kg of either vitexin (1) or Isovitexin (2) significantly (p<0.05) reduced the postprandial blood glucose level in sucrose loaded normoglycemic mice at 30 min. The percentage of postprandial blood glucose reduction was highest in sucrose loaded induced diabetic rats administered orally with 200 mg/kg of vitexin (1) or 100 mg/kg of Isovitexin (2). Both vitexin (1) and Isovitexin (2) did not exert any signs of toxicity at the highest dose of 2 g/kg administered orally to normoglycemic mice and induced diabetic rats. Conclusion Both the C-glycosyl bioflavonoids, namely, vitexin (1) and Isovitexin (2) exhibited in vivo α-glucosidase inhibition.
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Vitexin and Isovitexin from the Leaves of Ficus deltoidea with in-vivo α-glucosidase inhibition
Journal of Ethnopharmacology, 2012Co-Authors: Chee Yan Choo, N Y Sulong, Tin Wui WongAbstract:Ethnopharmacological relevance The leaves of Ficus deltoidea are used as a traditional medicine by diabetes patients in Malaysia. Aim of the study The objective of the study is to identify and evaluate bioactive constituents with in vivo α-glucosidase inhibition. Materials and Methods The partitioned extracts, subfractions and pure bioactive constituents were subjected to α-glucosidase inhibition assay. The identified bioactive constituents were administered orally to sucrose loaded normoglycemic mice and induced diabetic rats. The postprandial blood glucose levels were monitored at 30 min interval. Acute toxicity was evaluated in both normoglycemic mice and induced diabetic rats. Results Bioactivity guided fractionation led to the isolation of both vitexin (1) and Isovitexin (2). Oral administration of 1 mg/kg of either vitexin (1) or Isovitexin (2) significantly (p
Merdelyn T Caasilit - One of the best experts on this subject based on the ideXlab platform.
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Isovitexin 2 o β 6 o e p coumaroylglucopyranoside from uv b irradiated leaves of rice oryza sativa l inhibits fertility of helicoverpa armigera
Photochemistry and Photobiology, 2007Co-Authors: Merdelyn T Caasilit, Gregory J Tanner, Murali Nayudu, Malcolm I WhitecrossAbstract:: UV-B irradiated rice leaves (Oryza sativa L.) contained four closely related flavonoids, with either an isoorientin or Isovitexin aglycone. These flavonoids have previously been purified and characterized, and were added to artificial diets of the African bollworm (Helicoverpa armigera Hubner) at 0.1x concentration found in irradiated rice leaves. Consumption of different diets had relatively small effects on laval, pupal and adult duration, weight and survival, indicating the insects lived near normal life cycles on all diets. However, one of the compounds, flavonoid IIa, Isovitexin-2''-O-beta-[6-O-E-p-coumaroylglucopyranoside], dramatically reduced the number of fertile eggs laid to 7% of control insects (P<0.001) when added to insect diets at 18 nmol gFW(-1) (14 ppm). A similar antifertility effect was observed when only the male partner consumed diet containing flavonoid IIa, indicating that the reduced fertility may be male specific. In contrast, the fecundity and fertility of insects eating diets containing the closely related flavonoids, isoorientin-2''-O-beta-[6-O-E-p-coumaroylglucopyranoside] or isoorientin-2''-O-beta-[6-O-E-p-feruloylglucopyranoside], were not significantly different to control diets.
Chien Tsu Chen - One of the best experts on this subject based on the ideXlab platform.
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Inhibitory effects of a rice hull constituent on tumor necrosis factor α, prostaglandin E2, and cyclooxygenase-2 production in lipopolysaccharide-activated mouse macrophages
Annals of the New York Academy of Sciences, 2020Co-Authors: Shengtung Huang, Chien Tsu Chen, Kur Ta Chieng, Shih Hao Huang, Been-huang Chiang, Leng-fang WangAbstract:Isovitexin, isolated from rice hull of Oryza sativa, has been characterized as a potent antioxidant. Its antioxidant activity, determined on the basis of inhibition of lipid peroxidation by the Fenton reaction, was comparable with that of aαtocopherol, a well-established antioxidant. Isovitexin was able to reduce the amount of hydrogen peroxide production induced by lipopolysaccharide (LPS) in mouse macrophage RAW264.7 cells. In this study, we assessed its effects on the production of tumor necrosis factor a (TNF-a), prostaglandin E2 (PGE 2 ), and the expression of cyclooxygenase-2 (COX-2) in LPS-activated RAW 264.7 macrophages. Isovitexin inhibited the release of TNF-α, a proinflammatory cytokine, upon LPS activation with a 50% inhibitory concentration (IC 5 0 ) of 78.6 μM. Isovitexin markedly reduced LPS-stimulated PGE 2 production in a concentration-dependent manner, with an IC 5 0 of 80.0 μM. The expression of COX-2 was also inhibited by Isovitexin treatment. Our results suggest that suppression of ROS-mediated COX-2 expression by Isovitexin is beneficial in reducing inflammation and carcinogenesis.
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Isovitexin suppresses lipopolysaccharide mediated inducible nitric oxide synthase through inhibition of nf kappa b in mouse macrophages
Planta Medica, 2005Co-Authors: Shengtung Huang, Yu Chih Liang, Chwen Ming Shih, Yuan Ching Chang, Tzong Yueh Chen, Chien Tsu ChenAbstract:: Isovitexin exhibits potent antioxidant activities. In this study, the activity of nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-activated RAW264.7 macrophages after incubation with Isovitexin was investigated. Isovitexin was able to reduce the production of hydrogen peroxide induced by LPS in mouse macrophage RAW264.7 cells. The cells incubated with Isovitexin had markedly reduced LPS-stimulated NO production with an IC (50) value of 58.5 microM. The expression of iNOS was also inhibited when the cells were treated with Isovitexin. A transient transfection experiment showed that Isovitexin suppressed the iNOS promoter and NF-kappaB-dependent transcriptional activities. It was also found to inhibit IKK kinase activity and prevent the degradation of IkappaBalpha in activated RAW264.7 cells. Additionally, Western blotting analysis revealed that Isovitexin prevented the translocation of NF-kappaB from the cytoplasm to the nucleus. Our results indicate that its ROS scavenger and IKK inhibitory activities also contribute to the suppression of ROS-mediated NF-kappaB activity. These results suggest that Isovitexin, a food phytochemical contained in dietary rice products, might have biological significance.
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prevention of cellular ros damage by Isovitexin and related flavonoids
Planta Medica, 2002Co-Authors: Chien Tsu ChenAbstract:: The antioxidant properties of Isovitexin and related flavonoids were studied. Isovitexin inhibited xanthine oxidase with an IC50 value of = 15.2 microM. The flavonoid analogues, apigenin, kaempferol, quercetin, myricetin, and genistein also inhibited xanthine oxidase with IC50 values of 0.58, 2.18, 1.09, 9.90, and 4.83 microM, respectively. Isovitexin protected DNA from the Fenton reaction-induced breakage in a dose-dependent manner with an IC50 value of 9.52 microM. Isovitexin also protected HL-60 cells from the ROS damage induced by the xanthine/xanthine oxidase reaction. Isovitexin exhibited the lowest cytotoxicity toward HL-60 cells (LD50 >400 microM) compared to the other flavonoids examined. In addition, excess hydrogen peroxide induced by cadmium in A2780 ovarian cells was significantly suppressed by Isovitexin. These results suggest that Isovitexin in rice may protect cells from oxidative stress.
