The Experts below are selected from a list of 405 Experts worldwide ranked by ideXlab platform
Hiroshi Tobe - One of the best experts on this subject based on the ideXlab platform.
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mode of pollen tube growth in pistils of ticodendron incognitum ticodendraceae fagales and the evolution of chalazogamy
Botanical Journal of the Linnean Society, 2008Co-Authors: Akiko Sogo, Hiroshi TobeAbstract:Ticodendron incognitum is the sole species of the Ticodendraceae, which was established as a new family in the Fagales less than 20 years ago. Considering the diverse modes of pollen tube growth observed in other Fagales, we investigated the growth of pollen tubes in the pistil of Ticodendron. At the time of pollination, T. incognitum had four immature ovules in a bilocular ovary, thus exhibiting delayed fertilization, as in other Fagales. During the period when fertilization was delayed, pollen tube growth in the pistil was intermittent, consisting of five steps associated with development of the ovules and embryo sacs. Four cessation sites occurred: in the style, in the tissue of the upper part of the ovary, inside and outside of the funicle and at the Chalaza. A single pollen tube eventually reaches a mature embryo sac through the Chalaza in one of the four ovules. While both delayed fertilization and intermittent pollen tube growth play a role in male and female gametophyte selection, as in other Fagales, the five-step process of pollen tube growth through the Chalaza (i.e. chalazogamy) is characteristic of lineages of the Casuarinaceae, Ticodendraceae and Betulaceae (the latter with the loss of one step). © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157, 621–631.
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Intermittent pollen-tube growth in pistils of alders (Alnus)
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Akiko Sogo, Hiroshi TobeAbstract:In alders, where fertilization occurs ≈8 weeks after pollination, the pollen tube (male gametophyte) grows intermittently in four steps in close association with the development of the ovary and its ovules. Pollen tubes stop growing in the style, at the ovarian locule, and at the Chalaza (ovule), before reaching an embryo sac for fertilization. At the stage when the ovary develops an ovule primordium in each of the two locules, many pollen tubes germinate on the stigma, and a few of them reach the style, where they remain for ≈7 weeks. Thereafter, a single tube resumes growing; with a short stop in the upper space of the ovarian locule, it reaches the older of the two ovules when it has developed a two-nucleate embryo sac. Except in the last step, where the tube grows from the Chalaza to an embryo sac (female gametophyte), an eight-nucleate mature embryo sac is not necessary for pollen-tube guidance in the pistil. Although the intermittent pollen-tube growth appears to play an important role in the selection of a single pollen tube from many and one ovule from two, its detection provides insight into the study of the mechanism of pollen-tube guidance.
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pollen tube growth pattern and chalazogamy in casuarina equisetifolia casuarinaceae
Journal of Plant Research, 2004Co-Authors: Akiko Sogo, Junko Noguchi, Tanguy Jaffre, Hiroshi TobeAbstract:For a better understanding of pollen-tube guidance in relation to pollen-pistil interaction, we investigated the mode of pollen-tube growth in pistils of Casuarina equisetifolia, a monoecious, wind-pollinated species that undergoes chalazogamous fertilization. The pistil is bicarpellate, but only one of the two carpels develops with two ovules. One of these ovules develops more than four embryo sacs. Pistils usually require more than 1 month to reach maturity after pollen grains have been deposited on the stigmas. During that period, pollen-tube growth proceeds discontinuously in five distinct steps that lead up to fertilization: (1) from the stigma to the upper region of the style, (2) from the upper region of the style to a septum in the ovary, (3) from the septum to the surface of the funiculus, (4) from the funiculus to Chalaza in the ovule, and (5) from the Chalaza to an egg apparatus. Probably because of competitive interaction between male and female gametophytes (or ovules), one pollen tube is selected from among many during the first step (just before the second step), one ovule from the two during the second and third steps, and one embryo sac from more than four during the fourth and fifth steps. On the basis of our results, erroneous drawings and explanations reported in earlier publications on chalazogamy in Casuarinaceae should be brought into question.
Klaus Harter - One of the best experts on this subject based on the ideXlab platform.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-9
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:Ive RT-PCR. Data are expressed as mean +/- SD (n = 3) (B) Scheme of seed anatomy adapted according to Debeaujon and colleagues []. Note the location of the Chalaza. (C) Confocal images of transgenic seeds at different developmental stages expressing a construct. Bright field, GFP images and overlays are presented from the left to the right. The bars represent 100 μm. (D) Immunolocalization of GFP on cryosections prepared from developing seeds of transgenic plants using a GFP-specific antibody (anti-GFP). The nuclei of the cells were visualised by DAPI staining (DAPI). The dotted line confines the Chalaza area. The bars represent 20 μm.Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-7
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:Sphorylatable Asp74 (D74) was mutated either to a Glu () or an Asn () are shown.Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-6
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:Ant and wild type (grey bars) by HPLC analysis as described in Methods. The data are expressed as mean ± SD (n = 5).Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-5
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:N bars) mutant and wild type (grey bars) by HPLC analysis as described in Methods. The data are expressed as mean ± SD (n = 5).Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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the arabidopsis thaliana response regulator arr22 is a putative ahp phospho histidine phosphatase expressed in the Chalaza of developing seeds
BMC Plant Biology, 2008Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:The Arabidopsis response regulator 22 (ARR22) is one of two members of a recently defined novel group of two-component system (TCS) elements. TCSs are stimulus perception and response modules of prokaryotic origin, which signal by a His-to-Asp phosphorelay mechanism. In plants, TCS regulators are involved in hormone response pathways, such as those for cytokinin and ethylene. While the functions of the other TCS elements in Arabidopsis, such as histidine kinases (AHKs), histidine-containing phosphotransfer proteins (AHPs) and A-type and B-type ARRs are becoming evident, the role of ARR22 is poorly understood. We present evidence that ARR22 is a preferentially cytoplasmic protein, exclusively expressed in the Chalaza of developing seeds. ARR22 specifically interacts with AHP2, AHP3 and AHP5 in yeast and living plant cells. Two new loss-of-function alleles, arr22-2 and arr22-3, were isolated and characterized. With respect to their morphology and metabolite status, no significant difference in the developing seeds of the arr22 mutants was observed compared to wild type. The genetic complementation of the arr22 mutants with a genomic ARR22 fragment resulted in plants (arr22/gARR22) with a pleiotropic phenotype of different penetrance. This phenotype was not observed when the phosphorylatable Asp74 of ARR22 was changed to either a dominant-active Glu or a dominant-inactive Asn. The phenotype of the arr22/gARR22 plants was comparable to that of multiple ahk, ahp and B-type arr mutants. Our results favor the model that ARR22 acts as a phospho-histidine phosphatase on specific AHPs in the cytoplasm of Arabidopsis Chalaza cells. The lack of any aberrant morphological and metabolite phenotype in the seeds of the arr22 mutants indicates that ARR22 is probably primarily responsible for the fine tuning of specific branches of Chalaza-based TCS signalling. Even when slightly mis-expressed, ARR22 interferes with hormone homeostasis in non-Chalaza tissues. Our data indicate that the chromatin status might play a crucial role in maintaining the Chalaza-restricted expression of ARR22.
Akiko Sogo - One of the best experts on this subject based on the ideXlab platform.
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mode of pollen tube growth in pistils of ticodendron incognitum ticodendraceae fagales and the evolution of chalazogamy
Botanical Journal of the Linnean Society, 2008Co-Authors: Akiko Sogo, Hiroshi TobeAbstract:Ticodendron incognitum is the sole species of the Ticodendraceae, which was established as a new family in the Fagales less than 20 years ago. Considering the diverse modes of pollen tube growth observed in other Fagales, we investigated the growth of pollen tubes in the pistil of Ticodendron. At the time of pollination, T. incognitum had four immature ovules in a bilocular ovary, thus exhibiting delayed fertilization, as in other Fagales. During the period when fertilization was delayed, pollen tube growth in the pistil was intermittent, consisting of five steps associated with development of the ovules and embryo sacs. Four cessation sites occurred: in the style, in the tissue of the upper part of the ovary, inside and outside of the funicle and at the Chalaza. A single pollen tube eventually reaches a mature embryo sac through the Chalaza in one of the four ovules. While both delayed fertilization and intermittent pollen tube growth play a role in male and female gametophyte selection, as in other Fagales, the five-step process of pollen tube growth through the Chalaza (i.e. chalazogamy) is characteristic of lineages of the Casuarinaceae, Ticodendraceae and Betulaceae (the latter with the loss of one step). © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157, 621–631.
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Intermittent pollen-tube growth in pistils of alders (Alnus)
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Akiko Sogo, Hiroshi TobeAbstract:In alders, where fertilization occurs ≈8 weeks after pollination, the pollen tube (male gametophyte) grows intermittently in four steps in close association with the development of the ovary and its ovules. Pollen tubes stop growing in the style, at the ovarian locule, and at the Chalaza (ovule), before reaching an embryo sac for fertilization. At the stage when the ovary develops an ovule primordium in each of the two locules, many pollen tubes germinate on the stigma, and a few of them reach the style, where they remain for ≈7 weeks. Thereafter, a single tube resumes growing; with a short stop in the upper space of the ovarian locule, it reaches the older of the two ovules when it has developed a two-nucleate embryo sac. Except in the last step, where the tube grows from the Chalaza to an embryo sac (female gametophyte), an eight-nucleate mature embryo sac is not necessary for pollen-tube guidance in the pistil. Although the intermittent pollen-tube growth appears to play an important role in the selection of a single pollen tube from many and one ovule from two, its detection provides insight into the study of the mechanism of pollen-tube guidance.
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pollen tube growth pattern and chalazogamy in casuarina equisetifolia casuarinaceae
Journal of Plant Research, 2004Co-Authors: Akiko Sogo, Junko Noguchi, Tanguy Jaffre, Hiroshi TobeAbstract:For a better understanding of pollen-tube guidance in relation to pollen-pistil interaction, we investigated the mode of pollen-tube growth in pistils of Casuarina equisetifolia, a monoecious, wind-pollinated species that undergoes chalazogamous fertilization. The pistil is bicarpellate, but only one of the two carpels develops with two ovules. One of these ovules develops more than four embryo sacs. Pistils usually require more than 1 month to reach maturity after pollen grains have been deposited on the stigmas. During that period, pollen-tube growth proceeds discontinuously in five distinct steps that lead up to fertilization: (1) from the stigma to the upper region of the style, (2) from the upper region of the style to a septum in the ovary, (3) from the septum to the surface of the funiculus, (4) from the funiculus to Chalaza in the ovule, and (5) from the Chalaza to an egg apparatus. Probably because of competitive interaction between male and female gametophytes (or ovules), one pollen tube is selected from among many during the first step (just before the second step), one ovule from the two during the second and third steps, and one embryo sac from more than four during the fourth and fifth steps. On the basis of our results, erroneous drawings and explanations reported in earlier publications on chalazogamy in Casuarinaceae should be brought into question.
Jakub Horák - One of the best experts on this subject based on the ideXlab platform.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-9
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:Ive RT-PCR. Data are expressed as mean +/- SD (n = 3) (B) Scheme of seed anatomy adapted according to Debeaujon and colleagues []. Note the location of the Chalaza. (C) Confocal images of transgenic seeds at different developmental stages expressing a construct. Bright field, GFP images and overlays are presented from the left to the right. The bars represent 100 μm. (D) Immunolocalization of GFP on cryosections prepared from developing seeds of transgenic plants using a GFP-specific antibody (anti-GFP). The nuclei of the cells were visualised by DAPI staining (DAPI). The dotted line confines the Chalaza area. The bars represent 20 μm.Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-7
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:Sphorylatable Asp74 (D74) was mutated either to a Glu () or an Asn () are shown.Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-6
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:Ant and wild type (grey bars) by HPLC analysis as described in Methods. The data are expressed as mean ± SD (n = 5).Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds-5
2011Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:N bars) mutant and wild type (grey bars) by HPLC analysis as described in Methods. The data are expressed as mean ± SD (n = 5).Copyright information:Taken from "The response regulator ARR22 is a putative AHP phospho-histidine phosphatase expressed in the Chalaza of developing seeds"http://www.biomedcentral.com/1471-2229/8/77BMC Plant Biology 2008;8():77-77.Published online 15 Jul 2008PMCID:PMC2478664.
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the arabidopsis thaliana response regulator arr22 is a putative ahp phospho histidine phosphatase expressed in the Chalaza of developing seeds
BMC Plant Biology, 2008Co-Authors: Jakub Horák, Christopher Grefen, Kenneth W Berendzen, Achim Hahn, York-dieter Stierhof, Bettina Stadelhofer, Mark Stahl, Csaba Koncz, Klaus HarterAbstract:The Arabidopsis response regulator 22 (ARR22) is one of two members of a recently defined novel group of two-component system (TCS) elements. TCSs are stimulus perception and response modules of prokaryotic origin, which signal by a His-to-Asp phosphorelay mechanism. In plants, TCS regulators are involved in hormone response pathways, such as those for cytokinin and ethylene. While the functions of the other TCS elements in Arabidopsis, such as histidine kinases (AHKs), histidine-containing phosphotransfer proteins (AHPs) and A-type and B-type ARRs are becoming evident, the role of ARR22 is poorly understood. We present evidence that ARR22 is a preferentially cytoplasmic protein, exclusively expressed in the Chalaza of developing seeds. ARR22 specifically interacts with AHP2, AHP3 and AHP5 in yeast and living plant cells. Two new loss-of-function alleles, arr22-2 and arr22-3, were isolated and characterized. With respect to their morphology and metabolite status, no significant difference in the developing seeds of the arr22 mutants was observed compared to wild type. The genetic complementation of the arr22 mutants with a genomic ARR22 fragment resulted in plants (arr22/gARR22) with a pleiotropic phenotype of different penetrance. This phenotype was not observed when the phosphorylatable Asp74 of ARR22 was changed to either a dominant-active Glu or a dominant-inactive Asn. The phenotype of the arr22/gARR22 plants was comparable to that of multiple ahk, ahp and B-type arr mutants. Our results favor the model that ARR22 acts as a phospho-histidine phosphatase on specific AHPs in the cytoplasm of Arabidopsis Chalaza cells. The lack of any aberrant morphological and metabolite phenotype in the seeds of the arr22 mutants indicates that ARR22 is probably primarily responsible for the fine tuning of specific branches of Chalaza-based TCS signalling. Even when slightly mis-expressed, ARR22 interferes with hormone homeostasis in non-Chalaza tissues. Our data indicate that the chromatin status might play a crucial role in maintaining the Chalaza-restricted expression of ARR22.
Jr Wei Chen - One of the best experts on this subject based on the ideXlab platform.
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protective effects of crude Chalaza hydrolysates against liver fibrogenesis via antioxidation anti inflammation anti fibrogenesis and apoptosis promotion of damaged hepatocytes
Poultry Science, 2021Co-Authors: Yiling Lin, Jr Wei Chen, Kuotai Yang, Wenyuan Yang, Jungkai Tseng, Yichen ChenAbstract:Four-hundred metric-ton Chalazae are produced annually from the liquid-egg processing and always cause a heavy burden due to handling cost in Taiwan. After Chalazae were hydrolyzed by protease A, the amounts of hydrophobic, aromatic, and branched-chain amino acids, as well as anserine were dramatically increased. This study was to understand the antifibrogenic effects of protease A-digested crude Chalaza hydrolysates (CCH-As) on livers of thioacetamide (TAA) treated rats. CCH-As improved (P< 0.05) growth performance, serum liver damage indices, histopathological liver inflammation, and liver collagen deposition in TAA-treated rats. The antifibrogenic effects of CCH-As were due to decreased (P < 0.05) inflammatory/fibrogenic cytokine contents, α-smooth-muscle-actin (α-SMA) protein expression, and matrix metallopeptidase (MMP)-2 and -9 activities, as well as increased (P < 0.05) the antioxidant capacity in livers. CCH-As also increased (P < 0.05) cleaved caspase-3 and cleaved poly ADP-ribose polymerase protein levels in livers of TAA-treated rats which accelerating cell renewal. Thus, this study does not only reveal a novel nutraceutical ingredient, CCH-As, against liver fibrogenesis, but also offer an alternative way to expand the utilization of poultry byproducts.
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ameliorative effects of functional crude Chalaza hydrolysates on the hepatosteatosis development induced by a high fat diet
Poultry Science, 2021Co-Authors: Jr Wei Chen, Yiling Lin, Shengyao Wang, Chunghsi Chou, Yichen ChenAbstract:Approximately 400 metric tons of egg Chalazae, a byproduct in the liquid-egg processing plant, are produced yearly but always regarded as a waste in Taiwan. Our team successfully developed a crude egg Chalaza hydrolysate by protease-A digestion (CCH-A). Free branched-chain amino acids, 3-aminoisobutyric acid, and β-alanine, and anserine were assayed in the CCH-A used in this study. Besides, the in vitro bile-acid binding ability and inhibitory lipase activity of CCH-As were demonstrated. Then, high-fat diet feeding for 10 wk caused hyperlipidemia, insulin resistance, and hepatosteatosis in hamsters (P < 0.05). However, CCH-A co-treatment decreased serum/liver triglyceride levels and lipid accumulation in livers by increasing daily fecal lipid/bile-acid outputs, upregulating fatty-acid β oxidation, and downregulating fatty-acid biosynthesis in livers (P < 0.05). CCH-A co-treatment also amended insulin resistance, augmented hepatic antioxidant capacity, and decreased liver damages and inflammatory responses (P < 0.05). Taken together, our results do not only demonstrate the hepatoprotective effects of CCH-As against a chronic high-fat dietary habit, achieving effects similar to Simvastatin, but also decrease the environmental burden of handling Chalazae in the liquid-egg industry.
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antiobesity and hypolipidemic effects of protease a digested crude Chalaza hydrolysates in a high fat diet
Journal of Functional Foods, 2020Co-Authors: Jr Wei Chen, Yiling Lin, Shengyao Wang, Chunghsi Chou, Yichen ChenAbstract:Abstract A high-fat diet is a major risk factor for obesity and heart failure. Our previous study has demonstrated that protease A-digested crude-Chalaza hydrolysates (CCH-As) with a specific free amino-acid and carnosine/anserine profile show lipid-lowering and antioxidant activities against chronic alcohol consumption. The antiobesity and hypolipidemic effects of our CCH-As against a high-fat diet was to investigated in this study. In high-fat-diet fed hamsters, supplementing CCH-As reduced liver/perirenal-adipose-tissue sizes, and serum triglyceride, LDLC/HDLC, and TBARS values (p