Gallated Form of Tea Catechin, Not Nongallated Form, Increases Fecal Starch Excretion in Rats

Unno, Toshihiro; Matsumoto, Yoshimi; Yamamoto, Yukari

doi:10.3177/jnsv.58.45

Cited by 4 publications

(5 citation statements)

References 23 publications

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“…The concentrations of undigested starch in the feces were determined after hydrolysis with thermostable α-amylase and amyloglucosidase, followed by a determination of the released glucose using an enzymatic colorimetric assay kit (Glucose CII-test, Wako Pure Chemical Industries, Ltd.). 18 Results were corrected to a starch basis by multiplying them by 0.9. Total fecal nitrogen was determined by Kjeldahl's method, 19 and results were multiplied by 6.25 to calculate the amount of protein in the feces.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

Hesperetin Modifies the Composition of Fecal Microbiota and Increases Cecal Levels of Short-Chain Fatty Acids in Rats

Unno

Hisada

Takahashi

2015

J. Agric. Food Chem.

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There has been particular interest in the prebiotic-like effects of commonly consumed polyphenols. This study aimed to evaluate the effects of hesperidin (HD) and its aglycone hesperetin (HT), major flavonoids in citrus fruits, on the structure and activity of gut microbiota in rats. Rats ingested an assigned diet (a control diet, a 0.5% HT diet, or a 1.0% HD diet) for 3 weeks. Terminal restriction fragment length polymorphism analysis revealed that the proportion of Clostridium subcluster XIVa in the feces collected at the third week of feeding was significantly reduced by the HT diet: 19.8 ± 4.3% for the control diet versus 5.3 ± 1.5% for the HT diet (P < 0.01). There was a significant difference in the cecal pool of short-chain fatty acids (SCFA), the sum of acetic, propionic, and butyric acids, between the control diet (212 ± 71 μmol) and the HT diet (310 ± 51 μmol) (P < 0.05), whereas the HD diet exhibited no effects (245 ± 51 μmol). Interestingly, dietary HT resulted in a significant increase in the excretion of starch in the feces. HT, but not HD, might reduce starch digestion, and parts of undigested starch were utilized to produce SCFA by microbial fermentation in the large intestine.

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Section: ■ Materials and Methodsmentioning

confidence: 99%

Hesperetin Modifies the Composition of Fecal Microbiota and Increases Cecal Levels of Short-Chain Fatty Acids in Rats

Unno

Hisada

Takahashi

2015

J. Agric. Food Chem.

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“…Table 3 shows that the feces of rats fed the 0.6% EGCG diet contained more starch than that of the control diet. Especially given that EGCG possesses the inhibitory activity for pancreatic a-amylase (18), it is acceptable to assume that appreciable amounts of undigested starch flowed into the large intestine, and were excreted in the feces. It is fair to say that dietary starch that reaches the large intestine could be a potential source of fermentable substrate for anaerobic bacteria, consequently leading to the production of SCFAs.…”

Section: Discussionmentioning

confidence: 99%

“…Before analysis, dried feces samples were ground by a grinder mill. Starch content in feces was determined after hydrolysis with thermostable a-amylase and amyloglucosidase (Wako Pure Chemical Industries, Ltd., Osaka, Japan), followed by a determination of the released glucose using an enzymatic colorimetric assay kit (Glucose CIItest, Wako Pure Chemical Industries, Ltd.) (18). Results were corrected to a starch basis by multiplying them by 0.9.…”

Section: Animals and Dietsmentioning

confidence: 99%

Effect of Dietary Supplementation of (^|^minus;)-Epigallocatechin Gallate on Gut Microbiota and Biomarkers of Colonic Fermentation in Rats

Unno

Sakuma

Mitsuhashi

2014

J Nutr Sci Vitaminol

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Summary Alterations in gut microbiota composition offer insights that may be relevant for several chronic conditions, including obesity. This study aimed to evaluate the effect of (2)-epigallocatechin gallate (EGCG) on the modulation of gut microbiota and biomarkers of colonic fermentation end-products in rats. Rats were fed an assigned diet of either a control diet, a 0.3% (w/w) EGCG diet, or a 0.6% (w/w) EGCG diet for 4 wk. Compared to the control group, the addition of 0.6% EGCG to the diet brought about a significant increase in the starch and protein contents in the feces collected in the fourth week of feeding, but the relative weights of abdominal adipose tissues of rats were inversely suppressed. Hostspecific bacterial community composition, as determined by terminal restriction fragment length polymorphism (T-RFLP) patterns for fecal 16S ribosomal RNA, showed a significant response in the reduced occupation of Clostridium spp. and an increased trend of Bacteroides by dietary supplementation with EGCG. The 0.6% EGCG diet also influenced the status of Bifidobacterium and Prevotella to a lesser extent. Interestingly, the cecum of rats fed the 0.6% EGCG diet contained lower levels of acetic and butyric acids, whereas EGCG had little influence on the cecal level of propionic acid. EGCG also reduced the cecal p-cresol concentration in a dose-dependent fashion. In conclusion, dietary EGCG affects the growth of certain species of gut microbiota in rats and is associated with the cecal pattern of short chain fatty acids which could be responsible for regulating energy metabolism in the body.

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“…It was found that gallated catechins, that is, ECg and EGCg, showed higher renin-inhibitory activities than the ungallated forms, suggesting that esterification with gallic acid could lead to quite favorable influence on elevating the renin-inhibitory activities of EC and EGC. Previous work reported that catechins with a galloyl moiety presented higher activities in various cases than those without this moiety, for example, with respect to inhibiting fatty-acid synthase (25), suppressing postprandial hypertriglyceridemia (19) and modulating the intestinal digestion of dietary starch (24). In the present study, taking into consideration that gallic acid itself exerted good renin-inhibitory activity close to that of ECg, it could be speculated that the galloyl moiety might be a critical structure for the inhibitory activities of catechin-related compounds against renin.…”

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confidence: 99%

Inhibitory effect of catechin-related compounds on renin activity

Takahashi

Yamaki

2013

Biomed. Res.

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Renin is a crucial enzyme in the renin-angiotensin system, and the inhibition of its activity is considered as a useful approach to the treatment of hypertension. The inhibitory effect of catechinrelated compounds on renin was investigated in this work. It was found that epigallocatechin gallate (EGCg) possessed the strongest activity with an IC 50 value of 44.53 μM and acted in an uncompetitive manner. Gallated catechins exerted higher inhibition than the ungallated forms, and gallic acid exhibited an inhibitory potency close to that of epicatechin gallate (ECg). Results indicated that the galloyl moiety and ortho-trihydroxy phenyl structures might be favorable for the renin-inhibitory activity of these compounds.Hypertension is significantly associated with the incidence of various cardiovascular diseases. The renin-angiotensin system (RAS) plays an important role in regulating blood pressure in animals, and its inhibition has been well established as an approach to the treatment of hypertension (15). In this system, renin (EC 3.4.23.15) and angiotensin I-converting enzyme (ACE; EC 3.4.15.1) are two key enzymes. Renin can cleave the N-terminus of angiotensinogen to yield angiotensin I, which is an inactive peptide and may further be processed by ACE to produce angiotensin II, a potent vasoconstrictor. Since the conversion catalyzed by renin is the rate-limiting step, it is thought that direct renin inhibition could lead to better suppression of high blood pressure than ACE inhibition can (2). Although many ACE inhibitors derived from foodstuffs have been identified in the past (7), only a few reports on natural renin inhibitors were available (6,11,20,21). Studies have supported that polyphenol-containing materials such as black and green tea (14), red wine (12), cocoa extract (5, 17) and azuki bean seed coats (13) could reduce blood pressure in several experimental hypertensive models. The mechanisms underlying this effect were proposed to be attributable to vasodilator action, the attenuation of vascular oxidative stress and inflammation, and the ability to reduce arginase-2 activity (18), as well as the inhibitory effect against ACE (1, 3). Nevertheless, to date, not much attention has been paid to their potential renin-inhibitory activities. Recently, researchers found that saponins (8, 20, 21), baicalin (6), and the polyphenolic extracts of two green leafy vegetables (2) showed renin-inhibitory activities, which thus suggested the promising prospect of discovering polyphenolic compounds as candidates for renin inhibitors. Catechins represent a major class of polyphenols and are widely distributed in plants. There are four principal kinds of catechins, that is, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate; the beneficial effects of these compounds on health have been continually studied (4, 10). In the present work, we investigated whether catechin-related compounds could exert renin-inhibitory activities in vitro and also primarily elucidated their structure-act...

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Gallated Form of Tea Catechin, Not Nongallated Form, Increases Fecal Starch Excretion in Rats

Cited by 4 publications

References 23 publications

Hesperetin Modifies the Composition of Fecal Microbiota and Increases Cecal Levels of Short-Chain Fatty Acids in Rats

Hesperetin Modifies the Composition of Fecal Microbiota and Increases Cecal Levels of Short-Chain Fatty Acids in Rats

Effect of Dietary Supplementation of (^|^minus;)-Epigallocatechin Gallate on Gut Microbiota and Biomarkers of Colonic Fermentation in Rats

Inhibitory effect of catechin-related compounds on renin activity

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