Effect of Green Tea on the Formation of Nitrosamines, and Cancer Mortality

Masuda, S.; Uchida, Shoji; Terashima, Yumeko; Kuramoto, Hiroko; Serizawa, Mika; Deguchi, Yuya; Yanai, Kazuhiro; Sugiyama, Chitose; Oguni, Itaro; Kinae, Naohide

doi:10.1248/jhs.52.211

Cited by 18 publications

(15 citation statements)

References 29 publications

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“…In general, the 3 polyphenols almost blocked NDEA formation at high molar ratio, but accelerated it at low molar ratio. The similar effects of some phenolic compounds on the nitrosomorpholine formation in vitro have been reported (Choi, Chung, & Sung, ; Masuda et al., ). Under acidic condition, phenolic compounds can react with nitrite to form C ‐nitroso derivative, inhibiting the N ‐nitrosation of amines via consumption of nitrosating agent (Lu & Chen, ; Vermeer et al., ).…”

Section: Resultssupporting

confidence: 80%

“…Under acidic condition, phenolic compounds can react with nitrite to form C-nitroso derivative, inhibiting the N-nitrosation of amines via consumption of nitrosating agent (Lu & Chen, 2007;Vermeer et al, 1999). Some phenolic compounds could form nitrosoquinone oxime derivatives, which react with the excess nitrite and act as kinds of more powerful nitrosating agent (Masuda et al, 2006). Thus, they appear to promote the nitrosation of amines at low polyphenol concentration (Davies & Mcweeny, 1977;Pignatelli, Bereziat, Descotes, & Bartsch, 1982;Walker, Pignatelli, & Castegnaro, 1979).…”

Section: Resultsmentioning

confidence: 99%

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Inhibitory Effect of Epigallocatechin Gallate, Epigallocatechin, and Gallic Acid on the Formation of N‐Nitrosodiethylamine In Vitro

Deng

Jin

2019

Journal of Food Science

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This study investigated the inhibitory effect of epigallocatechin gallate (EGCG), epigallocatechin (EGC), and gallic acid (GA) on the formation of N‐nitrosodiethylamine (NDEA) in vitro. Results show that the three polyphenols are capable to block NDEA formation when the molar ratio of phenols to nitrite is higher than 0.8, and a more acidic environment is prone to promote the inhibitory potential of phenols. It is also found that the inhibitory effect tends to decrease in the order: EGCG, EGC, GA, which is in accordance with the order of their DPPH scavenging activity, suggesting that the inhibitory effect of polyphenols on NDEA formation may work through a free radical way. Kinetic study further revealed the three polyphenols react with nitrite at a much faster rate than diethylamine does (P < 0.05). By scavenging nitrite at a faster rate than the nitrosation of diethylamine, polyphenols at high concentration can significantly block NDEA formation. These observations may promote a possible application of polyphenol compounds to inhibit the formation of nitrosamines in food processing. Practical Application The presence of N‐nitrosamines in human diet should be an etiological risk factor for human cancers. This work may provide a useful guideline for phenolic compounds to inhibit the formation of nitrosamines in food processing, such as in the process of curing meats. Polyphenols have been proved to block NDEA formation under normal gastric juice condition, suggesting the intake of polyphenols is a potential way to prevent diseases caused by nitrite.

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Section: Resultssupporting

confidence: 80%

Section: Resultsmentioning

confidence: 99%

Inhibitory Effect of Epigallocatechin Gallate, Epigallocatechin, and Gallic Acid on the Formation of N‐Nitrosodiethylamine In Vitro

Deng

Jin

2019

Journal of Food Science

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“…In this study, plant polyphenols and ascorbic acid decreased (P < 0.05) total N-nitrosamine formation after 28 day of ripening. To our knowledge, there are no reports concerning green tea or GSPs on the formation of N-nitrosamines in meat products, while there were many reports about green tea on the formation of N-nitrosamines in vivo or in simulated gastric acid (Pignatelli et al, 1982;Choi et al, 2002;Masuda et al, 2006).…”

Section: N-nitrosaminesmentioning

confidence: 99%

“…To our knowledge, there are no reports concerning green tea or GSPs on the formation of N-nitrosamines in meat products, while there were many reports about green tea on the formation of N-nitrosamines in vivo or in simulated gastric acid (Pignatelli et al, 1982;Choi et al, 2002;Masuda et al, 2006). To our knowledge, there are no reports concerning green tea or GSPs on the formation of N-nitrosamines in meat products, while there were many reports about green tea on the formation of N-nitrosamines in vivo or in simulated gastric acid (Pignatelli et al, 1982;Choi et al, 2002;Masuda et al, 2006).…”

Section: N-nitrosaminesmentioning

confidence: 99%

Effect of plant polyphenols and ascorbic acid on lipid oxidation, residual nitrite and N‐nitrosamines formation in dry‐cured sausage

Shao

Zhu

et al. 2013

Int J of Food Sci Tech

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Summary The effects of green tea,grape seed polyphenols and ascorbic acid on pH, water activity (aw), microbiological counts, TBARS, residual nitrite and N‐nitrosamines were determined in dry‐cured sausages during the ripening period. Results showed that TBARS increased gradually during ripening (P < 0.05), but were significantly reduced with plant polyphenols and ascorbic acid (P < 0.05). Green tea polyphenol (GTP) was most effective (P < 0.05) in reducing TBARS. Plant polyphenols and ascorbic acid significantly decreased residual nitrite, ascorbic acid being most effective (P < 0.05). The amount of N‐nitrosamines increased during ripening, but was significantly reduced with plant polyphenols and ascorbic acid (P < 0.05). Plant polyphenols had no significant effects on moisture content, aw, pH or microbiological counts in dry‐cured sausage during ripening (P > 0.05). It was concluded that plant polyphenols and ascorbic acid were effective in maintaining the quality and safety of dry‐cured sausages.

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“…Then, the scavenging of toxic quinones and/or charge-transfer complexes produced in the stomach increases with the increase in the concentration of thiocyanic acid in saliva. In addition, Figure 4 suggests that i) if the gastric concentration of nitrous acid is lower than that of ascorbic acid, the oxidation of phenolic compounds does not proceed resulting in the increase in the efficiency of the transport of phenolic compounds to the intestine, and that ii) the reactions of phenolic compounds with nitrous acid may result in the suppression of carcinogenic nitrosoamine formation in the stomach as has been discussed previously [66,75,76]. Further studies, however, on the nitrous acid-induced oxidation of phenolic compounds in ingested foods are necessary under simulated stomach conditions to discuss their beneficial and unbeneficial effects of their products.…”

Section: Summarization Of the Reactions In Nitrous Acid-flavonoid Sysmentioning

confidence: 78%

Possible Reactions of Dietary Phenolic Compounds with Salivary Nitrite and Thiocyanate in the Stomach

Takahama

Hirota

2017

Preprint

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Foods are mixed with saliva in the oral cavity and swallowed. During staying in the stomach, saliva is contentiously provided to mix with the ingested foods. Because a salivary component nitrite is protonated to produce active nitrous acid at acidic pH, the redox reactions of nitrous acid with phenolic compounds in foods become possible in the stomach. In the reactions, nitrous acid is reduced to nitric oxide ( • NO), producing various products from phenolic compounds. In the products, stable hydroxybezoyl benzofuranone derivatives, which are produced from quercetin and its 7-O-glucoside, are included. Caffeic acid, chlorogenic acid, and rutin are oxidized to quinones and the quinones can react with thiocyanic acid derived from saliva producing stable oxathiolone derivatives. 6,8-Dinitrosocatechis are produced from catechins by the redox reaction, and the dinitrocatechins are oxidized further by nitrous acid producing the quinones, which can make charge transfer complexes with the dinitrosocatechin and can react with thiocyanic acid producing the stable thiocyanate conjugates. In this way, various products can be produced by the reactions of salivary nitrite with dietary phenolic compounds, and reactive and toxic quinones formed by the reactions are postulated to be removed in the stomach by thiocyanic acid derived from saliva.

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Effect of Green Tea on the Formation of Nitrosamines, and Cancer Mortality

Cited by 18 publications

References 29 publications

Inhibitory Effect of Epigallocatechin Gallate, Epigallocatechin, and Gallic Acid on the Formation of N‐Nitrosodiethylamine In Vitro

Inhibitory Effect of Epigallocatechin Gallate, Epigallocatechin, and Gallic Acid on the Formation of N‐Nitrosodiethylamine In Vitro

Effect of plant polyphenols and ascorbic acid on lipid oxidation, residual nitrite and N‐nitrosamines formation in dry‐cured sausage

Possible Reactions of Dietary Phenolic Compounds with Salivary Nitrite and Thiocyanate in the Stomach

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