Supplementation with Brazil nuts and green tea extract regulates targeted biomarkers related to colorectal cancer risk in humans

Abstract

Se and green tea have been shown in epidemiological, observational and preclinical studies to be inversely related to the risk of developing colorectal cancer (CRC). However, there are limited studies to evaluate their regulatory effects on genes/proteins that relate to CRC oncogenesis in human subjects, such as selenoproteins, WNT signalling pathway, inflammation and methylation. This study examined the effects of supplementation of Se using Brazil nuts and green tea extract (GTE) capsules, alone and in combination, on targeted biomarkers. In total, thirty-two volunteers (>50 years of age) with plasma Se≤1·36 µmol/l were randomised to one of three treatment groups: nine to Se (approximately 48 µg/d) as six Brazil nuts, eleven to four GTE capsules (800 mg (-)-epigallocatechin-3-gallate) and twelve to a combination of Brazil nuts and GTE. Blood and rectal biopsies were obtained before and after each intervention. Plasma Se levels, rectal selenoprotein P (SePP) and β-catenin mRNA increased significantly in subjects consuming Brazil nuts alone or in combination, whereas rectal DNA methyltransferase (DNMT1) and NF-κB mRNA were reduced significantly in subjects consuming GTE alone or in combination. None of the interventions significantly affected rectal acetylated histone H3 or Ki-67 expression at the protein level or plasma C-reactive protein. Effects of the combination of Brazil nuts and GTE did not differ from what would be expected from either agent alone. In conclusion, supplementation of Brazil nuts and/or GTE regulates targeted biomarkers related to CRC oncogenesis, specifically genes associated with selenoproteins (SePP), WNT signalling (β-catenin), inflammation (NF-κB) and methylation (DNMT1). Their combination does not appear to provide additional effects compared with either agent alone.

The effect of green tea on inflammatory mediators: A systematic review and meta‐analysis of randomized clinical trials

“…By considering criteria for inclusion and exclusion, 22 articles were excluded due to following reasons: not having a control group ( N = 3; Alghadir, Gabr, & Al‐Eisa, ; Lee et al, ; Sung et al, ), intervention less than 1 day ( N = 3; Alexopoulos et al, ; Hsu et al, ; Koutelidakis et al, ), and using other nutrients beside green tea in the intervention group ( N = 16; Bakker et al, ; Braga et al, ; Cialdella‐Kam et al, ; de Jesus Romero‐Prado et al, ; Dominiak, McKinney, Heilbrun, & Sarkar, ; Kim et al, ; Madaric et al, ; Nieman et al, ; Nieman et al, ; Ormsbee et al, ; Peluso et al, ; Rondanelli et al, ; Rubio‐Perez, Albaladejo, Zafrilla, Vidal‐Guevara, & Morillas‐Ruiz, ; Scolaro et al, ; Soriano‐Maldonado, Hidalgo, Arteaga, de Pascual‐Teresa, & Nova, ; Thomas, Williams, Sharma, Chaudry, & Bellamy, ; Figure ). Therefore, 17 articles were included in our systematic review (Basu et al, ; Bogdanski et al, ; de Maat et al, ; Dower et al, ; Fukino et al, ; Fukino, Shimbo, Aoki, Okubo, & Iso, ; Gutierrez‐Salmean et al, ; Hu et al, ; Hussain, Habib Ur, & Akhtar, ; Mielgo‐Ayuso et al, ; Mombaini & Jafarirad, ; Nogueira, Nogueira Neto, Klein, & Sanjuliani, ; Oyama et al, ; Oyama, Maeda, Sasaki, et al, ; Ryu et al, ; Shin et al, ; Sone et al, ); because the article by Ryu et al () did not report baseline values, we did not include it in our meta‐analysis (Table ). Interventions were performed by taking both green tea leaves and green tea extract.…”

“…In total, 16 articles with 887 participants measured hs‐CRP (Basu et al, ; Bogdanski et al, ; de Maat et al, ; Dower et al, ; Fukino et al, ; Fukino et al, ; Gutierrez‐Salmean et al, ; Hu et al, ; Hussain et al, ; Mielgo‐Ayuso et al, ; Mombaini & Jafarirad, ; Nogueira et al, ; Oyama, Maeda, Kouzuma, et al, ; Ryu et al, ; Shin et al, ; Sone et al, ), seven articles with 302 participants measured IL‐6 (Basu et al, ; de Maat et al, ; Dower et al, ; Mombaini & Jafarirad, ; Nogueira et al, ; Oyama, Maeda, Sasaki, et al, ; Ryu et al, ), and six articles with 256 participants measured TNF‐α (Bogdanski et al, ; de Maat et al, ; Dower et al, ; Mombaini & Jafarirad, ; Nogueira et al, ; Oyama, Maeda, Sasaki, et al, ).…”

“…Interventions were performed by taking both green tea leaves and green tea extract. Participants in four articles took green tea leaves (Oyama, Maeda, Kouzuma, et al, 2010;Oyama, Maeda, Sasaki, et al, 2010;Ryu et al, 2006;Sone et al, 2011), in two articles, both green tea extract and green tea leaves were taken, which were included as two separate effects (Basu et al, 2011;de Maat et al, 2000), and 11 articles had prescribed green tea extract (Bogdanski et al, 2012;Dower et al, 2015;Fukino et al, 2008;Fukino et al, 2005;Gutierrez-Salmean et al, 2016;Hu et al, 2016;Hussain et al, 2017;Mielgo-Ayuso et al, 2014;Mombaini & Jafarirad, 2017;Nogueira et al, 2017;Sone et al, 2011). Our meta-analysis included 875 participants with age ≥18 years old, and intervention duration ranged between 2 and 48 weeks.…”

“…not having a control group (N = 3;Alghadir, Gabr, & Al-Eisa, 2016;Lee et al, 2005;Sung et al, 2005), intervention less than 1 day (N = 3;Alexopoulos et al, 2008;Hsu et al, 2007;Koutelidakis et al, 2014), and using other nutrients beside green tea in the intervention group (N = 16;Bakker et al, 2010;Braga et al, 2012;Cialdella-Kam et al, 2016;de Jesus Romero-Prado et al, 2015;Dominiak, McKinney, Heilbrun, & Sarkar, 2010;Kim et al, 2016;Madaric et al, 2013;Nieman et al, 2013;Nieman et al, 2017;Ormsbee et al, 2014;Peluso et al, 2014;Rondanelli et al, 2013;Rubio-Perez, Albaladejo, Zafrilla, Vidal-Guevara, & Morillas-Ruiz, 2016; Scolaro et al, 2018; Soriano-Maldonado, Hidalgo, Arteaga, de Pascual-Teresa, & Nova, 2014; Thomas, Williams, Sharma, Chaudry, & Bellamy, 2014; Figure 1).Therefore, 17 articles were included in our systematic review(Basu et al, 2011;Bogdanski et al, 2012;de Maat et al, 2000;Dower et al, 2015;Fukino et al, 2008;Fukino, Shimbo, Aoki, Okubo, & Iso, 2005;Gutierrez-Salmean et al, 2016;Hu et al, 2016;Hussain, Habib Ur, & Akhtar, 2017;Mielgo-Ayuso et al, 2014;Mombaini & Jafarirad, 2017;Nogueira, Nogueira Neto, Klein, & Sanjuliani, 2017;Oyama, Maeda, Sasaki, et al, 2010;Ryu et al, 2006;Shin et al, 2018;Sone et al, 2011)…”

The effect of nut consumption on markers of inflammation and endothelial function: a systematic review and meta-analysis of randomised controlled trials

“…Among all studies, duration ranged from 4 weeks to 5 years, although 20 14 15 17 18 21 22 35 36 41 42 47 49 52–56 58–60 out of 32 studies (63%) had a duration of less than 3 months. Studies were conducted in Spain, 16 18 20 36 38 43–47 53 the USA, 14 17 22 39 41 48 50 52 54 55 58 59 61 Australia, 49 51 India, 19 40 Canada, 56 South Korea, 15 China, 21 Brazil, 42 South Africa, 35 Iran, 57 New Zealand 13 and Germany. 60 Studies included participants who were healthy, 49 52 had risk factors for chronic disease such as overweight or obesity, dyslipidaemia, hypertension or prediabetes, 13 17 18 20 36 40–42 47 50 51 53 55 56 58–60 had type 2 diabetes mellitus, 14 21 22 48 57 met the criteria for metabolic syndrome, 15 16 19 35 38 had diagnosed coronary artery disease 54 or included a mixture of the aforementioned conditions.…”