Safety assessment of heat-sterilized green tea catechin preparation: A 6-month repeat-dose study in rats

Morita, Osamu; Kirkpatrick, Jeannie B.; Tamaki, Yasushi; Chengelis, Christopher P.; Beck, Melissa J.; Bruner, Richard H.

doi:10.1016/j.fct.2009.04.033

Cited by 35 publications

(23 citation statements)

References 37 publications

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“…Green tea extracts of 0, 120, 400, and 1200 mg/kg were administered orally (by gavage) to rats for 6 mo. None of these doses had any negative effects on biochemical and clinical indicators (Morita and others ).…”

Section: Toxicology Of Hop Componentsmentioning

confidence: 87%

Biologically Active Compounds from Hops and Prospects for Their Use

Karabín

Hudcová

Jelínek

et al. 2016

Comp Rev Food Sci Food Safe

201

181

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Although female cones of the hop plant (Humulus lupulus) are known primarily as raw material supplying characteristic bitterness and aroma to beer, their equally significant health-promoting effects have been known to mankind for several thousand years and hop is a plant traditionally utilized in folk medicine. This paper summarizes the scientific knowledge on the effects of all 3 major groups of secondary metabolites of hops; polyphenols, essential oils, and resins. Because of their chemical diversity, it is no coincidence that these compounds exhibit a wide range of pharmacologically important properties. In addition to antioxidant, anti-inflammatory, and anticancer-related properties, particular attention is being paid to prenylflavonoids that occur almost exclusively in hops and are considered to be some of the most active phytoestrogens known. Hop oils and resins are well known for their sedative and other neuropharmacological properties, but in addition, these compounds exhibit antibacterial and antifungal effects. Recently, alpha bitter acids have been shown to block the development of a number of complex lifestyle diseases that are referred to by the collective name "metabolic syndrome." Information presented in this review confirms the significant potential for the use of hops in the pharmaceutical industry and provides an understanding of beer as a natural drink that, although moderately consumed, may become a source of many health-promoting compounds.

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Section: Toxicology Of Hop Componentsmentioning

confidence: 87%

Biologically Active Compounds from Hops and Prospects for Their Use

Karabín

Hudcová

Jelínek

et al. 2016

Comp Rev Food Sci Food Safe

201

181

View full text Add to dashboard Cite

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“…General toxicity studies of several types of GTE in rodents have been conducted. In 4 and 26 wk oral studies of GTE-exposed rats conducted by Kao Corporation (Tokyo, Japan), the no-observed-adverse-effect doses were 1000 mg/kg and 400 mg/kg, respectively 28 , 29 , and no hepatic damage could be detected clinicopathologically or histopathologically. Intraperitoneal injection of 82 mg/kg EGCG for 7 days into SD rats did not change biochemical markers of liver damage, such as AST, ALT or ALP 30 .…”

Section: Discussionmentioning

confidence: 99%

Green Tea Extract-induced Acute Hepatotoxicity in Rats

et al. 2014

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Although green tea is considered to be a healthy beverage, hepatotoxicity associated with the consumption of green tea extract has been reported. In the present study, we characterized the hepatotoxicity of green tea extract in rats and explored the responsible mechanism. Six-week-old IGS rats received a single intraperitoneal (ip) injection of 200 mg/kg green tea extract (THEA-FLAN 90S). At 8, 24, 48 and 72 hrs and 1 and 3 months after exposure, liver damage was assessed by using blood-chemistry, histopathology, and immunohistochemistry to detect cell death (TUNEL and caspase-3) and proliferative activity (PCNA). Analyses of malondialdehyde (MDA) in serum and the liver and of MDA and thymidine glycol (TG) by immunohistochemistry, as oxidative stress markers, were performed. Placental glutathione S-transferase (GST-P), which is a marker of hepatocarcinogenesis, was also immunohistochemically stained. To examine toxicity at older ages, 200 mg/kg green tea extract was administered to 18-wk-old female rats. In 6-wk-old rats, 12% of males and 50% of females died within 72 hrs. In 18-wk-old rats, 88% died within 72 hrs. The serum levels of aspartate aminotransferase, alanine aminotransferase and/or total bilirubin increased in both males and females. Single-cell necrosis with positive signs of TUNEL and caspase-3 was seen in perilobular hepatocytes from 8 hrs onward in all lobular areas. PCNA-positive hepatocytes increased at 48 hrs. MDA levels in the serum and liver tended to increase, and MDA- and TG-positive hepatocytes were seen immunohistochemically. GST-P–positive hepatocellular altered foci were detected in one female rat at the 3-month time point. In conclusion, a single injection of green tea extract induced acute and severe hepatotoxicity, which might be associated with lipid peroxidation and DNA oxidative stress in hepatocytes.

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“…Over the past decades, green tea has been brought to scientific studies to investigate its biological effects including antioxidative and anticarcinogenic functions due to various polyphenols (Morita, Kirkpatrick, Tamaki, & Chengelis, 2009;Morita, Knapp, Tamaki, & Stump, 2009;Ogura, Ikeda, Yuki, & Morita, 2008). The major polyphenols found in green tea are catechins consisting of (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-epigallocatechin-gallate (EGCG), and (−)-epicatechin-gallate (ECG).…”

Section: Introductionmentioning

confidence: 99%