Effect of Acute Ingestion of Green Tea Extract and Lemon Juice on Oxidative Stress and Lipid Profile in Pigs Fed a High-Fat Diet.

Xi Fang,Jennifer Mumaw,Michele Barletta,Hea Jin Park,Kristi Crowe-White,Chad Schmiedt,Michael Azain,Srujana Rayalam,Janet A Grimes

doi:10.3390/antiox8060195

Xi Fang, Jennifer Mumaw + Show 7 more

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https://doi.org/10.3390/antiox8060195

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Abstract

Green tea and its catechins have been shown to ameliorate high fat diet-induced oxidative stress and hyperlipidemia. However, low bioavailability of catechins limits their therapeutic potential. Lemon juice (LJ) has been suggested to enhance the bioavailability of catechins in vitro. This study investigated the antioxidative and hypolipidemic efficacy of a single dose of green tea extract (GTE) or GTE plus LJ (GTE + LJ) in high-fat diet fed pigs. Sixteen pigs ingested a single dose of GTE (190 mg/kg/day) or GTE + LJ (0.75 mL/kg/day) mixed with low-fat (LF; 5% fat) or high-fat (HF; 22% fat) diets and blood samples were collected for 24 h. Plasma catechin level peaked at two hours, and gradually returned to baseline after six hours following the intake. The addition of LJ significantly increased plasma catechin level. The diet containing GTE did not lower plasma cholesterol and triacylglycerol (TG) concentrations, superoxide dismutase (SOD) and catalase activity, or malondialdehyde concentration in 24 h in HF-fed pigs. Addition of a single dose of LJ, however, significantly decreased plasma TG level in LF groups but did not cause further changes on any other markers compared to the GTE alone. Our findings indicate limited effect of a single meal containing GTE on plasma antioxidant enzymes, lipid profile, and lipid peroxidation in pigs and no significant synergistic/additive action of adding LJ to GTE within 24 h in pigs. A study with a longer treatment period is warranted to further understand the potential role of GTE in reducing HF diet-induced oxidative stress and the possible synergistic role of LJ.

Highlights

Oxidative stress is a key component in numerous metabolic disorders and disease pathologies, such as diabetes, cardiovascular disease, and cancer [1]
In order to determine the level of catechin in the systemic circulation, plasma EGCG and EGC were measured at 2, 4, and 6 h after the acute intake of LF diet with green tea extract (GTE) or GTE + Lemon juice (LJ) in pigs
In accordance with findings reported by Huang et al, and Lee et al, we found plasma concentration of catechin peaked at two hours upon single dose ingestion and gradually decreased to baseline between 6–8 h after oral consumption both in rodents and humans [37,38]

Summary

Introduction

Oxidative stress is a key component in numerous metabolic disorders and disease pathologies, such as diabetes, cardiovascular disease, and cancer [1]. Diet pattern is of great importance as a modulatory risk factor for oxidative stress in the body [2]. Antioxidants 2019, 8, 195 metabolic outcomes where oxidative stress is increased by free radical production and an elevated inflammatory response characterized by macrophage migration and higher levels of inflammatory cytokines [3,4]. Green tea and its catechins exhibit anti-oxidative and anti-inflammatory properties making them potentially potent therapeutics for diseases where these processes are critical negative elements [6,7,8,9,10]. Green tea supplementation has been shown to have beneficial effects by reducing oxidative stress, high blood pressure, lipid absorption and glucose intolerance induced by a HF diet

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