Saturated fatty acid attenuates anti-obesity effect of green tea

Eicosapentaenoic acid increases proportion of type 1 muscle fibers through PPARδ and AMPK pathways in rats

Muscle fiber type composition (% slow-twitch and % fast-twitch fibers) is associated with metabolism, with increased slow-twitch fibers alleviating metabolic disorders. Previously, we reported that dietary fish oil intake induced a muscle fiber-type transition in a slower direction in rats. The aim of this study was to determine the functionality of eicosapentaenoic acid (EPA), a unique fatty acid in fish oil, to skeletal muscle fiber type and metabolism in rats. Here, we showed that dietary EPA promotes whole-body oxidative metabolism and improves muscle function by increasing proportion of slow-twitch type 1 fibers in rats. Transcriptomic and metabolomic analyses revealed that EPA supplementation activated the peroxisome proliferator-activated receptor δ (PPARδ) and AMP-activated protein kinase (AMPK) pathways in L6 myotube cultures, which potentially increasing slow-twitch fiber share. This highlights the role of EPA as an exercise-mimetic dietary component that improves metabolism and muscle function, with potential benefits for health and athletic performance.

Transcriptome Analysis of the Adipose Tissue of Luchuan and Duroc Pigs

Simple Summary

Fat is a vital body tissue of pigs and a crucial index that affects the production efficiency of pigs. In this study, Duroc pigs and Luchuan pigs were used as animal materials, transcriptome sequencing was used to compare the back adipose tissue of the two breeds, to explore the key reason of difference in fat deposition. The result provided new ideas and reference for further study of fat development.

Abstract

Fat deposition is a crucial element in pig production that affects production efficiency, quality and consumer choices. In this study, Duroc pigs, a Western, famous lean pig breed, and Luchuan pigs, a Chinese, native obese pig breed, were used as animal materials. Transcriptome sequencing was used to compare the back adipose tissue of Duroc and Luchuan pigs, to explore the key genes regulating fat deposition. The results showed that 418 genes were highly expressed in the Duroc pig, and 441 genes were highly expressed in the Luchuan pig. In addition, the function enrichment analysis disclosed that the DEGs had been primarily enriched in lipid metabolism, storage and transport pathways. Furthermore, significant differences in the metabolic pathways of alpha-linolenic acid, linoleic acid and arachidonic acid explained the differences in the flavor of the two kinds of pork. Finally, the gene set enrichment analysis (GSEA) exposed that the difference in fat deposition between Duroc and Luchuan pigs may be due to the differential regulation of the metabolism pathway of fatty acid. Therefore, this study described the differential expression transcriptional map of adipose tissue of Duroc pig and Luchuan pig, identified the functional genes regulating pig fat deposition, and provided new hypotheses and references for further study of fat development.

67-kDa Laminin Receptor-Mediated Cellular Sensing System of Green Tea Polyphenol EGCG and Functional Food Pairing

The body is equipped with a “food factor-sensing system” that senses food factors, such as polyphenols, sulfur-containing compounds, and vitamins, taken into the body, and plays an essential role in manifesting their physiological effects. For example, (–)-epigallocatechin-3-O-gallate (EGCG), the representative catechin in green tea (Camellia sinensi L.), exerts various effects, including anti-cancer, anti-inflammatory, and anti-allergic effects, when sensed by the cell surficial protein 67-kDa laminin receptor (67LR). Here, we focus on three representative effects of EGCG and provide their specific signaling mechanisms, the 67LR-mediated EGCG-sensing systems. Various components present in foods, such as eriodictyol, hesperetin, sulfide, vitamin A, and fatty acids, have been found to act on the food factor-sensing system and affect the functionality of other foods/food factors, such as green tea extract, EGCG, or its O-methylated derivative at different experimental levels, i.e., in vitro, animal models, and/or clinical trials. These phenomena are observed by increasing or decreasing the activity or expression of EGCG-sensing-related molecules. Such functional interaction between food factors is called “functional food pairing”. In this review, we introduce examples of functional food pairings using EGCG.

Chemical characterization of Tianshan green tea polysaccharides and its protective effects on cell oxidative injury

The purpose of this study was to analyze the chemical characterization of Tianshan green tea polysaccharides (TSPS), and evaluate its antioxidant activity by chemical-based and cellular-based antioxidant models in vitro. The results showed that the TSPS were composed of mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose with a molar ratio of 14.5:33.5:10.5:6.5:111.5:22.3:59.5:51: 1.0, and an average molecular weight of 19.49 kDa. TSPS exhibited excellent antioxidant ability to DPPH radical, hydroxyl radical, and ABTS radical, and enhanced the ferric-reducing power (FRAP). The antioxidation model of LO2 and HepG2 cells was established, and found that TSPS had no significant toxicity to either of the two cells at the range of 0.1-5 mg/mL, but clearly protected cells from H₂ O₂ -induced apoptosis and significantly reduced intracellular ROS level. In addition, the activities of antioxidant-associated enzymes were detected in LO2 cells, which suggested that TSPS could significantly improve the activities of SOD and CAT enzyme when the concentration was higher than 0.5 mg/mL. Furthermore, TSPS activated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway by promoting Nrf2 nuclear translocation and inhibited the expression of Kelch-like ECH-associated protein 1 (Keap-1) and enhanced the expression of heme oxygenase-1 (HO-1). PRACTICAL APPLICATIONS: Tianshan green tea, a local variety in Fujian Province, belongs to unfermented tea. Polysaccharide is considered as the most promising component in Tianshan green tea. This study showed that TSPS had excellent antioxidant activity and had no significant toxicity to cells, which provides a scientific foundation and new idea for its further development and application in functional foods.

Korean traditional foods as antiviral and respiratory disease prevention and treatments: A detailed review

BACKGROUND

Korean traditional food (KTF), originated from ancestral agriculture and the nomadic traditions of the Korean peninsula and southern Manchuria, is based on healthy food that balances disease prevention and treatment. Fermented foods that include grains, herbs, fruits, and mushrooms are also an important practice in KTF, providing high levels of Lactobacilli, which confer relevant health benefits, including antiviral properties. Some of these probiotics may also protect against the Influenza virus through the modulation of innate immunity.

SCOPE AND APPROACH

The emerging of the COVID-19 pandemic, in addition to other diseases of viral origin, and the problems associated with other respiratory disorders, highlight how essential is a healthy eating pattern to strengthen our immune system.Key Findings and Conclusions: The present review covers the information available on edible plants, herbs, mushrooms, and preparations used in KTF to outline their multiple medicinal effects (e.g., antidiabetic, chemopreventive, antioxidative, anti-inflammatory, antibacterial), emphasizing their role and effects on the immune system with an emphasis on modulating properties of the gut microbiota that further support strong respiratory immunity. Potential functional foods commonly used in Korean cuisine such as Kimchi (a mixture of fermented vegetables), Meju, Doenjang, Jeotgal, and Mekgeolli and fermented sauces, among others, are highlighted for their great potential to improve gut-lung immunity. The traditional Korean diet and dietary mechanisms that may target viruses ACE-2 receptors or affect any step of a virus infection pathway that can determine a patient's prognosis are also highlighted. The regular oral intake of bioactive ingredients used in Korean foods can offer protection for some viral diseases, through protective and immunomodulatory effects, as evidenced in pre-clinical and clinical studies.

Green tea and metabolic syndrome: A 10-year research update review

Metabolic syndrome (MetS) has turned into a prevalent condition that has imposed a tremendous financial strain on public health care systems. It is believed that the MetS consists of four main factors (hypertension, dyslipidemia, hyperglycemia, and obesity) and may lead to cardiovascular events. Camellia sinesis, in the form of green tea (GT), is one of the most consuming beverages worldwide. Catechins are the dominant component of green tea leaves. Epigallocatechin gallate has the maximum potency. GT has been widely used as a supplement in various health conditions. As the oxidative stress pathway is one of the probable mechanisms of MetS etiologies and GT beneficial effects, GT may be a novel strategy to overcome the MetS. This review aims to reveal the probable pharmacological effects of GT on MetS. The last 10-year original articles on MetS parameters and GT have been gathered in this review. This manuscript has summarized the probable effects of green tea and its catechins on MetS and focused on each different aspect of MetS separately, which can be used as a basis for further investigations for introducing effective compounds as a way to interfere with MetS.

It seems that GT can reduce MetS parameters commonly via anti-inflammatory and anti-oxidative mechanisms. Further clinical trials are needed to confirm the use of GT and its constituents for the treatment of MetS.

Oral Administration of Flavonifractor plautii, a Bacteria Increased With Green Tea Consumption, Promotes Recovery From Acute Colitis in Mice via Suppression of IL-17

Flavonifractor plautii (FP) has been reported to participate in the metabolism of catechins in the human gut. However, there is limited information on the immune regulatory effects of this bacterium. We confirmed that the administration of green tea increases the abundance of FP in the gut microbiota and investigated the effect of FP in a mouse colitis model. Mice were orally administered FP for 10 consecutive days; colonic inflammation was evaluated daily on the basis of stool consistency, gross rectal bleeding, and body weight. In the dextran sodium sulfate model, FP-exposed animals exhibited lower levels of inflammation and strong inhibition of interleukin (IL)-17 signaling. Moreover, lipoteichoic acid from FP was identified as the active component mediating IL-17 suppression. Thus, oral administration of FP appears to modulate gut inflammation and represents a viable and inexpensive oral microbial therapeutic.

Epigallocatechin Gallate During Dietary Restriction - Potential Mechanisms of Enhanced Liver Injury

Green tea extract (GTE) is popular in weight loss, and epigallocatechin gallate (EGCG) is considered as the main active component. However, GTE is the primary cause of herbal and dietary supplement-induced liver injury in the United States. Whether there is a greater risk of liver injury when EGCG is consumed during dieting for weight loss has not been previously reported. This study found for the first time that EGCG could induce enhanced lipid metabolism pathways, suggesting that EGCG had the so-called “fat burning” effect, although EGCG did not cause liver injury at doses of 400 or 800 mg/kg in normal mice. Intriguingly, we found that EGCG caused dose-dependent hepatotoxicity on mice under dietary restriction, suggesting the potential combination effects of dietary restriction and EGCG. The combination effect between EGCG and dietary restriction led to overactivation of linoleic acid and arachidonic acid oxidation pathways, significantly increasing the accumulation of pro-inflammatory lipid metabolites and thus mediating liver injury. We also found that the disruption of Lands’ cycle and sphingomyelin-ceramides cycle and the high expression of taurine-conjugated bile acids were important metabolomic characteristics in EGCG-induced liver injury under dietary restriction. This original discovery suggests that people should not go on a diet while consuming EGCG for weight loss; otherwise the risk of liver injury will be significantly increased. This discovery provides new evidence for understanding the “drug-host” interaction hypothesis of drug hepatotoxicity and provides experimental reference for clinical safe use of green tea-related dietary supplements.

Differential effects of Chinese high-fat dietary habits on lipid metabolism: mechanisms and health implications

Background

The traditional Chinese diet blends lard with vegetable oil, keeping the fatty acid balance intake ratio of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids at nearly 1:1:1. However, the effects of a mixture of lard and vegetable oil on lipid metabolism have never been researched. In the present study, by simulating Chinese high-fat dietary habits, we explored the effects of a mixture of lard and vegetable oil on lipid metabolism.

Methods

We randomly assigned 50 male C57BL/6 J mice to 5 groups (10 in each group) and fed them lard, sunflower oil (SFO), soybean oil (SBO), lard blended with sunflower oil (L-SFO), or lard blended with soybean oil (L-SBO) for 12 weeks.

Results

We found that the final body weights of mice in the lard group were significantly higher than those of mice in the SFO and SBO groups. Body fat rate and volume of fat cell of the lard group were significantly higher than those of the SFO, SBO, and L-SBO groups. Liver triglyceride level of the lard group increased significantly compared to the other groups. Although body fat rate and liver triglyceride level in the SBO and SFO groups decreased compared to those in the other groups, the high-density lipoprotein cholesterol/low-density lipoprotein cholesterol ratio were also significantly decreased in the SBO and SFO groups.

Conclusions

We found that a lard diet induced accumulation of body fat, liver and serum lipids, which can increase the risk of obesity, non-alcoholic fatty acid liver disease, and atherosclerosis. The vegetable oil diet resulted in cholesterol metabolism disorders even though it did not lead to obesity. The mixed oil diet induced body fat accumulation, but did not cause lipid accumulation in the liver and serum. Thus, differential oil/fat diets have an impact on differential aspects in mouse lipid metabolism.

Graphical abstract

The effects of green tea on lipid metabolism and its potential applications for obesity and related metabolic disorders - An existing update

Obesity is one of the top global issues, which induces several serious health consequences both physically and mentally, such as type 2 diabetes, cardiovascular diseases, dyslipidemia, eating disorders, depression and stress. However, the effective therapy to prevent and treat obesity and overweight, up to now, cannot be found nowadays. Several methods/medicines namely diet control, energy balance, environmental changes, genetic and stem cell therapies, new drugs/chemicals have been extensively studied to enhance the ability to control bodyweight and prevent obesity. Of all the aforementioned methods, green tea, used as a daily beverage, has shown beneficial impacts for the health, especially its anti-obesity effects. Available evidence shows that green tea can interrupt lipid emulsification, reduce adipocyte differentiation, increase thermogenesis, and reduce food intake, thus green tea improves the systemic metabolism and decreases fat mass. Here, we highlight and sum up the update investigations of anti-obesity effect of green tea as well as discuss the potential application of them for preventing obesity and its related metabolic disorders.