Aged green tea reduces high-fat diet-induced fat accumulation and inflammation via activating the AMP-activated protein kinase signaling pathway

Abstract

Background: Obesity is a global public health concern and increases the risk of metabolic syndrome and other diseases. The anti-obesity effects of various plant-derived bioactive compounds, such as tea extracts, are well-established. The mechanisms underlying the anti-obesity activity of Jinxuan green tea (JXGT) from different storage years are still unclear.
 Objective: The aim of this study was to evaluate the effects of JXGTs from three different years on the high fat diet (HFD)-fed mouse model.
 Design: The mice were divided into six groups, the control group received normal diet and the obese model group received HFD. We analyzed the effects of JXGTs from 2005, 2008, and 2016 on HFD-fed obese mice over a period of 7 weeks.
 Results: The JXGTs reduced the body weight of the obese mice, and also alleviated fat accumulation and hepatic steatosis. Mechanistically, JXGTs increased the phosphorylation of AMP-activated protein kinase (p-AMPK)/AMP-activated protein kinase (AMPK) ratio, up-regulated carnitine acyl transferase 1A (CPT-1A), and down-regulated fatty acid synthase (FAS), Glycogen synthase kinase-3beta (GSK-3β), Peroxisome proliferator-activated receptor-gamma co-activator-1alpha (PGC-1α), Interleukin 6 (IL-6), and Tumour necrosis factor alpha (TNFα). Thus, JXGTs can alleviate HFD-induced obesity by inhibiting lipid biosynthesis and inflammation, thereby promoting fatty acid oxidation via the AMPK pathway.
 Discussion: The anti-obesity effect of three aged JXGTs were similar. However, JXGT2016 exhibited a more potent activation of AMPK, and JXGT2005 and JXGT2008 exhibited a more potent inhibiting glycogen synthase and inflammation effect. Furthermore, the polyphenol (–)-epicatechin (EC) showed the strongest positive correlation with the anti-obesity effect of JXGT.
 Conclusions: These findings demonstrate that JXGT treatment has a potential protection on HFD-induced obesity mice via activating the AMPK/CPT-1A and down-regulating FAS/GSK-3β/PGC-1α and IL-6/TNFα. Our study results also revealed that different storage time would not affect the anti-obesity and anti-inflammation effect of JXGT.

Shibi Tea (Adinandra nitida) and Camellianin A Alleviate CCl4-Induced Liver Injury in C57BL-6J Mice by Attenuation of Oxidative Stress, Inflammation, and Apoptosis

“…An equal amount of protein per sample was collected and boiled for Western blotting analysis. Western blotting was performed as previously described [ 21 ]. The antibodies used in this work included Nrf2 (12721S, CST, Danvers, MA, USA), HO-1 (43966S, CST), β-actin (A1978, Sigma, MO, USA), NF-κB (8242S, CST), p-NF-κB (Ser536) (13346, CST), p-MAPK (3510, CST), Bcl2 (ab117115, Abcam, Cambridge, U.K.), and Bax (ab32503, Abcam).…”

Targeting Cancer Hallmarks with Epigallocatechin Gallate (EGCG): Mechanistic Basis and Therapeutic Targets

“…By suppressing lipid synthesis, EGCG can interfere with the formation of lipid membranes essential for tumor cell proliferation. Additionally, EGCG can activate AMP-activated protein kinase (AMPK), a metabolic regulator that inhibits lipid biosynthesis and promotes fatty acid oxidation [ 114 ]. In the literature, it was informed that EGCG sensitizes radioresistance by reducing fatty acid synthase, and EGCG acts as a radiosensitizer for better treatment of nasopharyngeal carcinoma [ 115 ].…”

Muscle Cell Insulin Resistance Is Attenuated by Rosmarinic Acid: Elucidating the Mechanisms Involved

“…AMPK is activated by an increased AMP/ATP ratio and/or via phosphorylation of its α-catalytic subunit by its upstream kinases, liver kinase B1 (LKB1), calmodulin-dependent protein kinase (CaMKKs), and transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1) [ 20 , 21 ]. AMPK activity is driven by muscle contraction/exercise [ 21 ] and stimulated by several compounds, including the currently used antidiabetic drugs metformin [ 22 ] and thiazolidineones [ 23 ], and by various polyphenols/flavanols found in tea [ 24 ], red wine, citrus fruit, and cocoa [ 25 ], including resveratrol [ 26 ], naringenin [ 27 ], and cocoa flavanol [ 28 ], resulting in increased skeletal muscle glucose uptake. The utilization of AMPK activators has gained increasing attention as a novel pharmacological intervention for the prevention/treatment of T2DM and insulin resistance [ 21 , 29 , 30 , 31 ].…”