Citrus maxima and tea regulate AMPK signaling pathway to retard the progress of nonalcoholic fatty liver disease.

Background: Nonalcoholic fatty liver disease (NAFLD) is a chronic metabolic disease that easily induces hepatitis, cirrhosis, and even liver cancer. The long-term use of NAFLD therapeutic drugs produces toxicity and drug resistance. Therefore, it is necessary to develop high efficiency and low-toxicity active ingredients to alleviate NAFLD. Objective: This study aimed to reveal the role and mechanism of a new functional food CMT in alleviating NAFLD. Results: In the ob/ob fatty liver mice models, the CMT extracts significantly inhibited the weight gain of the mice and reduced the accumulation of white fat. The anatomical and pathological results showed that CMT relieved fatty liver in mice and reduced excessive lipid deposition and inflammatory infiltration. Serological and liver biochemical indicators suggest that CMT reduced dyslipidemia and liver damage caused by fatty liver. CMT obviously activated the adenosine 5'-monophosphate-activated protein kinase (AMPK)/acetyl-coA carboxylase (ACC) and AMPK/fatty acid synthase (FAS) signaling pathways, promoted fat oxidation, and inhibited synthesis. Moreover, CMT regulated the expression of inflammatory factors to relieve hepatitis caused by NAFLD. Conclusion: The study explained the role and mechanism of CMT in alleviating NAFLD and suggested that the active ingredients of CMT might be beneficial in NAFLD therapy.

Mixtures of Tea and Citrus maxima (pomelo) Alleviate Lipid Deposition in HepG2 Cells Through the AMPK/ACC Signaling Pathway.

Tea and citrus maxima are natural, medicinal homologous plants, typically used for making beverages, which have anticancer, antiobesity, and antioxidation properties. Green tea, yellow tea, and black tea were combined with citrus maxima to obtain green tea and Citrus maxima (GTCM), yellow tea and Citrus maxima (YTCM), and black tea and Citrus maxima (BTCM). The biochemical components of these mixtures were analyzed, and their possible effects and mechanisms on relieving liver lipid deposition were explored. The tea polyphenols, free amino acids, phenolamine ratio, and caffeine were comparable in YTCM and GTCM, being significantly higher than those in BTCM. In addition, the content of esterified catechins, nonesterified catechins, and total catechins in YTCM was significantly higher than those in GTCM and BTCM. All three mixtures of Citrus maxima tea significantly reduced lipid deposition in HepG2 cells, with GTCM and YTCM being slightly more effective than BTCM. Regarding the possible mechanism, Western blot analysis revealed that the three Citrus maxima tea mixtures could activate the AMPK/ACC signaling pathway, upregulate the expression of p-AMPK, p-ACC, and CPT-1 proteins, and downregulate the expression of SREBP1c and fatty acid synthase proteins to inhibit fat synthesis, thereby relieving lipid deposition in liver cells. In conclusion, as a novel and healthy beverage, Citrus maxima tea has the potential to alleviate liver lipid deposition, and further could be responsible for obesity treatment.

Topical delivery of l-theanine ameliorates TPA-induced acute skin inflammation via downregulating endothelial PECAM-1 and neutrophil infiltration and activation.

l-theanine, the most abundant free amino acid in tea, has been documented to possess many different bioactive properties through oral or intragastrical delivery. However, little is known about the effect of topical delivery of l-theanine on acute inflammation. In the present study, by using 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 µg/ear)-induced ear edema model in mice, we first found that single-dose local pretreatment of l-theanine 30 min before TPA time- and dose-dependently suppressed the increases in both skin thickness and weight. Subsequently l-theanine ameliorated TPA-induced erythema, vascular permeability increase, epidermal and dermal hyperplasia, neutrophil infiltration and activation via downregulating the expression of PECAM-1 (a platelet endothelial adhesion molecule-1) in blood vessels and the production of pro-inflammatory cytokines IL-1ß, TNF-α, and mediator cyclooxygenase-2 (COX-2), which is mainly expressed in neutrophils. It highlighted the potential of l-theanine as a locally administrable therapeutic agent for acute cutaneous inflammation.