Pu-erh Tea Reduces Nitric Oxide Levels in Rats by Inhibiting Inducible Nitric Oxide Synthase Expression through Toll-Like Receptor 4

Yang Xu; Guan Wang; Chunjie Li; Min Zhang; Hang Zhao; Jun Sheng; Wei Shi
June 2012
International Journal of Molecular Sciences;Jun2012, Vol. 13 Issue 6, p7174
Academic Journal
Pu-erh tea undergoes a unique fermentation process and contains theabrownins, polysaccharides and caffeine; although it is unclear about which component is associated with the down regulation of nitric oxide levels or how this process is mediated. To address this question we examined the effects of pu-erh tea on nitric oxide synthase (NOS) genes. Cohorts of rats were separately given four-week treatments of water as control, pu-erh tea, or the tea components: theabrownins, caffeine or polysaccharides. Five experimental groups were injected with lipopolysaccharides (LPS) to induce nitric oxide (NO) production, while the corresponding five control groups were injected with saline as a negative control. The serum and liver NO concentrations were examined and the NOS expression of both mRNA and protein was measured in liver. The results showed that the rats which were fed pu-erh tea or polysaccharides had lower levels of NO which corresponded with the down-regulation of inducible nitric oxide synthase (iNOS) expression. We further demonstrate that this effect is mediated through reduction of Toll-like receptor 4 (TLR4) signaling. Thus we find that the polysaccharide components in pu-erh tea reduce NO levels in an animal model by inhibiting the iNOS expression via signaling through TLR4.


Related Articles

  • Enteroglial-derived S100B protein integrates bacteria-induced Toll-like receptor signalling in human enteric glial cells. Turco, Fabio; Sarnelli, Giovanni; Cirillo, Carla; Palumbo, Ilaria; De Giorgi, Francesco; D'Alessandro, Alessandra; Cammarota, Marcella; Giuliano, Mariateresa; Cuomo, Rosario // Gut;Jan2014, Vol. 63 Issue 1, p105 

    Objective Enteric glial cells (EGC) have been suggested to participate in host-bacteria cross-talk, playing a protective role within the gut. The way EGC interact with microorganisms is still poorly understood. We aimed to evaluate whether: EGC participate in host-bacteria interaction; S100B and...

  • The Adenosine-Dependent Angiogenic Switch of Macrophages to an M2-Like Phenotype is Independent of Interleukin-4 Receptor Alpha (IL-4Rα) Signaling. Ferrante, Christopher; Pinhal-Enfield, Grace; Elson, Genie; Cronstein, Bruce; Hasko, Gyorgy; Outram, Shalini; Leibovich, Samuel // Inflammation;Aug2013, Vol. 36 Issue 4, p921 

    Murine macrophages are activated by interferon-γ (IFN-γ) and/or Toll-like receptor (TLR) agonists such as bacterial endotoxin (lipopolysaccharide [LPS]) to express an inflammatory (M1) phenotype characterized by the expression of nitric oxide synthase-2 (iNOS) and inflammatory cytokines...

  • Immune evasion: Mycobacteria hide from TLRs. Kugelberg, Elisabeth // Nature Reviews Immunology;Feb2014, Vol. 14 Issue 2, p62 

    The article cites the research "Mycobacteria manipulate macrophage recruitment through coordinated use of membrane lipids" by C. J. Cambier. The authors investigated the microbicidal potential of the different macrophages by comparing the expresion of inducible nitric oxide synthase. Moreover,...

  • The retinal pigment epithelium (RPE) induces FasL and reduces iNOS and Cox2 in primary monocytes. Hettich, Christin; Wilker, Sebastian; Mentlein, Rolf; Lucius, Ralph; Roider, Johann; Klettner, Alexa // Graefe's Archive of Clinical & Experimental Ophthalmology;Nov2014, Vol. 252 Issue 11, p1747 

    Purpose: Retinal pigment epithelium (RPE) cells may alter the phenotype of monocytes by soluble factors that may be influenced by stimulation of the RPE. Since RPE cells carry the toll-like receptor-3 (TLR3) that detects and reacts to viral infection through binding of dsRNA we investigated the...

  • Inhibitory Effect of Baicalin on iNOS and NO Expression in Intestinal Mucosa of Rats with Acute Endotoxemia. Feng, Aiwen; Zhou, Guangrong; Yuan, Xiaoming; Huang, Xinli; Zhang, Zhengyuan; Zhang, Ti // PLoS ONE;Dec2013, Vol. 8 Issue 12, p1 

    The mechanism by which baicalin modulated the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) in the mucosa of distal ileum was investigated in a rat model of acute endo-toxemia induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS). The experiment...

  • Signalling: Pellino3 - a self-control strategy for TLR3. Bordon, Yvonne // Nature Reviews Immunology;Nov2012, Vol. 12 Issue 11, p747 

    The article discusses research being done on the regulation by Pellino3 of type 1 interferon (IFN) expression for toll-like receptor 3 (TLR3), which references the article "Pellino3 targets the IRF7 pathway and facilitates autoregulation of TLR3- and viral-induced expression of type I...

  • Toll-like receptor 4 mediates microglial activation and production of inflammatory mediators in neonatal rat brain following hypoxia: role of TLR4 in hypoxic microglia. Linli Yao; Kan, Enci Mary; Jia Lu; Aijun Hao; Thameem Dheen, S.; Kaur, Charanjit; Eng-Ang Ling // Journal of Neuroinflammation;2013, Vol. 10 Issue 1, p1 

    Background: Hypoxia induces microglial activation which causes damage to the developing brain. Microglia derived inflammatory mediators may contribute to this process. Toll-like receptor 4 (TLR4) has been reported to induce microglial activation and cytokines production in brain injuries;...

  • Effects of Ginsenoside Rg1 on the Expression of Toll-Like Receptor 3, 4 and Their Signalling Transduction Factors in the NG108-15 Murine Neuroglial Cell Line. Bao-Sheng Zhao; Yang Liu; Xiao-Yan Gao; Hua-Qiang Zhai; Jian-You Guo; Xue-Yong Wang // Molecules;Oct2014, Vol. 19 Issue 10, p16925 

    As one of the most important components of Panax ginseng, ginsenoside Rg1 has certain anti-aging effects, improving the activity of learning and memory. Studies have showed that ginsenoside Rg1 improves the memory impairment associated with Alzheimer's disease (AD). In this study, the effects of...

  • The TLR4 antagonist CRX-526 protects against advanced diabetic nephropathy. Lin, Miao; Yiu, Wai Han; Li, Rui Xi; Wu, Hao Jia; Wong, Dickson W L; Chan, Loretta Y Y; Leung, Joseph C K; Lai, Kar Neng; Tang, Sydney C W // Kidney International;May2013, Vol. 83 Issue 5, p887 

    We recently showed that Toll-like receptor (TLR) TLR4 was overexpressed in the human diabetic kidney, which could promote tubular inflammation. Here we explored whether the TLR4 antagonist, CRX-526, has therapeutic potential to attenuate renal injuries and slow the progression of advanced...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics