Article

Differential regulation of CD4(+) T helper cell responses by curcumin in experimental autoimmune encephalomyelitis

Neuroscience Research Laboratory, Methodist Research Institute, Indiana University Health, Indianapolis, IN 46202, USA.
The Journal of nutritional biochemistry (Impact Factor: 4.59). 03/2012; 23(11):1498-507. DOI: 10.1016/j.jnutbio.2011.10.002
Source: PubMed

ABSTRACT Nutraceuticals and phytochemicals are important regulators of human health and diseases. Curcumin is a polyphenolic phytochemical isolated from the rhizome of the plant Curcuma longa (turmeric) that has been traditionally used for the treatment of inflammation and wound healing for centuries. Systematic analyses have shown that curcumin exerts its beneficial effects through antioxidant, antiproliferative and anti-inflammatory properties. We and others have shown earlier that curcumin ameliorates experimental autoimmune encephalomyelitis (EAE) model for multiple sclerosis. In this study, we show that C57BL/6 mice induced to develop EAE express elevated levels of interferon (IFN) γ and interleukin (IL)-17 in the central nervous system (CNS) and lymphoid organs that decreased significantly following in vivo treatment with curcumin. The EAE mice also showed elevated expression of IL-12 and IL-23 that decreased after treatment with curcumin. Ex vivo and in vitro treatment with curcumin resulted in a dose-dependent decrease in the secretion of IFNγ, IL-17, IL-12 and IL-23 in culture. The inhibition of EAE by curcumin was also associated with an up-regulation of IL-10, peroxisome proliferator activated receptor γ and CD4(+)CD25(+)Foxp3(+) Treg cells in the CNS and lymphoid organs. These findings highlight that curcumin differentially regulates CD4(+) T helper cell responses in EAE.

0 Followers
 · 
119 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Multiple sclerosis (MS) is a chronic progressive, neurological disease characterized by the targeted immune system-mediated destruction of central nervous system (CNS) myelin. Autoreactive CD4+ T helper cells have a key role in orchestrating MS-induced myelin damage. Once activated, circulating Th1-cells secrete a variety of inflammatory cytokines that foster the breakdown of blood-brain barrier (BBB) eventually infiltrating into the CNS. Inside the CNS, they become reactivated upon exposure to the myelin structural proteins and continue to produce inflammatory cytokines such as tumor necrosis factor α (TNFα) that leads to direct activation of antibodies and macrophages that are involved in the phagocytosis of myelin. Proliferating oligodendrocyte precursors (OPs) migrating to the lesion sites are capable of acute remyelination but unable to completely repair or restore the immune system-mediated myelin damage. This results in various permanent clinical neurological disabilities such as cognitive dysfunction, fatigue, bowel/bladder abnormalities, and neuropathic pain. At present, there is no cure for MS. Recent remyelination and/or myelin repair strategies have focused on the role of the neurotrophin brain-derived neurotrophic factor (BDNF) and its upstream transcriptional repressor methyl CpG binding protein (MeCP2). Research in the field of epigenetic therapeutics involving histone deacetylase (HDAC) inhibitors and lysine acetyl transferase (KAT) inhibitors is being explored to repress the detrimental effects of MeCP2. This review will address the role of MeCP2 and BDNF in remyelination and/or myelin repair and the potential of HDAC and KAT inhibitors as novel therapeutic interventions for MS.
    Molecular Neurobiology 01/2015; DOI:10.1007/s12035-014-9074-1 · 5.29 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Prolonged inflammation and increased oxidative stress impairs healing in diabetics and application of curcumin, a well known antioxidant and anti-inflammatory agent, could be an important strategy in improving impaired healing in diabetics. So, the present study was conducted to evaluate the cutaneous wound healing potential of topically applied curcumin in diabetic rats. Open excision skin wound was created in streptozotocin induced diabetic rats and wounded rats were divided into three groups; i) control, ii) gel-treated and iii) curcumin-treated. Pluronic F-127 gel (25%) and curcumin (0.3%) in pluronic gel were topically applied in the gel- and curcumin-treated groups, respectively, once daily for 19days. Curcumin application increased the wound contraction and decreased the expressions of inflammatory cytokines/enzymes i.e. tumor necrosis factor-1alpha, interleukin (IL)-1beta and matrix metalloproteinase-9. Curcumin also increased the levels of anti-inflammatory cytokine i.e. IL-10 and antioxidant enzymes i.e. superoxide dismutase, catalase and glutathione peroxidase. Histopathologically, the curcumin-treated wounds showed better granulation tissue dominated by marked fibroblast proliferation and collagen deposition, and wounds were covered by thick regenerated epithelial layer. These findings reveal that the anti-inflammatory and antioxidant potential of curcumin caused faster and better wound healing in diabetic rats and curcumin could be an additional novel therapeutic agent in the management of impaired wound healing in diabetics.
    International immunopharmacology 03/2014; 20(2). DOI:10.1016/j.intimp.2014.03.009 · 2.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The exact pathophysiological change concerning mitochondrial injury and oligodendrocyte apoptosis in MS and EAE model is still unknown. Whether curcumin is able to inhibit mitochondrial injury and suppress the apoptosis in the early stages of MS/EAE is still unclear. We first explored mitochondrial injury and apoptosis at different time points p.i. in C57 BL/6 EAE mice. We then explored the effects of curcumin on mitochondria and apoptosis. Results showed that mitochondrial injury can be observed 3 days p.i. Apoptosis in the spinal cord occurred 3 days p.i. and the apoptotic cells were shown to be oligodendrocytes and neuronal cells. Curcumin significantly reduced the number of apoptotic cells and inhibited the upregulation of cyt-c, caspase-9, and caspase-3 at 7 days p.i. in the EAE mice. These observations demonstrate that mitochondrial injury and oligodendrocyte/neuronal apoptosis occur in the early stages of EAE. Curcumin can inhibit apoptosis in EAE mice which maybe act through protection of mitochondrial injury and inhibition of the intrinsic apoptotic pathway.
    Oxidative medicine and cellular longevity 04/2014; 2014:728751. DOI:10.1155/2014/728751 · 3.36 Impact Factor