Bring it on.
Curcumin steps up to the plate................the pitch...........BOOM!
recent studies released this week
Immune system
Inhibition of homodimerization of Toll-like receptor 4 by curcumin.
Youn HS, Saitoh SI, Miyake K, Hwang DH.
USDA, ARS, Western Human Nutrition Research Center, and Department of Nutrition, University of California, Davis, Meyer Hall, One Shields Ave., CA 95616, USA.
Toll-like receptors play a key role in sensing microbial components and inducing innate immune responses. Ligand-induced dimerization of TLR4 is required for the activation of downstream signaling pathways. Thus, the receptor dimerization may be one of the first lines of regulation in activating TLR-mediated signaling pathways and induction of subsequent immune responses. LPS induces the activation of NF-kappaB and IRF3 through MyD88- or TRIF-dependent pathways. Curcumin, a polyphenol found in the plant Curcuma longa, has been shown to suppress the activation of NF-kappaB induced by various pro-inflammatory stimuli by inhibiting IKKbeta kinase activity in MyD88-dependent pathway. Curcumin also inhibited LPS-induced IRF3 activation. These results imply that curcumin inhibits both MyD88- and TRIF-dependent pathways in LPS-induced TLR4 signaling. However, in TRIF-dependent pathway, curcumin did not inhibit IRF3 activation induced by overexpression of TRIF in 293T cells. These results suggest that TLR4 receptor complex is the molecular target of curcumin in addition to IKKbeta. Here, we report biochemical evidence that phytochemicals (curcumin and sesquiterpene lactone) inhibit both ligand-induced and ligand-independent dimerization of TLR4. Furthermore, these results demonstrate that small molecules with non-microbial origin can directly inhibit TLRs-mediated signaling pathways at the receptor level. These results imply that the activation of TLRs and subsequent immune/inflammatory responses induced by endogenous molecules or chronic infection can be modulated by certain dietary phytochemicals we consume daily.
Cytotoxic effect of curcumin on Giardia lamblia trophozoites.
Perez-Arriaga L, Mendoza-Magana ML, Cortes-Zarate R, Corona-Rivera A, Bobadilla-Morales L, Troyo-Sanroman R, Ramirez-Herrera MA.
Departamento de Fisiologia, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Sierra Mojada 950, Guadalajara, Jalisco, CP 44340, Mexico.
Giardia lamblia is one of the most important worldwide causes of intestinal infections produced by protozoa. Thus, the search for new alternative therapeutic approaches for this parasitic disease is very important. Common drugs used to control and eradicate this infection, frequently exhibit side effects that force patients to abandon treatment. The present work evaluates the anti-protozoan activity of curcumin, the main constituent of turmeric. Axenic G. lamblia (Portland 1 strain) cultures were exposed to different concentrations of curcumin. Its effects were evaluated on parasite growth, adhesion capacity and parasite morphology. We also evaluated the capacity of curcumin to induce an apoptosis-like effect. All curcumin concentrations inhibited trophozoite growth and adhesion in more than 50% in dose and time dependent manner. Morphological changes were described as protrusions formed under the cytoplasmic membrane, deformation due to swelling and cell agglutination. Curcumin induced apoptosis-like nuclear staining in dose and time dependent manner. In conclusion, curcumin exhibited a cytotoxic effect in G. lamblia inhibiting the parasite growth and adherent capacity, induced morphological alterations, provoked apoptosis-like changes. Future in vitro and in vivo experiments are endowed to elucidate the effect of curcumin in an experimental model of G. lamblia infection, analyze the involvement of ion channels in the swelling effect of curcumin during an apparent osmotic deregulation in G. lamblia trophozoites. This will lead to the proposal of the action mechanism of curcumin as well as the description of mechanism involved during the activation process for the apoptotic-like effect.
Antio-oxidant
Curcumin activates defensive genes and protects neurons against oxidative stress.
Scapagnini G, Colombrita C, Amadio M, D'Agata V, Arcelli E, Sapienza M, Quattrone A, Calabrese V.
Institute of Neurological Sciences, National Research Council (CNR), Catania, Italy., Blanchette Rockefeller Neurosciences Institute, West Virginia University, Rockville, Maryland.
Spices and herbs often contain active phenolic substances endowed with potent antioxidative properties. We had previously shown that curcumin, the yellow pigment in curry, strongly induced HO-1 expression and activity in rat astrocytes. In the CNS, HO-1 has been reported to operate as a fundamental defensive mechanism for neurons exposed to an oxidant challenge. Treatment of astrocytes with curcumin upregulated expression of HO-1 protein at both cytoplasmic and nuclear levels, as shown by immunofluorescence analysis under laser-scanning confocal microscopy. A significant expression of quinone reductase and glutathione Stransferase, two members of phase II detoxification enzymes, was found in astrocytes exposed to 5-15 microM curcumin. Moreover, the effects of curcumin on HO-1 activity were explored in cultured hippocampal neurons. Elevated expression of HO-1 mRNA and protein were detected after 6 h incubation with 5-25 microM curcumin. Higher concentrations of curcumin (50-100 microM) caused a substantial cytotoxic effect with no change in HO-1 protein expression. Interestingly, pre-incubation (18 h) with curcumin resulted in an enhanced cellular resistance to glucose oxidase-mediated oxidative damage; this cytoprotective effect was considerably attenuated by zinc protoporphyrin IX, an inhibitor of heme oxygenase activity. This study gives additional support to the possible use of curcumin as a dietary preventive agent against oxidative stress-related diseases.
PMID: 16677086 [PubMed - in process]
Anti-arthritic
Turmeric extracts containing curcuminoids prevent experimental rheumatoid arthritis.
Funk JL, Oyarzo JN, Frye JB, Chen G, Lantz RC, Jolad SD, Solyom AM, Timmermann BN.
Arizona Center for Phytomedicine Research, Department of Medicine, Department of Cell Biology and Anatomy, University of Arizona, Tucson, 85724, USA. jfunk@u.arizona.edu
Turmeric has been used for centuries in Ayurvedic medicine as a treatment for inflammatory disorders including arthritis. On the basis of this traditional usage, dietary supplements containing turmeric rhizome and turmeric extracts are also being used in the western world for arthritis treatment and prevention. However, to our knowledge, no data are available regarding antiarthritic efficacy of complex turmeric extracts similar in composition to those available for use as dietary supplements. Therefore, the studies described here were undertaken to determine the in vivo efficacy of well-characterized curcuminoid-containing turmeric extracts in the prevention or treatment of arthritis using streptococcal cell wall (SCW)-induced arthritis, a well-described animal model of rheumatoid arthritis (RA). Arthritic index, a clinical measure of joint swelling, was used as the primary endpoint for assessing the effect of extracts on joint inflammation. An essential oil-depleted turmeric fraction containing 41% of the three major curcuminoids was efficacious in preventing joint inflammation when treatment was started before, but not after, the onset of joint inflammation. A commercial sample containing 94% of the three major curcuminoids was more potent in preventing arthritis than the essential oil-depleted turmeric fraction when compared by total curcuminoid dose per body weight. In conclusion, these data (1) document the in vivo antiarthritic efficacy of an essential oil-depleted turmeric fraction and (2) suggest that the three major curcuminoids are responsible for this antiarthritic effect, while the remaining compounds in the crude turmeric extract may inhibit this protective effect.
PMID: 16562833 [PubMed - indexed for MEDLINE]
More info about curcumin (in the form of a PDF monograph) can be found here