OBJECTIVETo assess the efficacy of curcumin in delaying development of type 2 diabetes mellitus (T2DM) in the prediabetic population.RESEARCH DESIGN AND METHODSThis randomized, double-blinded, placebo- controlled trial included subjects (n = 240) with criteria of prediabetes. All subjects were randomly assigned to receive either curcumin or placebo capsules for 9 months. To assess the T2DM progression after curcumin treatments and to determine the number of subjects progressing to T2DM, changes in β-cell functions (homeostasis model assessment [HOMA]-β, C-peptide, and proinsulin/insulin), insulin resistance (HOMA-IR), anti-inflammatory cytokine (adiponectin), and other parameters were monitored at the baseline and at 3-, 6-, and 9-month visits during the course of intervention.RESULTSAfter 9 months of treatment, 16.4% of subjects in the placebo group were diagnosed with T2DM, whereas none were diagnosed with T2DM in the curcumin-treated group. In addition, the curcumin-treated group showed a better overall function of β-cells, with higher HOMA-β (61.58 vs. 48.72; P < 0.01) and lower C-peptide (1.7 vs. 2.17; P < 0.05). The curcumin-treated group showed a lower level of HOMA-IR (3.22 vs. 4.04; P < 0.001) and higher adiponectin (22.46 vs. 18.45; P < 0.05) when compared with the placebo group.CONCLUSIONSA 9-month curcumin intervention in a prediabetic population significantly lowered the number of prediabetic individuals who eventually developed T2DM. In addition, the curcumin treatment appeared to improve overall function of β-cells, with very minor adverse effects. Therefore, this study demonstrated that the curcumin intervention in a prediabetic population may be beneficial.
BackgroundPhikud Navakot (PN), a combination of nine herbs, has been used traditionally in Thai medicinal formulas to relieve circulatory disorder. The present study aimed to compare the synergistic antioxidant efficacy and toxicity of the hydroethanolic and water extracts of PN at cellular level.MethodsPN and its nine herbs were extracted with either 50% ethanol or water. All extracts were tested for in vitro antioxidant potential using standard antioxidant assays. Evaluation of cytotoxicity, genotoxicity, and intracellular reactive oxygen species were performed using human endothelial ECV304 cells.ResultsAntioxidant assays in cell-free systems showed that the hydroethanolic extract of PN scavenged superoxide, hydroxyl, nitric oxide radicals, and hydrogen peroxide more effectively than its water extract. Combination indices were calculated to show that the ingredients of the hydroethanolic extract acted synergistically to exhibit antioxidant activities against all tested radicals, whereas, in the case of water extract, this effect was observed only against 2,2-diphenyl-1-picrylhydrazyl, superoxide, and hydroxyl radicals. A cell-based assay also revealed that the hydroethanolic extract concentration-dependently attenuated hydrogen peroxide-induced stress more effectively than the water extract. At the antioxidant and cytotoxic concentrations of both extracts, no genotoxicity was found.ConclusionOur findings demonstrate that the synergistic antioxidant action of PN ameliorates endothelial stress, which may provide some clues for understanding the traditional use of PN for the treatment of circulatory disorder. Additionally, the selection of a suitable solvent for the extraction of PN herbal combination is essential for maximal efficacy and safety.
This study suggests that cholesteryl linoleate is the primary target of oxidative modification induced by NTBI in beta-thal/Hb E patients and that reduction in cholesteryl linoleate in lipoproteins could be used as a severity index for beta-thal/Hb E.
The anoikis-sensitization activity of imperatorin, an active furanocoumarin component of Angelica dahurica root, is reported herein for the first time. The present study demonstrated that the imperatorin treatment at sub-toxic concentrations enhanced human lung cancer H23 cell apoptosis after detachment. A Western blot analysis showed that imperatorin significantly enhanced the p53 protein level, which subsequently down-regulated Mcl-1 protein and up-regulated Bax, while it had a minimal effect on Bcl-2 expression. In addition, an anchorage-independent growth assay was performed to support the anti-metastasis potential of imperatorin. Consistent with anoikis assay, imperatorin exhibited a strong inhibitory effect on the anchorage-independent growth of the cells. Further, this study demonstrated that imperatorin sensitizes anoikis in other lung cancer cells, namely, H292 and A549. Because anoikis was shown to be a critical hindrance in preventing cancer cell metastasis, the knowledge regarding such an activity and an underlying mechanism may lead to the development of this compound for a cancer therapy.
Hemin is an oxidative mediator elevated in disease states including sickle cell anemia and thalassemia. The rhizome of Curcuma longa L. contains yellow pigments called curcuminoids which have antioxidant and anti-inflammatory activities. The aim of the study was to compare the protective effects of curcuminoids, curcumin, demethoxycurcumin, bisdemethoxycurcumin, and tetrahydrocurcumin on hemin-induced LDL oxidation (he-oxLDL). He-oxLDL showed the depletion of a-tocopherol, an increase in thiobarbituric acid reactive substances (TBARs), and alteration of the lipid composition in low-density lipoprotein. The levels of cholesteryl arachidonate, cholesteryl linoleate and the cholesteryl linoleate/cholesteryl oleate ratio were decreased. All test compounds showed antioxidant activity that protected against hemin-induced lipid peroxidation, based on the inhibition of TBARs formation, reduced depletion of a-tocopherol, decreased damage to lipids, and a reduced decrease in the cholesteryl linoleate/cholesteryl oleate ratio. A significant protective effect against he-oxLDL was found to be tetrahydrocurcumin curcumin curcuminoids > demethoxycurcumin bisdemethoxycurcumin a-tocopherol (p < .05).
Practical applicationsCurcuma longa L. has traditionally been used in Ayurvedic medicine for treatment of conditions such as arthritis, ulcer, jaundice, wounds, and skin diseases. It has also been used as a food additive. The results from this study demonstrated that curcuminoids derived from the rhizome of Curcuma longa L. are the potential substances for protecting hemin-induced LDL oxidation which may be developed as a functional food for the prevention of diseases related to low-density lipoprotein oxidation.
K E Y W O R D Scholesteryl ester, curcuminoids, hemin, oxidized LDL, tetrahydrocurcumin
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