curcumin and curcumenol

Phytophthora capsici is a plant oomycete pathogen, which causes many devastating diseases on a broad range of hosts. Zedoary turmeric oil (ZTO) is a kind of natural plant essential oil that has been widely used in pharmaceutical applications. However, the antifungal activity of ZTO against phytopathogens remains unknown. In this study, we found ZTO could inhibit P. capsici growth and development in vitro and in detached cucumber and Nicotiana benthamiana leaves. Besides, ZTO treatment resulted in severe damage to the cell membrane of P. capsici, leading to the leakage of intracellular contents. ZTO also induced a significant increase in relative conductivity, malondialdehyde concentration and glycerol content. Furthermore, we identified 50 volatile organic compounds from ZTO, and uncovered Curcumol, β-elemene, curdione and curcumenol with strong inhibitory activities against mycelial growth of P. capsici. Overall, our results not only shed new light on the antifungal mechanism of ZTO, but also imply a promising alternative for the control of phytophthora blight caused by P. capsici.

Topics: Antifungal Agents; Cell Membrane; Curcuma; Oils, Volatile; Phytophthora; Plant Extracts; Plant Oils; Sesquiterpenes; Sesquiterpenes, Germacrane

Topics: Curcuma; Glucose; Hep G2 Cells; Humans; Molecular Structure; Plant Tubers; Polycyclic Sesquiterpenes; Sesquiterpenes; Sesquiterpenes, Germacrane; Terpenes

The present study was designed to identify the chemical constituents of the methanolic extract of Curcuma longa L. rhizomes and their inhibitory effect on a hepatoma cell line. The methanolic extract was subjected to GC-MS analysis to identify the volatile constituents and the other part of the same extract was subjected to liquid column chromatographic separation to isolate curcumin. The inhibition of cell growth in the hepatoma cell line and the cytopathological changes were studied. GC-MS analysis showed the presence of fifty compounds in the methanolic extract of C. longa. The major compounds were ar-turmerone (20.50 %), β-sesquiphellandrene (5.20 %) and curcumenol (5.11 %). Curcumin was identified using IR, 1H and 13C NMR. The inhibition of cell growth by curcumin (IC50 = 41.69 ± 2.87 μg mL-1) was much more effective than that of methanolic extract (IC50 = 196.12 ± 5.25 μg mL-1). Degenerative and apoptotic changes were more evident in curcumin- treated hepatoma cells than in those treated with the methanol extract. Antitumor potential of the methanolic extract may be attributed to the presence of sesquiterpenes and phenolic constituents including curcumin (0.051 %, 511.39 μg g-1 dried methanol extract) in C. longa rhizomes.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Cell Proliferation; Cell Survival; Chromatography, High Pressure Liquid; Chromatography, Liquid; Curcuma; Curcumin; Cyclohexane Monoterpenes; Cyclohexenes; Drug Discovery; Gas Chromatography-Mass Spectrometry; Hep G2 Cells; Humans; Inhibitory Concentration 50; Ketones; Liver Neoplasms; Monoterpenes; Plant Extracts; Rhizome; Sesquiterpenes; Volatile Organic Compounds

Curcumenol, a sesquiterpene isolated from Curcuma zedoaria is known to possess a variety of health and medicinal values which includes neuroprotection, anti-inflammatory, anti-tumor and hepatoprotective activities. The current study aim is to investigate the modulatory effects of curcumenol towards the lipopolysaccharides (LPS)-induced inflammation in BV-2 microglia. Curcumenol markedly decreased LPS-induced production of nitric oxide (NO), pro-inflammatory cytokines [(IL-6) and (TNF-α)] and pro-inflammatory proteins expression, iNOS and COX-2. Moreover, curcumenol inhibited NF-κB activation by suppressing the nuclear translocation of the NF-κB p65 subunit and blocking IκBα phosphorylation and degradation. Furthermore, an NF-κB inhibitor, ethyl 3,4-dihydroxycinnamate also known as caffeic acid ethyl ester (CAEE), attenuated LPS-stimulated iNOS and COX-2 expression, suggesting that NF-κB inhibition is a regulator in the expression of iNOS and COX-2 proteins. Further mechanistic study with an Akt inhibitor, triciribine hydrate (API-2), revealed that curcumenol acted through Akt-dependent NF-κB activation. Moreover, curcumenol inhibition on LPS-induced phosphorylation of p38 MAPK is confirmed by its inhibitor (SB 202190). These results indicate that curcumenol diminishes the proinflammatory mediators and the expression of the regulatory genes in LPS-stimulated BV-2 by inhibiting Akt-dependent NF-κB activation and downregulation of Akt and p38 MAPKs signaling.

Topics: Animals; Anti-Inflammatory Agents; Curcuma; Cytokines; Down-Regulation; Inflammation; Lipopolysaccharides; MAP Kinase Signaling System; Mice; Microglia; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase Type II; Phosphorylation; Phytotherapy; Proto-Oncogene Proteins c-akt; Sesquiterpenes; Signal Transduction

Curcumenol, one of the major components of Zedoary turmeric oil, has been widely used to treat cancer and inflammation. As an antibiotic or anticancer drug, curcumenol is highly likely to be used in combination with various synthetic drugs in most cases, thus it is necessary to evaluate potential pharmacokinetic drug-drug interactions induced by curcumenol. In this study, the inhibitory effects of curcumenol on seven CYP isoforms were investigated, and the results demonstrated that only CYP3A4 was strongly inhibited (IC(50) = 12.6 +/- 1.3 microM). Kinetic analysis showed the inhibition type was competitive with K(i) value of 10.8 microM. Time- and NADPH-dependent inhibitions were also investigated to show curcumenol is not a mechanism-based inhibitor. Employing these in vitro data and maximum plasma concentration of curcumenol in human predicted from beagle dog's in vivo pharmacokinetic data, the change in AUC of victim drugs was predicted to be 0.4%, which suggested that curcumenol may be safely used without inducing metabolic drug-drug interaction through P450 inhibition. Nevertheless, due to the limited pharmacokinetic data available for curcumenol in humans, it is still not possible to evaluate its potential clinical effects on human patients from in vitro data. Thus, the magnitude of drug-drug interaction (DDI) induced by curcumenol warrants further investigation.

Topics: Animals; Area Under Curve; Curcuma; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inhibitors; Dogs; Drug Interactions; Enzyme Inhibitors; Female; Humans; Inhibitory Concentration 50; Liver; Male; Microsomes, Liver; Sesquiterpenes