stilbenes and allyl-sulfide

Multidrug resistance is a principal mechanism by which tumors become resistant to structurally and functionally unrelated anticancer drugs. Resistance to chemotherapy has been correlated with overexpression of p-glycoprotein (p-gp), a member of the ATP-binding cassette (ABC) superfamily of membrane transporters. P-gp mediates resistance to a broad-spectrum of anticancer drugs including doxorubicin, taxol, and vinca alkaloids by actively expelling the drugs from cells. Use of specific inhibitors/blocker of p-gp in combination with clinically important anticancer drugs has emerged as a new paradigm for overcoming multidrug resistance. The aim of this paper is to review p-gp regulation by dietary nutraceuticals and to correlate this dietary nutraceutical induced-modulation of p-gp with activity of anticancer drugs.

Topics: Abietanes; Alkaloids; Allyl Compounds; Animals; Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B; Benzodioxoles; beta Carotene; Biflavonoids; Capsaicin; Catechin; Catechols; Curcumin; Dietary Supplements; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Drug Synergism; Fatty Alcohols; Furocoumarins; Humans; Indoles; Limonins; Neoplasms; Phytotherapy; Piperidines; Polyunsaturated Alkamides; Proanthocyanidins; Quercetin; Resveratrol; Stilbenes; Sulfides; Tea; Triterpenes; Xanthophylls

Topics: Administration, Oral; Administration, Topical; Allyl Compounds; Animals; Anticarcinogenic Agents; Antioxidants; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cocarcinogenesis; Curcumin; Female; Flavonoids; Humans; Male; Mice; Mice, Inbred SENCAR; Neoplasms, Radiation-Induced; Papilloma; Phenols; Phytotherapy; Plants, Medicinal; Polymers; Reactive Oxygen Species; Resveratrol; Silymarin; Skin Neoplasms; Stilbenes; Sulfides; Tea; Ultraviolet Rays; Zingiber officinale

The abnormalities associated with cancer cachexia include anorexia, weight loss, muscle loss and atrophy, anaemia and alterations in carbohydrate, lipid and protein metabolism. The aim of the present investigation was to examine the anti-wasting effects of some nutraceuticals such as genistein, resveratrol, epigallocatechin gallate and diallyl sulphide (DAS).. The in vitro effects of these nutraceuticals on proteolysis were examined in muscle cell cultures submitted to hyperthermia. The in vivo effects of DAS were also tested in cachectic tumour-bearing rats (Yoshida AH-130 ascites hepatoma).. Although all the nutraceuticals tested inhibited muscle proteolysis, the most promising effects were related with DAS. In vivo administration of DAS only leads to a small improvement in tibialis muscle and heart weights; however, administration of DAS to healthy animals increased all muscle weights, this being associated with a decreased gene expression of proteolytic systems components.. It may be suggested that DAS could be used to improve muscle mass during healthy conditions.

Topics: Allyl Compounds; Animals; Anorexia; Cachexia; Catechin; Cells, Cultured; Dietary Supplements; Genistein; Male; Muscle, Skeletal; Muscular Atrophy; Neoplasms; Rats; Rats, Wistar; Resveratrol; Stilbenes; Sulfides; Weight Loss

Since flavonoids and other natural compounds exert beneficial effects on human health, their consumption rapidly increases. However, they can modulate the activity of xenobiotic-metabolizing enzymes involved in activation and detoxification of food and environmental carcinogens. Thus, their potential negative effects should be examined.. The induction effects of selected chemopreventive compounds, administered per orally by gastric gavages to rats, on cytochrome P450 (CYP) 1A and 2B were determined in liver and small intestine using Western blotting analysis and specific metabolic activity assays.. Comparing CYPs expression along small intestine, the highest induction was observed in the proximal part near pylorus with rapid decrease towards the distal part. In response to chemopreventive compounds, the marked induction of CYP1A and CYP2B in liver was observed after diallyl sulphide and flavone treatment. In small intestine, beta-naphthoflavone, diallyl sulphide and curcumin induced CYP1A1 and CYP2B1. In both tissues, resveratrol did not significantly affect CYPs expression. The results of Western blotting detection of CYPs correlate well with their specific enzymatic activities.. Presented data indicate ambiguous impact of chemopreventive compounds on cytochromes P450, main xenobiotic-metabolizing enzymes. Thus, the question of safety and unlimited consumption of these compounds arises.

Topics: Allyl Compounds; Animals; Anticarcinogenic Agents; beta-Naphthoflavone; Blotting, Western; Curcumin; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP2B1; Cytochrome P-450 Enzyme System; Flavonoids; Intestine, Small; Liver; Male; Rats; Rats, Wistar; Resveratrol; Stilbenes; Sulfides; Xenobiotics

Treatment with the microsomal enzyme inducer trans-stilbene oxide (TSO) can decrease biliary excretion of acetaminophen-glucuronide (AA-GLUC) and increase efflux of AA-GLUC into blood. The hepatic canalicular multidrug resistance protein (Mrp) 2 and sinusoidal protein Mrp3 transport AA-GLUC conjugates into bile and blood, respectively. Thus, TSO-induced alterations in the vectorial excretion of AA-GLUC may occur via increased hepatic Mrp3 levels. The goal of this study was to determine whether TSO, diallyl sulfide (DAS), and oltipraz (OLT) treatments can up-regulate Mrp3 protein expression, and whether treatment with DAS and OLT can correspondingly increase hepatovascular efflux of AA metabolites. Rats were administered phenobarbital, TSO, DAS, OLT, or vehicle for 4 days. Interestingly, all of the chemicals increased the plasma concentration and urinary excretion of AA-GLUC and decreased its biliary excretion. In control animals, approximately 77% and 23% of AA-GLUC was excreted into bile or urine, respectively, whereas with inducer-pretreated animals, <32% of AA-GLUC was excreted into bile and >68% was excreted into urine. Correspondingly, all of the compounds increased hepatic Mrp3 mRNA levels by 13- to 37-fold and protein levels by 2- to 6-fold, respectively. In conclusion, these studies correlate increased Mrp3 protein levels in liver with increased hepatovascular excretion of AA-GLUC and suggest that induction of Mrp3 affects the route of drug excretion.

Topics: Acetaminophen; Allyl Compounds; Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Transporters; Bile; Blotting, Western; Branched DNA Signal Amplification Assay; Drug Resistance, Multiple; Kidney; Liver; Male; Mitochondrial Proteins; Phenobarbital; Pyrazines; Rats; Rats, Sprague-Dawley; Ribosomal Proteins; RNA, Messenger; Saccharomyces cerevisiae Proteins; Stilbenes; Sulfides; Thiones; Thiophenes; Time Factors

Oxidative biotransformation, coupled with genetic variability in enzyme expression, has been the focus of hypotheses interrelating environmental and genetic factors in the etiology of central nervous system disease processes. Chemical modulation of cerebral cytochrome P450 (P450) monooxygenase expression character may be an important determinant of in situ metabolism, neuroendocrine homeostasis, and/or central nervous system toxicity resulting from exposure to neuroactive drugs and xenobiotic substances. To examine the capacity of the rat brain to undergo phenobarbital (PB)-mediated induction, we developed reverse transcription-polymerase chain reaction methods and evaluated the effects of several PB-like inducers on P450 and microsomal epoxide hydrolase gene expression. Animals treated i.p. with four daily doses of PB demonstrated markedly induced levels of CYP2B1, CYP2B2, and CYP3A1 mRNA in the striatum and cerebellum. In contrast, 1 or 2 days of PB treatment resulted in unchanged or even slightly decreased levels of CYP2B1 and CYP2B2 in the brain, although the latter treatments produced marked induction of the corresponding genes in the liver. Only slight increases in epoxide hydrolase RNA levels resulted in brains of PB-treated animals. Substantial activation of cerebral CYP2B1, CYP2B2, and CYP3A1 mRNA levels also resulted when animals were treated with the neuroactive drugs diphenylhydantoin and amitryptiline, and with the potential PB-like xenobiotic inducers trans-stilbene oxide and diallyl sulfide, whereas dichlorodiphenyltrichloroethane was less efficacious. Although the time course of the induction response is delayed in brain relative to that required for the liver, these results clearly establish that brain P450s are markedly PB inducible.

Topics: Allyl Compounds; Amitriptyline; Animals; Aryl Hydrocarbon Hydroxylases; Blotting, Northern; Brain; Cytochrome P-450 CYP2B1; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; DDT; Enzyme Induction; Epoxide Hydrolases; Liver; Male; Mixed Function Oxygenases; Phenobarbital; Phenytoin; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Steroid Hydroxylases; Stilbenes; Sulfides