A Japanese Patient with Gastric Cancer and Dihydropyrimidine Dehydrogenase Deficiency Presenting with DPYD Variants.

A 63-year-old Japanese male with stomach adenocarcinoma received oral 5-fluorouracil derivative, cisplatin and trastuzumab chemotherapy. On day 8, severe diarrhea and mucositis developed; chemotherapy was stopped. On day 14, the patient developed renal dysfunction and febrile neutropenia.

Magnolol protects PC12 cells from hydrogen peroxide or 6-hydroxydopamine induced cytotoxicity.

Magnoliae Cortex contains a range of bioactive components including terpenes (e.g. α-, β- and γ-eudesmol), phenylpropanoids (e.

4-(Hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone glucuronide has the potential to form 2'-deoxyguanosine and N-acetylcysteine adducts.

Cigarette smoking is a risk factor for the development of various cancers, such as lung, nasal, liver and bladder cancers. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific nitrosamine, is implicated in human lung cancer. NNK-induced DNA adducts are found in target tissues for NNK carcinogenesis.

Procyanidins from Cinnamomi Cortex promote proteasome-independent degradation of nuclear Nrf2 through phosphorylation of insulin-like growth factor-1 receptor in A549 cells.

Many lines of evidence demonstrate that transcription factor nuclear factor-E2-related factor 2 (Nrf2) plays essential roles in cancer cell proliferation and resistance to chemotherapy, thereby indicating that suppression of abnormal Nrf2 activation is needed for a new therapeutic approach. Our previous studies reported that procyanidins prepared from Cinnamomi Cortex extract (CCE) have an ability to suppress cytoprotective enzymes and cell proliferation in human cancer cells with activated Nrf2. In the present study, we investigated the mechanism of CCE procyanidin-mediated antagonization of Nrf2.

Selective antagonization of activated Nrf2 and inhibition of cancer cell proliferation by procyanidins from Cinnamomi Cortex extract.

Nuclear factor-E2-related factor 2 (Nrf2) is an important transcription factor and plays a central role in inducible expression of many cytoprotective genes. Recent studies have reported that various cancer cells having unrestrained Nrf2 due to its overexpression exhibit increased proliferation and resistance to chemotherapy. Suppression of abnormal Nrf2 activation is needed for a new therapeutic approach against these cancers.

5-Fluorouracil Chemotherapy for Dihydropyrimidine Dehydrogenase-deficient Patients: Potential of the Dose-escalation Method.

Background: Dihydropyrimidine dehydrogenase (DPD) degrades approximately 85% of administered 5-fluorouracil (5-FU). With a reported high mortality rate, chemotherapy is generally contraindicated for patients with DPD deficiency.

Patients And Methods: Chemotherapy was initiated for a 73-year-old man with DPD deficiency.

Formation and stability of 4-(hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone glucuronide, a stable form of reactive intermediate produced from 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, in mice.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific nitrosamine, induced lung tumors in rodents and is likely involved in human lung cancer. 4-(Hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (HO-methyl NNK) glucuronide, a glucuronide of the reactive intermediate of NNK, has been identified in rats. The aim of this study is to estimate the role of HO-methyl NNK glucuronide in the tumorigenic effects of NNK.

Tissue distributions of 4-(hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone glucuronide, a stable form of reactive intermediate produced from 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, in the rat.

The tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), induces lung tumors in rodents and has been suggested as a causative factor in human lung cancer. NNK is activated by α-hydroxylation at either the methyl or methylene carbon adjacent to the N-nitroso group to yield unstable intermediates that spontaneously decompose to produce alkylating agents. 4-(Hydroxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (HO-methyl NNK) glucuronide, a glucuronide of the reactive intermediate of NNK has been identified.

Enhanced sensitivity of A549 cells to the cytotoxic action of anticancer drugs via suppression of Nrf2 by procyanidins from Cinnamomi Cortex extract.

Nuclear factor-E2-related factor 2 (Nrf2) is an important cytoprotective transcription factor because Nrf2-regulated enzymes play a key role in antioxidant and detoxification processes. Recent studies have reported that lung cancer cells overexpressing Nrf2 exhibit increased resistance to chemotherapy. Suppression of overexpressed Nrf2 is needed for a new therapeutic approach against lung cancers.

Dietary diacetylene falcarindiol induces phase 2 drug-metabolizing enzymes and blocks carbon tetrachloride-induced hepatotoxicity in mice through suppression of lipid peroxidation.

Falcarindiol is a diacetylenic natural product containing unique carbon-carbon triple bonds. Mice were orally administrated falcarindiol (100 mg/kg), and drug-metabolizing and antioxidant enzymes were monitored in several tissues of mice. Treatment with falcarindiol was found to increase glutathione S-transferase (GST) and NAD(P)H: quinone oxidoreductase 1 activities in liver, small intestine, kidney, and lung.

Organic anion-transporting polypeptide 1b2 (Oatp1b2) is important for the hepatic uptake of unconjugated bile acids: Studies in Oatp1b2-null mice.

Unlabelled: The organic anion-transporting polypeptide 1b family (Oatp1b2 in rodents and OATP1B1/1B3 in humans) is liver-specific and transports various chemicals into the liver. However, the role of the Oatp1b family in the hepatic uptake of bile acids (BAs) into the liver is unknown. Therefore, in Oatp1b2-null mice, the concentrations of BAs in plasma, liver, and bile were compared with wild-type (WT) mice.

Cooperation of NAD(P)H:quinone oxidoreductase 1 and UDP-glucuronosyltransferases reduces menadione cytotoxicity in HEK293 cells.

Previous studies have shown that NAD(P)H:quinone oxidoreductase 1 (NQO1) plays an important role in the detoxification of menadione (2-methyl-1,4-naphthoquinone, also known as vitamin K3). However, menadiol (2-methyl-1,4-naphthalenediol) formed from menadione by NQO1-mediated reduction continues to be an unstable substance, which undergoes the reformation of menadione with concomitant formation of reactive oxygen species (ROS). Hence, we focused on the roles of phase II enzymes, with particular attention to UDP-glucuronosyltransferases (UGTs), in the detoxification process of menadione.

Activation of the Nrf2/ARE pathway via S-alkylation of cysteine 151 in the chemopreventive agent-sensor Keap1 protein by falcarindiol, a conjugated diacetylene compound.

Under basal conditions, the interaction of the cytosolic protein Kelch-like ECH-associated protein 1 (Keap1) with the transcription factor nuclear factor-E2-related factor 2 (Nrf2) results in a low level of expression of cytoprotective genes whose promoter region contains the antioxidant response element (ARE). In response to oxidants and electrophiles, Nrf2 is stabilized and accumulates in the nucleus. The mechanism for this effect has been proposed to involve thiol-dependent modulation of Keap1, leading to loss of its ability to negatively regulate Nrf2.

Induction of antioxidant and phase 2 drug-metabolizing enzymes by falcarindiol isolated from Notopterygium incisum extract, which activates the Nrf2/ARE pathway, leads to cytoprotection against oxidative and electrophilic stress.

In the present study, we isolated falcarindiol from Notopterygium incisum and investigated the effect of falcarindiol on the expression of antioxidant enzymes (AOEs), such as catalase, and phase 2 drug-metabolizing enzymes (DMEs), such as glutathione S-transferase and NAD(P)H:quinone oxidoreductase 1, in a cultured cell line from normal rat liver, Clone 9 cells. Exposure of Clone 9 cells to falcarindiol resulted in the significant induction of AOEs and phase 2 DMEs. Western blot analysis and transfection studies using a luciferase reporter construct demonstrated that the induction of AOEs and phase 2 DMEs by falcarindiol was caused through the Nrf2/ARE (nuclear factor-E2-related factor 2/antioxidant response element) pathway.

Inhibitory effects of herbal extracts on the activity of human sulfotransferase isoform sulfotransferase 1A3 (SULT1A3).

Sulfotransferase 1A3 (SULT1A3) is a phase II detoxifying enzyme of xenobiotics predominantly expressed in the intestinal epithelium. Recent increase in the use of herbal extracts as dietary supplements may lead to an increase in the possibility of dietary supplement-drug interactions. The purpose of the present study was to investigate the effects of 18 herbal extracts on SULT1A3 activity and the possibility of interaction between medicinal drugs and herbal extracts.

Amino acid positions 69-132 of UGT1A9 are involved in the C-glucuronidation of phenylbutazone.

Phenylbutazone (PB) is known to be biotransformed to its O- and C-glucuronide. Recently, we reported that PB C-glucuronide formation is catalyzed by UGT1A9. Interestingly, despite UGT1A8 sharing high amino acid sequence identity with UGT1A9, UGT1A8 had no PB C-glucuronidating activity.

Plasma profiling of intact isoflavone metabolites by high-performance liquid chromatography and mass spectrometric identification of flavone glycosides daidzin and genistin in human plasma after administration of kinako.

The roles of isoflavones in the prevention of several hormone-dependent cancers and osteoporosis are of great interest. Despite many pharmacokinetics studies of the isoflavones, the actual types of conjugates circulating in the body and the position(s) of conjugation sites on the flavone skeleton are still uncertain because, in general, conjugated compounds in biological fluids have been evaluated by measuring the free aglycones obtained after selective enzymatic hydrolysis. Using an high-performance (HPLC)-UV-diode-array detector (DAD) method combined with solid-phase extraction, we have obtained HPLC profiles of isoflavone glycosides [daidzin (Din) and genistin (Gin)] and of intact isoflavone metabolites in human plasma: daidzein, genistein, daizein-7-glucuronide, daidzein-4'-glucuronide, genistein-7-glucuronide, genistein-4'-glucuronide, daidzein-7-sulfate, daidzein-4'-sulfate, genistein-7-sulfate, and genistein-4'-sulfate.

UDP-glucuronosyltransferases 1A6 and 1A10 catalyze reduced menadione glucuronidation.

Menadione (2-methyl-1,4-naphthoquine), also known as vitamin K3, has been widely used as a model compound in the field of oxidative stress-related research. The metabolism of menadione has been studied, and it is known that menadione undergoes a two-electron reduction by NAD(P)H:Quinone oxidoreductase 1 (NQO1) after which the reduced form of menadione (2-methyl-1,4-naphthalenediol, menadiol) is glucuronidated and excreted in urine. To investigate which human UDP-glucuronosyltransferase (UGT) isoforms participate in the glucuronidation of menadiol reduced by NQO1 from menadione, we first constructed heterologously expressed NQO1 in Sf9 cells and tested the menadiol glucuronidating activity of 16 human recombinant UGT isoforms.

Characterization of organic anion transporting polypeptide 1b2-null mice: essential role in hepatic uptake/toxicity of phalloidin and microcystin-LR.

The liver-specific importer organic anion transporting polypeptide 1b2 (Oatp1b2, Slco1b2, also known as Oatp4 and Lst-1) and its human orthologs OATP1B1/1B3 transport a large variety of chemicals. Oatp1b2-null mice were engineered by homologous recombination and their phenotype was characterized. Oatp1b2 protein was absent in livers of Oatp1b2-null mice.

Inhibitory effects of various beverages on human recombinant sulfotransferase isoforms SULT1A1 and SULT1A3.

Sulfotransferase (SULT) 1A1 and SULT1A3 play important roles in the presystemic inactivation of beta(2) agonists in the liver and intestine, respectively. The study aimed to investigate the inhibitory effects of grapefruit juice, orange juice, green tea, black tea and oolong tea and their constituents on the activities of SULT1A1 and SULT1A3. The activities of both SULT1A1 and SULT1A3 were significantly inhibited by all the beverages investigated at a concentration of 10%.

Identification of human UDP-glucuronosyltransferase isoform(s) responsible for the C-glucuronidation of phenylbutazone.

Glucuronidation is a major metabolic pathway in the biotransformation of many xenobiotics and endogeneous compounds. There have been many studies on the formation of O-, N- or S-glucuronides and identification of the UDP-glucuronosyltransferase (UGT) isoforms responsible for the formation of these glucuronides. However, there is no information available on which UGT isoform(s) catalyzes C-glucuronidation.

[Dihydropyrimidine dehydrogenase activity and its genetic aberrations].

Dihydropyrimidine dehydrogenase (DPD, EC 1.3.1.

Quaternary ammonium-linked glucuronidation of trans-4-hydroxytamoxifen, an active metabolite of tamoxifen, by human liver microsomes and UDP-glucuronosyltransferase 1A4.

Tamoxifen (TAM), a nonsteroidal antiestrogen, is the most widely used drug for chemotherapy of hormone-dependent breast cancer in women. Trans-4-hydroxy-TAM (trans-4-HO-TAM), one of the TAM metabolites in humans, has been considered to be an active metabolite of TAM because of its higher affinity toward estrogen receptors (ERs) than the parent drug and other side-chain metabolites. In the present study, we found a new potential metabolic pathway of trans-4-HO-TAM and its geometrical isomer, cis-4-HO-TAM, via N-linked glucuronic acid conjugation for excretion in humans.

Formation of tamoxifen-DNA adducts via O-sulfonation, not O-acetylation, of alpha-hydroxytamoxifen in rat and human livers.

Tamoxifen (TAM) is used as the standard endocrine therapy for breast cancer patients and as a chemopreventive agent for women at high risk for this disease. Unfortunately, treatment of TAM increases the incidence of endometrial cancer; this may be due to the genotoxic damage induced by TAM metabolites. Formation of TAM-DNA adducts in rat liver correlates with the development of hepatocarcinoma.