A pilot study on transient ischemic stroke induced with endothelin-1 in the rhesus monkeys.

Endothelin-1 (ET-1), a vasoconstrictor, has recently been used to induce focal ischemia in rodents and marmoset monkeys. The rhesus monkey, however, has numerous advantages to the rodent and marmoset that make it a superior and irreplaceable animal model for studying stroke in the brain. In the present study, after mapping the preferred hand representation in two healthy male monkeys with intracortical micro-stimulation, ET-1 was microinjected into the contralateral motor cortex (M1) to its preferred hand.

Species- and gender-dependent differences in the glucuronidation of a flavonoid glucoside and its aglycone determined using expressed UGT enzymes and microsomes.

Flavonoids occur naturally as glucosides and aglycones. Their common phenolic hydroxyl groups may trigger extensive UDP-glucuronosyltransferase (UGT)- catalysed metabolism. Unlike aglycones, glucosides contain glucose moieties.

A combined strategy of mass fragmentation, post-column cobalt complexation and shift in ultraviolet absorption spectra to determine the uridine 5'-diphospho-glucuronosyltransferase metabolism profiling of flavones after oral administration of a flavone mixture in rats.

The use of dietary flavones is becoming increasingly popular for their prevention of cancers, cardiovascular diseases, and other diseases. Despite many pharmacokinetic studies on flavone mixtures, the position(s) of glucuronidation sites on the flavone skeleton in vivo remain(s) uncertain because of the lack of a convenient method to differentiate the isomers in biological samples. Accordingly, this study aimed to develop a new strategy to identify the position of the mono-O-glucuronide of flavones in vivo and to simultaneously determine the parent agent and its major metabolites responsible for complex pharmacokinetic characteristics.

UDP-Glucuronosyltransferases 1A6 and 1A9 are the Major Isozymes Responsible for the 7-O-Glucuronidation of Esculetin and 4-Methylesculetin in Human Liver Microsomes.

Esculetin (6,7-dihydroxycoumarin, ET) and 4-methylesculetin (6,7-dihydroxy-4-methylcoumarin, 4-ME) are typical coumarin derivatives that are attracting considerable attention because of their wide spectrum of biologic activities, but their metabolism remains unknown. This study aimed to elucidate the in vitro UDP-glucuronosyltransferase (UGT) metabolism characteristics of ET and 4-ME. 7-O-monoglucuronide esculetin (ET-G) and 7-O-monoglucuronide 4-methylesculetin (4-ME-G) were identified by liquid chromatography-mass spectrometry (LC-MS) and (1)H-nuclear magnetic resonance ((1)HNMR) when ET or 4-ME was incubated with human liver (HLM) in the presence of UDP-glucuronic acid.

Triple Recycling Processes Impact Systemic and Local Bioavailability of Orally Administered Flavonoids.

Triple recycling (i.e., enterohepatic, enteric and local recycling) plays a central role in governing the disposition of phenolics such as flavonoids, resulting in low systemic bioavailability but higher gut bioavailability and longer than expected apparent half-life.

Multidrug resistance-associated protein 2 is involved in the efflux of Aconitum alkaloids determined by MRP2-MDCKII cells.

Aims: Aconitum alkaloids mainly contain highly toxic aconitine (AC), mesaconitine (MA), and hypaconitine (HA) and less toxic benzoylaconine (BAC), benzoylmesaconine (BMA), benzoylhypaconine (BHA), aconine, mesaconine, and hypaconine. The efflux transporters including P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance-associated protein 2 (MRP2) can efflux toxicants to prevent poisoning. Our previous publication has proved that P-gp and BCRP contributed to the efflux of AC, MA and HA, which is demonstrated in the human colonic adenocarcinoma cell lines (Caco-2 cells), Mardin-Darby canine kidney cell lines transfected with MDR1 or BCRP (MDR1-MDCKII and BCRP-MDCKII cells).

Pharmacokinetic comparisons of benzoylmesaconine in rats using ultra-performance liquid chromatography-tandem mass spectrometry after administration of pure benzoylmesaconine and Wutou decoction.

Wutou decoction is widely used in China because of its therapeutic effect on rheumatoid arthritis. Benzoylmesaconine (BMA), the most abundant component of Wutou decoction, was used as the marker compound for the pharmacokinetic study of Wutou decoction. The aim of the present study was to compare the pharmacokinetics of BMA in rats after oral administration of pure BMA and Wutou decoction.

Nanog expression is negatively regulated by protein kinase C activities in human cancer cell lines.

Nanog is a transcription factor that is essential for the maintenance of pluripotency of the embryonic stem cells. Nanog has been shown to be expressed in various kinds of human tumors, suggesting a role in tumorigenesis. In this study, we found that Nanog expression was upregulated by inhibition of protein kinase C (PKC) activity in six human cancer cell lines examined.

Glycogen synthase kinase-3beta regulates DeltaNp63 gene transcription through the beta-catenin signaling pathway.

Overexpression of DeltaNp63 has been observed in a number of human cancers, suggesting a role for DeltaNp63 in carcinogenesis. In the present study, we show that inhibition of glycogen synthase kinase-3beta (GSK-3beta) by lithium chloride (LiCl) elicited a stimulatory effect on DeltaNp63 promoter activity in HEK 293T cells. Exposure to LiCl induced DeltaNp63 promoter activation as well as DeltaNp63 protein expression in the cells.

Transcriptional activity of the DeltaNp63 promoter is regulated by STAT3.

The N terminus-truncated splicing variant of TAp63 is known as DeltaNp63. DeltaNp63 lacks transactivation function and is thought to antagonize the transcriptional regulation of the p53 and TAp63 target genes. Overexpression of DeltaNp63 has been observed in a number of human cancers, suggesting a role in carcinogenesis.