Involvement of UDP-Glucuronosyltransferases and Sulfotransferases in the Excretion and Tissue Distribution of Resveratrol in Mice.

Resveratrol is a naturally occurring polyphenolic compound with various pharmacological activities. It is unknown whether the expression of metabolizing enzymes correlates with resveratrol levels in organs and tissues. Therefore, we investigated the metabolism and tissue distribution of resveratrol in mice and assessed its association with the expression of UDP-glucuronosyltransferase (Ugt) and sulfotransferase (Sult) genes. Plasma, urine, feces, and various organs were analyzed using high-performance liquid chromatography at up to 8 h after intragastric resveratrol administration. The metabolism of resveratrol was pronounced, leading to the formation of resveratrol glucuronides and sulfates. Concentrations of resveratrol and its metabolites were high in the gastrointestinal organs, urine, and feces, but low in the liver and kidneys. In lung, heart, thymus, and brain tissues, parent resveratrol levels exceeded the sulfate and glucuronide concentrations. The formation of resveratrol conjugates correlated with the expression of certain Ugt and Sult genes. Reverse transcription quantitative PCR (RT-qPCR) analysis revealed high mRNA expression of Ugt1a1 and Ugt1a6a in the liver, duodenum, jejunum, ileum, and colon, leading to high concentrations of resveratrol-3-O-glucuronide in these organs. Strong correlations of resveratrol-3-O-sulfate and resveratrol-3-O-4'-O-disulfate formation with Sult1a1 mRNA expression were also observed, particularly in the liver and colon. In summary, our data revealed organ-specific expression of Sults and Ugts in mice that strongly affects resveratrol concentrations; this may also be predictive in humans following oral uptake of dietary resveratrol

Organic anion‑transporting polypeptides contribute to the uptake of curcumin and its main metabolites by human breast cancer cells: Impact on antitumor activity

Curcumin is a natural polyphenolic compound with pronounced anticancer properties, despite its low bioavailability caused by extensive glucuronidation and sulfation. Information on the cellular uptake mechanisms and their contribution to the anticancer effects of curcumin and its biotransformation products is limited. The present study, therefore, investigated the role of organic anion‑transporting polypeptides (OATPs) in the cellular uptake of curcumin and its major metabolites in OATP‑expressing Chinese hamster ovary (CHO) and human ZR‑75‑1 breast cancer cells. The uptake rates for curcumin in OATP1B1‑, OATP1B3‑ and OATP2B1‑transfected CHO cells were 2‑ to 3‑fold higher than wild‑type cells. Curcumin sulfate was transported by all three OATPs, although to a much lesser extent, while uptake of tetrahydrocurcumin was the highest but only via OATP1B1 and OATP1B3. Notably, curcumin glucuronide did not exhibit any affinity for these OATPs. The increased mRNA levels of OATP1B1 in wild‑type human breast cancer ZR‑75‑1 cells compared with OATP1B1 knockdown cells was associated with a higher initial uptake of curcumin and tetrahydrocurcumin leading to decreased IC50 values. In conclusion, our data revealed that OATPs act as cellular uptake transporters for curcumin and its major metabolites, and this may also be applicable to patients undergoing cancer therapy

Role of Organic Anion Transporting Polypeptides (OATPs) in the cellular accumulation of antitumor agents in lung, breast and liver cancer

Weil eine medikamentöse Therapie Effizienz und Arzneimittelsicherheit erfordert, ist es wichtig, pharmakokinetische Parameter genauestens zu charakterisieren. Ziel dieser Dissertation war es, zelluläre Aufnahmemechanismen und die Art und Weise, wie Biotransformation die Medikamentenaufnahme beeinflusst, zu erforschen. Aus diesem Grund untersuchten wir Transporter und den zellulären Metabolismus mit dem Schwerpunkt OATPs (Organic Anion Transporting Polypetides). OATPs sind speziell bei Krebs relevant, weil sich ihr Expressionsmuster während der Tumorgenese ändert. Abgesehen von OATPs untersuchten wir auch dir Rolle von Phase 2-Metaboliten bei Aufnahme und Bioverfügbarkeit eines Arzneistoffs, denn auch dessen Biotransformation kann die Effizient einer Behandlung beeinflussen. Weil die Leber eines der wichtigsten am Stoffwechsel beteiligten Organe ist, untersuchten wir OATPs in der Leber sowie in Lebertumoren und entdeckten ein bestimmtes OATP-Expressionsmuster. Weiters wurden Unterschiede in der OATP-Expression in Lungenkrebs-Zelllinien und –Geweben erforscht und eine starke Korrelation zwischen dem OATP-Expressionsmuster und dem Ursprung der Zellen beobachtet. Außerdem wurde der Einfluss von OATPs auf die Tumorprogression und die Chemoresistenz bestimmt. In weiteren Studien konzentrierten wir uns auf natürliche Stoffe wie Resveratrol und seine Metabolite, das Antitumor-Mittel Flavopiridol, unterschiedliche Anthocyane und die Rolle von OATPs in deren Transport, sowie deren Einfluss auf die Expression von OATPs. Es bleibt zu hoffen, dass diese Ergebnisse dabei helfen, die komplexen Prozesse von Aufnahme und Metabolismus in vivo besser zu verstehen.Since a drug therapy requires efficacy and safety, pharmacokinetic parameters should be properly characterized. The aim of this thesis was to elucidate cellular uptake mechanisms and the way biotransformation influences drug uptake by investigating transporters and metabolism in cells with a focus on OATPs (organic anion transporting polypetides). Because their expression pattern changes during tumor development OATPs are of special interest in cancer. Also, biotransformation can influence the efficacy of a treatment and therefore, the role of phase II-metabolites in uptake and bioavailability of a drug was investigated. By focusing on the liver, as it is the main organ responsible for biotransformation and elimination processes, we detected a distinct OATP expression pattern in liver and hepatic cancer. Also, differences in OATP expression in lung cancer cell lines and tissues were investigated and revealed a strong correlation between the OATP expression pattern and the origin of the cells. Furthermore, the influence of OATPs on tumor progression and chemotherapy resistance was determined. In further studies we concentrated on natural compounds like resveratrol and its metabolites, the antitumor agent flavopiridol, various anthocyans and the role of OATPs in their transport as well as their influence on OATP expression. Finally, the present findings might help to better understand the complex processes of uptake and metabolism in vivo

Involvement of UDP-Glucuronosyltransferases and Sulfotransferases in the Excretion and Tissue Distribution of Resveratrol in Mice

Resveratrol is a naturally occurring polyphenolic compound with various pharmacological activities. It is unknown whether the expression of metabolizing enzymes correlates with resveratrol levels in organs and tissues. Therefore, we investigated the metabolism and tissue distribution of resveratrol in mice and assessed its association with the expression of UDP-glucuronosyltransferase (Ugt) and sulfotransferase (Sult) genes. Plasma, urine, feces, and various organs were analyzed using high-performance liquid chromatography at up to 8 h after intragastric resveratrol administration. The metabolism of resveratrol was pronounced, leading to the formation of resveratrol glucuronides and sulfates. Concentrations of resveratrol and its metabolites were high in the gastrointestinal organs, urine, and feces, but low in the liver and kidneys. In lung, heart, thymus, and brain tissues, parent resveratrol levels exceeded the sulfate and glucuronide concentrations. The formation of resveratrol conjugates correlated with the expression of certain Ugt and Sult genes. Reverse transcription quantitative PCR (RT-qPCR) analysis revealed high mRNA expression of Ugt1a1 and Ugt1a6a in the liver, duodenum, jejunum, ileum, and colon, leading to high concentrations of resveratrol-3-O-glucuronide in these organs. Strong correlations of resveratrol-3-O-sulfate and resveratrol-3-O-4′-O-disulfate formation with Sult1a1 mRNA expression were also observed, particularly in the liver and colon. In summary, our data revealed organ-specific expression of Sults and Ugts in mice that strongly affects resveratrol concentrations; this may also be predictive in humans following oral uptake of dietary resveratrol

The effect of organic anion-transporting polypeptides 1B1, 1B3 and 2B1 on the antitumor activity of flavopiridol in breast cancer cells

The contribution of organic anion transporting polypeptides (OATPs) to the cellular uptake of flavopiridol was investigated in OATP1B1-, OATP1B3- and OATP2B1-expressing Chinese hamster ovary (CHO) cells. Uptake of flavopiridol into these cells showed typical Michaelis-Menten kinetics with much higher transport capacity for OATP1B3 compared to OATP1B1 and OATP2B1 (Vmax/Km, 33.9 vs. 8.84 and 2.41 µl/mg/min, respectively). The predominant role of OATPs was further supported by a dramatic inhibition of flavopiridol uptake in the presence of the OATP substrate rifampicin. Uptake of flavopiridol by OATPs also seems to be an important determinant in breast cancer cells. The much higher mRNA level for OATP1B1 found in wild-type compared to ZR-75-1 OATP1B1 knockdown cells correlated with higher flavopiridol initial uptake leading to 4.6-fold decreased IC50 values in the cytotoxicity assay (IC50, 1.45 vs. 6.64 µM). Cell cycle profile also showed a clear incidence for a stronger cell cycle arrest in the G2/M phase for ZR-75-1 wild-type cells compared to OATP1B1 knockdown cells, further indicating an active uptake via OATP1B1. In conclusion, our results revealed OATP1B1, OATP1B3 and OATP2B1 as uptake transporters for flavopiridol in cancer cells, which may also apply in patients during cancer therapy

Involvement of UDP-Glucuronosyltransferases and Sulfotransferases in the Excretion and Tissue Distribution of Resveratrol in Mice.

Resveratrol is a naturally occurring polyphenolic compound with various pharmacological activities. It is unknown whether the expression of metabolizing enzymes correlates with resveratrol levels in organs and tissues. Therefore, we investigated the metabolism and tissue distribution of resveratrol in mice and assessed its association with the expression of UDP-glucuronosyltransferase (Ugt) and sulfotransferase (Sult) genes. Plasma, urine, feces, and various organs were analyzed using high-performance liquid chromatography at up to 8 h after intragastric resveratrol administration. The metabolism of resveratrol was pronounced, leading to the formation of resveratrol glucuronides and sulfates. Concentrations of resveratrol and its metabolites were high in the gastrointestinal organs, urine, and feces, but low in the liver and kidneys. In lung, heart, thymus, and brain tissues, parent resveratrol levels exceeded the sulfate and glucuronide concentrations. The formation of resveratrol conjugates correlated with the expression of certain Ugt and Sult genes. Reverse transcription quantitative PCR (RT-qPCR) analysis revealed high mRNA expression of Ugt1a1 and Ugt1a6a in the liver, duodenum, jejunum, ileum, and colon, leading to high concentrations of resveratrol-3-O-glucuronide in these organs. Strong correlations of resveratrol-3-O-sulfate and resveratrol-3-O-4'-O-disulfate formation with Sult1a1 mRNA expression were also observed, particularly in the liver and colon. In summary, our data revealed organ-specific expression of Sults and Ugts in mice that strongly affects resveratrol concentrations; this may also be predictive in humans following oral uptake of dietary resveratrol

Involvement of UDP-Glucuronosyltransferases and Sulfotransferases in the Excretion and Tissue Distribution of Resveratrol in Mice

Resveratrol is a naturally occurring polyphenolic compound with various pharmacological activities. It is unknown whether the expression of metabolizing enzymes correlates with resveratrol levels in organs and tissues. Therefore, we investigated the metabolism and tissue distribution of resveratrol in mice and assessed its association with the expression of UDP-glucuronosyltransferase (Ugt) and sulfotransferase (Sult) genes. Plasma, urine, feces, and various organs were analyzed using high-performance liquid chromatography at up to 8 h after intragastric resveratrol administration. The metabolism of resveratrol was pronounced, leading to the formation of resveratrol glucuronides and sulfates. Concentrations of resveratrol and its metabolites were high in the gastrointestinal organs, urine, and feces, but low in the liver and kidneys. In lung, heart, thymus, and brain tissues, parent resveratrol levels exceeded the sulfate and glucuronide concentrations. The formation of resveratrol conjugates correlated with the expression of certain Ugt and Sult genes. Reverse transcription quantitative PCR (RT-qPCR) analysis revealed high mRNA expression of Ugt1a1 and Ugt1a6a in the liver, duodenum, jejunum, ileum, and colon, leading to high concentrations of resveratrol-3-O-glucuronide in these organs. Strong correlations of resveratrol-3-O-sulfate and resveratrol-3-O-4′-O-disulfate formation with Sult1a1 mRNA expression were also observed, particularly in the liver and colon. In summary, our data revealed organ-specific expression of Sults and Ugts in mice that strongly affects resveratrol concentrations; this may also be predictive in humans following oral uptake of dietary resveratrol.© 2017 by the author