Although phototherapy was introduced as early as 1950's, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells.
- MeSH
- bilirubin chemie izolace a purifikace farmakologie MeSH
- buněčné linie MeSH
- buněčný cyklus účinky léků MeSH
- cirkulární dichroismus MeSH
- fototerapie MeSH
- hem metabolismus MeSH
- isomerie MeSH
- kinetika MeSH
- lidé MeSH
- ligandy MeSH
- regulace genové exprese účinky léků MeSH
- sérový albumin metabolismus MeSH
- spektrofotometrie ultrafialová MeSH
- světlo * MeSH
- viabilita buněk účinky léků MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bilirubin MeSH
- hem MeSH
- ligandy MeSH
- sérový albumin MeSH
Bilirubin is degraded in the human gut by microflora into urobilinoids. In our study we investigated whether the bilirubin-reducing strain of Clostridium perfringens can reduce bilirubin ditaurate (BDT), a bile pigment of some lower vertebrates, without hydrolysis of the taurine moiety. C. perfringes was incubated under anaerobic conditions with BDT; reduction products were quantified by spectrophotometry and separated by TLC. Based on Rf values of BDT reduction products and synthetic urobilinogen ditaurate, three novel taurine-conjugated urobilinoids were identified. It is likely that bilirubin-reducing enzyme(s) serve for the effective disposal of electrons produced by fermentolytic processes in these anaerobic bacteria.
- MeSH
- bilirubin analogy a deriváty izolace a purifikace metabolismus MeSH
- chromatografie na tenké vrstvě MeSH
- Clostridium perfringens izolace a purifikace metabolismus MeSH
- feces mikrobiologie MeSH
- hydrolýza MeSH
- lidé MeSH
- novorozenec MeSH
- oxidace-redukce MeSH
- střeva mikrobiologie MeSH
- taurin analogy a deriváty izolace a purifikace metabolismus MeSH
- urobilinogen MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bilirubin ditaurine MeSH Prohlížeč
- bilirubin MeSH
- taurin MeSH
- urobilinogen MeSH
- MeSH
- bilirubin izolace a purifikace MeSH
- feces analýza MeSH
- fotochemoterapie * MeSH
- hyperbilirubinemie farmakoterapie MeSH
- lidé MeSH
- nemoci novorozenců farmakoterapie MeSH
- novorozenec MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- ženské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- bilirubin MeSH
