title: Cytochrome P450-mediated metabolism in brain: functional roles and their implications.
abstract: BACKGROUND
  Cytochromes P450 (P450) and associated monooxygenases are a family of heme proteins involved in metabolism of endogenous compounds (arachidonic acid, eicosanoids and prostaglandins) as also xenobiotics including drugs and environmental chemicals. Liver is the major organ involved in P450-mediated metabolism and hepatic enzymes have been characterized. Extrahepatic organs, such as lung, kidney and brain have the capability for biotransformation through P450 enzymes. Brain, including human brain, expresses P450 enzymes that metabolize xenobiotics and endogenous compounds.
  
  
  METHODS
  An overview of P450-mediated metabolism in brain is presented focusing on distinct differences seen in expression of P450 enzymes, generation of unique P450 enzymes in brain through alternate splicing and their consequences in terms of metabolism of psychoactive drugs and inflammatory prompts, such as leukotrienes, thus modulating inflammatory response.
  
  
  CONCLUSIONS
  The brain possesses unique P450s that metabolize drugs and endogenous compounds through pathways that are markedly different from that seen in liver indicating that extrapolation directly from liver to brain is not appropriate. It is therefore necessary to characterize the unique brain P450s and their ability to metabolize xenobiotics and endogenous compounds to better understand the functions of this important class of enzymes in brain, especially human brain.
authors: Indian Institute of Science, Centre for Neuroscience, C.V. Raman Avenue, Bangalore 560012, India. viji@cns.iisc.ernet.in
authors: Vijayalakshmi
authors: V
authors: Ravindranath
authors: Henry W
authors: HW
authors: Strobel
mesh_terms: D017398:Alternative Splicing; D016718:Arachidonic Acid / Q000378:metabolism; D001711:Biotransformation; D001921:Brain / Q000201:enzymology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D015777:Eicosanoids / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D008099:Liver / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000378:metabolism; D011453:Prostaglandins / Q000378:metabolism; D015262:Xenobiotics / Q000378:metabolism
chemical_list: D015777:Eicosanoids; D011453:Prostaglandins; D015262:Xenobiotics; D016718:Arachidonic Acid; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases