Table 1.

Commonly used CYP450s and their substrate in probe assays along with the HPLC-MS methods.

Enzyme	Tissue Sites	Probe	Metabolite	Ref.
CYP1A1	Liver, intestine	Phenacetin	Phenacetin O-deethylation (Acetaminophen)	[45]
		Ethoxyresorufin	Ethoxyresorufin O-de-ethylase	[46]
CYP1A2	Liver	Phenacetin	Phenacetin O-deethylation (Acetaminophen)	[47]
		Caffeine	Paraxanthine	[48,49,50]
		Methoxyresorufin	Methoxyresorufin O-demethylase	[46]
CYP2A6	Liver, lung	Coumarin	Coumarin 7-hydroxylation	[47]
		Methoxsalen	N/A	[51]
CYP2B6	Liver, lung	Bupropion	Bupropion hydroxylation	[47]
CYP2C6	Liver	Tolbutamide	N/A	[52]
CYP2C8	Liver	Paclitaxel	Paclitaxel 6-hydroxylation	[47]
CYP2C9	Liver, intestine	Diclofenac	Diclofenac 4′-hydroxylation	[47,53]
		Tolbutamide	Tolbutamide 4-hydroxylation	[54]
CYP2C19	Liver, intestine	(R)-Omeprazole	(R)-Omeprazole 5-hydroxylation	[47]
		S-Mephenytoin	S-Mephenytoin 4-hydroxylation	[55,56]
CYP2C11	Liver	S-Mephenytoin	S-Mephenytoin 4-hydroxylation	[57]
		Tolbutamide	Tolbutamide 4-hydroxylation	[49,58]
CYP2D6	Liver, intestine	Dextromethorphan	Dextromethorphan O-demethylation (dextrorphan)	[47,59]
		Bufuralol	Bufuralol 1-hydroxylation	[55]
CYP2E1	Liver, lung	Chlorzoxazone	Chlorzoxazone 6-hydroxylation	[47]
		4-Methylpyrazole	N/A	[60]
CYP3A1	Liver	Dapsone	N-acetyl dapsone	[61]
		Midazolam	Midazolam 1-hydroxylation	[62]
CYP3A4	Liver, intestine	Midazolam	Midazolam 1-hydroxylation	[47]
		Daclatasvir	N/A	[63]
		Testosterone	Testosterone 6β-hydroxylation	[21,64,65]