Identification of chemicals and their metabolites from PHY906, a Chinese medicine formulation, in the plasma of a patient treated with irinotecan and PHY906 using liquid chromatography/tandem mass spectrometry (LC/MS/MS)

Abstract

Traditional Chinese Medicine (TCM) is increasingly being used in combination with Western medicine. In general, TCM is comprised of multiple components in sharp contrast to Western medicine, where a single active chemical is used. Presently, there are no well-established standards for most of the chemical compounds of TCM and their respective metabolites. Moreover, there are no formal analytical methods for the identification of these chemicals, especially in trace amounts. The ability to measure the pharmacokinetic behaviors of chemicals and their metabolites from these herbal formulations are critical in understanding of the action of TCM. This paper describes the use of LC/MS/MS along with enzyme treatments and n-octanol/water partition coefficient, to investigate the chemical components of PHY906 and their metabolites in the plasma of a patient with metastatic colorectal cancer (mCRC) treated with irinotecan and PHY906. The chemicals from an aqueous extract of PHY906 and the plasma from a patient was prepared and separated on an Agilent ZORBAX-SB C(18) column, and eluted with acetonitrile/0.05% (v/v) formic acid. From the PHY906 aqueous extract, a total of 57 compounds and 27 metabolites were identified and tentatively assigned structures based on their identified mass spectrometry, enzyme digestion and n-octanol/water partition coefficient. In contrast, analysis of patient plasma identified only 33 chemicals and new metabolites. These findings demonstrated that LC/MS/MS was and effective and reliable method for studying the parent chemicals of the Chinese herbal medicine PHY906 and their metabolites in a patient with metastatic colorectal cancer.

Fig. 1

Representative TIC and UV chromatograms of PHY906 and metabolites in human plasma samples. Blue represents the plasma sample before administration of PHY906; Red represents the plasma sample 2 hours after administration of PHY906.

Fig. 2

(A) Extraction ion current chromatograms of 621>445 in the patient plasma (1) before administration ;( 2)2.0 hr after administration of PHY906; (3) sample (2) after β-glucuronidase treatment (B) LC-MS² spectra of 621>445 in PHY906-treated patient plasma (1) M1; (2) M2.

Fig. 3

(A) Extraction ion current chromatograms of 445>269 in patient plasma (1) before administration; (2) 2.0 hr after administration of PHY90 ; (3) sample (2) after β-glucuronidase treatment. (B) LC-MS² spectra of 445>269 in PHY90-treated patient plasma (1) M3; (2) M4; (3) M5.

Fig. 4

(A) Extraction ion current chromatograms of 283>268 in the patient plasma (1) before administratio ; (2) 2.0 hr after administration of PHY906; (3) sample (2) after β-glucuronidase treatment.(B) LC-MS² spectra of 283>268 in PHY906-treated patient plasma (1) M6; (2) M7;(3) M8.

Fig. 5

(A) Extraction ion current chromatograms of 607>431 in patient plasma (1) before administration; (2) 2.0 hr after administration of PHY906; (3) sample (2) after β-glucuronidase treatment. (B) LC-MS² spectra of M9 in PHY906-treated patient plasma.

Fig. 6

(A) Extraction ion current chromatograms of 349>269 in patient plasma (1) before administration; (2)2.0 hr after administration of PHY906; (3) sample (2) after β-glucuronidase treatment; (4) sample (2) after sulfatase treatment. (B) LC-MS² spectra of 349>269 in PHY906-treated patient plasma (1) M10; (2) M11; (3) M12.

Fig. 7

(A) Extraction ion current chromatograms of 525>445 in patient plasma (1) before administration; (2) 2.0 hr after administration of PHY906; (3) sample (2) after β-glucuronidase treatment. (B). LC-MS² spectra of 525>445 in the PHY906 treated patient plasma (1) M13; (2) M14.

Fig. 8

Extraction ion current chromatograms of baicalein in PHY906-treated plasma before and after β-glucuronidase treatment.

Fig. 9

Proposed metabolites of baicalein and baicalin in plasma following oral administration of PHY906.