RESUMO
ObjectiveTo investigate the brain absorption components of Tianyuan Zhitong prescription and their distribution based on ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS）， desorption electrospray ionization mass spectrometry imaging（DESI-MSI） and hyperspectral imaging techniques. MethodTen BALB/c mice were randomly divided into blank group（n=3） and administration group（n=7）， the administration group was gavaged with 0.3 mL of Tianyuan Zhitong prescription liquid at a concentration of about 5 g·mL-1 of the raw material， and the blank group was gavaged with an equal volume of normal saline， and the whole brain of the mice were taken for the preparation of tissue homogenates and frozen sections， respectively. The tissue homogenates were qualitatively analyzed by UPLC-Q-TOF-MS for the brain absorption components in positive and negative ion modes， frozen sections were used for imaging to observe the distribution of these components in the brain. Cytoviva dark-field enhancement microscope was used to perform hyperspectral imaging scanning on the brain sections of mice from each group， and the scattered light data of at least 1 000 pixels in the visible-near-infrared（400-1 000 nm） band in the microscopic field of view were collected and average spectrum were created， which were used to compare the components in the brain tissues of mice from the blank and administration groups. ResultA total of 27 brain absorption components of Tianyuan Zhitong prescription were identified by UPLC-Q-TOF-MS， including 10 organic acids， 5 glycosides， 4 alkaloids， 1 phenol， 4 flavonoids， 2 phthalides and 1 other compound， which were mainly derived from Gastrodiae Rhizoma， Chuanxiong Rhizoma， vinegar-processed Corydalis Rhizoma， Ziziphi Spinosae Semen and processed Morindae Officinalis Radix. A total of 14 components were identified by mass spectrometry imaging， of which ferulic acid， tetrahydropalmatine and N-methyl dehydroberberine were mainly distributed in the cerebral cortex， vitamin B5， vemonoic acid and ricinoleic acid were mainly distributed in the hypothalamus， elemicin， octadecenic acid and octadecanoic acid were mainly distributed in the cortex and hypothalamus， while senkyunolide B， ligustilide， linoleic acid， 9，12-octadecadienoyl ethyl ester and spinosin were distributed in most regions of the brain tissues. Hyperspectral imaging showed that in the visible-near-infrared band range， the average spectrum of the brain tissues of mice in the administration group was significantly red-shifted， indicating that there were differences in the physical properties or contents of the chemical components in the brain between mice in the blank group and those in the administration group， and further verified the results of mass spectrometry imaging. ConclusionThrough the combination of UPLC-Q-TOF-MS and imaging techniques， the pharmacodynamic components of Tianyuan Zhitong prescription in the treatment of headache and the regional characteristics in brain tissue are clarified， which can provide reference for the selection of the index components of the research on the quality standard of this prescription and the research on the mechanism of the pharmacological effect.
RESUMO
Objective: Using ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD) and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) to analyze 15 batches of Shaoyao Gancao Decoction (SGD) substance benchmark and lyophilized powder in order to investigate the advantages of DESI-MSI in quality control of famous classical formulas. Methods: Taking SGD as the research model, fingerprints of the substance benchmark were established by UHPLC-DAD, and the content of index components (paeoniflorin, liquiritin, glycyrrhizic acid) and the yield of dry extract were also investigated. Meanwhile, as the research carrier, the lyophilized powder corresponding to SGD was dissolved in methanol and dotted on qualitative filter paper with quantitative capillary, and fixed it on the slide to make samples. The samples were analyzed on a DESI-MSI system in positive and negative ion mode with methanol-formic acid (1 000:1, flow rate of 3 μL/min) as spray solvent, N2 as spray gas (pressure of 0.5 MPa). The scanning range was m/z 100-1 200, the spatial resolution was 300 μm, the ion source temperature was 120 ℃. Results: DESI-MSI can detect not only the index components of paeoniflorin, liquiritin, glycyrrhizic acid, but also the common peaks of albiflorin. At the same time, DESI-MSI could detect 11 other components from Glycyrrhizae Radix et Rhizoma and Paeoniae Radix Alba, such as licoricesaponin G2, licoricesaponin J2, gallic acid, citric acid, p-hydroxybenzoic acid, and present their relative content visually. The qualitative analysis ability of DESI-MSI was much better than UHPLC-DAD. Conclusion: DESI-MSI can be used as the quality control method for substance benchmark and lyophilized powder and dispensing granules of classical famous formulas with advantages of high sensitivity, strong analytical ability, no complex sample pretreatment, qualitative and relative content analysis of complex samples without reference substance.