In vitro human fecal microbial metabolism of Forsythoside A and biological activities of its metabolites.

In vitro human fecal microbial metabolism of Forsythoside A and biological activities of its metabolites.

Fitoterapia (2014-10-05)

Shihua Xing, Ying Peng, Mengyue Wang, Daofeng Chen, Xiaobo Li

ABSTRACT

The present study aimed to investigate the metabolism of Forsythoside A (FTA) by human fecal bacteria to clarify the relationship between its intestinal metabolism and its pharmacological activities. FTA was incubated with human fecal microflora in vitro to investigate its metabolic process, and highly sensitive and specific ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was performed using MetaboLynx software for metabolite analysis. Caffeic acid (CA) and hydroxytyrosol (HT) were obtained by hydrolysis of FTA, and CA was further hydrogenated to form 3,4-dihydroxybenzenepropionic acid (DCA). The anticomplementary, antimicrobial and antiendotoxin activities of FTA and its metabolites by human fecal microflora were evaluated in vitro with a hemolysis assay, the agar disc-diffusion method, the MIC value and the gel clot LAL assay, respectively. The metabolites showed higher biological activity than FTA, especially HT and DCA. Orally administered FTA may be metabolized to HT and DCA, and the pharmacological effects of FTA may be dependent on intestinal bacterial metabolism.

MATERIALS

Product Number

Brand

Product Description

34885

Sigma-Aldrich

Methanol, suitable for HPLC, gradient grade, ≥99.9%

322415

Sigma-Aldrich

Methanol, anhydrous, 99.8%

717975

Sigma-Aldrich

Methanol, suitable for NMR (reference standard)

644374

Sigma-Aldrich

Methanol, purification grade, 99.8%

PHR1320

Supelco

Residual Solvent - Acetonitrile(solution in DMSO), Pharmaceutical Secondary Standard; Certified Reference Material

676780

Sigma-Aldrich

Methanol, ACS reagent, ≥99.8%

494437

Sigma-Aldrich

Methanol, BioReagent, ≥99.93%

646377

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Methanol, HPLC Plus, ≥99.9%

179337

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Methanol, ACS reagent, ≥99.8%

154903

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Methanol, ACS spectrophotometric grade, ≥99.9%

179957

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Methanol, Laboratory Reagent, ≥99.6%

34860

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Methanol, suitable for HPLC, ≥99.9%

PHR1372

Supelco

Methanol, Pharmaceutical Secondary Standard; Certified Reference Material

PHR1551

Supelco

Acetonitrile(Neat), Pharmaceutical Secondary Standard; Certified Reference Material

439193

Sigma-Aldrich

Methanol, suitable for HPLC, gradient grade, suitable as ACS-grade LC reagent, ≥99.9%

320390

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Methanol, ACS reagent, ≥99.8%

32213

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Methanol, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.8% (GC)

82762

Supelco

Methanol, analytical standard

24229

Sigma-Aldrich

Methanol, puriss., meets analytical specification of Ph Eur, ≥99.7% (GC)

721956

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Methanol solution, suitable for NMR (reference standard), 4% in methanol-d₄ (99.8 atom % D), NMR tube size 3 mm × 8 in.

CN34891

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Acetonitrile, Preparateur, ≥99.9% (GC), One-time steel-plastic (SP) drum

633240

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Methanol solution, contains 0.50 % (v/v) triethylamine

360457

Sigma-Aldrich

Acetonitrile, ACS reagent, ≥99.5%

439134

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Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%

34851

Sigma-Aldrich

Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

C0625

Sigma-Aldrich

Caffeic acid, ≥98.0% (HPLC)

60018

Supelco

Caffeic acid, suitable for matrix substance for MALDI-MS, ≥99.0% (HPLC)

271004

Sigma-Aldrich

Acetonitrile, anhydrous, 99.8%

1601340

USP

Residual Solvent Class 2 - Acetonitrile, United States Pharmacopeia (USP) Reference Standard