The Traditional Chinese Medicine Houttuynia cordata Thunb decoction alters intestinal barrier function via an EGFR dependent MAPK (ERK1/2) signalling pathway

BACKGROUND

A traditionally prepared aqueous extract (= decoction) of Houttuynia cordata Thunb (Yu xing cao) (HC) is widely used in Traditional Chinese Medicine (TCM) to treat inflammatory disease. Previous chemical and biological studies on HC have mainly focused on organic extracts rather than the aqueous decoction, which is the traditional formulation.

PURPOSE

The study aimed to investigate whether the chemical composition of HC aqueous decoction (HCD) varies with geographical sourcing, to investigate the mechanism of action of HCD, and to determine if chemical variation impacts on HCDs anti-inflammatory activity.

METHOD

Sixteen samples of HC were purchased from Sichuan, Hubei and Anhui provinces in the People's Republic of China (PRC) and were prepared by the traditional decoction method to yield their corresponding HCDs. A Quality Control (QC) sample was prepared by combining individual HCD extracts. HCDs were analysed by Nuclear Magnetic Resonance (NMR) and High-Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS). The anti-inflammatory activities associated with intestinal barrier function of HCD were studied by tumor necrosis factor-α (TNF-α) activated Caco-2 monolayers in vitro and in vivo using Dextran Sulfate Sodium (DSS)-induced murine colitis. Proteins involved in inflammation, mRNA levels, disease severity scores, and histology involved in intestinal inflammation were analysed.

RESULTS

HCD samples exhibited different chemical fingerprints and three regional outliers were identified by Principal Component Analysis (PCA). Fifteen phytochemical metabolites were identified and quantified. HCD showed in vitro anti-inflammatory activity, enhancing zonula occludens-1 (ZO-1), occludin, interleukin (IL)-10 and decreasing IL-1β, IL-6 and epidermal growth factor receptor (EGFR) via an EGFR-dependent mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase 1/2 (ERK 1/2) signaling pathway. This beneficial effect on intestinal inflammation was also seen in the in vivo colitis model at a molecular level in colonic tissues.

CONCLUSION

This study shows that the test HCDs were chemically different, resulting in different levels of activity on intestinal barrier function and inflammation. Moreover, a "Daodi" product showed the greatest biological activity in this study, thus validating the importance of the "Daodi" quality material in TCM and supporting the traditional used of HCD for the treatment of inflammation.

A Practical Method for Determination of Nine Nucleosides in Tricholoma matsutake by UPLC/MS and Quantitative Analysis of Multicomponents Using Single Marker Method

Nucleosides can be used as quality evaluation indicators of Tricholoma matsutake. In this work, a new ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS) strategy for quantitative analysis of multiple components using a single marker (QAMS) was proposed to determine nine nucleosides (adenosine, cytidine, guanosine, inosine, uridine, 2'-deoxyadenosine, 2'-deoxycytidine, 2'-deoxyguanosine, and 2'-deoxyuridine) in T. matsutake. Guanosine was set as the internal reference substance, whose content in T. matsutake was determined using the conventional external standard method. Relative correction factors (RCFs) between guanosine and eight other nucleosides were measured. The concentrations of the eight components were calculated with the obtained RCFs by QAMS. An ultrasonic extraction method is used for sample preparation. This method was validated to be sensitive, precise, and accurate with the LODs of 0.31-1.9 ng, the overall intraday and interday variations less than 4.08%, and the overall recovery over 89.0%. The correlation coefficients (r ²) of the calibration curves were higher than 0.9918. The values of vector angle analysis were above 0.99845, which indicates no significant differences between the conventional external standard method and the present QAMS method. As far as we know, this is also the first report of UPLC/MS analysis of nucleoside compounds by QAMS, providing an efficient and feasible quality assessment method for other natural products containing nucleosides.

Chemical profiling of Houttuynia cordata Thunb. by UPLC-Q-TOF-MS and analysis of its antioxidant activity in C2C12 cells

Houttuynia cordata Thunb. ("Yu-Xing-Cao"), a traditional Chinese medicinal herb, has long been used to treat various diseases. However, detailed information regarding the chemical constituents of H. cordata aqueous extract is lacking, and the molecular basis of its beneficial effects on muscle is unknown. To investigate these points, in this study, we used ultra-performance liquid chromatography coupled with quadrupole-time-of-flight-mass spectrometry (UPLC-Q-TOF-MS) in positive and negative ion modes to profile and identify the major constituents of H. cordata water extract. A total of 63 peaks were identified based on mass and fragmentation characteristics, including 29 organic acids and their glycosides, 17 flavonoids, 7 volatiles, 4 pyrimidine and purine derivatives, 2 alkaloids, 2 amino acids, 1 isovanillin, and 1 coumarin. The total flavonoid and polyphenol contents of the extract were 4.77 and 139.15 mg/mL, respectively, by ultraviolet spectrophotometry. The cytoprotective activity of H. cordata aqueous extract was evaluated using C2C12 cells treated with tumor necrosis factor (TNF)-α to induce oxidative challenge. The TNF-α induced decrease in cell viability was reversed by treatment for 48 h with the extract; moreover, superoxide dismutase activity was increased while reactive oxygen species level was decreased. These results provide molecular-level evidence for the antioxidant effect of H. cordata extract and highlight its therapeutic potential for the treatment of muscle injury or diseases caused by oxidative stress.

A holistic strategy for quality and safety control of traditional Chinese medicines by the "iVarious" standard system

An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines (TCMs). However, the current quality standard research lacks the top-design and systematic design, mostly based on specific technologies or evaluation methods. To resolve the challenges and questions of quality control of TCMs, a brand-new quality standard system, named "iVarious", was proposed. The system comprises eight elements in a modular format. Meaning of every element was specifically illustrated via corresponding research instances. Furthermore, frankincense study was taken as an example for demonstrating standards and research process, based on the "iVarious" system. This system highlighted a holistic strategy for effectiveness, security, integrity and systematization of quality and safety control standards of TCMs. The establishment of "iVarious" integrates multi-disciplinary technologies and progressive methods, basis elements and key points of standard construction. The system provides a novel idea and technological demonstration for regulation establishment of TCMs quality standards.