ABSTRACT
The epidemic of COVID-19 has brought great challenges to the global public health prevention and control system combined with clinical diagnosis and treatment system, and it makes the development of effective antiviral drugs an important task in current pharmaceutical research. Traditional Chinese medicine (TCM) has played an important role in the prevention and control of COVID-19. Due to its numerous chemical components and various structural types, TCM becomes a natural library for searching for lead compounds against SARS-CoV-2. In this study, a novel dual-target surface plasmon resonance (SPR) biosensor was developed for S protein receptor binding domain (SRBD) and angiotensin converting enzyme 2 (ACE2) which are two key proteins in the process of SARS-CoV-2 invading cells according to characteristics of synergistic effects of multiple components and comprehensive regulation of multiple targets of TCM. The SPR biosensor was applied to screen and identify active components from six TCMs, and daidzin from Puerariae Lobatae Radix was identified to bind with SRBD and ACE2. The affinity constant (KD) of daidzin and ACE2 was 5.18 μmol·L-1 through the SPR affinity assay. Competitive ELISA assay showed that daidzin could inhibit the binding of SRBD and ACE2, and the inhibition rate of daidzin (20 μmol·L-1) was 38.6%. Molecular docking experiments further confirmed that daidzin had the best binding near the binding region of SRBD-ACE2 complex. This study shows that the dual-target SPR screening system is accurate and efficient, and is particularly suitable for screening of complex drug systems and effective substances study of TCM. It provides a material basis for exploring the mechanism of TCM active constituents against SARS-CoV-2, and provides a source of lead compounds for the development of anti-SARS-CoV-2 drugs.
ABSTRACT
To identify the active constituents in vitro and blood-absorbed ingredients in vivo from Yin Chen Hao decoction provides scientific evidence for probing its prevention and treatment mechanism on acute liver injury. An ultrahigh performance liquid chromatography quadrupole-time of flight-mass spectrometry (UPLC-QTOF/MS) method was applied for analysis of Yin Chen Hao decoction and the serum samples of mice with con-A induced acute liver injury after preventive oral administration for 14 days (the use of all laboratory animals in this study was approved by the Ethics Committee of the Naval Medical University, 19YF1459400). A total of 90 chemical constituents were identified from Yin Chen Hao decoction, mainly were flavonoids, terpenoids, tannins, quinones. 5 prototype compounds were identified in the serum, including chrysophanol, deoxyrhapontin-8-O-gallate, mussaenosidic acid, herniarin, emodin. The established UPLC-QTOF/MS method could efficiently and sensitively identify the constituents in vitro and blood-absorbed ingredients of Yin Chen Hao decoction, primarily clarify the material basis of its hepatoprotective effect, and provided a scientific basis for the quality marker selection and the pharmacodynamic material basis research on the decoction.