UPLC-Q-Exactive/MS based analysis explore the correlation between components variations and anti-influenza virus effect of four quantified extracts of Chaihu Guizhi decoction

Chaihu Guizhi decoction (CGD) is a classic Traditional Chinese Medicine (TCM) prescription for the treatment of influenza and fever, composes of Bupleuri Radix (Chaihu), Cinnamomi Ramulus (Guizhi), Scutellariae Radix (Huangqin), Codonopsis Radix (Dangshen), Glycyrrhizae Radix Et Rhizoma Praeparata Cum Melle (Zhigancao), Pinelliae Rhizoma Praeparatum (Fabanxia), Zingiberis Rhizoma Recens (Shengjiang), Paeoniae Radix Alba (Baishao) and Jujubae Fructus (Dazao) in the ratio of 12:4.5:4.5:4.5:3:6:4.5:4.5:4. The efficacy of TCM, if there are differences, depends on the different extraction methods and extracted components. This study was to evaluate the anti-influenza virus effect of CGD extracts with different extraction methods, analyze the components and explore their correlation. CGD were prepared with four extraction methods respectively, the traditional decoction (TD), two steps alcohol-water extraction (AWE), alcohol reflux extraction (AE) and water reflux extraction (WE). Based on the influenza mouse model, the efficacy of anti-influenza virus in vivo of the four CGD extracts were evaluated with the therapeutic index of body weight, rectal temperature, lung index, thymus index and lung viral load of mice. The chemical components in four CGD extracts, and compounds absorbed in rats blood with prototypes or metabolites were identified by UPLC-Q-Exactive/MS. The partial least squares (PLS) method was used to explore the correlation between the components variation in CGD extracts and the comprehensive efficacy index. The potential effective components were further accessed by molecular docking. Comparing with the other three extracts, AWE has the best anti-influenza effect. It could ameliorate the symptoms caused by influenza virus infection in mice, increase body weight and rectal temperature, reduce the lung index and virus load in lung tissue. 129, 144, 140 and 129 components were identified from TD, AWE, AE, and WE respectively. The identified components were mainly including flavonoids, terpenoids, organic acids, phenylpropanoids, amino acids, nucleosides, phenols, alkaloids, etc. 43 prototypes and 49 metabolites of CGD were detected in rat plasma after oral administration. Seven components, cinnamaldehyde, wogonoside, baicalin, baicalein, gallic acid, oroxylinA-7-O-glucuronide and coumarin, showed significant correlation with anti-influenza effects, all of which had good binding activity with NA, IL-6, STAT3, AKT1, EGFR and TNF. Two steps alcohol-water extraction was optimal for CGD preparation. Cinnamaldehyde, wogonoside, oroxylinA-7-O-glucuronide, coumarin, gallic acid, baicalein and baicalin play a certain essential role in anti-influenza effects and may be taken as a potential maker compounds for quality evaluation of CGD.