Exploration of molecular targets and mechanisms of Chinese medicinal formula Acacia Catechu -Scutellariae Radix in the treatment of COVID-19 by a systems pharmacology strategy.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In China, the Acacia catechu (AC)-Scutellariae Radix (SR) formula has been widely used for pulmonary infection in clinical practice for several centuries. However, the potential role and mechanisms of this formula against COVID-19 remains unclear. The present study was designed to dissect the active ingredients, molecular targets, and the therapeutic mechanisms of AC-SR formula in the treatment of COVID-19 based on a systems pharmacology strategy integrated by ADME screening, target prediction, network analysis, GO and KEGG enrichment analysis, molecular docking, and molecular dynamic (MD) simulations. Finally, Quercetin, Fisetin(1-), kaempferol, Wogonin, Beta-sitosterol, Baicalein, Skullcapflavone II, Stigmasterol were primarily screened to be the potentially effective active ingredients against COVID-19. The hub-proteins were TP53, JUN, ESR1, MAPK1, Akt1, HSP90AA1, TNF, IL-6, SRC, and RELA. The potential mechanisms of AC-SR formula in the treatment of COVID-19 were the TNF signaling pathway, PI3K-Akt signaling pathway and IL-17 signaling pathway, etc. Furthermore, virtual docking revealed that baicalein, (+)-catechin and fisetin(1-) exhibited high affinity to SARS-CoV-2 3CLpro, which has validated by the FRET-based enzymatic inhibitory assays with the IC50 of 11.3, 23.8, and 44.1 µM, respectively. And also, a concentration-dependent inhibition of baicalein, quercetin and (+)-catechin against SARS-CoV-2 ACE2 was observed with the IC50 of 138.2, 141.3, and 348.4 µM, respectively. These findings suggested AC-SR formula exerted therapeutic effects involving "multi-compounds and multi-targets." It might be working through directly inhibiting the virus, improving immune function, and reducing the inflammatory in response to anti-COVID-19. Ultimately, this study would provide new perspective for discovering potential drugs and mechanisms against COVID-19.

Optimized Fluorescent Probe for Specific Imaging of Glutathione S-Transferases in Living Cells and Mice.

GSTP1 has been considered to be a marker for malignancy in many tissues. However, the existing GST fluorescent probes are unfavorable for in vivo imaging because of the limited emission wavelength or insufficient fluorescence enhancement (six-fold). The limited fluorescence enhancement of GST fluorescent probes is mainly ascribed to the high background signals resulting from the spontaneous reaction between GSH and the probes. In this work, a highly specific GST probe with NIR emission has been successfully developed through optimization of the essential unit of the probe to repress the spontaneous reaction. The novel GST probe exhibits over 100-fold fluorescence enhancement upon incubation with GSTP1/GSH and high selectivity over other potential interference. In addition, the probe has been proved to be capable of tracking endogenous GST in A549 cells. Finally, the in vivo imaging results demonstrate that the probe can be used for effective imaging of endogenous GST activity in subcutaneous tumor mouse with high contrast.

Simultaneous determination of Rivaroxaban and TAK-438 in rat plasma by LC-MS/MS: application to pharmacokinetic interaction study.

Aim: A sensitive and reliable LC-MS/MS method has been established and validated to the quantitation of rivaroxaban (RIV) and TAK-438 in rat plasma using carbamazepine as internal standard. Results: The procedure of method validation was conducted according to the guidelines of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and TAK-438 for the first time. When RIV and TAK-438 co-administration to rats, main pharmacokinetic parameters of TAK-438 like AUC(0-t), AUC(0-∞) and Cmax had statistically significant increase. The main pharmacokinetic parameters of RIV have no statistically significant difference (p > 0.05) when co-administered except for t1/2 (p < 0.01). Conclusion: The results indicated that drug-drug interactions occurred between RIV and TAK-438 when co-administered to rats.

Beneficial effects of combination therapy of phloretin and metformin in streptozotocin-induced diabetic rats and improved insulin sensitivity in vitro.

The GLUT4 and PI3K/AKT signaling pathways are the key sensors of energy status and they regulate glucose and lipid metabolism. Phloretin activates the PI3K/AKT pathway by promoting GLUT4 translocation and expression, thereby improving glucose consumption and tolerance. As metformin can regulate glucose metabolism, we hypothesized that phloretin can amplify its gluco-regulatory effects. Male Sprague Dawley rats were fed with a high-fat and high-sugar diet for 8 weeks and injected with a low dose of streptozotocin to induce type 2 diabetes. The diabetic rats were randomized to receive phloretin (100 mg kg-1 d-1), metformin (250 mg kg-1 d-1), or phloretin + metformin via oral gavage for another 4 weeks. Random blood glucose, serum insulin, free fatty acid, total cholesterol, triglyceride, and low-density lipoprotein levels were detected in type 2 diabetic rats. Hematoxylin-eosin and Oil Red O staining were used to observe the pathological changes in the liver, pancreas, and adipose tissues of type 2 diabetic rats. The expression levels of IRS-1, PI3K, P-AKT, and GLUT4 in skeletal muscle were detected using western blotting. Phloretin plus metformin improved fasting blood glucose levels, glucose tolerance, and insulin sensitivity in type 2 diabetic rats. In addition, this combination reduced lipid accumulation, improved the pathological changes in the liver, pancreas, and adipose tissue, and increased IRS-1, PI3K, P-AKT, and GLUT4 expression in skeletal muscle and the liver of type 2 diabetic rats. Thus, phloretin can be used in a potential combination therapy with metformin for the prevention and rescue of type 2 diabetes.

LC-MS/MS method for simultaneous determination of rivaroxaban and metformin in rat plasma: application to pharmacokinetic interaction study.

Aim: A reliable, sensitive and simple LC-MS/MS method has been established and validated for the quantitation of rivaroxaban (RIV) and metformin (MET) in rat plasma. Results: The procedure of method validation was conducted according to the guiding principles of EMA and US FDA. At the same time, the method was applied to pharmacokinetic interactions study between RIV and MET for the first time. When RIV and MET coadministered to rats, pharmacokinetic parameters of MET like AUC(0-t), AUC(0-∞) and Cmax had statistically significant increased. tmax of RIV was prolonged without affecting t1/2 obviously and Cmax was inhibited significantly (p < 0.05) by comparison to the single group. Conclusion: The results indicated that drug-drug interactions occurred when the coadministration of RIV and MET.

Acacia catechu (L.f.) Willd and Scutellaria baicalensis Georgi extracts suppress LPS-induced pro-inflammatory responses through NF-кB, MAPK, and PI3K-Akt signaling pathways in alveolar epithelial type II cells.

Acacia catechu (L.f.) Willd (ACW) and Scutellaria baicalensis Georgi (SBG) are one of the most famous couplet Chinese medicines, widely used for treating infantile cough, phlegm, and fever caused by pulmonary infection. However, the underlying molecular mechanism of their anti-inflammatory activity has not been determined. The aim of this study was to evaluate the protective effect of this couplet Chinese medicines (ACW-SBG) on lipopolysaccharide (LPS)-induced inflammatory responses in acute lung injury (ALI) model of rats and the potential molecular mechanisms responsible for anti-inflammatory activities in alveolar epithelial type II cells (AEC-II). Standardization of the 70% ethanol extract of ACW and SBG was performed by using a validated reversed-phase high-pressure liquid chromatography method. Rats were pretreated with ACW-SBG for 7 days prior to LPS challenge. We assessed the effects of ACW-SBG on the LPS-induced production of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1ß) in the bronchoalveolar lavage fluid (BALF). The wet-to-dry weight ratio was calculated, and hematoxylin and eosin staining of lung tissue was performed. Cell viability of AEC-II was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Real-time quantitative reverse transcription polymerase chain reaction assay was carried out to quantify the relative gene expression of TNF-α and IL-1ß in AEC-II. The western blotting analysis was executed to elucidate the expression of mediators linked to nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and phosphatidylinositol-3 kinase-protein kinase B (PI3K-Akt) signaling pathways. ACW-SBG significantly decreased lung wet-to-dry weight ratio, ameliorated LPS-induced lung histopathological changes, and reduced the release of inflammatory mediators such as TNF-α and IL-1ß in BALF. In AEC-II, we found that the expression of TNF-α mRNA was also inhibited by ACW-SBG. ACW-SBG blocked NF-κB activation by preventing the phosphorylation of NF-κB (p65) as well as the phosphorylation and degradation of the inhibitor of kappa B kinase. ACW-SBG extracts also inhibited the phosphorylation of respective MAPKs (c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38) as well as Akt. The present study demonstrated that ACW-SBG played a potent anti-inflammatory role in LPS-induced ALI in rats. The potential molecular mechanism was involved in attenuating the NF-κB, MAPKs, and PI3K-Akt signaling pathways in LPS-induced AEC-II.

Fluorescence detection of glutathione S-transferases in a low GSH level environment.

Glutathione S-transferases (GSTs) play crucial roles in the detoxification process and the development of drug-resistance and are proved to be important markers for various tumors. Different from the previous probes, we developed a fluorescent probe enabling the detection of intracellular GSTs in a low GSH level environment by pre-treatment of the cells with thiol-scavengers.

Simultaneous determinations of four major bioactive components in Acacia catechu (L.f.) Willd and Scutellaria baicalensis Georgi extracts by LC-MS/MS: Application to its herb-herb interactions based on pharmacokinetic, tissue distribution and excretion studies in rats.

BACKGROUND: Acacia catechu (L.f.) Willd (ACW) and Scutellaria baicalensis Georgi (SBG) are two famous herbs and often used in many traditional Chinese compound prescriptions. In clinical practice, ACW-SBG couple as a famous traditional herb couple, was widely used for treating infantile cough, phlegm and fever which caused by pulmonary infection. Meanwhile, a standardized bioflavonoid composition-UP446 with ACW extract and SBG extract has been used in both special nutritional products and joint care dietary supplements. However, its herb-herb interactions based on absorption, distribution, metabolism and excretion (ADME) study had not been investigated. PURPOSE: The aim of this study was to evaluate potential pharmacokinetic, tissue distribution and excretion interactions between ACW and SBG, and to provide useful information for the development of suitable dosage forms and clinical applications. STUDY DESIGN AND METHODS: A sensitive and reliable LC-MS/MS method was established to the quantification of four major bioactive components in rat biological samples. The method was validated for accuracy, precision, linearity, range, selectivity, lower limit of quantification (LLOQ), recovery, and matrix effect. All validation parameters met the acceptance criteria according to regulatory guidelines. Based on this, we obtained and compared the parameters about pharmacokinetics, tissue distribution and excretion of four major bioactive components in this study. RESULTS: This work revealed that the parameters including plasma pharmacokinetics, tissue distribution and excretion of (+)-catechin (C), (-)-epicatechin (EC), baicalin (BL) and baicalein (BLE) in single administration had significant differences compared co-administration. The results illustrated that interactions between two herbs are related to the effect of competitive gastrointestinal absorption inhibition and drug metabolism by liver metabolic enzymes. Moreover, the alteration of C and EC in the tissue of lung maybe could enhance the pharmacological activity for treating pulmonary infection. CONCLUSION: This is the first report to evaluate the pharmacokinetics, tissue distribution and excretion of co-administration of ACW or SBG to rats and compared its properties of four major bioactive components. The results demonstrate that herb -herb interactions occurred in this herb couple.