Search

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), turned into a global pandemic, and there remains an urgent demand for specific/targeted drugs for the disease. The 3C-like protease (3CLpro) is a promising target for developing anti-coronavirus drugs. Schisandra sphenanthera fruit is a well-known traditional Chinese medicine (TCM) with good antiviral activity. This study found that the ethanolic extract displayed a significant inhibitory effect against SARS-CoV-2 3CLpro. Forty-four compounds were identified in this extract using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Combining molecular docking and in vitro experiments, we found that two epimeric 7,8-secolignans, rel-(1S,2R)-1-(3,4-dimethoxyphenyl)-2-methyl-3-oxobutyl-3,4-dimethoxybenzoate (2) and rel-(1S,2S)-1-(3,4-dimethoxyphenyl)-2-methyl-3-oxobutyl-3,4-dimethoxybenzoate (4), potently inhibited 3CLpro with IC50 values of 4.88 ± 0.60 μM and 4.75 ± 0.34 μM, respectively. Moreover, in vivo and in vitro experiments indicated that compounds 2 and 4 were potent in regulating the inflammatory response and preventing lung injury. Our findings indicate that compounds 2 and 4 may emerge as promising SARS-CoV-2 inhibitors via 3CLpro inhibition and anti-inflammatory mechanisms.

Background: Schisandra chinensis fruit is a well-known traditional Chinese medicine (TCM), whose extract has a potent inhibitory effect on the severe acute respiratory syndrome-coronavirus-2 (SARS‑CoV‑2) 3-chymotrypsin-like protease (3CLpro) and papain-like protease (PLpro). Purpose: This work aims to find the active components from the fruit of S. chinensis against SARS‑CoV‑2 3CLpro and PLpro. Materials and methods: The chemical constituents of the fruit of S. chinensis were retrieved based on the electronic databases, such as Web of Science, PubMed, Medline Plus, and CNKI. Molecular docking was used to screen the active components against SARS‑CoV‑2 3CLpro and PLpro. Potential hit compounds were further evaluated by enzymatic activity assay. Furthermore, the anti-inflammatory activities of the active compounds were further explored using the phorbol-12-myristate-13-acetate (PMA)-induced THP1 cells model. Results: In this work, we retrieved 75 components of S. chinensis fruit, including 62 dibenzocyclooctadiene-type lignans, 3 diarylbutane-type lignans, 2 tetrahydrofuran-type lignans, and 8 nortriterpenoids. Combining molecular docking study and in vitro experiments, we found that pregomisin (63), meso‑dihydroguaiaretic acid (64), and nordihydroguaiaretic acid (65) could potently inhibit 3CLpro with IC50 values of 3.07 ± 0.38, 4.12 ± 0.38, and 6.06 ± 0.62 μM, respectively, and inhibit PLpro with IC50 values of 5.23 ± 0.33, 4.24 ± 0.46, and 16.28 ± 0.54 μM, respectively. Interestingly, compounds 63, 64, and 65 also have potent activities of regulating the inflammatory response in vitro. Conclusion: Our results suggest that compounds 63, 64, and 65 may be promising SARS-CoV-2 3CLpro and PLpro inhibitors and anti-inflammatory.

The potential medicinal value of Ma bamboo (Dendrocalamus latiflorus), one of the most popular and economically important bamboo species in China, has been underestimated. In the present study, we found that D. latiflorus leaf extract (DLE) reduced fasting blood glucose levels, body weight, and low-density lipoprotein cholesterol with low liver toxicity in db/db mice. In addition, gene expression profiling was performed and pathway enrichment analysis showed that DLE affected metabolic pathways. Importantly, DLE activated the AKT signaling pathway and reduced glucose production by downregulating glucose-6-phosphatase (G6PC) and phosphoenolpyruvate carboxykinase 1 (PCK1) expression. Moreover, network pharmacology analysis identified rutin as an active component in DLE through targeting insulin growth factor 1 receptor (IGF1R), an upstream signaling transducer of AKT. Due to its hypoglycemic effects and low toxicity, DLE may be considered an adjuvant treatment option for type 2 diabetes patients.