Volume 78, Issue 9-10

Suppressors of cytokine signaling (SOCSs) are implicated in viral infection and host antiviral innate immune response. Recent studies demonstrate that viruses can hijack SOCSs to inhibit Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway, block the production and signaling of interferons (IFNs). At the same time, viruses can hijack SOCS to regulate non-IFN factors to evade antiviral response. Host cells can also regulate SOCSs to resist viral infection. The competition of the control of SOCSs may largely determine the fate of viral infection and the susceptibility or resistance of host cells, which is of significance for development of novel antiviral therapies targeting SOCSs. Accumulating evidence reveal that the regulation and function of SOCSs by viruses and host cells are very complicated, which is determined by characteristics of both viruses and host cell types. This report presents a systematic review to evaluate the roles of SOCSs in viral infection and host antiviral responses. One of messages worth attention is that all eight SOCS members should be investigated to accurately characterize their roles and relative contribution in each viral infection, which may help identify the most effective SOCS to be used in “individualized” antiviral therapy.

The current study describes the chemical identification, antimicrobial, and mosquito larvicidal activities of essential oils from Meistera caudata and Conamomum vietnamense , growing in Vietnam. Essential oils were extracted from the leaves and rhizomes, and characterized by the GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analysis. Monoterpenes (33.1–89.2 %) were the main chemical class found in these oils. β -Pinene (30.8 %) and α -pinene (23.8 %) were two major compounds in M. caudata leaf oil. C. vietnamense leaf and rhizome essential oils were dominated by 1,8-cineole (47.9–62.0 %) and limonene (10.3–16.2 %). With the same MIC (minimum inhibitory concentration) value of 25 μg/mL, C. vietnamense leaf and rhizome essential oils strongly inhibited the growth of Gram-positive bacteria Staphylococcus aureus ATCC 29213 and Bacillus subtilis ATCC 6501, respectively. For 24 and 48-h treatments, C. vietnamense leaf essential oil strongly controlled the growth of mosquito Aedes aegypti with the respective LC 50 values of 7.67 and 6.73 μg/mL, and the respective LC 90 values of 13.37 and 10.83 μg/mL. In the same manner, C. vietnamense rhizome essential oil also showed strong mosquito larvicidal activity against Aedes albopictus with the LC 50 values of 12.37 and 12.00 μg/mL, and the LC 90 values of 20.56 and 18.58 μg/mL, respectively. C. vietnamense essential essential oils containing a high amount of 1,8-cineole are generally better than M. caudata essential essential oils in both two biological assays.

A systematic chemical study of the secondary metabolites of the marine fungus, Penicillium chrysogenum (No. Y20-2), led to the isolation of 21 compounds, one of which is new (compound 3 ). The structures of the 21 compounds were determined by conducting extensive analysis of the spectroscopic data. The pro-angiogenic activity of each compound was evaluated using a zebrafish model. The results showed that compounds 7 , 9 , 16 , and 17 had strong and dose-dependent pro-angiogenic effects, with compound 16 demonstrating the strongest pro-angiogenic activity, compounds 6 , 12 , 14 , and 18 showing moderate activity, and compounds 8 , 13 , and 19 exhibiting relatively weak activity.

Tuliposides (Pos) are major defense-related secondary metabolites in tulip, having 4-hydroxy-2-methylenebutanoyl and/or (3 S )-3,4-dihydroxy-2-methylenebutanoyl groups at the C-1 and/or C-6 positions of d -glucose. The acyl group at the C-6 position is converted to antimicrobial lactones (tulipalins) by an endogenous Pos-converting enzyme. Based on this enzyme activity, we examined tulip bulb extracts and detected HPLC peaks that disappeared following the reaction by the Pos-converting enzyme. Spectroscopic analyses of the three purified compounds revealed that one of them was a glucose ester-type Pos, while the other two were identified as a glucoside ester-type Pos. These compounds were designated as PosK, L, and M. They were specific to bulbs, with the highest content in the outermost layer, but they were markedly less abundant than PosG, the minor bulb Pos we identified earlier. The study results suggest that tulip bulbs contain at least four minor Pos in addition to the major 6-PosA. Although PosK–M were present in almost all of the tested tulip cultivars, they were detected in only a few wild species, indicative of their potential utility as chemotaxonomic markers in tulip. Identification of PosK–M as 6-PosA derivatives unveils the biosynthetic diversity of Pos, the well-known group of secondary metabolites in tulip.

Ricinus communis L. is a medicinal plant that displays valuable pharmacological properties, including antioxidant, antimicrobial, analgesic, antibacterial, antiviral and anti-inflammatory properties. This study targeted to isolate and identify some constituents of R. communis leaves using ultra-performance liquid chromatography coupled with mass spectroscopy (UPLC-MS/MS) and different chromatographic techniques. In vitro anti-MERS and anti-SARS-CoV-2 activity for different fractions and for two pure isolated compounds, lupeol (RS) and ricinine (RS1) were evaluated using a plaque reduction assay with three different mechanisms and IC 50 based on their cytotoxic concentration (CC 50 ) from an MTT assay using Vero E6 cell line. Isolated phytoconstituents and remdesivir are assessed for in-silico anti-COVID-19 activity using molecular docking tools. The methylene chloride extract showed pronounced virucidal activity against SARS-CoV-2 (IC 50  = 1.76 μg/ml). It was also shown that ricinine had superior potential activity against SARS-CoV-2, (IC 50  = 2.5 μg/ml). Lupeol displayed the most potency against MERS, (IC 50  = 5.28 μg/ml). Ricinine appeared to be the most biologically active compound. The study showed that R. communis and its isolated compounds have potential natural virucidal activity against SARS-COV-2; however, additional exploration is necessary and study for their in vivo activity.

This study was to compare GABase [a mixture of γ -aminobutyric acid (GABA) aminotransferase and succinic semialdehyde dehydrogenase] and glutaminase inhibitory activities of 20 herbal extracts and investigate the isolation, structural elucidation and those inhibitory activities of three acylated flavonol monoglycosides from the selected extract of Laurus nobilis L. (laurel). On the basis of the NMR spectroscopic data and the ESI MS spectra together with the comparison with the literature values, three compounds were identified as kaempferol-3- O -(4″- E - p -coumaroyl)- α - l -rhamnopyranoside ( 1 ), kaempferol-3- O -(3″,4″-di- E - p -coumaroyl)- α - l -rhamnopyranoside ( 2 ) and kaempferol-3- O -(2″,4″-di- E - p -coumaroyl)- α - l -rhamnopyranoside ( 3 ), respectively. The IC 50 values of GABase inhibitory activity of 1–3 and p -hydroxybenzaldehyde (HBA) as control were 0.24 mM, 0.14 mM, 0.12 mM and 0.43 mM, respectively. Additionally, the IC 50 values of glutaminase inhibitory activity of 1–3 and 6-diazo-5-oxo- l -norleucine (DON) as control were 0.34 mM, 0.13 mM, 0.14 mM and 0.33 mM, respectively. The results suggest that the extract from laurel shows the strongest biological activities among 20 herbal extracts and three acylated flavonol monoglycosides may serve as potential lead compounds for the prevention and treatment of neurodegenerative and lifestyle-related diseases by targeting GABase and glutaminase. This is the first report on GABase and glutaminase inhibitory activities of 1–3 .