ABSTRACT
Major threats to the human lifespan include cancer, infectious diseases, diabetes, mental degenerative conditions and also reduced agricultural productivity due to climate changes, together with new and more devastating plant diseases. From all of this, the need arises to find new biopesticides and new medicines. Plants and microorganisms are the most important sources for isolating new metabolites. Lampedusa Island host a rich contingent of endemic species and subspecies. Seven plant species spontaneously growing in Lampedusa, i.e., Atriplex halimus L. (Ap), Daucus lopadusanus Tineo (Dl), Echinops spinosus Fiori (Es) Glaucium flavum Crantz (Gf) Hypericum aegypticum L: (Ha), Periploca angustifolia Labill (Pa), and Prasium majus L. (Pm) were collected, assessed for their metabolite content, and evaluated for potential applications in agriculture and medicine. The HPLC-MS analysis of n-hexane (HE) and CH2Cl2 (MC) extracts and the residual aqueous phases (WR) showed the presence of several metabolites in both organic extracts. Crude HE and MC extracts from Dl and He significantly inhibited butyrylcholinesterase, as did WR from the extraction of Dl and Pa. HE and MC extracts showed a significant toxicity towards hepatocarcinoma Huh7, while Dl, Ha and Er HE extracts were the most potently cytotoxic to ileocecal colorectal adenocarcinoma HCT-8 cell lines. Most extracts showed antiviral activity. At the lowest concentration tested (1.56 µg/mL), Dl, Gf and Ap MC extracts inhibited betacoronavirus HCoV-OC43 infection by> 2 fold, while the n-hexane extract of Pm was the most potent. In addition, at 1.56 µg/mL, potent inhibition (>10 fold) of dengue virus was detected for Dl, Er, and Pm HE extracts, while Pa and Ap MC extracts dampened infections to undetectable levels. Regarding to phytotoxicity, MC extracts from Er, Ap and Pm were more effective in inhibiting tomato rootlet elongation; the same first two extracts also inhibited seed cress germination while its radicle elongation, due to high sensitivity, was affected by all the extracts. Es and Gf MC extracts also inhibited seed germination of Phelipanche ramosa. Thus, we have uncovered that many of these Lampedusa plants displayed promising biopesticide, antiviral, and biological properties.
ABSTRACT
Inosine 5'-monophosphate dehydrogenase (IMPDH) is a key enzyme catalyzing the rate-limiting step of de novo nucleotide synthesis in vivo. In recent years, it has become a therapeutic target for anti-virus, antibacterial, anti-cancer, anti-parasitic and other diseases. IMPDH inhibitors have been shown to inhibit viral proliferation in host cells by depleting guanosine 5'-monophosphate (GMP), the raw material required for viral replication in host cells, with broad-spectrum antiviral properties. In order to find novel anti-coronavirus drugs, this study screened 22 potential IMPDH inhibitors from 70 000 natural small molecule libraries based on IMPDH protein structure using molecular docking and ROC calculation for virtual screening. With ribavirin as the positive control drug, Huh7 cell and H460 cell models were used to verify the anti-coronavirus HCoV-229E and HCoV-OC43 activities of 22 selected target compounds. Among them, compounds 11, 12, 15 and 16 showed inhibitory activity against coronavirus HCoV-229E. The compounds 4, 12, 13 and 15 showed inhibitory activities against coronavirus HCoVOC43. 12 and 15 showed significant inhibitory activity against both two coronaviruses, and their efficacy was similar to ribavirin at the same dose, which can be further studied as a lead compound for IMPDH inhibitors. Copyright © 2022, Chinese Pharmaceutical Association. All rights reserved.