Screening of Clinically Approved and Investigation Drugs as Potential Inhibitors of SARS-CoV-2: A Combined in silico and in†vitro Study.

In the current study, we used 7922 FDA approved small molecule drugs as well as compounds in clinical investigation from NIH's NPC database in our drug repurposing study. SARS-CoV-2 main protease as well as Spike protein/ACE2 targets were used in virtual screening and top-100 compounds from each docking simulations were considered initially in short molecular dynamics (MD) simulations and their average binding energies were calculated by MM/GBSA method. Promising hit compounds selected based on average MM/GBSA scores were then used in long MD simulations. Based on these numerical calculations following compounds were found as hit inhibitors for the SARS-CoV-2 main protease: Pinokalant, terlakiren, ritonavir, cefotiam, telinavir, rotigaptide, and cefpiramide. In addition, following 3 compounds were identified as inhibitors for Spike/ACE2: Denopamine, bometolol, and rotigaptide. In order to verify the predictions of in silico analyses, 4 compounds (ritonavir, rotigaptide, cefotiam, and cefpiramide) for the main protease and 2 compounds (rotigaptide and denopamine) for the Spike/ACE2 interactions were tested by in vitro experiments. While the concentration-dependent inhibition of the ritonavir, rotigaptide, and cefotiam was observed for the main protease; denopamine was effective at the inhibition of Spike/ACE2 binding.

Prenatal expressions of hyperpolarization-activated cyclic-nucleotide-gated channel (HCN) genes in dysplastic hippocampi in rats.

AIM: Hyperpolarization-activated cyclic nucleotide-gated (HCN or h-channel) channels mediate hyperpolarization-activating currents in the hippocampus and neocortex. The aim of this study is to present prenatal h-channel gene expressions (HCN1 and HCN2; HCN1-Entrez-Gene ID: 84390; HCN2- Entrez Gene ID: 114244) in dysplastic hippocampal pyramidal neurons induced by in utero irradiation in rats. MATERIALS AND METHODS: Time-pregnant Wistar albino rats were irradiated and the dysplastic hippocampus in their 2 month-old litters was studied. Gene expression was studied by RNA extraction and polymerase chain reaction methods. RESULTS: None of the rats showed seizure activity. mRNA levels of HCN1 and HCN2 genes were decreased especially in the CA1 and CA3 pyramidal neurons in the hippocampi of experimental rats; however, the differences were not significant compared to controls. In CA2, mRNA levels of both genes were increased and this rise did not reach significant level. The CA4 sub-region showed a different pattern of expression: HCN1 increased but HCN2 decreased insignificantly compared to controls. CONCLUSION: Our results demonstrated that dysplastic neurons showed decreased levels of mRNA expression of HCN1 and HCN2 genes, in particularly CA1 and CA3 pyramidal neurons. The rationale for how these changes contribute to epileptogenesis in dysplastic tissues still requires further studies.