RESUMO
An escalating pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is impacting global health. Specific treatment options for diseases caused by SARS-CoV-2 are largely lacking. Herein, we used a pseudotype virus (pv) bearing the SARS-CoV-2 S glycoprotein to screen a botanical drug library to identify an agent against SARS-CoV-2 entry. All the four hits, including angeloylgomisin O, schisandrin B, procyanidin, and oleanonic acid, were identified for effective inhibition of SARS-CoV-2 S pv entry in the micromolar range. A mechanistic study revealed that these four agents inhibit SARS-CoV-2 S pv entry by blocking S-mediated membrane fusion. Furthermore, angeloylgomisin O, schisandrin B, and oleanonic acid inhibited authentic SARS-CoV-2 with a high selective index (SI). We also showed that all the four hits could also inhibit the entry of pv of Middle East respiratory syndrome coronavirus (MERS-CoV) and newly emerged SARS-CoV-2 variants (D614G, K417N/E484K/N501Y/D614G). In drug combination studies performed in cellular antiviral assays, angeloylgomisin O and schisandrin B displayed synergistic effects in combination with remdesivir. These results indicated that angeloylgomisin O, schisandrin B, procyanidin, and oleanonic acid can inhibit SARS-CoV-2 and that they are potential therapeutic agents for COVID-19.
RESUMO
BACKGROUND:Apoptosis of islet cel s is closely related to the long-term hyperglycemia-and hyperlipemia-induced injuries. OBJECTIVE:To observe the effect of Shizidaiping formula on the apoptosis and insulin secretion in MIN6 cel s under the high glucose and lipid environment, and to explore the protective effect of Shizidaiping formula and the related apoptosis mechanism. METHODS:MIN6 cel s were divided into normal, model, melbine, low-, medium-and high-dose Shizidaiping formula groups. The cel activity was examined by cel counting kit-8, the insulin secretion was measured by ELISA, the rate of apoptosis was measured by Annexin V-FITC&PI and the expression levels of MEK1/2, ERK1/2 and p-ERK1/2 were examined by western blot assay. RESULTS AND CONCLUSION:Shizidaiping formula significantly improved MIN6 cel activity under high glucose and lipid condition (P<0.05), decreased early cel apoptosis, increased the level of insulin stimulated by low glucose in cel supernatant (P<0.05), and improved the expression levels of MEK1/2, ERK1/2 and p-ERK1/2 (P<0.05). These results suggest that Shizidaiping formula can protect islet cel s from hyperglycemia and hyperlipemia damage by improving the activity of MIN6 cel s, reducing the insulin secretion and inhibiting the apoptosis of pancreaticβcel s in MIN6 cel s.
