RESUMO
The worldwide outbreak of COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. Alongside vaccines, antiviral therapeutics are an important part of the healthcare response to countering the ongoing threat presented by COVID-19. Here, we report the discovery and characterization of PF-07321332, an orally bioavailable SARS-CoV-2 main protease inhibitor with in vitro pan-human coronavirus antiviral activity and excellent off-target selectivity and in vivo safety profiles. PF-07321332 has demonstrated oral activity in a mouse-adapted SARS-CoV-2 model and has achieved oral plasma concentrations exceeding the in vitro antiviral cell potency in a phase 1 clinical trial in healthy human participants.
Assuntos
Tratamento Farmacológico da COVID-19 , Lactamas/farmacologia , Lactamas/uso terapêutico , Leucina/farmacologia , Leucina/uso terapêutico , Nitrilas/farmacologia , Nitrilas/uso terapêutico , Prolina/farmacologia , Prolina/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , Inibidores de Protease Viral/farmacologia , Inibidores de Protease Viral/uso terapêutico , Administração Oral , Animais , COVID-19/virologia , Ensaios Clínicos Fase I como Assunto , Coronavirus/efeitos dos fármacos , Modelos Animais de Doenças , Quimioterapia Combinada , Humanos , Lactamas/administração & dosagem , Lactamas/farmacocinética , Leucina/administração & dosagem , Leucina/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Nitrilas/administração & dosagem , Nitrilas/farmacocinética , Prolina/administração & dosagem , Prolina/farmacocinética , Ensaios Clínicos Controlados Aleatórios como Assunto , Ritonavir/administração & dosagem , Ritonavir/uso terapêutico , SARS-CoV-2/fisiologia , Inibidores de Protease Viral/administração & dosagem , Inibidores de Protease Viral/farmacocinética , Replicação Viral/efeitos dos fármacosRESUMO
Steroidinduced avascular necrosis of the femoral head (SANFH) is a common orthopaedic disease that is difficult to treat. The present study investigated the effects of total flavonoids of Rhizoma drynariae (TFRD) on SANFH and explored its underlying mechanisms. The SANFH rat model was induced by intramuscular injection of lipopolysaccharides and methylprednisolone. Osteoblasts were isolated from the calvariae of neonatal rats and then cultured with dexamethasone (Dex). TFRD was used in vitro and in vivo, respectively. Haematoxylin and eosin staining was used to assess the pathological changes in the femoral head. Terminal deoxynucleotidyl transferasemediated deoxyuridine triphosphate nick end labelling assay and flow cytometry were conducted to detect apoptosis of osteoblasts. The 2',7'dichlorofluoresceindiacetate staining method was used to detect reactive oxygen species (ROS) levels in osteoblasts and the 3(4,5dimethylthiazol2yl)2,5diphenyltetrazolium bromide assay was used to detect osteoblast proliferation. The expression of caspase3, Bax, Bcl2, VEGF, runtrelated transcription factor 2 (RUNX2), osteoprotegerin (OPG), osteocalcin (OCN), receptor activator of nuclear factor κB ligand (RANKL) and phosphoinositide 3kinase (PI3K)/AKT pathway relatedproteins were detected via western blotting. It was found that TFRD reduced the pathological changes, inhibited apoptosis, increased the expression of VEGF, RUNX2, OPG and OCN, decreased RANKL expression and activated the PI3K/AKT pathway in SANFH rats. TFRD promoted proliferation, inhibited apoptosis and reduced ROS levels by activating the PI3K/AKT pathway in osteoblasts. In conclusion, TFRD protected against SANFH in a rat model. In addition, TFRD protected osteoblasts from Dexinduced damage through the PI3K/AKT pathway. The findings of the present study may contribute to find an effective treatment for the management of SANFH.