Antiviral and Therapeutic Effects of a Mixture of Boswellia serrata, Commiphora myrrha, and Propolis for SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mainly affects respiratory tracts including the trachea and lungs. As inflammation and cytokine storm are major pathological features in a Syrian hamster for SARS-CoV-2 infection, reducing inflammatory responses or antiviral therapy is an effective strategy for treating SARS-CoV-2 infections. Herbal medicines and natural substances are applied worldwide due to their health-beneficial effects. Although chemical and pharmacological verifications have not been made for all substances, the pharmacological effects of many substances are being studied. In this study, Boswellia serrata, Commiphora myrrha, and propolis known to have anti-inflammatory and antimicrobial properties were selected as candidates for therapeutic herbal medicine targeting SARS-CoV-2. When this herbal mixture was treated to SARS-CoV-2 infected Vero E6 and Calu-3 cells, effective antiviral effects were demonstrated. Next, this herbal mixture was administered to SARS-CoV-2-infected Syrian hamsters, and histopathological lesions were significantly reduced. Viral spike protein and viral enzyme gene were also significantly less detected in immunohistochemistry and quantitative real-time PCR results, respectively. Thus, it can be concluded that a mixture of Boswellia serrata, Commiphora myrrha, and propolis as natural substances has the potential to reduce lesions of respiratory tracts upon SARS-CoV-2 infection.