ANTIVIRAL ACTION OF GREEN PROPOLIS AGAINST SARS-COV-2, AND DEVELOPMENT OF ORO-DISPERSIBLE FILM.
Phenolic, Box-Benkhen, Covid
Green propolis has proven pharmacological properties, such as antivirais, anti-inflammatory and antioxidant action. In view of the SARS-CoV-2 pandemic, its use has gained prominence as a potential therapeutic approach, especially with innovative forms such as orodispersible films. The present study aimed to investigate the chemical composition of Brazilian green propolis, evaluate its antiviral activity against SARS-CoV-2 in vitro and develop an orodispersible film from this extract.
Ultrasound-assisted extraction, maceration and percolation methods followed by identification by high-performance liquid chromatography with a diode array detector (HPLC-DAD), quantification of total phenolics, total flavonoids and antioxidant activity were also analyzed. The interaction of the bioactive compounds present in the extracts with the SARS-CoV-2 Spike RBD protein and the ACE2 receptor and proteases PLpro and 3CLpro, as well as cytotoxicity assays, were also analyzed. Finally, the formulation of an orodispersive film was performed, where the characterization was performed through analyses of weight uniformity, swelling capacity, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), x-ray diffraction (XRD) and gravimetric analysis (TGA).
The results showed that the green propolis extracts presented a significant inhibitory activity against the viral enzymes PLpro (64.96% - 93.16%), 3CLpro (0 - 76.79%) and Spike protein (26.42% - 96.41%), indicating its potential as an antiviral agent. These results were related to the compounds identified in the green propolis extracts (Chlorogenic, Caffeic, p-Coumaric, Ferulic, Rosmarinic Acids, Kaempferol, Kaempferide, Artepellina C, Drupamine, Baccharin, Chromene, Pinobanksin). The optimization of the ultrasound extraction methods resulted in high levels of phenolic compounds (76.34% - 75.96%) and flavonoids (29.81% - 27.80%), correlated with the antioxidant capacity of the extracts: DPPH (IC50 4.08 - 4.15) and FRAP (1492.14% - 1450.31%). The orodispersible films developed demonstrated good uniformity and swelling capacity for controlled release of bioactive compounds, suggesting a new form of administration for antiviral treatments. The FTIR, SEM and DRX characterizations
indicated interaction between the polymer and the extract components, however without the formation of new bonds and with uniformity on the surface. In the TGA it was possible to observe small changes in thermal stability attributed to the presence of the extracts.
This study highlights the relevance of green propolis as a promising source of compounds with antiviral activity against SARS-CoV-2, in addition to presenting a new pharmaceutical formulation that can be explored in future research. The combination of optimized extraction methods and the development of orodispersible films opens new possibilities for the use of natural products in antiviral therapy.