Phytotherapy in response to COVID-19 and risks of intoxication: A field study in the city of Meknes (Morocco)

Context: The contagious global pandemic of coronavirus 2019 (COVID-19) has prompted many Moroccans to turn to traditional phytoremedies. Aims: To highlight the ethnopharmacological information and the risks of intoxication related to the use of herbal medicine to combat COVID-19. Methods: Through a semi-structured questionnaire and using the "Free listing" technique, an ethnobotanical survey was conducted among 36 herbalists of the Meknes prefecture to collect ethnopharmacological data on species used in the fight against COVID-19. Then, many databases were used to document their pharmacological and toxicological activities. Results: A total of 36 species in 22 families were reported to be used to prepare traditional recipes against COVID-19. According to the relative frequency index of citation, the species Artemisia herba-alba Asso, Eucalyptus globulus Labill, Syzygium aromaticum (L.) Merr. & L.M. Perry, Citrus limon (L.) Osbeck, and Zingiber officinale Roscoe. were recommended by all respondents and recorded the highest usage values. Based on the value of the plant parts index, leaves were the most used part (PPV = 0.37). Most of the remedies were prepared as infusions and administered orally. The bibliographic research revealed that the plants used have several biological activities and are frequently used to treat respiratory diseases. However, some of them have been reported to be toxic. Conclusions: Recommended species are endowed with innumerable biological activities. They can be a promising alternative to combat COVID-19. However, their toxic effects require pharmacotoxicological studies to ensure the safety and efficacy of these natural remedies.