Avian influenza viruses (H5N1) exhibit both high and low virulence in numerous mammalian species, highlighting the connection between the route of inoculation and virus pathogenicity [34]. Since 2003, there have been over 600 documented cases of human infection with H5N1 viruses, with most cases among young, previously healthy individuals [35]. The essential oils extracted from Citrus reshni leaves and peel (unripe and ripe fruits) were tested against H5N1 virus by plaque reduction assay. The oils showed moderate inhibition of the H5N1 virus at a concentration of 2.5 μL/mL. Sabinene (40.5%), linalool (23.3%), and terpinen-4-ol (8.3%) were the main constituents in the leaf oil while limonene (82.4%, 91.6%) was the main compound in the fruit peel essential oils (unripe and ripe, respectively) [36].