Antiradical, Antioxydant and Antimicrobial Properties of Essential Oil of Eucalyptus tereticornis Used in the Treatment of Respiratory Diseases in Togo: A Phytochemical Study Approach

Introduction: Traditional medicine has seen a resurgence of attention and interest worldwide. Eucalyptus tereticornis is a medicinal plant belonging to the Myrtaceae family. This study was initiated to assess the therapeutic potential of Eucalyptus tereticornis essential oil. Methods: The essential oil was obtained by steam distillation and analyzed by GC/MS. Refractive index was assessed in accordance with ISO 280 (1998). Antiradical activity was assessed by the DPPH free radical scavenging method, while antioxidant activity was assessed by the FRAP test. Antimicrobial activity was assessed using the plate microdilution method coupled with nutrient agar spreading. Results: Essential oil yield was 0.75%. The refractive index was 1.475 ± 0.004. Thirty-three compounds, representing 99.09% of the oil, were identified in the EO. The major constituents are α-Pinene (55.72%), β-Pinene (16.73%), O-Cymene (7.40%), Eucalyptol (5.45%), β- terpineol acetate (2.69%) and Aromadendrene (1.99%). Anti-free radical activity was estimated at 4.11 ± 0.01 µg EAA/g EO and antioxidant activity at 0.60 ± 0.11 mg EAA/g EO. The antimicrobial activity results show that Eucalyptus tereticornis essential oil has antibacterial activity against all the different micro-organisms selected. Conclusion: The results of this study justify the traditional use of this plant against respiratory illnesses, and encourage research into new natural molecules with antioxidant and antibacterial properties, with a view to investing them in the pharmaceutical, cosmetics and food industries.