Antioxidant, dermal and acute toxicological effects of Eucalyptus camaldulensis (Dehn-Blakely) essential oil on male Wistar rats

During the era of the COVID-19 lockdown, many Nigerians resorted to home remedies like herbal mixtures for therapy because they could not have access to orthodox medicine. Eucalyptus camaldulensis (E. camaldulensis) essential oil was one of such remedies as many believed it had the potential to treat colds, flu, sore throats, bronchitis and even prevent SARS-CoV-2 infection. 
The objective of the study is to check the antioxidant, dermal and acute toxicological effects of the E. camaldulensis essential oil. Rats were grouped into 8 of 5 each. Normal and corn oil (2ml/kg body weight) control groups. E. camaldulensis essential oil from Jos, Niger, Nasarawa, Kogi, Kwara, and Benue zones were given at 2ml/kg body weight for 14 days as well as applied on the shaved skin of the rats. No mortality was recorded in the sub-acute toxicity study at low and high doses (10mg/kg and 5000mg/kg). The levels of AST, ALT, TNF-α and IL-6 did not significantly differ from normal control rats. Lungs Investigation recorded a significant increase in the TNF-α. Antioxidant enzyme assays showed a significant increase in catalase, superoxide dismutase and glutathione-s-transferase. Histological examination showed focal inflammation with moderate cytoplasmic clearing in the liver and focal mild epidermal sclerosis of the skin. Dermal application of the oil shows no significant toxic effect except some mild inflammation (skin irritation). Oral administrations were relatively safe with mild adverse effect observed in the lung inflammatory markers.