Investigation of Essential Oil of Melissa Officinalis for Acute and Sub-Chronic Oral Toxicity

Abstract

Background: Medicinal plants continue to play central roles in the healthcare system of a large proportion of the world’s population. Aim: To determine the acute and Sub-chronic oral toxicity of Melissa officinalis essential oil and to serve as criteria to recommend the ethno pharmacological uses of the plant. Methods: In the acute toxicity test, oral administration of 300 and 2000mg/kg of the Melissa officinalis essential oil was evaluated in mice. Sub-chronic toxicity was studied by a daily oral dose of 100 and 200mg/kg for three months. On day 0, 30, 60 and 90, blood samples collected from retro-orbital sinus of the eye rats were used for evaluation of serum biochemistry, hematology and histopathological examination of the heart, lungs, liver, kidney and spleen. Results: The acute toxicity oral study revealed no observable signs of toxicity. In rats, the examination of signs, animal behavior and the changes in body and organs weights showed no abnormalities in the test groups as compared to the controls. There were no significant variations in the hematological parameters of both Melissa officinalis essential oil treated and untreated rats. However, biochemical parameters showed a significant decrease in blood sugar. Melissa officinalis essential oil significantly (p<0.05) increased serum urea suggesting degenerative changes in the kidney. Conclusion: We can conclude that Melissa officinalis essential oil is well tolerated in short-term therapies but may have long-term toxic effects on the kidney.