Safety Evaluation of Essential Oil Formulation (EOF) in Albino Wistar Rats: An Experimental Study.

BACKGROUND

Many people in Iraq utilize olive, rosemary, and lavender oils for cosmetics. However, there is no significant evidence supporting the plant's safety regarding its oils.

OBJECTIVES

This study is aimed at examining the acute and subchronic toxicities of essential oil formulation (EOF) in albino Wistar rats using various parameters.

MATERIALS AND

METHODS

The collected EO was analyzed by GC-MS. For acute toxicity assay, 18 rats were divided equally into 3 groups of 6 animals each as low-dose, median-dose, and high-dose and received a single oral dose (500, 1000, and 2000 mg/kg, respectively). Whereas for subchronic toxicity assay, a total of 30 rats were allocated to five groups of six experimental rats were randomly assigned to Group I (control), which received tap water, whereas Groups II-V received 50, 150, 250, and 350 mg/kg of EOF prepared from olive, rosemary, and lavender oils, respectively. Rats underwent a 90-day repeated-dose oral toxicity investigation in accordance with OECD 408 (Oral Toxicity-Fixed Dose Procedure). Following a humane euthanasia using sodium pentobarbital, blood samples were collected for liver and renal function tests, hematological parameters, and electrolyte balance indicators. In contrast, the liver and kidney were removed for histopathological analysis.

RESULTS

Olive oil was mostly composed of oleic acid with tiny amounts of linoleic and palmitic acids. The principal components of rosemary oil include α-pinene, 1,8-cineole, and camphor, whereas lavender oil contains linalool, linalyl acetate, 1,8-cineole, β-ocimene, terpinen-4-ol, and camphor. EOF's NOAEL exceeded 2000 mg/kg body weight. EOF-treated rats at 50, 150, 250, and 350 mg/kg exhibited no toxicity or death after 3 months of treatment. Liver and renal function tests, electrolyte balance, and blood marker indicators were not significantly affected in EOF-treated rats compared with controls. Liver and renal histopathology showed unremarkable changes after treatments with various doses of EOF.

CONCLUSIONS

No significant toxicity was observed for assessed parameters, including the immunological, blood, enzyme, and essential organ systems. Thus, EOF is considered relatively safe and nontoxic for usage as its NOAEL exceeded 2000 mg/kg body weight.