ACUTE AND SUBACUTE DERMAL TOXICITY EVALUATION OF A COMBINED CYMBOPOGON NARDUS AND EUCALYPTUS GLOBULUS ESSENTIAL OIL FORMULATION IN ALBINO WISTAR RATS

Mankelklot Kasahun Depeso 1*, Abay Mulu2, Zelalem Animaw3, Yonas Girma4, Sileshi Degu5

 

1. College of health and medical science, Haramaya University, Harar, Ethiopia, 2. School of Biomedicine and Laboratory Science, Addis Ababa University, Addis Ababa, Ethiopia, 3. Department of Biomedical science, College of health science, Debre Tabor University, Debre Tabor City, Ethiopia, 4. Department of Pathology, School of Biomedicine and Laboratory Science, Addis Ababa University, Addis Ababa, Ethiopia, 5. Traditional and Modern Drug Research Directorate, Armauer Hansen Research Institute, Addis Ababa, Ethiopia.

Corresponding Author: College of health and medical science, Haramaya University, Harar, Ethiopia, Email: mankelklotkasahundepeso@gmail.com.

Citations: Mankelklot Kasahun Depeso et,al. Acute and subacute dermal toxicity evaluation of a combined cymbopogon nardus and eucalyptus globulus essential oil formulation in albino wistar rats. Eco Science Journals. 2026 3(8). 

Copyrights © 2026, Mankelklot Kasahun Depeso. This article is licensed under the Creative Common Attribution-NonCommercial-4.0-international-License-(CCBY-NC).

ABSTRACT:  

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Background: Mosquito-borne diseases, such as malaria, remain a major public health concern in Ethiopia and elsewhere globally. While synthetic repellants are effective, their repeated use has been associated with skin irritation, allergic reactions, and environmental concerns. Natural repellents, like essential oils from C. nardus and E. globulus, offer promising repellent and therapeutic advantages. However, the dermal safety of their combined use has not been scientifically evaluated.  

Objectives: To evaluate the acute and sub-acute dermal toxicity of a combined Cymbopogon nardus and Eucalyptus globulus formulation on hematological, biochemical parameters, and histopathology of the skin, kidney, and liver of albino Wistar rats. 

Methodology: The plant material was harvested about 270 kilometers south of Addis Ababa, in the Wondogenet region. The formulation was prepared by the Traditional and Modern Medicine Research Directorate of the Armauer Hansen Research Institute (AHRI). Essential oils were extracted by hydro distillation using a Clevenger-type apparatus. A topical formulation was prepared by incorporating essential oils of C. nardus and E. globulus (2 mL each; 1:1, v/v) into 100 g of white petrolatum, corresponding to approximately 3.5% w/w total essential oils based on estimated density. Acute dermal toxicity was evaluated following OECD guideline 402, while sub-acute (28-day) dermal toxicity was assessed according to OECD guideline 410. Forty adult albino Wistar rats (8–12 weeks old) were randomly assigned into four groups (n=10 per group; 5 males and 5 females). The test groups received dermal applications of 250, 500, and 1000 mg/kg body weight/day of the formulation, while the control group received the vehicle (white petrolatum). The formulation was applied once daily to approximately 10% of the shaved dorsal skin for 28 consecutive days. Hematological and biochemical parameters were analyzed at the end of the study. Following euthanasia under sodium pentobarbital anesthesia (150 mg/kg), the liver, kidneys, and skin were collected for Histopathological evaluation. 

Result: The dermal mean lethal dose LD50 of the C. nardus and E. globulus formulation was found to be above 5000mg/kg b.w, placing the formulation in GHS category 5 (Lowest toxicity). No mortality or clinical sign of toxicity was observed in either study. There were no significant differences (P>0.05) in body weight gain, food intake, and water intake, hematological indices, serum biochemical markers, or relative organ weights between treated and control groups. Histopathological examination revealed normal architecture of liver, kidneys, and skin across all dose groups.

Keywords: Cymbopogon nardus, Eucalyptus globulus, Acute toxicity, Sub-acute toxicity, Dermal, Wistar rats