Repeated-Dose Dermal Toxicity of Tagetes erecta Essential Oil in Wistar Rats

Marigold essential oil has gained widespread acceptance in medicinal and cosmetic applications due to its reported therapeutic properties. However, emerging evidence suggests potential toxicity effects may occur following topical application and exposure of some marigold species. This study aimed to investigate the effect of single and multiple dermal exposure of the African marigold (Tagetes erecta) essential oil and evaluate its impact on haematological (blood) parameters in experimental animals (Wistar rats). Twenty wistar rats were used for this experiment, the rats were grouped into four with each group containing five rats with no vehicle control, the essential oil was applied at 0.1ml/BSA (10% Body Surface Area) on the cleared surface of the skin as the test was a dermal test and the period of exposure was varied between 2 weeks to 6 weeks. At the end of the experiment, parameters such as packed cell volume (PCV), haemoglobin (HB), red blood cell count (RBC), and white blood cell count (WBC) were measured. The mean values observed were PCV: 40.53% ± 0.86, HB: 12.76 g/dL ± 0.49, RBC: 7.07 × 10^12/L ± 0.32, and WBC: 4665.14 × 10^9/L ± 984.65. Statistical analysis revealed no significant differences between groups (p > 0.05), indicating that the treatment had no significant effect on the blood parameters of the treated animals. Additionally, no physiological signs of toxicity were observed in the animals. This study shows that at the applied quantity of the essential oil, it does not have any significant toxic effect on the test animals.