Effects of Long-Term Administration of Rosemarinus officinalis Essential Oil on Blood Factors and Liver and Kidney Cells in Adult Rats

Background: Rosmarinus officinalis is a useful medicinal plant with numerous ethnopharmacological applications and widespread use in the industry. The main constituent of this plant is essential oil. There is a misconception that there is no restriction to using medicinal plants. The present study examined the effects of the chronic administration of Rosemarinus officinalis essential oil on the liver and kidney. Methods: Twenty-Eight Wistar rats were divided into 4 groups. Moreover, the study animals were Intraperitoneally (IP) injected for 21 days with 0.2%, 1%, and 2% Rosemarinus officinalis essential oil and the solvent, respectively. After this period, the study animals’ blood samples were collected for renal and hepatical biochemical evaluations. Tissue samples from these organs were obtained for histomorphometric and histopathological studies.  Results: The chronic treatment of animals with Rosemarinus officinalis essential oil increased blood urea nitrogen and aspartate aminotransferase in the study samples’ blood (P<0.05). The diameter of the hepatocytes distal to the central vein significantly increased, compared to the proximal ones (P<0.05). Atrophic and degenerative changes in the liver and kidney tissues were observed by 1% and 2% administration of Rosemarinus officinalis essential oil. Conclusion: Our findings indicated that chronic and high administration of Rosemarinus officinalis may harm the liver and kidney.