Assessment of the effect of copaiba oil (copaifera sp.) on the kidneys of rats with hepatic dysfunction

Copaiba oil reveals therapeutic properties and has actions such as anti-inflammatory, healing, antiseptic, antitumor, antibacterial, germicidal, expectorant, diuretic and analgesic. Given the anti-inflammatory properties of copaiba oil, the present study aims to evaluate the action of the oil on possible nephrotoxic effects of rats with liver dysfunction caused by the drug thioacetamide. Wistar rats were randomly divided into four groups, consisting of the control group (C), copaiba oil group (O), thioacetamide group (TAA) and thioacetamide + copaiba oil group (TAA + O). The animals received treatment via gavage for eight weeks and were fed standard rodent chow. The kidney fragments were histologically prepared using the historresin technique and HE staining and, later, the images were photographed and processed in an image analyzer for histological characterization of the kidney tissue. The histological results showed an intact kidney tissue with a homogeneous pattern between the groups. Typical cortical and medullary layers and very distinct renal tubules with their well stained and healthy cells. The renal corpuscles showed regular contours, well-distributed anastomosed capillaries and typical macula densa. Histopathological analysis of the kidneys did not reveal alterations or any type of lesion in important structures such as renal tubules and renal corpuscles, and no lymphocytic infiltrate was observed in the renal interstitium. In contrast, the liver tissue from the parallel histological study developed cirrhosis in the group treated with thioacetamide, however, this drug did not compromise the renal histological pattern of the present study. It is concluded that the kidney tissue did not show morphological changes when submitted to thioacetamide, supposedly due to the exposure time, the dose used or that the thioacetamide has been metabolized into less toxic compounds to the kidneys to the detriment of hepatic damage. However, the parallel study of liver tissue and the present study ensure the use of copaiba oil for therapeutic purposes.