Investigation of ameliorative effects of 1,8 cineole on liver toxicity induced by Aroclor 1254 in rat model

In this study, the aim was to demonstrate the protective effect of 1,8 cineole against Aroclor 1254 (A1254)-induced liver toxicity in male rats and to elucidate the underlying mechanisms. Polychlorinated biphenyls (PCBs) are among the persistent organic pollutants (POPs) used globally and locally, with A1254 being a toxic substance that can cause serious damage in various organs such as the liver, brain, testes, ovaries, and lungs. 1,8 Cineole, a monoterpene, is known to possess significant pharmacological activities such as antimicrobial, antiviral, anticancer, and antioxidant effects. Thirty-two healthy young male Wistar albino rats (200–300 g) were used in this study. The animals were randomly divided into four equal groups: Control, Aroclor, Cineole, and Aroclor + Cineole (n=8). A1254 (1 mg/kg) or 1,8 cineole (100 mg/kg) was orally administered to the rats in corn oil for 30 days. After the experimental process was completed, liver tissues and sera were collected from the animals under anesthesia. The protective effect of 1,8 cineole against A1254-induced liver damage was demonstrated using ELISA, RT-PCR, histopathological analysis, and immunohistochemical evaluation methods. A1254 (1 mg/kg) administration increased the total oxidant status (TOS) level and triggered oxidative stress by decreasing total antioxidant status (TAS) in liver tissues. However, 1,8 cineole application significantly reduced TOS levels and increased TAS levels (p<0.05). A1254 increased the pro-apoptotic Bax gene expression in liver tissues, while cineole application significantly decreased Bax gene expression compared to the Aroclor group (p<0.05). Similarly, A1254 increased the gene expressions of pro-inflammatory cytokines TNF-α, IL-1β, and INF-γ in liver tissues, whereas cineole application significantly decreased the expression of these genes compared to the Aroclor group (p<0.05). Moreover, 1,8 cineole significantly reduced the histopathological changes associated with A1254-induced oxidative stress and inflammation in liver tissues (p<0.05). In conclusion, 1,8 cineole (100 mg/kg) may serve as a protective agent due to its anti-apoptotic effect, reduction of oxidative damage, anti-inflammatory efficacy, and mitigation of histopathological changes in rat liver tissues induced by A1254 (1 mg/kg).