Roselle Seed Oil and its Nano-Formulation Alleviated Oxidative Stress, Activated Nrf2 and Downregulated m-RNA Expression Genes of Pro-inflammatory Cytokines in Paracetamol-intoxicated Rat Model

Abstract:  Roselle (Hibiscus sabdariffa L.) seeds, traditionally used in liver disorders, have recently attracted more attention as a new source of healthy edible oil with anti-inflammatory and antioxidant activities. However, its hepatoprotective effect has not been explored yet. In the current study, the hepatoprotective potential of roselle seed oil (RSO; 0.6, 4 and 8 ml/kg) and its nano-formulation (RSO-NE; 4 and 8 ml/kg), and their possible underlying mechanism were investigated in a paracetamol-induced hepatotoxicity rat model, compared to silymarin.  RSO and RSO-NE protected the liver against paracetamol-intoxication and maintained the overall architecture of liver tissues in a dose dependent manner. Additionally, hepatic nuclear factor-erythroid 2-related factor2 (Nrf2) and glutathione (GSH) increased significantly in pre-treated groups, while malondialdehyde (MDA) decreased. Moreover, RSO and RSO-NE significantly inhibited paracetamol-induced mRNA expression of pro-inflammatory cytokines (TNF-α and IL-6). Chemical analysis of RSO showed fatty acids (mainly linoleic, oleic, palmitic and stearic acids), n-eicosane, β-sitosterol and tocopherols as the major constituents, which contributed synergistically to its protective effect. The efficacy of RSO-NE (8 ml/Kg) was superior to its corresponding unformulated oil (0.6 ml/kg), indicating its enhanced bioavailability. These findings encourage the use of RSO in development of health promoting products such as food supplements, functional food and nutraceuticals for the prevention of liver disease.