engleski

Polyphenols: modulating the antioxidant status in support of the liver regeneration in mice

Affecting antioxidant status is one mechanism of interfering with cell proliferation. Some plant constituents modulate redox-signaling pathways and thus may be of value in tissue regeneration. Hence, regulation of antioxidant state in response to olive oil polyphenols extract (PF) pretreatment during liver regeneration (LR) after partial hepatectomy (pH) in mice was exploited. Changes in the liver antioxidant profile were evaluated in the group of mice: a) subjected only to pH, b) receiving PF prior to 1/3 pH, and c) receiving vehicle alone. Total hepatic glutathione (GSH) concentration, the activities of enzymes involved in GSH utilization (glutathione peroxidase ; GP) and recycling (glutathione reductase ; GR), along with catalase (KAT) activity were determined spectrophotometrically. Withal, liver mass restoration was calculated, and the quantitative real-time polymerase chain reaction was employed to examine hepatic mRNA levels of NF-κB gene and its targets: antioxidant SOD2 gene, and γ-glutamylcystein synthetase (GCS) gene, which regulates GSH biosynthesis. Mice subjected only to pH exerted induced GP activity during the first 3h of LR, followed by GR activity induction and increase in GSH content 12h after pH. In contrast, in periods up to 3h after pH, PF treatment provoked KAT activity induction and GSH depletion, pointing to the increase in oxidative stress. These changes were accompanied by the NF-κB gene upregulation in all time intervals and concomitantly, by a higher and prolonged expression level of the SOD2 and GCS gene. Consequently, GSH levels increased in periods up to 12h, with reflection of these events in higher liver mass restoration compared to the untreated group. PF related oxidative stress induction during the early course of regeneration process may function as a signaling pathway supporting liver growth. Such function is likely mediated through the NF-κB induction, which enhances GSH biosynthetic capacity and confers antioxidant protection.

liver regeneration; olive oil polyphenols; NF-κB; enymatic and non enzymatic antioxidants

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