The objective of this study was to characterize several bioactive xenobiotic phytochemicals from a dried grape pomace (GP) derived from a Romanian winery and further to evaluate their effect on inflammation and oxidative markers in liver of pig. 20 crossbred TOPIG hybrid fattening pigs were randomly assigned (n = 10) to two experimental treatments: a normal diet (control group) and a diet included 5% grape pomace (GP group) for 24 days. The total polyphenols concentration of pomace was 36.2g gallic acid equiv. /100g. The pomace was rich in polyphenols from the flavonoids group, the main class being flavanols (epicatechins, catechin, epigallocatechin, procyanidins) and antocyanins (Malvidin 3-O-glucoside). The highest concentration was recorded for epicatechin (51.96g/100g) and procyanidin dimer (22.79g/100g). A high concentration of total polyunsaturated fatty acids (PUFA) especially ω-6 fatty acids (59.82 g/100g fat) were found also in grape pomace. The GP diet lowered the gene expression and protein concentration of IL-1β, IL-8, TNF-α and IFN-γ cytokines suggesting an anti-inflammatory effect of GP diet. Concentration of hepatic TBARS also decreased significantly. The total antioxidant capacity (liver TEAC) and activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) did not differ between the GP and control diet while their gene expression tended to decrease. The results showed that GP diet exerted an anti-inflammatory effect, but 5% dietary inclusion modulated only partially the oxidative response and suggest other rate of inclusion need to be investigated. [ABSTRACT FROM AUTHOR]