Dietary Houttuynia cordata Thunb. extract supplementation influences on antioxidant enzymes, meat quality, and gene expressions in fresh rabbit Longissimus thoracis et lumborum meat.

This study aimed to observe the effects of Houttuynia cordata Thunb. extract (HCTE) on the antioxidant activity, meat quality and antioxidant gene expression of rabbit Longissimus thoracis et lumborum (LTL) muscles from rabbits. Rabbits were fed a control diet or a control diet supplemented with 500, 1000 or 1500 mg/kg HCTE. The addition of 1000 mg/kg HCTE increased (P < 0.05) the average daily gain and decreased (P < 0.05) the feed conversion ratio of the rabbits. Additionally, dietary HCTE supplementation increased (P < 0.05) the vitamin C, vitamin E, protocatechuic acid and quercetin concentrations and the catalase (CAT) activity in LTL muscles. The rabbits that received HCTE exhibited decreased (P < 0.05) water loss and shear force values. Moreover, HCTE supplementation increased (P < 0.05) the methionine content; increased the C18:3 n-3, C22:5 n-3, and n-3 polyunsaturated fatty acid levels; and improved (P < 0.05) the volatile profile of LTL meat from rabbits. Furthermore, dietary supplementation with 1000 mg/kg HCTE increased (P < 0.05) Nrf2, superoxide dismutase 1, glutathione peroxidase (GPX) 1, GPX2 and CAT gene expression. Overall, dietary HCTE supplementation increased vitamin, protocatechuic acid and quercetin contents, increased antioxidant activity, improved meat quality and upregulated antioxidant gene expression in the LTL muscles of rabbits. Under the experimental conditions of this study, the addition of 1000 mg/kg HCTE to the diet exerted the strongest positive effects.