Dietary effects of plant extracts, based on verbascoside, lycopene and horseradish on several blood variables and plasma oxidative status in growing rabbits

Oxidative stress can cause damage to lipids, proteins and nucleic acids in several biological systems, leading to the functional and structural impairment of individual molecules that may be involved in various diseases. The aim of study was to evaluate the effect of dietary plant extract supplementation, based on Lippia citriodora, horseradish (Raphanus sativus L.) and lycopene (Solanum lycopersicum L.), on several blood parameters and plasma oxidative status in growing rabbits. The experiment lasted 80 days and was conducted on 160 weaned rabbits, divided into four groups of 40 animals each, matched by age (38 +/- 2 days) and body weight (1.49 +/- 0.07 kg). The control group (CON) received a weaning-fattening feed without any feed additives, while of the other three experimental groups, the first group received a supplement of plant extract based on Lippia citriodora, containing 5 mg of verbascoside/kg feed (VB group), the second group received 5 mg of lycopene/kg feed, tomato fruit extract (LIC group), and the third received 350 mg of Raphanus sativus root extract/kg feed (RAF group). The feed additives, based on verbascoside (Lippia citriodora), horseradish (Raphanus sativus L.) and lycopene (Solarium lycopersicum L.) resulted in a marked decrease in blood content of low density lipoprotein cholesterol and bilirubin. In addition, only when verbascoside was supplemented, were improvements in high density lipoprotein cholesterol and AST enzyme levels observed. Plasma oxidative markers significantly improved for all three extract groups. There was a significant reduction in ROMs and TBARS values, as well as an increase in the content of retinol and alfa-tocopherol, confirming the strong antioxidant ability of the plant extracts used. A dietary supplementation with phyto-extracts, based on Lippia citriodora, horseradish and lycopene can thus be effectively used in rabbit feeding due to the positive effects observed on the blood parameters and plasma oxidative status, with possible beneficial effects on the welfare of livestock animals.