Antioxidants are usually understood as chemicals which could eliminate oxidative stress
by removing intracellular reactive oxygen species but high doses may block their beneficial
effect and moreover, could be toxic. Understanding exact mechanism of action of plant
components in animal organism help to propose dose, method and duration of their application.Thymol
with strong antioxidant properties is the main component of thyme oil. After absorption
from the intestine, thymol enters the bloodstream and is transported to the tissues.
We found significant correlation between thymol levels in plasma and feed and duodenal
wall, which points to the efficient thymol absorption from the digestive tract into
circulation. Erythrocytes play a crucial role in the distribution of circulating polyphenols
due to binding to their surface and being able to act like depots. That is why the
real thymol concentration in blood could be higher than it was found in plasma. Thyme
oil (0.1%, thymol 460 µg/g DM feed) significantly increased superoxide dismutase activity,
had tendency to increase glutathione peroxidase activity and significantly decreased
malondialdehyde as a product of lipid peroxidation in plasma which points to modulation
of antioxidant enzymes activity and improvement of the oxidative stability. Obtained
the lowest thymol concentrations in muscle (139 ng/g DM) in comparison with plasma
(854 ng/mL), liver (568 ng/g DM) and kidney (5541 ng/g DM) could be due to low thymol
penetration or high activity of efflux transporters, hence insufficient to affect
antioxidant defence system. In conclusion, thymol effectiveness depends on its systemic
availability for the targeted organ.
