Bacterial infections require special care since the indiscriminate use of
antibiotics to treat them has been linked to the emergence of resistant strains. In this sense, phytoterapeutic alternatives such as
curcumin and its
nanocapsules have emerged as a promising supplement in optimizing availability of bioactives and reducing the development of antimicrobial resistance. Thus, the aim of this study was to verify the effects of pure and nanoencapsulated
curcumin in the treatment of experimental
listeriosis in gerbils regarding many aspects including antibacterial effect,
antioxidant mechanisms involved and the energetic metabolism. Four groups were used containing 6 animals each: T0 (control), T1 (infected), T2 (infected and treated with free
curcumin - dose of 30 mg/kg/day) and T3 (infected and treated with
nanocapsules containing
curcumin - a dose of 3 mg/kg/day). Treated animals received
curcumin for 6 consecutive days starting 24 h after Listeria monocytogenes
infection. All animals were euthanized on the 12th day after L. monocytogenes
infection. Quantitative polymerase chain reaction (qPCR) identified L. monocytogenes
DNA in the spleens of all animals of the T1 group, as well as T2 (2 out of 6) and T3 (5 out of 6). The weight of the spleens confirmed the
infection, since it was larger in the T1 group, differing statistically from T0, and similarly to T2 and T3. Hepatic histopathological examination showed mild infiltration of neutrophils and macrophages, except for the T3 group (only 1/6). In the liver, the
pyruvate kinase activity was higher in T1 and T2 compared to T0 and T3. The
adenylate kinase activity did not differ between groups. The Na+/K+ATPase activity was lower in T1 group compared to T0 and T3. Lipoperoxidation was lower in the T3 group compared to groups T0, T1 and T2. The
antioxidant capacity against peroxyl radicals was higher in T1, T2 and T3 groups compared to T0. In conclusion, free
curcumin showed potent antibacterial effects; however, the nanoencapsulated form was able to minimize the effects caused by L. monocytogenes regarding tissue injury, changes on
enzymes of the energetic metabolism, in addition to an
antioxidant effect against lipoperoxidation.