Melaleuca alternifolia essential oil prevents bioenergetics dysfunction in spleen of silver catfish naturally infected with Ichthyophthirius multifiliis.

Some evidence has demonstrated that Ichthyophthirius multifiliis, etiologic agent of "white spot disease", causes severe bioenergetics dysfunction in the spleen of naturally infected silver catfish (Rhamdia quelen), which contributes directly to disease pathogenesis. Recently, several studies have demonstrated the efficacy of Melaleuca alternifolia essential oil, popularly known as tea tree oil (TTO), in the treatment of freshwater fish naturally or experimentally infected with I. multifiliis. In this sense, the aim of this study was to evaluate whether TTO is capable of preventing or reducing splenic bioenergetics dysfunction in silver catfish naturally infected with I. multifiliis. Splenic cytosolic and mitochondrial creatine kinase (CK) and pyruvate kinase (PK) activities decreased in infected animals compared to uninfected animals, while adenylate kinase (AK) activity increased. Treatment with TTO was able to prevent the inhibition on splenic CK and PK activities but was not able to prevent the stimulation of AK activity. Based on this evidence, treatment with TTO prevents the impairment on energetic metabolism via improvement of enzymes belonging to the phosphotransfer network, such as CK and PK. In summary, this treatment can be considered an interesting approach to prevent the bioenergetics imbalance in spleen of silver catfish naturally infected with I. multifiliis.