Survival of White Spot Syndrome Virus–Infected <scp><i>Litopenaeus vannamei</i></scp> Fed with Ethanol Extract of <i>Uncaria Tomentosa</i>

Abstract

Abstract With the present project, the phytochemical composition of Uncaria tomentosa cultivated in Chapecó (Brazil) was analyzed and then the potential of using this local plant extract to protect by oral feeding virus‐infected Litopenaeus vannamei shrimp was also investigated. For this study, five treatments were tested: uninfected shrimp fed with pelleted feed (T C ), WSSV‐infected shrimp fed with pelleted feed (T 1 ), infected shrimp fed with pelleted feed with 1% ethanol extract of U. tomentosa (EEUT) (T 2 ), infected shrimp fed with pelleted feed with 2% EEUT (T 3 ), and infected shrimp fed pelleted feed with 4% EEUT (T 4 ). The chemical analysis of EEUT showed the presence of alkaloids, flavonoids, sterols, terpenes, coumarins, and tannins and also a high in vitro free radical‐scavenging activity as well as high total phenolic content. Shrimp fed with 2 and 4% EEUT (T 3 and T 4 ) showed a survival probability significantly higher than T 1 and T 2 treatments and no clinical symptoms of WSSV infection. Immunological assay also showed a positive phenoloxidase activity effect on shrimp fed with EEUT.