showed that Clinacanthus nutans
ethanolic extract inactivated Yellow-Head Virus (YHV) in vitro at concentrations
as low as 1 μg/mL, and when black tiger shrimp (Penaeus
monodon) were fed with the extract, the cumulative mortality decreased
from 75% in control group to 33% in 1% enriched diet. In other
studies P. monodon challenged with White Spot Syndrome Virus
(WSSV) and intramuscularly injected or orally administered aqueous
extract of Bermuda grass displayed no mortality and no signs of white
spot disease compared to 100% mortality observed in control group
(Balasubramanian et al., 2007, 2008a,b).