After 30 days of culture, shrimps were challenged with virulent WSSV and studied for
WSSV VP 28 gene expression, biochemical, haematological and immunological changes. Surprisingly,
groups treated with lower concentrations of fraction F-III (HS1 or HS2) significantly
(P< 0.05) suppressed the viral replication. Different levels of protein and glucose, improved total
haemocyte count (THC), coagulase activity and oxyhaemocyanin level all were comparable to controls.
Also, immunological parameters such as prophenol oxidase and intracellular superoxide
anion production were significantly increased (F= 97.18; P 6 0.001 and F =5.70; P 6 0.05) in
the groups treated with the three test concentrations. The presence of antiviral and immunostimulant
active principles in the F-III fraction effectively suppressed the WSSV load and boosted F. indicus’s
immune system. This research will help to develop novel antiviral drugs from plants against
aquatic important pathogens.