Screening, isolation and optimization of anti-white spot syndrome virus drug derived from terrestrial plants

Objective: To screen, isolate and optimize anti-white spot syndrome virus (WSSV) drug derived from various terrestrial plants and to evaluate the efficacy of the same in host-pathogen interaction model.

Methods: Thirty plants were subjected to Soxhlet extraction using water, ethanol, methanol and hexane as solvents. The 120 plant isolates thus obtained were screened for their in vivo anti-WSSV property in Litopenaeus vannamei. The best anti-WSSV plant isolate, TP22C was isolated and further analyzed. The drug was optimized at various concentrations. Viral and immune genes were analysed using reverse transcriptase PCR to confirm the potency of the drug.

Results: Seven plant isolates exhibited significant survivability in host. The drug TP22C thus formulated showed 86% survivability in host. The surviving shrimps were nested PCR negative at the end of the 15 d experimentation. The lowest concentration of TP22C required intramuscularly for virucidal property was 10 mg/mL. The oral dosage of 750 mg/kg body weight/day survived at the rate of 86%. Neither VP28 nor ie 1 was expressed in the test samples at 42nd hour and 84th hour post viral infection.

Conclusions: The drug TP22C derived from Momordica charantia is a potent anti-white spot syndrome virus drug.