Screening the antiviral activity of Indian medicinal plants against white spot syndrome virus in shrimp

Twenty species of Indian traditional medicinal plants were selected for this study. They were Aegle marmelos, Allium sativum, Aristolochia indica, Azadirachta indica, Cassia fistula, Catharanthus roseus, Curcuma longa, Cynodon dactylon, Lantana camara, Melia azedarach, Mimosa pudica, Momordica charantia, Morus alba, Ocimum americanum, Phyllanthus amarus, Phyllanthus emblica, Psidium guajava, Solanum nigrum, Tridax procumban and Tylophora indica. These plants were used to extract antiviral substances with petroleum ether, benzene, diethyl ether, chloroform, ethyl acetate, methanol, ethanol and distilled water separately using a Soxhlet apparatus. Each extract was tested for its activity against WSSV in marine shrimp and fresh water crabs. Only five plants among these twenty (A. marmelos, C. dactylon, L. camara, M. charantia and P. amarus) showed antiviral activity against WSSV. The aqueous extract of C. dactylon showed strong antiviral activity at the concentration of 100 mg/kg of animal body. The methanol extract of M. charantia showed significant antiviral activity at the concentration of 150 mg/kg of animal body weight. The aqueous extract of L. camara and P. amarus and methanol extract of A. marmelos showed partial antiviral activity at the concentration of 150 mg/kg of animal body weight.