Background and Aim: There has been continuous effort to search for alternative medicinal plants that are applicable to ameliorate viral disease on shrimp pond. This study aimed to examine the effect of Acanthus ilicifolius leaf extract on clinical symptoms and non-specific immune response of black tiger shrimp (Penaeus monodon).

Materials and Methods: A total of 330 shrimps were equally assigned into three extract forms (crude extract, ethyl acetate extract, and n-butanol extract, respectively) in which three levels were provided for each extract. Negative control (without leaf extract) and positive control (with oxytetracycline at 0.05 mg/mL) were used, giving a total of 11 experimental treatments.

Results: The results showed that shrimps induced into all form of leaf extracts had significantly higher survival rates, clinical symptoms, and pathological anatomy than those negative control (C–) and positive control (C+). Total hemocyte cells, granulocytes, percentage of phagocytic, and prophenoloxidase activity were similar among leaf extract treatments (p>0.05), but those groups were significantly higher than those of C– and C+ (p<0.05).

Conclusion: n-butanol leaf extract at 300 mg/L is suggested to be the most effective treatment since it showed the highest efficacy on the parameters observed. Thus, it is possible to use the leaf extract of A. ilicifolius on-farm as a strategy to enhance bacterial disease resistance and prevent mortality.

Keywords: Acanthus ilicifolius, herbal plant extract, immunity, Penaeus monodon.