Antiparasitic efficacy of piperine against Argulus spp. on Carassius auratus (Linn. 1758): in vitro and in vivo study

Argulus are common aquatic ectoparasites that create one of the major threats to aquaculture due to absence of suitable therapy. Piperine, a bioactive component of Piper longum, has medicinal properties and acts as anti-inflammatory, antibacterial, and antifungal, considering eco-friendliness and cost-effectiveness. The present study aimed to evaluate antiparasitic effect of piperine against an ectoparasite Argulus spp. on Carassius auratus. Artificial Argulus infection was carried out by cohabitation method, and the fishes were selected for in vivo study when intensity of Argulus infestation was observed to be 15–20 Argulus per fish. In vitro and in vivo studies were performed at different concentration 1.0 (T1), 3.0 (T2), 5.0 (T3), 7.0 (T4), and 9.0 mg l−1 (T5) of piperine solution to treat Argulus for 3 and 72 h, respectively. The acute toxicity test for piperine EC 97 % against goldfish was performed for 96 h. The 96 h median lethal concentration (LC50) for piperine was found to be 52.64 mg l−1. In vitro effect of piperine solution led to 100 % mortality of Argulus at 9.0 mg l−1 in 3 h whereas, under in vivo test, the 100 % antiparasitic efficacy of piperine solution was found at 9.0 mg l−1 in 48 h. The EC50 for 48 h was 9.0 mg l−1, and thus, therapeutic index is 5.8. The results revealed that piperine at a concentration of 9.0 mg l−1 can be used as a potential natural agent for controlling Argulus parasite.