Quercetin: An anthelmintic potential against zoonotic tapeworm Hymenolepis diminuta (Rudolphi, 1819)

Quercetin, a vital flavonoid found in many medicinal plants, has shown anti-inflammatory, anti-cancerous, anti-aging, anti-tumour, anti-viral, anti-fungal, anti-bacterial, anti-obesity, anti-diabetic, and anti-protozoal activity. However, very little is known of its anthelmintic activity; there is no literature against tapeworm infection so far. The present study was performed to expose its cestocidal role by using the zoonotic tapeworm Hymenolepis diminuta as a parasite model. The parasite was exposed to different concentrations of 0.125, 0.25, 0.5, 1, 2.5, 5, 10, 20, and 40 mg/mL Quercetin prepared in RPMI 1640, with 1% Tween 20. Another set of parasites was treated with a standard dose of Praziquantel (0.001 mg/ml), and another set of parasites was kept as control. All experiments were maintained at 37°C ± 1°C in the incubator. Quercetin activity was assessed through viability test, and time of motility was observed through paralysis. After the experiment, worms were processed for light and electron microscopic analysis to observe the post-treatment effect on their tegument. Dose-dependent efficacy was observed in all the treatments. Time of paralysis and time of mortality for 20 mg/mL Quercetin dose was 1.40±0.03h and 2.35±0.03h, respectively, which is at par with the drug Praziquantel. Histological study showed constrictions in the tegument, while extensive damage in suckers and neck region with deformed and shrunken proglottids, sloughed-off microtriches and undistinguished nucleus with loss of envelope architecture were observed in treated parasites under electron microscopic studies, which indicates the negative activity of Quercetin on the parasite thus suggesting its cestocidal activity.