Anthelmintic action of plant cysteine proteinases against the rodent stomach nematode, Protospirura muricola, in vitro and in vivo
Cysteine proteinases from the fruit and latex of plants, including papaya, pineapple and fig, were previously shown to have a rapid detrimental effect, in vitro, against the rodent gastrointestinal nematodes, Heligmosomoides polygyrus (which is found in the anterior small intestine) and Trichuris muris (which resides in the caecum). Proteinases in the crude latex of papaya also showed anthelmintic efficacy against both nematodes in vivo. In this paper, we describe the in vitro and in vivo effects of these plant extracts against the rodent nematode, Protospirura muricola, which is found in the stomach. As in earlier work, all the plant cysteine proteinases examined, with the exception of actinidain from the juice of kiwi fruit, caused rapid loss of motility and digestion of the cuticle, leading to death of the nematode in vitro. In vivo, in contrast to the efficacy against H. polygyrus and T. muris, papaya latex only showed efficacy against P. muricola adult female worms when the stomach acidity had been neutralized prior to administration of papaya latex. Therefore, collectively, our studies have demonstrated that, with the appropriate formulation, plant cysteine proteinases have efficacy against nematodes residing throughout the rodent gastrointestinal tract.(Received July 4 2006)
(Revised July 27 2006)
(Accepted July 28 2006)
(Published Online October 11 2006)
Key Words: Protospirura muricola; plant cysteine proteinases; papaya; pineapple; fig; in vitro; in vivo; antacid; anthelmintic; gastrointestinal nematodes.
c1 School of Biology, University of Nottingham, University Park, Nottingham NG7 2RD, UK. Tel: 44 115 951 3208. Fax: 44 115 951 3251. E-mail: firstname.lastname@example.org
p1 Current address: Department of Veterinary Parasitology, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow G61 1QH, UK.