Anthelmintic efficacy of Flemingia vestita (Fabaceae): alterations in glucose metabolism of the cestode, Raillietina echinobothrida Bidyadhar Das, Veena Tandon * , Nirmalendu Saha Department of Zoology, North Eastern Hill University, Shillong-793 022, India Received 6 January 2004; accepted 17 June 2004 Available online 24 August 2004 Abstract The root-tuber peel of Flemingia vestita and its active component, genistein, were tested in respect of glucose metabolism in the cestode, Raillietina echinobothrida . Live R. echinobothrida , collected from the intestine of freshly slaughtered domestic fowl, were incubated at 39F1 8C in defined concentrations of the root-peel crude extract (5 mg/ml), genistein (0.2 mg/ml) and praziquantel (1 Ag/ml) in phosphate buffered saline with 1% of dimethyl sulphoxide with simultaneous maintenance of controls. In the treated worms, there was a significant decrease in the glycogen concentration accompanied with the decrease of glucose by 14–32%, whereas the malate concentration increased by 49–134% as compared to controls. Both in controls and treated parasites, however, the pyruvate content was not measurable. While alanine and lactate contents showed a decline by 7–25% in the parasites exposed to all test materials, the lactate efflux into the incubation medium showed 37–71% increase in treatments indicating an overall increase of lactate production in comparison to controls. The results showing a decline in the glycogen and glucose contents and a significant rise in the malate content and lactate efflux under treatment conditions suggest that the energy demand in the parasites possibly got enhanced under stress, though it did not influence a switch over towards aerobic degradation of glucose in the parasites. D 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Raillietina echinobothrida; Intermediary metabolites; Flemingia vestita; Anthelmintic; Genistein; Praziquantel 1. Introduction Traditional medicine practice among the natives in Meghalaya (Northeast India) relies on treatment with tuberous roots of an indigenously grown leguminous plant Flemingia vestita (Family: Fabaceae) for the purpose of eliminating intestinal worms; in case of suspected worm infections, the raw fleshy roots are consumed unpeeled. Earlier studies on the anthelmintic efficacy of the plant- derived materials have provided evidences that support and authenticate the usage of the tuberous root of this plant as vermifuge/vermicide. The root-peel extract and its major isoflavone component, genistein, caused a flaccid paralysis, damage to tegumental architecture, and alterations in the activity of enzymes associated with the tegument and coordination system both in cestodes and trematodes [1–6]. Glycogen, which is the major carbohydrate in both larval and adult cestodes, serves typically as the most important energy reserve in the parenchymatous tissue [7]. Several chemotherapeutic agents have been shown to influence glycogen metabolism in helminth parasites [8–10]. Cestodes and trematodes mainly ferment the glucose and other simple carbohydrates to meet their energy requirements [11,12]. Glucose 1-phosphate, released by the glycogenolysis, is converted by the enzyme phosphoglucomutase to glucose 6- phosphate which enters into the type 2 fermentation, characterized by a CO 2 -fixation step (by phosphoenolpyr- uvate carboxykinase) and malate dismutation, found in most cestodes [13]. There are conflicting reports regarding the effect of anthelmintic drugs on carbohydrate metabolism. While it has been suggested that in the cestode, Cotugnia 1383-5769/$ - see front matter D 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.parint.2004.06.002 * Corresponding author. Tel.: +91 364 2722312; fax: +91 364 2550300/2721000. E-mail address: tandonveena@hotmail.com (V. Tandon). Parasitology International 53 (2004) 345 – 350 www.elsevier.com/locate/parint