Effects of Millettia pachycarpa on the trace metals and tegumental enzymes of Raillietina echinobothrida

The root bark extract of Millettia pachycarpa Bentham is known to certain Mizo tribes of north-east India as a curative to gastrointestinal infestations. An in vitro treatment of the poultry gastrointestinal cestode Raillietina echinobothrida Megnin with the crude ethanolic extract of the plant part reportedly indicate remarkable cestocidal effects on the survival and morphological structures of the worm. In an attempt to further explore the anthelmintic activity of the plant and with a view to understand the primary mode of action, the parasites were exposed to 20 mg mL-1 of the different extracts (viz ethanol, methanol and acetone) of M. pachycarpa root bark till they reached paralytic state. Similar dose of albendazole was used as a reference standard drug. The levels of the vital trace elements such as calcium, magnesium, potassium and sodium, and the activities of tegumental enzymes such as acid phosphatase (AcPase) and alkaline phosphatase (AlkPase) of the worms were assessed. The plant extracts clearly indicated significant reduction (P < 0.05) in the levels of the trace metals compared to control worms. The enzymatic activities of AcPase and AlkPase were also significantly inhibited. Among the three extracts, the ethanol extract was the most potent in causing these biochemical alterations, and the effects were comparable to those of albendazole. The overall results show that the plant extracts exert anthelmintic activity by acting trans-tegumentally, inhibiting the major enzymes to induce tegumental damages, and depleting the trace metals to bring about flaccid paralysis and mortality of the cestodes.