Abstract

GLUTATHIONE-S-TRANSFERASE OF HAEMONCHUS CONTORTUS - A VULNERABLE TARGET FOR ALLIUM SATIVUM AND ANDROGRAPHIS PANICULATA

L. Veerakumari and N. Chitra*

ABSTRACT

Haemonchosis has been identified as major gastrointestinal parasitic disease in livestock caused by Haemonchus contortus. It is an important bloodsucking parasite of ovines and causes an insidious drain on production and high mortality in all classes of livestock. Drug resistance necessiated the exploration of alternative control methods. Therefore, there is a need for developing cheaper, less toxic and ecofriendly novel drugs. Indigenous medicinal plants offer an important alternative source. Glutathione-S-transferase (GST) are major metabolic enzymes and may play an important role in the parasite’s survival. GST’s are able to scavenge the products of lipid peroxidation and to metabolize toxic products, including anthelmintics. The effect of ethanol extract of Allium sativum (AsEE) and chloroform extract of Andrographis paniculata (ApCE) on GST activity of the nematode H. contortus was studied. The worms were exposed to various sublethal concentrations of AsEE and ApCE for 2, 4 and 8h. GST was assayed in control and drug-treated worms. Maximum inhibition of GST activity was observed at 0.5 mg/ml of AsEE and ApCE after 8 h of exposure. Inhibition of GST activity was dose and time dependent. Reduction in GST leads to accumulation of toxic metabolites which ultimately kill the parasites. The present study thus enlightened the anthelmintic effect of AsEE and ApCE, which can be used to combat nematode infection in livestock.

Keywords: Allium sativum, Andrographis paniculata, Haemonchus contortus and Glutathione-S-transferase.