Enzymes in Selected Tissues of Catfish Hybrid Exposed to Aqueous Extracts from Lepidagathis alopecuroides Leaves

Hybrid catfish, Heterobranchus longifilus c x Clarias gariepinus ¥ (mean total length, 29.96±2.23 cm, SD; mean weight, 207.83±12.63g SD) were exposed individually in quadruplicate to 40 L of sublethal aqueous extracts of Lepidagathis alopecuroides (0.25, 0.50, 0.75, 1.00, 1.25 and a control, 0.0 mg L-1) for 21 days in a daily static renewal bioassay. The liver, kidney, gill and muscle tissues were then assayed for enzymes activities. The activities of AST and ALT in the liver were most inhibited at 0.75 mg L_1, AST activity was inhibited in all the exposure concentrations below the control value, (p<0.05). Generally ALT activity was inhibited. The activities of AST and ALT in the kidney were generally retarded below control values. Activities of AST and ALT declined in gill tissues below the control values. ALP activity was generally enhanced in the liver, kidney and gill of exposed fish. The activities of AST and ALP in the muscle were mostly enhanced at 1.25 mg L_1, but ALP was inhibition at 0.50 and 0.75 mg L_1. Although the bio-indicator enzymes could be used for monitoring the toxic effects of the plant in the fish species this will depend on the exposure levels and organs of choice.