Lactate dehydrogenase disturbance in the desert locust Schistocerca gregaria (Forskal) (Orthoptera: Acrididae) by extracts of Punica granatum Linn. and Ammi visnaga L.

The current work was planned and conducted to investigate the effects of Punica granatum Linn. (Lythraceae) peel extracts and Ammi visnaga L. (Apiaceae) fruit extracts on lactate dehydrogenase (LDH) activity in haemolymph and fat bodies of last instar nymphs and newly emerged adult females of Schistocerca gregaria. A prevalent enhancing effect was exhibited by P. granatum peel extracts on last instar nymphs of all ages to gain considerably increasing LDH activity in haemolymph, with an exceptional case of inhibited activity in the mid-aged nymphs by n-butanol extract. A similar promoting action was exerted by A. visnaga fruit extracts with an exceptional case of an inhibited activity in the late-aged nymphs by petroleum ether extract. LDH activity in haemolymph of the newly emerged adult females was drastically suppressed by all P. granatum peel extracts. The ethanol extract of A. visnaga fruits prohibited the enzyme activity but both petroleum ether extract and n-butanol extract induced it. All P. granatum peel extracts caused remarkable inhibition of LDH in fat bodies of early-aged nymphs. In fat bodies of the mid- and late-aged nymphs, petroleum ether extract prohibited the enzyme activity but both ethanol extract and n-butanol extract stimulated it. Treatment with A. visnaga fruit extracts resulted in dramatically declined enzyme level in both early- and late-aged nymphs but enhanced in mid-aged ones. With regard to adults, LDH activity was unexceptionally induced in fat bodies by all plant extracts.