Alterations in the lactate dehydrogenase activity of the desert locust Schistocerca gregaria by the wild plant Fagonia bruguieri (Zygophyllaceae).

Abstract

The wild plant F. bruguieri extracts caused some alterations in the lactate dehydrogenase activity in haemolymph and fat body of the last instar nymphs and newly emerged adults of the desert locust S. gregaria. Each of two concentration levels of methanolic (7.5 and 3.7%), petroleum ether (30.0 and 15.0%) or n-butanolic extract (30.0 and 15.0%) was applied against the penultimate instar nymphs through the fresh clover leaves, Medicago sativa, as a food. Unexceptionally, all F. bruguieri extracts induced the LDH activity in the haemolymph along the nymphal instar, irrespective of the solvent or concentration level. The strongest inducing effect was exhibited in the mid-aged nymphs (62601.3±467.4 U/L in comparison with 53696.8±467.4 U/L of control congeners) after treatment with the higher concentration level of methanolic extract. On the contrary, the LDH activity was significantly prohibited in the newly emerged adults. The most drastically inhibited enzyme activity was determined (57744.3±467.4 U/L, compared to 62871.2±934.7 U/L of control congeners) after nymphal treatment with higher concentration level of n-butanolic extract. With regard to the fat body, all F. bruguieri extracts prohibited LDH activity along the nymphs instar, irrespective of the concentration level. The most dramatically reduced activity was expressed in (9166.4±119.0 U/L vs. 22839.5±289.1 U/L of control congeners) after treatment with the lower concentration level of n-butanolic extract. In contrast, the plant extracts pronouncedly enhanced the enzyme activity in the fat body of adults, regardless to the extract. The most stimulatory effect was exhibited after treatment of the nymphs with the lower concentration level of n-butanolic extract.