Identification and characterization of adipokinetic hormone (Locusta migratoria)-like immunoreactivity in the human cerebrospinal fluid

Effects of adipokinetic hormone/red pigment-concentrating hormone family of peptides in olfactory bulbectomy model and posttraumatic stress disorder model of rats

One of the major neuropeptide groups in insects is adipokinetic hormone/red pigment-concentrating hormone (AKH/RPCH) family of peptides. AKH had improving effects on depression and anxiety in animal models and it may be a new treatment choice in these disorders. Aim of this study was to investigate effects of Anax imperator AKH (Ani-AKH), Libellula auripennis AKH (Lia-AKH) and Phormia-Terra hypertrehalosemic hormone (Pht-HrTH) on animal behavior in olfactory bulbectomy (OBX) model and in posttraumatic stress disorder (PTSD) model of Wistar-albino rats. Lia-AKH and Pht-HrTH significantly increased time spent in escape platform's quadrant compared to sham control while Lia-AKH significantly increased time spent in escape platform's quadrant compared to OBX controls in probe trial of Morris water maze (MWM). Ani-AKH, Lia-AKH and Pht-HrTH significantly decreased immobility time compared to OBX controls in forced swimming test (FST). Pht-HrTH significantly increased %open arm time compared to OBX controls in elevated plus maze (EPM) test. Ani-AKH significantly increased %open arm entry compared to sham control while Ani-AKH and Pht-HrTH significantly increased %open arm entry compared to OBX controls in EPM. In PTSD study Ani-AKH and Lia-AKH significantly decreased immobility time compared to traumatized controls in FST. In acoustic startle reflex test, Ani-AKH, Lia-AKH and Pht-HrTH significantly decreased average startle amplitude compared to non-traumatized controls in PTSD study. Metabolomic studies showed that AKH may affect glutamatergic and dopaminergic system and neurochemistry. In conclusion, AKH peptides had wide ranging effects on behavior and improved performance in OBX and PTSD models in rats.

Effects of a dragonfly (Anax i.) homeopathic remedy on learning, memory and cell morphology in mice

BACKGROUND

Homeopathy is a form of alternative medicine in which uses highly diluted preparations that are believed to cause healthy people to exhibit symptoms similar to those exhibited by patients. The aim of this study was to investigate the effects of dragonfly (Anax imperator, Anax i.) on learning and memory in naive mice using the Morris water maze (MWM) test; moreover, the effects of dragonfly on MK-801-induced cognitive dysfunction were evaluated.

METHODS

Male balb-c mice were treated with dragonfly (30C and 200C) or MK-801 (0.2 mg/kg) alone or concurrently (n = 10). Dragonfly (D) and MK-801 were administered subchronically for 6 days intraperitoneally 60 min and 30 min, respectively, before the daily performance of the MWM test.

RESULTS

This study revealed that in the familiarization session and first session of the MWM test, Anax i. D30 significantly decreased escape latency compared to the control group, although MK-801, D30 and D200 significantly increased escape latency at the end of five acquisition sessions. Anax i. combined with dizocilpine maleate (MK-801) also significantly decreased escape latency in the familiarization session and first session of the MWM test, although this combination increased escape latency compared to the MK-801 alone group at the end of the test. Time spent in escape platform's quadrant in the probe trial significantly decreased while mean distance to platform significantly increased in MK-801, D30 and D200 groups. In the MWM test, Anax i. combined with MK-801 significantly decreased speed of the animals compared to the MK-801 alone group. General cell morphology was disturbed in the MK-801 group while D30 and D200 seemed to improve cell damage in the MK-801 group.

CONCLUSIONS

These results suggest that the homeopathic Anax i. can impair learning acquisition and reference memory, and it has beneficial effects on disturbed cell morphology.

Isolation and primary structure of a novel adipokinetic peptide from the pyrgomorphid grasshopper, Phymateus leprosus

Using a heterologous bioassay, monitoring lipid increase in the haemolymph of migratory locusts, two peptides have been purified from methanolic extracts of corpora cardiaca of the pyrgomorphid grasshopper, Phymateus leprosus. The structures of both peptides were elucidated by a combination of Edman degradation, after deblocking the N-terminal pyroglutamic acid residue, and mass spectrometric techniques. One peptide is an octapeptide (pGlu-Leu-Asn-Phe-Ser-Thr-Gly-Trp-NH2) which also occurs in desert locusts; the second peptide is a novel decapeptide member of the AKH-family (pGlu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-Gly-Ser-NH2).

The fruitfly Drosophila melanogaster contains a novel charged adipokinetic-hormone-family peptide

A member of the RPCH/AKH (red-pigment-concentrating hormone/adipokinetic hormone) family of arthropod neuropeptides was identified in the fruitfly Drosophila melanogaster, and its structure was determined by automated Edman degradation and m.s. using fast-atom-bombardment ionization and a tandem hybrid instrument capable of high sensitivity. The sequence of this peptide, which we call 'DAKH', is pGlu-Leu-Thr-Phe-Ser-Pro-Asp-Trp-NH2 (where pGlu is pyroglutamic acid and Trp-NH2 is tryptophan carboxyamide). H.p.l.c. analyses of extracts of the three body segments revealed that more than 80% of the peptide is contained in the thorax. Although DAKH is typical of family members in its general structure and distribution in the animal, it is unique in containing a residue which is charged under physiological conditions. The evolutionary significance of this change is considered.