The Effect of Agelena Labyrinthica Total Venom and its Agatoxin Fraction on the Kainic Acid-Induced Cognitive Disorder in Rat

Overactivation of P/Q type of calcium channels leads to neurological disorders. The venom of Agelena labyrinthica consists of substances which can inhibit this channel. One of the most important compounds is agatoxin. This study aimed to investigate the preventive and therapeutic effects of total venom or agatoxin component on kainic acid-induced amnesia.

The spider, Agelena labyrinthica, was collected from Mazandaran Province, Iran, and their total venom was extracted. The agatoxin fraction was purified using the fast protein liquid chromatography (FPLC) method. The total venom or agatoxin was injected into the rat hippocampus before or after injection of kainic acid. A week after the drug injection, the memory of animals was assessed using Morris water maze (MWM) task.

Kainic acid significantly reduced the time spent in the target quadrant (TQ) in water maze compared to the control group (P < 0.001). Intra-hippocampal injection of total venom or agatoxin fraction either before or after kainic acid caused a significant increase in TQ time compared to kainic acid group (P < 0.001). Of note, their injection before the kainic acid increased the TQ time more than injection after the kainic acid. In comparison to total venom, agatoxin fraction remarkably increased the TQ time.

Total venom and agatoxin fraction prevented the memory impairment due to the excitotoxicity of kainic acid. The effect of agatoxin was greater than total venom. These two substances showed less ameliorative effect when administered after kainic acid injection.