Investigating the Effects of Rivastigmine and Ketamine on Brine Shrimp Morphology, Mortality, and Acetylcholinesterase Activity

Research Article

Abstract

Brine shrimp (Artemia salina) has emerged as a valuable alternative animal model for preclinical pharmacological research due to its cost-effectiveness, ease of maintenance, and sensitivity to a wide range of toxins. This study aimed to investigate the effects of rivastigmine, an acetylcholinesterase inhibitor, and ketamine, an NMDA receptor blocker, on the morphology, mortality, and acetylcholinesterase (AChE) activity of brine shrimp and their egg homogenates. Brine shrimp eggs were hatched in 5% and 2% NaCl solutions, and the live shrimps were exposed to various concentrations of rivastigmine and ketamine for 24 hours. Morphological changes and mortality were assessed using a binocular microscope. Additionally, the effects of these drugs on AChE activity in brine shrimp egg homogenates were evaluated using Ellman's method. The results revealed that 5% NaCl solution yielded higher hatchability (>90%) compared to 2% NaCl. No significant morphological abnormalities or mortality were observed in shrimps treated with different doses of rivastigmine and ketamine. Rivastigmine (100-800 μg/ml) significantly increased AChE activity in egg homogenates, confirming the presence of AChE in brine shrimp. However, ketamine did not show any significant effect on AChE activity. These findings suggest that brine shrimp and their egg homogenates can serve as a valuable model for studying the effects of neuroactive compounds on cholinergic systems and provide insights into the potential use of this model in neuropharmacological research