A galantamine-curcumin hybrid lacks the depressant side effect of acetylcholinesterase inhibitors

Acetylcholinesterase inhibitors (AChEIs) are drugs that enhance cholinergic neuro-transmission and are used for the treatment of Alzheimer's disease and myasthenia gravis. Common AChEIs include rivastigmine, donepezil and galantamine (GAL), but they can cause side effects like nausea, vomiting, depression and bradycardia. A potential link exists between AChEIs and increased depression risk. Recently, we have discovered a hybrid compound (4b) combining GAL and curcumin (CCN), which shows improved anticholinesterase activity and neuroprotective effects. It could be developed as a potential multitarget agent for neurodegenerative disorders. Here, we examine the compound's depressant side effect on mice, comparing it to GAL and CCN. Tests were conducted twice using the tail suspension test (TST) and the forced swim test over an 8-day treatment period. The results showed that 4b lacked the depressant effect of GAL and even displayed a mild antidepressant effect similar to CCN in TST. This suggests that incorporating antidepressant fragments, like CCN, into AChEIs can potentially neutralize their depressive side effects.