|Ph.D Student||Liu Wei|
|Subject||Development of Novel Multifunctional Cholinesterase/|
Monoamine Oxidase Inhibitors as Derivatives of
Rivastigmine and Rasagiline for
Treatment of ...
|Department||Department of Medicine||Supervisors||Professor Emeritus Moussa Youdim|
|Dr. Orly Weinreb|
|Full Thesis text|
Current novel therapeutic approach suggests that multifunctional compounds, with diverse biological activities and a single bioavailability and pharmacokinetic and metabolism, will produce higher significant advantages in treatment of Alzheimer’s diseases (AD). Based on this rational, a new class of cholinesterase (ChE)-monoamine oxidase (MAO) inhibitors, MT series were designed and synthesized by amalgamating the propargyl moiety of the irreversible selective MAO-B inhibitor and neuroprotective/neurorestorative anti-Parkinsonian drug, rasagiline, into the methylamino-position of the ChE inhibitor anti-AD drug, rivastigmine. The present research premises underlying hypothesizes that MT series might preserve dual MAO and ChE inhibitory properties of the parent drugs and exert good treatment potency on AD regards to neuroprotective ability, cognitive enhancing activities and anti-inflammatory effects.
To test this assumption, we initially examined the inhibitory effect of MT series on MAO and ChE activities both in vitro and in vivo. Among them, MT-031 exhibited higher potency as a dual MAO and ChE inhibitor than other compounds, in acute-treated mice and rats. Furthermore, chronic treatment with MT-031 in mice, displayed a greater selective irreversible inhibition of MAO-A than -B activities. In particular, no significant MAO-A inhibition was observed in liver and intestine of MT-031-treated mice, which reduces the likelihood of MT-031 to produce "cheese effect". Additionally, MT-031 was found to increase the levels of striatal dopamine (DA), serotonin (5-HT) and norepinephrine, and prevent the metabolism of DA and 5-HT.
Our studies demonstrated that once daily administration of MT-031 (5-10 mg/kg) for 2 weeks in mice was shown to release behavioral anxiety of mice in open field test. MT-031 significantly inhibited brain MAO-A by 60-80%, ChE by 25-50%, and antagonized scopolamine-induced memory impairments; improved the learning ability, spatial and retention memory, and decreased the escape latency time (determined by Y-maze and Morris water maze tests) in scopolamine mouse model. In accordance, MT-031 was shown to exert neuroprotective effects. Firstly, MT-031 attenuated the effect of scopolamine on mRNA expression levels of the neuronal survival Bcl-2 like 1, neuronal growth factor, brain derived neurotrophic factor and pro-inflammatory cytokine, interleukin-6. In addition, MT-031 significantly up-regulated the mRNA expression levels of the antioxidant enzyme catalase, neurotrophic tyrosine receptor kinase and glial derived neurotrophic factor in chronic drug-treated mice.
Further, we have evaluated the neuroprotective potency of MT-031 in vitro. MT-031 exerted neuroprotective effect against H2O2-induced neurotoxicity and reactive oxygen species (ROS) generation in SH-SY5Y cells.
Finally, we have investigated the potency of MT-031 on anti-inflammation in several cell models. It was shown that MT-031 significantly prevented anti-CD3-activated proliferation in splenocytes and LPS-induced intracellular ROS accumulation in activated microglia cells. In line with that, MT-031 significantly altered levels of inflammatory cytokines by up-regulating the anti-inflammatory and down-regulating the pro-inflammatory cytokines of cells.
Together, our findings demonstrated that MT-031 is a brain permeable novel multifunctional MAO-A/ChE inhibitor possesses neuroprotective, cognitive enhancing and anti-inflammatory properties. These results provide the evidence that MT-031 may preserve the beneficial properties of its parent drugs, rasagiline and rivastigmine, and thus may be suggested as novel treatment for combating AD.