Neuroprotective Effect of the Novel Compound ITH33/IQM9.21 Against Oxidative Stress and Na super(+) and Ca super(2+) Overload in Motor Neuron-like NSC-34 Cells

Alternatives for the treatment of amyotrophic lateral sclerosis (ALS) are scarce and controversial. The etiology of neuronal vulnerability in ALS is being studied in motor neuron-like NSC-34 cells to determine the underlying mechanisms leading to selective loss of motor neurons. One such mechanism is associated with mitochondrial oxidative stress, Ca super(2+) overload, and low expression of Ca super(2+)-buffering proteins. Therefore, in order to elicit neuronal death in ALS, NSC-34 cells were exposed to the following cytotoxic agents: (1) a mixture of oligomycin 10 mu M and rotenone 30 mu M (O/R), or (2) phenylarsine oxide 1 mu M (PAO) (to mimic excess free radical production during mitochondrial dysfunction), and (3) veratridine 100 mu M (VTD) (to induce overload of Na super(+) and Ca super(2+) and to alter distribution of Ca super(2+)-buffering proteins [parvalbumin and calbindin-D28k]). Thus, the aim of the study was to test the novel neuroprotective compound ITH33/IQM9.21 (ITH33) and to compare it with riluzole on in vitro models of neurotoxicity. Cell viability measured with MTT showed that only ITH33 protected against O/R at 3 mu M and PAO at 10 mu M, but not riluzole. ITH33 and riluzole were neuroprotective against VTD, blocked the maximum peak and the number of [Ca super(2+)] sub(c) oscillations per cell, and restored the effect on parvalbumin. However, only riluzole reversed the effect on calbindin-D28k levels. Therefore, ITH33 was neuroprotective against oxidative stress and Na super(+)/Ca super(2+) overload, both of which are involved in ALS.