Oral administration of coenzyme Q₁₀ reduces MPTP-induced loss of dopaminergic nerve terminals in the striatum in mice

Coenzyme Q10 and Parkinsonian Syndromes: A Systematic Review

Coenzyme Q₁₀ (CoQ₁₀) has an important role as an antioxidant. Being that oxidative stress is one of the mechanisms involved in the pathogenesis of Parkinson’s disease (PD) and other neurodegenerative diseases, several studies addressed the concentrations of CoQ₁₀ in the different tissues of patients with PD and other parkinsonian syndromes (PS), trying to elucidate their value as a marker of these diseases. Other studies addressed the potential therapeutic role of CoQ₁₀ in PD and PS. We underwent a systematic review and a meta-analysis of studies measuring tissue CoQ₁₀ concentrations which shows that, compared with controls, PD patients have decreased CoQ₁₀ levels in the cerebellar cortex, platelets, and lymphocytes, increased total and oxidized CoQ₁₀ levels in the cerebrospinal fluid and a non-significant trend toward decreased serum/plasma CoQ₁₀ levels. Patients with multiple system atrophy (MSA) showed decreased CoQ₁₀ levels in the cerebellar cortex, serum/plasma, cerebrospinal fluid, and skin fibroblasts. Patients with Lewy body dementia (LBD) showed decreased cerebellar cortex CoQ₁₀, and those with progressive supranuclear palsy (PSP) had decreased CoQ₁₀ levels in the cerebrospinal fluid. A previous meta-analysis of studies addressing the therapeutic effects of CoQ₁₀ in PD showed a lack of improvement in patients with early PD. Results of the treatment with CoQ₁₀ in PSP should be considered preliminary. The potential role of CoQ₁₀ therapy in the MSA and selected groups of PD patients deserves future studies.

Preventative effects of 1-methyl-1,2,3,4-tetrahydroisoquinoline derivatives (N-functional group loading) on MPTP-induced parkinsonism in mice

1,2,3,4-Tetrahydroisoquinoline (TIQ) is endogenously present in human brain, and some of its derivatives are thought to contribute to the induction of Parkinson's disease (PD)-like signs in rodents and primates. In contrast, the endogenous TIQ derivative 1-methyl-TIQ (1-MeTIQ) is reported to be neuroprotective. In the present study, we compared the effects of artificially modified 1-MeTIQ derivatives (loading an N-propyl, N-propenyl, N-propargyl, or N-butynyl group) on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD-like signs in mice. In a behavioral study, MPTP-induced bradykinesia was significantly decreased by all compounds. However, only 1-Me-N-propargyl-TIQ showed an inhibitory effect by blocking the MPTP-induced reduction in striatal dopamine content and the number of nigral tyrosine hydroxylase-positive cells. Western blot analysis showed that 1-Me-N-propargyl-TIQ and 1-Me-N-butynyl-TIQ potently prevented the MPTP-induced decrease in dopamine transporter expression, whereas 1-MeTIQ and 1-Me-N-propyl-TIQ did not. These results suggest that although loading an N-propargyl group on 1-MeTIQ clearly enhanced neuroprotective effects, other N-functional groups showed distinct pharmacological properties characteristic of their functional groups. Thus, the number of bonds and length of the N-functional group may contribute to the observed differences in effect.

Pathophysiology and animal modeling of underactive bladder

While the symptomology of underactive bladder (UAB) may imply a primary dysfunction of the detrusor muscle, insights into pathophysiology indicate that both myogenic and neurogenic mechanisms need to be considered. Due to lack of proper animal models, the current understanding of the UAB pathophysiology is limited, and much of what is known about the clinical etiology of the condition has been derived from epidemiological data. We hereby review current state of the art in the understanding of the pathophysiology of and animal models used to study the UAB.

An alternative medical approach for the neuroprotective therapy to slow the progression of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the core symptoms such as bradykinesia, resting tremor, rigidity and postural instability. Currently, pharmacotherapy and surgical approaches for the treatments of PD can only improve the neurological symptoms. Therefore, to search neuroprotective therapies using pharmacological and nonpharmacological approaches could be important to delay the progression of pathogenesis in PD. Coenzyme Q10 (CoQ10) is a component of the electron transport chain as well as an important antioxidant in mitochondrial and lipid membranes. The central role of CoQ10 in two areas implicated in the pathogenesis of PD, mitochondrial dysfunction and oxidative damages, suggest that it may be useful for treatment to slow the progression of PD. The neuroprotective effect of CoQ10 has been reported in several in vivo and in vitro models of neurodegenerative disorders. Although CoQ10 attenuated the toxin-induced reduction of dopamine content and tyrosine hydroxylase-immunoreactive neurons in the striatum of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model, it is still unknown how this nutrition affects the mitochondrial function. We demonstrated that oral administration of CoQ10 significantly attenuated the loss of dopaminergic nerve terminals induced by MPTP treatment. Furthermore, our experimental data indicate that an inhibition of mitochondrial cytochrome c release is one of the primary targets for CoQ10 and may lead to a potent neuroprotection.