Background: In multiple sclerosis
during periods of remission a limited degree of myelin repair can be
observed mediated by oligodendroglial precursor cells. Phosphodiesterase
inhibitors act as anti-inflammatory agents and might hold promise for
future multiple sclerosis
treatment.
Aims: To investigate whether phosphodiesterase inhibitors
could also influence myelin repair.
Methods: We stimulated primary
oligodendroglial precursor cells with cilostazol, rolipram and
vinpocetine and assessed their effects on repair related cellular
processes.
Results: We found that vinpocetine exerted a strong negative
effect on myelin expression while cilostazol and rolipram did not show
such effects. In addition, vinpocetine decreased morphological
complexities suggesting an overall negative impact on oligodendroglial
cell maturation. We provide evidence that this is not mediated via a
blockade of phosphodiesterase-1 but rather by inhibition of IĸB kinase.
Conclusion: These findings suggest that vinpocetine via IĸB inhibition
exerts a strong negative impact on oligodendroglial cell maturation and
may therefore provide the rationale to restrict its application during
periods of remission in multiple sclerosis
patients. This is of particular interest since vinpocetine is widely
used as a health supplement thought to act as a cognitive and memory
enhancer for healthy people and patients with neurological or muscle
diseases.
I would not be using PDE4 inhibitors such as rolipram because it
inhibits pathways associated with boosting MS, cilostazol is a PDE3
inhibitor. Vinpocetine has been shown to selectively inhibit voltage-sensitive
Na+ channels and could be neuroprotective. Vinpocetine is also a phosphodiesterase (PDE) type-1 inhibitor but the doses for this activity are very high. Vinpocetine's action on PDE, vinpocetine inhibits IKK preventing IκB degradation and the following translocation of NF-κB to the cell nucleus. As will all nutricueticals we like to see evidence that they are useful and that they are not doing harm. This study suggests that vinpocetine may inhibit remyelination. How the findings of this study equate to nutriceutical use is unclear. However it serves as a warning concerning the use of nutriceuticals.