Regrettably, there are no clinical studies that been done to date to directly address whether PQQ is effective in the treatment of Parkinson’s disease, although the assertion is sometimes made in nutritional supplement-oriented blogs and websites less scrupulous than ours. However, there are a number of basic studies that appear promising, which suggest pyrroloquinoline quinone may be beneficial in slowing or altering the progression of Parkinson’s disease.
What is known to date? In studies using experimental animal models, PQQ does interact with the neurotransmitter systems. It appears to be a neuroprotective (also see the post, PQQ, glutamate, nitric oxide and N-methyl-D-aspartic acid receptors). PQQ could potentially protect against neurotoxicity induced by compounds that promote or produce Parkinson-like symptoms in laboratory animals. Moreover, PQQ in chemical assays inhibits the aggregation of alpha-synuclein, a process that is associated with the progression to Parkinson’s disease. Pyrroloquinoline quinone also seems to protect nerve cells by blocking new amyloid beta molecular structures from forming before they can cause cellular damage akin to what is observed in Parkinson’s disease. Although these observations are promising, questions nevertheless remain regarding how direct and specific the actions of PQQ are as they relate to altering the functions of alpha-synuclein and amyloid beta, if and when they are abnormally aggregated.
If you would like to do a deeper dive on this topic you should read:
1. Kobayashi, M; Kim, J; Kobayashi, N; Han, S; Nakamura, C; Ikebukuro, K; Sode, K. Pyrroloquinoline quinone (PQQ) prevents fibril formation of alpha-synuclein. 2006 Biochemical and Biophysical Research Communications 349: 1139–44.
2. Zhang JJ; Zhang RF; Meng XK. Protective effect of pyrroloquinoline quinone against Abeta-induced neurotoxicity in human neuroblastoma SH-SY5Y cells. 2009 Neuroscience Letters 464: 165–9.
3. Kim, J; Kobayashi, M; Fukuda, M; Ogasawara, D; Kobayashi, N; Han, S; Nakamura, C; Inada, M et al. Pyrroloquinoline quinone inhibits the fibrillation of amyloid proteins. Prion 4: 26–31.