Cerebral ABC transporter-common mechanisms may modulate neurodegenerative diseases and depression in elderly subjects

Arch Med Res. 2014 Nov;45(8):738-43. doi: 10.1016/j.arcmed.2014.10.010. Epub 2014 Nov 11.


In elderly subjects, depression and dementia often coincide but the actual reason is currently unknown. Does a causal link exist or is it just a reactive effect of the knowledge to suffer from dementia? The ABC transporter superfamily may represent a causal link between these mental disorders. Since the transporters ABCB1 and ABCC1 have been discovered as major β-amyloid-exporting molecules at the blood-brain barrier and ABCC1 was found to be directly activated by St. John's wort (SJW), depression and dementia certainly share an important pathophysiologic link. It was recognized that herbal anti-depressant formulations made from SJW are at least as effective for the treatment of unipolar depression in old age as classical pharmacotherapy, while having fewer side effects (Cochrane reports, 2008). SJW is known to activate various metabolizing and transport systems in the body, with cytochrome P450 enzymes and ABC transporters being most important. Does the treatment of depression in elderly subjects using pharmacological compounds or phytomedical extracts target a mechanism that also accounts for peptide storage in Alzheimer's disease and perhaps other proteopathies of the brain? In this review we summarize recent data that point to a common mechanism and present the first promising causal treatment results of demented elderly subjects with distinct SJW extracts. Insufficient trans-barrier clearance may indeed present a common problem in all the proteopathies of the brain where toxic peptides are deposited in a location-specific manner. Thus, activation of efflux molecules holds promise for future treatment of this large group of devastating disorders.

Keywords: ABC transporter; Alzheimer's disease; Blood–brain barrier; Dementia; Depression; St. John's wort.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B / metabolism
  • ATP-Binding Cassette Transporters / metabolism
  • Aged
  • Alzheimer Disease / drug therapy
  • Alzheimer Disease / physiopathology*
  • Amyloid beta-Peptides / metabolism
  • Biological Transport
  • Blood-Brain Barrier / metabolism*
  • Depression / drug therapy
  • Depression / physiopathology*
  • Humans
  • Hypericum / chemistry
  • Male
  • Multidrug Resistance-Associated Proteins / metabolism*
  • Plant Preparations / therapeutic use


  • ABCA2 protein, human
  • ABCB1 protein, human
  • ATP Binding Cassette Transporter, Subfamily B
  • ATP-Binding Cassette Transporters
  • Amyloid beta-Peptides
  • Multidrug Resistance-Associated Proteins
  • Plant Preparations
  • multidrug resistance-associated protein 1