Researchers
from the NEUROFAN group, dedicated to the neuropharmacology
of addictions and degenerative disorders, have successfully identified a
new biomarker of cocaine abuse disorder and, more specifically, of withdrawal
from this drug. "Elevated levels of midkine have been
detected in patients with early withdrawal from cocaine that then decrease as
the period without consuming is prolonged", says
Professor Gonzalo Herradón. Therefore, the
authors insist,: “it is possible to propose the pharmacological
potential of the effects of midkine as a future therapeutic strategy for the
treatment of cocaine abuse disorder and the prevention of relapses in its use,
which could also be extended to other drugs of abuse”.
The research
has been published in the journal Addictions and
constitutes the transition from animal models to patients in the group's
previous discoveries with midkine, a protein that regulates the effects of
different drugs of abuse such as cocaine or alcohol. In 2014, the group led by
Professor Gonzalo Herradón published the first evidence showing that mice which
had not been administered midkine had greater difficulties in eradicating the
reinforcing effects of cocaine in animal models related to drug-seeking
behaviour. These results, along with other subsequent evidence, suggest that
midkine opposes the addictive and neurotoxic effects of cocaine, so that its
production could increase in the brain as part of a natural mechanism of
protection against the harmful effects of the drug. This hypothesis has been
supported by the recent work carried out in collaboration with the University
Hospital of Málaga and directed by Professor Luis Fernando Alguacil,
a researcher for the NEUROFAN group
and Director of the Institute for Addiction Studies
IEA-CEU. In this study, researchers have measured plasma levels of
midkine in 75 patients with cocaine use withdrawal disorder in 26
tests. "We have found that patients in early
withdrawal show a 60% increase in their plasma concentration of midkine
in tests, a difference that tends to disappear when withdrawal periods
are longer", details Professor Alguacil.
These
findings, the result of several research projects funded during the last decade
by the State Program I+D+i and
the National Plan on Drugs, suggest that, in humans, as in
animal models, high levels of midkine could play a very important role in
limiting the biological effects of psychostimulants such as cocaine, and they
open the possibility that either midkine itself or other drugs with analogous
biological effects could be useful to limit the neurotoxicity associated with
cocaine use and facilitate the cessation process. On this basis, the research
groups NEUROFAN, PROLIGAR 7 and GESTOBES of CEU San Pablo University have
collaborated to develop new compounds that regulate the activity of midkine,
something which could lead to the discovery of new drugs to combat drug
addiction.