Fungi May Hold Key to Reducing Grapefruit Juice
Interactions with Medications
November 16, 2009
A fungus may help solve a problem
of a grapefruit compound that interacts negatively with certain prescription
drugs, according to studies by Agricultural
Research Service (ARS) scientists.
Grapefruit contains furanocomarins (FCs), which inhibit the enzymatic
activity responsible for metabolizing certain prescribed medications and
allowing more of the medication to enter the bloodstream. FCs are
phytochemicals commonly found in plants. Two well-known phytochemicals are
Vitamins C and E.
Grapefruit juice can interfere with the metabolism of certain medications
used to treat a wide range of conditions such as allergies, abnormal heart
rhythm, depression, hypertension, infections, heart disease, and high
cholesterol. The grapefruit industry may have lost customers who no longer
drink grapefruit juice due to their medications.
Manthey and microbiologist
Narciso at the ARS
and Subtropical Products Laboratory in Winter Haven, Fla., began the study
using a fungusAspergillus nigerto bind and break down FCs in
Grapefruit juice contains three main FCs. Myung found that A. niger
either bound these FCs or enzymatically broke them down into other products.
Enzymatic inactivation of these compounds may be a means of eliminating them
from commercial grapefruit juice, and work to identify these enzymes in A.
niger is in progress. A. niger is one of the most common species of
the genus Aspergillus that can cause black mold on certain fruits and
vegetables but often doesnt cause human disease.
Myung and his team decided to also test edible fungi, or mushrooms. In
studies, they found that edible mushrooms such as morels, oyster and button
mushroomswhen dried, pulverized and added to grapefruit juicealso
removed FCs. That provides researchers with evidence that fungal proteins could
be responsible for removing the FCs from the grapefruit juice.
This research was published in the Journal of Applied
Microbiology and Biotechnology and the
Agricultural and Food Chemistry.
ARS is the principal intramural scientific research agency in the
U.S. Department of Agriculture.