Drug-proof grapefruit

Drug-proof grapefruit
Nature Biotechnology 31, 186 (2013)

Citrus breeders at the University of Florida’s Citrus Research and Education Center display new varieties of grapefruit and pomelo hybrids that could resolve the problem of grapefruit/drug interactions.
The team developed the hybrid fruit as a cross between grapefruit and pummelo, a citrus species…


Effect of grapefruit juice on cabergoline pharmacokinetics in patients with Parkinson’s disease
Clinical Pharmacology & Therapeutics 77, P84 (February 2005)
M. Nagai, et. al.

Background: Cabergoline is one of the synthetic ergoline dopamine agonists, which is widely used for the treatment of Parkinson’s disease (PD). Cytochrome P-450 (CYP) 3A4 contributes to metabolize Cabergoline. It has been well known that grapefruit juice inhibits CYP3A4 enzyme located in the gut wall. To investigate whether grapefruit juice influences the pharmacokinetics of cabergoline, plasma level of cabergoline in patients of PD was evaluated.

Methods: Five patients with PD treated with cabergoline were enrolled. Plasma concentrations of cabergoline before and after coadministration of grapefruit juice were evaluated. The plasma concentration of cabergoline was determined using a LC/MS/MS.

Results: The plasma concentration of cabergoline increased approximately 1.7 times, when grapefruit juice was taken together with cabergoline. Adverse events were not observed during this trial.

Conclusions: Coadministration of grapefruit juice with cabergoline increases bioavailability of cabergoline. A relatively large therapeutic window of cabergoline may allow the concomitant treatment with grapefruit juice, and this combination treatment may augment the antiparkisonian effect of cabergoline.



Nootkatone, a new insect repellent

Chemistry Research Roundup
September 13, 2013

Richard Burlingame is vice president of Research and Development at Allylix in Lexington, Kentucky.

nootkatone is a compound that’s – it’s called a sesquiterpene.
It’s a 15-carbon compound that’s a member of the class of the compounds called terpenes, which are the most diverse class of natural products. It’s a compound that is the defining flavor in the fragrance of grapefruits.
So if you cut open a grapefruit, what you smell and what you taste when you eat a grapefruit is nootkatone.

And it’s found in other sources, too. It’s also found in Alaska yellow cedar, for example.

it’s not surprising that it would be useful as an insect repellent.
In fact, terpenes in general are compounds that serve protective functions for plants.
So they can act as repellents for harmful insects, or attractants for beneficial insects.

Nootkatone is present in pretty low abundance in grapefruits.
And grapefruit peels are something that really is in limited supply, at least for applications such as this.
So, we at Allylix are developing technology to produce compounds like nootkatone more cost-effectively, and also produce it more sustainably and reliably.

So we’ve developed a yeast system in which we have genetically engineered yeast to produce various terpenes, and produce those terpenes by fermentation, then from the yeast strains.

nootkatone is effective against a variety of different insects.
It’s effective against mosquitoes, ticks – including the tick that’s responsible for the transmission of Lyme disease – bedbugs and fleas. So it is a pretty broad spectrum.

FLATOW: And since it comes from a grapefruit, or is derived from that, we would assume that it’s pretty safe, then.

BURLINGAME: Yeah. It’s on the GRAS list of compounds.
GRAS stands for generally regarded as safe. It’s a component of grapefruit.
I don’t know of anybody that’s ever died from overexposure to grapefruits. So it is a safe compound.

there are still some regulatory issues that need to be resolved.
It has to be registered with the EPA, for example, to use it in the environment.
So it’ll still be a while before it’s actually on the market. But it could be in the next few years.