story to find out more.
Citrus slices. Click the image for more
information about it.
Hasegawa (retired), who pioneered this work in ARS, prepares to analyze
limonoids in orange juice. Click the image for more information about
Health Benefits of Citrus Limonoids
Explored By Marcia Wood February 8, 2005
Oranges rich in vitamin C offer another important yet lesser-known
nutritional bonus: citrus limonoids. In laboratory tests with animals and with
human cells, citrus limonoids have been shown to help fight cancers of the
mouth, skin, lung, breast, stomach and colon.
Agricultural Research Service
scientists in northern California, led by chemist
Manners, are uncovering new details about these compounds. Manners and
coinvestigators have reported their findings in studies published during the
past several years. They've demonstrated, for example, that each time we bite
into a citrus slice or drink a glass of orange juice, our bodies can readily
access a limonoid called limonin. The team was the first to show limonin's
The body derives limonin from a parent compound--limonin
glucoside--that's present in citrus and citrus juices in about the same amount
as vitamin C, according to Manners. He's with the agency's
Regional Research Center in Albany, Calif.
In other early work, Manners and colleagues found that limonin may
lower cholesterol. The researchers showed that, when exposed to limonin, human
liver cells in petri dishes produced less apo B, a compound associated with
higher cholesterol levels. High cholesterol levels are linked to increased risk
of heart disease and other health problems.
Now, Manners and coinvestigators are taking a closer look at limonin's
cholesterol-lowering effects. They're doing that in a first-of-its-kind study
with healthy volunteers. Manners is collaborating with researchers at Albany
and at the ARS
Human Nutrition Research Center in Davis, Calif. Preliminary results of the
cholesterol study are expected later this year.
about this research in the February issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.