People have used herbs as medicine for
thousands of years. Today, with medical
researchers continually hunting for
better alternative treatments, some are
revisiting these remedies.

, A recent study
looks at herbs that people believe can
treat hypertension.

Lavender was one of the plants that the scientists
tested in the recent study.

Currently, hypertension affects an estimated 1 in 3
adults in the United States.

Although dietary and lifestyle changes can
sometimes be sufficient, medication is necessary in
some cases.

Antihypertensive medications work well for some
people but not for others, and the side effects can
be unpleasant.

For these reasons, researchers are keen to find
innovative ways to tackle the growing issue of
hypertension.

Some scientists are turning back the clock and
looking to ancient herbal remedies. Humans have
been self-medicating with the herbs that they find
since before history began.

The fact that people have used these treatments for
millennia is certainly not evidence that they are
effective, but they are surely worth a second look.

Researchers from the University of California, Irvine
recently zeroed in on a group of plants that have,
historically, been a treatment for hypertension. They
published their findings in Proceedings of the
National Academy of Sciences.

Diverse plants
The scientists took herbal extracts from a diverse
range of unrelated plants, including lavender, fennel
seed extract, basil, thyme, marjoram, ginger , and
chamomile.

Under the leadership of Prof. Geoff Abbott, Ph.D.,
they identified a bioactive trait that all of the
extracts shared. This trait, the scientists believe,
might help explain why some herbs appear to have
mild antihypertensive properties.

Specifically, they found that these herbs activate a
particular potassium channel called KCNQ5. This
potassium channel and others are present in the
vascular smooth muscles — the muscles that line
blood vessels.

When vascular smooth muscles contract, blood
pressure increases; when they relax, blood pressure
drops. The activation of KCNQ5 results in the
relaxation of these muscles. The authors think that
this might help explain some herbs' antihypertensive
properties.

The researchers also tested a range of other plants
that research has not shown to reduce blood
pressure, such as wheatgrass and parsley. In these
cases, they found no activation of KCNQ5.

Not all herbs are equal
When they compared plant species, the researchers
found differing levels of KCNQ5 activity. " Lavandula
angustifolia , commonly called lavender, was among
those we studied," Prof. Abbot explains. "We
discovered it to be among the most efficacious
KCNQ5 potassium channel activators, along with
fennel seed extract and chamomile."

Next, the scientists drilled down to determine which
plant compound is responsible for activating the
potassium channel.

They isolated a chemical called aloperine, which is
an alkaloid. In a further set of experiments, they
demonstrated that aloperine opens KCNQ5 by
binding to the foot of the potassium channel.

Interestingly, current medications do not target the
KCNQ5 channel. Spotting this gap in the drug
market, Prof. Abbott hopes that the "discovery of
these botanical KCNQ5-selective potassium channel
openers may enable development of future targeted
therapies for diseases including hypertension."

Of course, the road that runs between identifying a
mechanism and getting a drug to market is long. It
is also worth noting that the KCNQ group of
receptors are relative newcomers and, as such,
scientists do not yet know the full range of their
functions.

However, because hypertension is so widespread,
and because it increases the risk of cardiovascular
diseases, such as stroke , there is likely to be
significant interest in taking these ideas to the next
stage.

For now, though, people should not switch their
current hypertension treatments for herbal remedies