Curcumin Update: Could Food Spice Be Low-Cost Antiviral?

In March 1993, researchers at Harvard Medical School
published results of laboratory tests of a new method of
screening for potential AIDS drugs.(1) They used genetically
engineered cells to test for inhibitors of the "LTR" (long
terminal repeat) sequence in HIV; the LTR is important for viral
activation. The new test found three inhibitors; one of them is
curcumin, a chemical found in the food spice turmeric. Curcumin
is the ingredient which gives curry its yellow color. It was
effective against HIV in both acutely and chronically infected
cells.

On May 7, 1993, AIDS TREATMENT NEWS published a short review
of the Harvard article. Since then, our readers have brought new
information about curcumin to our attention:

* In Trinidad, about 40 percent of the population is of
Indian descent, and uses curry extensively in their diet.
Another 40 percent of the population is of African descent, and
seldom uses curry. Several years ago, studies of AIDS in Trinidad
found that persons of African descent were more than 10 times as
likely to have the disease as persons of Indian descent.(2) (We
do not have recent data; however, a new report on AIDS
epidemiology in Trinidad, by F. Cleghorn, W. Blattner, and
others, is expected at the Berlin conference.)

* One reader of AIDS TREATMENT NEWS started using a turmeric
extract with a very high concentration of curcumin -- about 100
times the concentration in ordinary turmeric -- which he obtained
from a San Francisco health-food store. He started using it on
May 7, 1993. A week later his regularly scheduled blood tests
showed a substantial drop in p24 antigen (a measure of viral
activity). This unexpected change impressed his physician, a
leading AIDS specialist in San Francisco.

The product he used was supplied in capsules, each
containing "300 mg. turmeric extract concentrated and
standardized for a minimum of preferred 95% curcumin" in a base
of whole turmeric, according to the label on the bottle. He took
three capsules three times a day -- about 2.5 grams of curcumin
per day, for a person who weighs about 100 kg. This dose was
chosen arbitrarily; it is considerably greater than the amount of
curcumin one would ordinarily get by eating curry, and we do not
know whether or not it is safe. Even for this large dose the
cost was low, about $2 per day retail in the U. S.

We mention this single case because it may be the first time
that anyone has taken curcumin as a potential treatment for HIV,
and compared viral-activity measurements before and after
starting.

Pharmacology

Curcumin is not soluble in water,(3) and animal tests have
found very little of it in the bloodstream after it is eaten.(4)
Therefore, it would seem that this chemical could not work as an
oral drug. But other researchers have reported much higher
absorption -- as much as 60 percent or more.(5,6) And in
laboratory studies curcumin is often given to animals in the
diet, and various effects are noted.

This apparent contradiction is resolved by results of animal
tests, some with radioactive curcumin. Much of the radioactivity
does reach the blood and organs, even though the curcumin
doesn't(4) -- meaning that the curcumin must have been changed
into something else and absorbed in a different form. The same
team had earlier reported that about 60 percent of the curcumin
was absorbed, since only about 40 percent of the quantity
administered was found remaining in the gut -- although only
traces were found in the blood.(5) Another paper by the same
group concluded that "curcumin undergoes transformation during
absorption from the intestine," and noted an unidentified
compound that it was changed into.(6) So the fact that chemists
do not find curcumin in the blood when they look for it does not
rule out the possibility that oral use could have biological
effects.

Curcumin is being studied as an anti-inflammatory,(7) as a
possible cancer inhibitor,(8) and for other potential medical
uses. It is a strong anti-oxidant. A recent search of the
Excerpta Medica database found citations to 149 papers,
abstracts, etc. which mention curcumin; the word "curcumin"
appears in the title of 74 of these. A review of some possible
medicinal uses of curcumin(9) was published in 1991.

Turmeric is a mild spice. When curry is hot, that is due to
other spices.

A recent paper listed the curcumin content of turmeric
powder as about 0.6 percent.(10)

Safety

Curcumin and turmeric have long been in daily human use, and
are believed to have little toxicity in moderate doses.(1)
However, one group found that large doses caused stomach ulcers
in rats.(11) A thorough literature review is needed before large
doses are used.

What Does This Mean?

The information above is only suggestive, and does not show
that curcumin will have any use in treating AIDS. Most new drug
or treatment ideas fail, after later information shows that they
are not useful. For curcumin as for any new treatment, the odds
are that it, too, will be one of the failures.

But the possibility that curcumin or turmeric might be
useful in treating HIV or AIDS is so important that it must be
studied further without delay. Curcumin is known to be safe, at
least in low and moderate doses, and could be available to
everyone. Also, in the laboratory tests it was active against
HIV not only in acutely infected but also in chronically infected
cells -- where the currently approved drugs such as AZT are
ineffective.

The next step in research should be to give a high but safe
dose to 10 to 20 people for several weeks, and measure changes in
viral activity, either with the readily available p24 test, or
with sophisticated research tests such as quantitative PCR, or
the branched DNA assay. Both natural turmeric and concentrated
curcumin should be tested. If there is a dramatic decrease in
viral activity in people (like that seen in the single case so
far), then this potential treatment will receive plenty of
attention. If there is little or no decrease, then we can forget
about curcumin (except as a possible lead compound for drug
development) and move on.

We do not know of anybody anywhere in the world doing such a
study, or making plans to do so, or otherwise following up on
curcumin as a possible AIDS treatment. This is not unusual;
there has never been a serious institutional effort to test such
treatment leads in early human trials. Medical research is
expensive, and requires considerable effort and resources to make
anything happen. Those with the resources -- mainly large
pharmaceutical companies -- have little commercial or
professional incentive to test low-cost, non- proprietary
treatments. And government and non-profit research organizations
have usually failed to focus on the critical need for getting
safe, inexpensive treatment possibilities into small but credible
tests for biological activity in humans.

We hope this article will help bring this treatment
possibility to wider attention, so that the appropriate research
can be organized.

References

1. Li CJ, Zhang LJ, Dezube BJ, Crumpacker CS, and Pardee AB.
Three inhibitors of type 1 human immunodeficiency virus long
terminal repeat-directed gene expression and virus replication.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES, USA. March 1993;
volume 90, pages 1839-1842.

2. Cleghorn F, Battoo K, Diaz C, Balbosa S, Jack N, Blattner W,
and Bartholomew C. Update on the epidemiology of AIDS in
Trinidad. International Conference on AIDS, San Francisco, June
20-23, 1990 [abstract #Th.C. 718].

3. The Merck Index, 1989.

4. Ravindranath V. and Chandrasekhara N. Metabolism of curcumin
-- studies with (sup 3H)curcumin. Toxicology (Ireland). 1982;
volume 22, number 4, pages 337-344.

5. Ravindranath V, and Chandrasekhara N. Absorption and tissue
distribution of curcumin in rats. TOXICOLOGY (Ireland). 1980;
volume 16, number 3, pages 259-265.

6. Ravindranath V, and Chandrasekhara N. In vitro studies on
the intestinal absorption of curcumin in rats. TOXICOLOGY
(Ireland). 1981; volume 20, pages 251-257.

7. Satoskar RR, Shah SJ, and Shenoy SG. Evaluation of anti-
inflammatory property of curcumin (diferuloyl methane) in
patients with postoperative inflammation. INT. J. CLIN.
PHARMACOL. THER. TOXICOL. 1986; volume 24, number 12, pages 651-
654.

8. Nagabhushan M and Bhide SV. Curcumin as an Inhibitor of
Cancer. JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION. 1992;
volume 11, number 2, pages 192-198.

9. Ammon HPT, and Wahl MA. Pharmacology of Curcuma longa.
PLANTA MEDICA. February 1991; volume 57, pages 1-7.

10. Mukhopadhyay A, Basu N, Ghatak N, and Gujral PK. Anti-
inflammatory and irritant activities of curcumin analogues in
rats. AGENTS ACTIONS. October 1982; volume 12, number 4, pages
508- 515.

11. Gupta B, Kulshrestha VK, Srivastava RK, and Prasad DN.
Mechanism of curcumin induced gastric ulcer in rats. INDIAN J.
MED. RES. 1980; volume 71, number 5, pages 806-814.