Can Ginseng Help Suppress HIV?

Background

The roots of the ginseng plant have been used for centuries by herbalists because of its anti-stress and anti-fatigue effects. Researchers in Hong Kong have been studying this herb and found that ginseng contains a protein called panaxagin which has anti-HIV activity in the test-tube. This protein appears to work by interfering with an enzyme used by HIV called RT (reverse transcriptase). This is the same enzyme that is attacked by AZT and other nucleoside analogues, or nukes, such as 3TC (lamivudine), d4T, ddI, ddC and ABC (abacavir, Ziagen).

Korean Red Ginseng

Researchers in Seoul, South Korea, have been studying the effect of one type of ginseng (Korean red ginseng) on HIV infection in people for the past decade. In one six-month study, subjects who received 5.4 grams, or 18 capsules of Korean red ginseng (KRG) daily were able to maintain or increase their CD4+ and CD8+ cell counts. These results prompted the researchers to conduct a more detailed investigation of the impact of KRG on HIV infection.

Study Details

Researchers enrolled 18 subjects (4 female, 14 male) who were taking AZT and monitored them for an average of six years. Note that the study was conducted between 1991 and 1997, when protease inhibitors were not widely available in South Korea. All subjects were free from symptoms of HIV/AIDS at the time they entered the study. Their average CD4+ count was 256 cells. Half the subjects were assigned to continue receiving AZT 400 mg to 600 mg/day and six capsules of KRG (each containing 300 mg) three times daily for a total of 18 capsules/day (5.4 grams). This compound is made using the roots of six-year-old KRG, and is sold in South Korea by the Korea Ginseng company. The quality of this product is monitored by the South Korean authorities. The remaining subjects were assigned to continue taking AZT but no KRG.

Effect On CD4+ Cell Count

On average, subjects who were in the group receiving both AZT and KRG did so for six years. During this time their average CD4+ cell count remained relatively unchanged, going from an average of 239 cells at the start to an average of 234 cells by the end. In the group receiving AZT alone, the average CD4+ cell count decreased from 272 cells to 146 cells over a period of four years.

Resistance To AZT

The researchers analysed blood samples from all subjects to check for changes or mutations in HIV's genetic material that allowed the virus to resist the effect of AZT. They found that on average, subjects taking AZT and KRG had about 22% of resistance mutations while subjects taking AZT alone had about 56% of resistance mutations to AZT. These findings suggest that KRG delays the onset of resistance to AZT.

At the time the study took place researchers did not have access to sophisticated techniques of viral load measurement that are now in regular use in developing countries.

The research team suggests that KRG may contain compounds that have the ability to enhance the activities of immune cells.

Caution and Concerns

More research is needed on KRG to find the following:

• Its impact on the immune systems of people with HIV/AIDS.

• Interactions between KRG and anti-HIV drugs, particularly protease inhibitors and non-nukes. This is because some herbs can interact with these drugs by either raising or lowering their levels and possibly weakening their anti-HIV effects or increasing side effects.

• Its impact on blood sugar levels.

• Its effect on blood pressure (ginseng may raise blood pressure over the long-term).

• Its effect on hormone levels, particularly in women. This is important because "menstrual abnormalities" have been reported with long-term use of ginseng in some women.

The effect of other types of ginseng preparations on the immune system may be very different from those seen in the Korean studies. KRG may be useful in resource-poor countries where it could be studied in combination with AZT and similar drugs. Further studies of KRG are underway in South Korea and Thailand.

A point not considered by the research team in Korea is possible contamination of ginseng used in supplements by heavy metals such as cadmium and lead as well as pesticides. This possible contamination is the focus of an upcoming CATIE news story.

References

1. Ng T.B. and Wang H. Panaxagin, a new protein from Chinese ginseng possesses anti-fungal, anti-viral, translation-inhibiting and ribonuclease activities. Life Sciences 2001;68(7):739-749.
2. Cho Y.K., Sung H., Lee H.J., et al. Long-term intake of Korean red ginseng in HIV-1-infected patients: development of resistance mutations to zidovudine is delayed. International Immunopharmacology 2001;1(7):1295-1305.
3. Anonymous. Product review: Asian and American ginseng. www.consumerlab.com/results/ginseng.asp accessed 18 July, 2001.