Release Date: July 19, 2005

NOT ENOUGH EVIDENCE FOUND TO WARRANT USE OF HERBAL MEDICINES FOR AIDS

Although many HIV-infected people use herbal medicines, particularly in developing countries, there is not enough evidence to show they actually work, a review of previous studies concludes.

Investigators at the National Research Center in Complementary and Alternative Medicine at the University of Tromso in Norway looked at nine randomized clinical trials in which herbal medicines were compared with no intervention, placebo or anti-HIV drugs in patients with HIV infection, HIV-related diseases or AIDS.

The trials tested eight herbal medicines, some of which were extracts from a single herb and others formulations composed of as many as 35 herbs. In all, 499 individuals with HIV infection or AIDS were included in the analyses.

The review appears in the July issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that produces systematic reviews of healthcare interventions, based on the content and quality of existing clinical trials on the topic.

Researchers were looking for evidence of HIV disease progression, indicators of immune system status, and HIV concentration in the blood. Also under study were measures of quality of life, such as psychological status, ability to work or function in life, and the degree to which HIV-related symptoms bother the patient.

The study found insufficient evidence to support the use of herbal medicines for treating HIV infection and AIDS. “There may be several reasons for this,” says lead author Dr. Jianping Liu. “One is that the different trials used different herbs. Only one herbal preparation was tested more than once.”

“Another is that the different trials treated different types of patients,” says Liu. “In some, the HIV-infected participants were asymptomatic; in others, they were symptomatic. Some trials looked at symptoms induced by AIDS, such as diarrhea.”

Liu is a visiting professor at the University of Tromso. His main appointment is at the Beijing University of Traditional Chinese Medicine, where he is head of the Evidence-Based Chinese Medicine Center for Clinical Research and Evaluation.

The review did identify three trials showing small to moderate positive effects of herbal medicines. A Chinese herbal formulation called IGM-1, composed of 31 herbs, improved overall satisfaction with life and reduced symptoms for HIV-infected patients. SP-303, a compound isolated from the Amazonian plant Croton lechleri, reduced abnormal stool frequency in patients with AIDS and diarrhea. And combining a Chinese herbal formulation called SH, containing five herbs, with two anti-HIV drugs led to greater antiviral activity in HIV-infected patients.

“Unfortunately, these trials have problems,” says Liu. “For example, they have small sample sizes and not enough treatment follow-up, so we cannot reach any firm conclusions. We suggest that these compounds be studied further in large, well-designed trials.” He says that he expects that herbal medicines are more likely to show benefit in quality of life measures, much as IGM-1 appears to do, rather than antiviral activity.

Dr. Chun-Su Yuan, director of the Tang Center for Herbal Medicine Research at the University of Chicago, says that he agrees with Liu about the clinical evidence regarding herbal medicines. “There is no strong evidence from controlled trials showing that herbs are effective against HIV,” he says. “In general, though, these studies are not well-designed.” He says that herbal medicines may eventually prove useful for countering side effects of HIV medications, such as nausea, vomiting, and fatigue.

Yuan is impressed with one Chinese herbal medicine that so far has been studied mostly in the laboratory. The plant is called Scutellaria baicalensis Georgi, otherwise known as Huang qin or Chinese skullcap.

One of the active ingredients in this medicine is a chemical called baicalin, which has been shown to inhibit the activity of the HIV enzyme reverse transcriptase, which helps HIV infect the DNA of target cells. Laboratory studies done in Japan have shown that baicalin inhibits HIV replication in immune cells from asymptomatic HIV-infected individuals. Liu says that Scutellaria baicalensis Georgi is currently being tested in a clinical trial with HIV-infected patients in South Africa.

In some developing countries, herbal medicines are used as primary treatments for HIV infection, largely because of the high cost of anti-HIV drugs.

The review was funded by the Ministry of Education in China, the National Center for Complementary and Alternative Medicine in the United States and the National Research Center in Complementary and Alternative Medicine in Norway.

Liu JP, Manheimer E, Yang M. Herbal medicines for treating HIV infection and AIDS. The Cochrane Database of Systematic Reviews 2005, Issue 3

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Visit http://www.cochrane.org for more information.

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