The Herb and Drug Mix of Immune Suppressants and Herbal Medicines


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Not long ago, a patient I’ll call Donna presented me with a challenging dilemma. Donna had suffered from a chronic respiratory disease that forced her to receive a lung transplant. To keep her immune system from rejecting the new lung, she was taking a drug called cyclosporine, an antibiotic-like substance produced by the soil-based fungus Beauveria nivea. She knew that she would be taking this drug for the rest of her life.

Donna came to see me because she felt a bad cold coming on. Would it be all right, she asked, if she took some echinacea (Echinacea spp.) or a similar herb to give her immune system a little boost? As simple as this question may seem, the issues raised in searching for an answer are quite complex and have implications that extend to a wide range of diseases, especially autoimmune disorders.

How immunosuppressants work

Cyclosporine acts as a potent immunosuppressant, meaning that it inactivates a part of the immune system—the T lymphocytes, which are responsible for rejecting foreign substances. This action makes it immensely useful for organ transplant patients. In fact, without this drug and others like it, most transplants would eventually be rejected by the recipient. In recent years, cyclosporine has also been used to treat autoimmune disorders such as rheumatoid arthritis (RA), a condition where the immune system attacks the joints. The rationale for using cyclosporine in these cases is that autoimmune disorders result from a so-called overactive immune system that needs to be chemically restrained.

Unfortunately, the T lymphocytes involved in transplant rejection or autoimmunity are also necessary for fighting off harmful bacteria, viruses, and cancer. Consequently, patients taking immunosuppressant drugs have a high risk of developing lymphoma and potentially life-threatening infections. In other words, the drugs solve one problem but can create another.

Conventional medicine tends to take an adversarial position against disease. It’s as if we’re fighting an all-out war against cancer, infection, and autoimmune diseases. The weapons we use in this war are potent drugs designed to wipe out the enemy. But there are two problems with this approach. First, the “enemy” is often very clever and finds ways to outwit the most powerful weapons. Second, the more powerful the drug, the higher the risk of toxicity. Herbal medicine offers an alternative: Instead of attacking the disease head-on, why not improve the person’s immune function so they can fight off or regulate the disease on their own?

Herbal immune enhancers

Echinacea is only one of a number of herbs known for this kind of immune-enhancing effect. Some of the other herbs I might have considered giving Donna include astragalus (Astragalus membranaceus), aloe (Aloe vera), isatis (Isatis tinctoria), licorice root (Glycyrrhiza glabra), Siberian ginseng (Eleutherococcus senticosus), and Western larch (Larix occidentalis). Additionally, numerous medicinal mushrooms such as maitake (Grifola frondosa), shiitake (Lentinula edodes), and reishi (Ganoderma lucidum), as well as extracts of baker’s yeast (Saccharomyces cerevisiae), have similar effects.

All of these herbs and fungi are rich in complex sugar molecules called polysaccharides. These polysaccharides appear to resemble fragments of the cell walls of bacteria and viruses. Many researchers believe that when a person ingests these substances, the substances end up binding to specialized receptor sites on the surface of immune cells (called macrophages) and natural killer cells. These sites are sensors, designed to detect the presence of microbial infection. The immune cells are thereby “fooled” into thinking that the body is under attack by an infection. In response, they send out chemical signals that mobilize immune activity throughout the body. Therefore, when a person with a bad cold takes a supplement of echinacea, the immune system gets a boost, which helps it fight off the infection more quickly and efficiently.

Are the herbs safe?

Although this immune-boosting effect may be desirable in the situation described, is it possible that it could be harmful if a person already has an “overactive” immune system, as in the case of RA? This has been the assumption made by numerous authors who have strongly warned patients with RA to avoid taking herbal or fungal immune boosters. It’s important to realize, however, that this concern is theoretical—there are no published reports of patients with autoimmune disorders actually getting worse from taking these immune boosters.

Part of the problem here is the tendency to think of the immune system as a single unit that performs one function instead of an extremely complex mixture of dozens of different types of cells, each of which has specific functions that lead to elaborate interactions. It’s simply not accurate to talk of an overactive or underactive immune system. The reality is that in some situations, specific parts of the immune system may be underactive or overactive.

Following this line of reasoning, it’s more accurate to refer to herbs such as echinacea or medicinal mushrooms as “biological response modifiers,” rather than immune boosters. This concept becomes even more significant when you realize that some herbalists intentionally use various combinations of these herbs and fungi to treat RA and other autoimmune disorders.

My recommendations

I told Donna that, unfortunately, we just don’t know enough about how cyclosporine works to accurately assess whether its effects would be neutralized by echinacea or similar herbs. Even though there’s little evidence to indicate that a short course of the herb would be harmful, the potential risk (of rejecting the transplant) is so great that I had to discourage her from using it. This may not be the end of the discussion, though, as there are now reports that transplant patients have been able to safely use a supplement of immune-enhancing beta glucan (derived from baker’s yeast). Only thoughtful, meticulous research will help resolve this issue.

However, I believe that it’s premature to tell all patients with autoimmune disorders to avoid immune enhancers, especially if they plan to use them for only a short period of time. The more sophisticated our knowledge of how herbs and medicinal mushrooms work becomes, the more we’ll be able to make recommendations about potential interactions based on real science instead of naive assumptions.


de Felippe, J., et al. “Infection prevention in patients with severe multiple trauma with the immunomodulator beta 1-3 polyglucose (glucan).” Surgery, Gynecology and Obstetrics 1993, 177: 383–388.

Wasser, S. P., and A. L. Weis. “Therapeutic effects of substances occurring in higher Basidiomycetes mushrooms: A modern perspective.” Critical Reviews in Immunology 1999, 19:65–96.

Robert Rountree, M.D., is a physician at the Helios Health Center in Boulder, Colorado, where he practices integrative medicine. He is coauthor of both Smart Medicine for a Healthier Child (Avery, 1994) and Immunotics (Putnam, 2000), and is an Herb Research Foundation advisory board member.