Herbs for Boosting the Immune System

By John Chen, PhD, PharmD, OMD, LAc

Q: I have a four year-old daughter who has just started attending preschool. She has not been very healthy, and I am afraid that she is going to get sick every time there is a flu.What can I do to boost her immune system?

A: One of the most important emphases of Chinese medicine is prevention. Herbs are commonly prescribed during a change of season to help a person adapt to the changing weather. By planning ahead and taking herbs accordingly, one can drastically reduce the frequency and severity of catching the common cold or the flu.

According to traditional Chinese medicine, defense (wei) qi is located at the exterior surface of the body and offers initial protection against foreign or pathogenic factors. When wei qi is strong, pathogenic factors cannot penetrate the body. When it is weak, a variety of infections can occur.

Prevention of infections relies on normal function of wei qi. From the Western perspective, many herbs that tonify qi enhance the immune system. Herbs that perform such functions include astragalus (huang qi), ganoderma (ling zhi) and cordyceps (dong chong xia cao).

Astragalus (huang qi) is one of the most frequently used Chinese herbs and has historically been used to tonify wei qi. It fortifies the lungs, strengthens the wei qi and indirectly protects against external pathogenic factors.

In terms of Western medicine, modern research has confirmed repeatedly that astragalus increases both specific and non-specific immunity.^1,2,3 In a clinical trial of 115 leucopenic patients, astragalus was found to be associated with an "obvious rise of the white blood cell (WBC) count" with a dose-dependent relationship.⁴ In addition, astragalus works well with concurrent drug therapy in enhancing the overall effectiveness of the treatment. It also potentiates the anti-tumor effect of chemotherapy drugs⁵ while reversing drug-induced immune suppression.⁶ Lastly, astragalus demonstrates anti-cancer activity by increasing the content of camp and inhibiting the growth of tumor cells.⁷

Ganoderma (ling zhi) has been traditionally used to tonify blood and vital energy. It is thus essential in rebuilding a patient's constitution.

Ganoderma increases the number of white blood cells and inhibits the growth of various viruses and bacteria associated with the flu. It has been demonstrated to enhance the immune system in various clinical studies. The specific effects of ganoderma include an increase in monocytes, macrophages and T-lymphocytes.^8-11 There is also an increased production of cytokine, interleukin, tumor necrosis factor and interferon. Furthermore, ganoderma has a broad spectrum of antibacterial activities, inhibiting the growth of pneumocci, streptocci (type A), staphylococci, e. coli, b. dysentarie and pseudomonas, among others.⁷

Cordyceps (dong chong xia cao) has traditionally been used in chronic debilitated patients. It is an excellent herb to tonify the kidney yin and yang and improve overall bodily constitution. Cordyceps is another herb which has marked immunomodulatory functions. It enhances overall immunity by increasing lymphocytes and natural killer cells and the production of interleukin, interferon and tumor necrosis factor.^12-16 Cordyceps was also found to significantly inhibit the proliferation of cancer cells;¹⁷ in some instances, the growth inhibition rate of the cancer cells reached between 78-83%.¹⁸

Keep in mind that while these herbs are effective individually, they should be prescribed in the content of an herbal formula to enhance synergistic action and minimize possible side-effects.

Q: Are there any contraindications for these herbs?

A: Astragalus, ganoderma, cordyceps and herbs that boost the immune system are contraindicated for patients taking immunosuppressants such as imuran (azathioprine) or sandimmune (cyclosporin). These drugs are commonly prescribed following organ transplant surgery to suppress the immune system and prevent tissue rejection. Because these herbs have potent immune enhancing effects, they should not be prescribed for patients taking immunosuppresants following organ transplant surgery. Despite their weak constitution, use of some immune enhancing herbs can increase the risk of rejection and severely compromise the patient's health.

References

1. Chu DT, et al. Immunotherapy with Chinese medicinal herbs. I. Immune restoration of local xenogenetic graft-versus-host reaction in cancer patients by fractionated astragalus membranaceus in vitro. Journal of Clinical & Laboratory Immunology Mar 1988;25(3):119-23.
2. Sun Y, et al. Immune restoration and/or augmentation of local graft versus host reaction by traditional Chinese medicinal herbs. Cancer July 1, 1983;52(1):70-3.
3. Sun Y, et al. Preliminary observations on the effects of the Chinese medicinal herbs astragalus membranaceus and ganoderma lucidum on lymphocyte blastogenic responses. Journal of Biological Response Modifiers 1983;2(3):227-37.
4. Weng XS. Chung Juo Chung Hsia I Chieh Ho Tsa Chih August 1995.
5. Chu DT, et al. Fractionated extract of astragalus membranaceus, a Chinese medicinal herb, potentiates LAK cell cytotoxicity generated by a low dose of recombinant interleukin-2. Journal of Clinical & Laboratory Immunology Aug 1988;26(4):183-7.
6. Chu DT, et al. Immunotherapy with Chinese medicinal herbs. II. Reversal of cyclophosphamide-induced immune suppression by administration of fractionated astragalus membranaceus in vivo.Journal of Clinical & Laboratory Immunology Mar 1988;25(3):125-9.
7. Yeung HC. Handbook of Chinese Herbs. Institute of Chinese Medicine, 1996.
8. Wang SY, et al. The anti-tumor effect of ganoderma lucidum is mediated by cytokines released from activated macrophages and T-lymphocytes. International Journal of Cancer Mar 17, 1997;70(6):699-705.
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11. Tanaka S, et al. Complete amino acid sequence of a novel immunomodulatory protein, ling zhi-9. An immuno-modulator from a fungus, ganoderma lucidum, having similar effect to immunoglobulin variable regions. Journal of Biological Chemistry Oct 5, 1989;264(28):16372-7.
12. Kuo YC, et al. Cordyceps sinensis as an immunomodulatory agent. American Journal of Chinese Medicine 1996;24(2):111-25.
13. Guan YJ, et al. Effect of cordyceps sinensis on T-lymphocyte subsets in chronic renal failure. Chung-Kuo Chung His I Chieh Ho Tsa Chih Jun 1992;12(6):323,338-9.
14. Liu C, et al. Effects of cordyceps sinensis (CS) on in vitro natural killer cells. Chung-Kuo Chung His I Chieh Ho Tsa Chih May 1992;12(5):259,267-9.
15. Xu RH, et al. Effects of cordyceps sinensis on natural killer activity and colony formation of B16 melanoma. Chinese Medical Journal Feb 1992;105(2):97-101.
16. Liu P, et al. Influence of cordyceps sinensis (berk. sacc.) and rat serum containing same medicine on IL-1, IFN and TNF produced by rat Kupffer's cells. Chung Kuo Chung Yao Tsa Chih Jun 1996;21(6):367-9,384.
17. Kuo YC, et al. Growth inhibitors against tumor cells in cordyceps sinensis other than cordycepin and polysaccharides. Cancer Investigation 1994;12(6):611-5.
18. Chen YJ, et al. Effect of cordyceps sinensis on the proliferation and differentiation of human leukemic U-937 cells. Life Sciences 1997;60(25):2349-59.