The Known Immunologically Active Components of Astragalus Account for Only a Small Proportion of the Immunological Adjuvant Activity When Combined with Conjugate Vaccines
Feng Hong1
, Weilie Xiao2
, Govind Ragupathi3
, Clara B. S. Lau4
, Ping Chung Leung4
, K. Simon Yeung5
, Constantine George1
, Barrie Cassileth5
, Edward Kennelly2
, Philip O. Livingston3
1Department of Medicine, Laboratory of Tumor Vaccinology, Memorial Sloan-Kettering Cancer Center, New York, New York, United States
2Department of Biological Sciences, Lehman College and The Graduate Center, City University of New York, Bronx, New York, United States
3Department of Medicine, Melanoma Sarcoma Service, Memorial Sloan-Kettering Cancer Center, New York, New York, United States
4Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
5Department of Medicine, Integrative Medicine Service, Memorial Sloan-Kettering Cancer Center, New York, New York, United States
The 95 % ethanol extract of Astragalus has been demonstrated to have potent activity as an immunological adjuvant when administered with vaccines of various types. We endeavor here to identify the components of this extract that are responsible for this adjuvant activity. Mice were immunized with KLH conjugated to cancer carbohydrate antigens globo H and GD3 and cancer peptide antigen MUC1 combined with different Astragalus fractions or with commercially available Astragalus saponins and flavonoids. The antibody responses against cancer antigens and KLH were quantitated in ELISA assays, and toxicity was calculated by weight loss. Astragalosides II and IV were the most active components, but the toxicity of these two differed dramatically. Astragaloside II was the most toxic Astragalus component with 5–10 % weight loss at a dose of 500 µg while astragaloside IV showed no weight loss at all at this dose, suggesting that astragaloside IV might be utilized as an immunological adjuvant in future studies. Several flavonoids also had significant adjuvant activity. However, when the activities of these known immunologically active components of Astragalus (and of endotoxin) are calculated based on the extent of their presence in the 95 % ethanol extract, they provide only a small proportion of the immunological activity. This raises the possibility that additional uniquely active components of Astragalus may contribute to adjuvant activity, or that the adjuvant activity of Astragalus is greater than the activity of the sum of its parts.
1
Ragupathi G, Park T K, Zhang S, Kim I J, Graeber K, Adluri S, Lloyd K O, Danishefsky S J, Livingston P O.
Immunization of mice with the synthetic hexasaccharide Globo H results in antibodies against human cancer cells.
Angew Chem Int Ed Engl.
1997;
36
125-128
2
Kim S K, Ragupathi G, Cappello S, Kagan E, Livingston P O.
Effect of immunological adjuvant combinations on the antibody and T-cell response to vaccination with MUC1-KLH and GD3-KLH conjugates.
Vaccine.
2000;
19
530-537
3
Ragupathi G, Yeung K S, Leung P C, Lee M, Lau C B, Vickers A, Hood C, Deng G, Cheung N K, Cassileth B, Livingston P.
Evaluation of widely consumed botanicals as immunological adjuvants.
Vaccine.
2008;
26
4860-4865
4
Ross G D, Vetvicka V, Yan J, Xia Y, Vetvickova J.
Therapeutic intervention with complement and beta-glucan in cancer.
Immunopharmacology.
1999;
42
61-74
7
Spellman K, Burns J, Nichols D, Winters N, Ottersberg S, Tenborg M.
Modulation of cytokine expression by traditional medicines: a review of herbal immunomodulators.
Altern Med Rev.
2006;
11
128-150
8
Kamiyama H, Takano S, Ishikawa E, Tsuboi K, Matsumura A.
Anti-angiogenic and immunomodulatory effect of the herbal medicine “Juzen-taiho-to” on malignant glioma.
Biol Pharm Bull.
2005;
28
2111-2116
11 Smith J E S R. Immunomodulatory activities of mushroom glucans and polysaccharide-protein complexes in animals and humans, Chapter 6. London; Cancer Res UK 2002: 106
13
Xiao W, Wang Q, Unachukwu U, Lau C B, Jiang B, Hong F, Leung P C, Motley T, Livingston P, Cassileth B, Kennelly E.
Chemical and genetic assessment of commercial Radix Astragali (Astragalus spp.) by ion trap LC-MS and nuclear ribosomal DNA sequence analyses.
J Agric Food Chem.
;
, , in press
14
Ragupathi G, Cappello S, Yi S S, Canter D, Spassova M, Bornmann W G, Danishefsky S J, Livingston P O.
Comparison of antibody titers after immunization with monovalent or tetravalent KLH conjugate vaccines.
Vaccine.
2002;
20
1030-1038
15
Ragupathi G, Meyers M, Adluri S, Howard L, Musselli C, Livingston P O.
Induction of antibodies against GD3 ganglioside in melanoma patients by vaccination with GD3-lactone-KLH conjugate plus immunological adjuvant QS-21.
Int J Cancer.
2000;
85
659-666
16
Gilewski T, Adluri S, Ragupathi G, Zhang S, Yao T J, Panageas K, Moynahan M, Houghton A, Norton L, Livingston P O.
Vaccination of high-risk breast cancer patients with mucin-1 (MUC1) keyhole limpet hemocyanin conjugate plus QS-21.
Clin Cancer Res.
2000;
6
1693-1701
17
Kim S K, Ragupathi G, Musselli C, Choi S J, Park Y S, Livingston P O.
Comparison of the effect of different immunological adjuvants on the antibody and T-cell response to immunization with MUC1-KLH and GD3-KLH conjugate cancer vaccines.
Vaccine.
1999;
18
597-603
18
Livingston P O, Adluri S, Helling F, Yao T J, Kensil C R, Newman M J, Marciani D.
Phase 1 trial of immunological adjuvant QS-21 with a GM2 ganglioside-keyhole limpet haemocyanin conjugate vaccine in patients with malignant melanoma.
Vaccine.
1994;
12
1275-1280
19
Chu D T, Wong W L, Mavligit G M.
Immunotherapy with Chinese medicinal herbs. II. Reversal of cyclophosphamide-induced immune suppression by administration of fractionated Astragalus membranaceus in vivo.
J Clin Lab Immunol.
1988;
25
125-129
20
Sun H X, Qin F, Ye Y P.
Relationship between haemolytic and adjuvant activity and structure of protopanaxadiol-type saponins from the roots of Panax notoginseng.
Vaccine.
2005;
23
5533-5542
21
Yang Z G, Sun H X, Fang W H.
Haemolytic activities and adjuvant effect of Astragalus membranaceus saponins (AMS) on the immune responses to ovalbumin in mice.
Vaccine.
2005;
23
5196-5203
22 Leung A Y, Foster S. Encyclopedia of common natural ingredients used in food, drugs and cosmetics, 2nd edition. New York, NY; John Wiley & Sons 1996
24
Kim Y J, Wang P, Navarro-Villalobos M, Rohde B D, Derryberry J, Gin D Y.
Synthetic studies of complex immunostimulants from Quillaja saponaria: synthesis of the potent clinical immunoadjuvant QS-21Aapi.
J Am Chem Soc.
2006;
128
11906-11915
25
Liu J, Hu X, Yang Q, Yu Z, Zhao Z, Yi T, Chen H.
Comparison of the immunoregulatory function of different constituents in radix astragali and radix hedysari.
J Biomed Biotechnol.
2010;
2010
479426
26
Qi L W, Yu Q T, Li P, Li S L, Wang Y X, Sheng L H, Yi L.
Quality evaluation of Radix Astragali through a simultaneous determination of six major active isoflavonoids and four main saponins by high-performance liquid chromatography coupled with diode array and evaporative light scattering detectors.
J Chromatogr A.
2006;
1134
162-169
27
Yu Q T, Qi L W, Li P, Yi L, Zhao J, Bi Z.
Determination of seventeen main flavonoids and saponins in the medicinal plant Huang-qi (Radix astragali) by HPLC-DAD-ELSD.
J Sep Sci.
2007;
30
1292-1299
