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Background: Saponins and beta glucans are widely distributed in the plant kingdom and as purified extracts are two of the most potent immunological adjuvants when injected mixed with antigen, or immunomodulators when orally ingested. Many widely consumed botanicals are advertised as immune enhancers but clear evidence for this is lacking. Globo H is a cell surface hexasaccharide expressed on many epithelial cancers. When conjugated to keyhole limpet hemocyanin (KLH) and mixed with an immunological adjuvant, the magnitude of the antibody response against globo H and KLH depends largely on the potency of the adjuvant or immunomodulators used. Methods: Using the globo H-KLH conjugate, groups of 5 mice were immunized subcutaneously 3 times at 1 week intervals and sera drawn 1 and 2 weeks after the 3rd immunization to measure antibody response. Widely used botanicals were either used as adjuvant mixed with globo H-KLH conjugate (adj) prior to injection or as immunomodulator administered by oral gavage (PO) three times a week to the mice for 1 week before and 3 weeks after the first immunization. Botanicals utilized were TJ-48 (Honsofarm.CO.), Coriolus Vesicolor (Nammex), Maitaki MD fraction (Yukiguni Maitaki CO.) yeast beta glucan (Biotec Pharmacon), semi-synthetic saponin GPI-0100 (Advanced BioTherapies Inc.) and quillaja saponaria molina saponin mix (Fischer Scientific). Sera were analyzed by ELISA against synthetic globo H ceramide and KLH, and splenocytes by proliferation assays against KLH to measure T-cell response. Results: 4 separate experiments have been performed. Administered as adjuvant, neither TJ-48, maitaki nor barley β-glucan had demonstrable activity, but PSK, yeast β-glucan and GPI-0100 had progressively significant adjuvant activity (p< .05, .01, .005), and β-glucan and GPI-0100 significantly augmented proliferation compared to no adjuvant (SI 2.2 and 6.8 respectively). When administered orally, neither TJ-48, PSK, Maitaki, nor barley β-glucan had impact on serologic titer or proliferation but in a final experiment, the saponin mix and β-glucan both significantly augmented the antibody response against KLH. Conclusions: PSK and yeast β-glucan demonstrate moderate adjuvant activity, the semi-synthetic saponin GPI-0100 demonstrates the strongest adjuvant activity. When administered by oral gavage, only β-glucan of yeast origin and the saponin mix have immunomodulatory activity. We are currently exploring whether PSK or yeast β-glucan administered as adjuvants or the mixed saponins and yeast β-glucan administered orally are able to add to the adjuvant activity of saponin fractions such as GPI-0100 or QS-21. We have also begun to test additional botanicals including Echinacea, Astragalus and Tumeric. Support by Botanical Research Center Grant P50 AT002779 from the NCCAM.

[Proc Amer Assoc Cancer Res, Volume 47, 2006]