Evaluation of water soluble β-d-glucan from Auricularia auricular-judae as potential anti-tumor agent

A water soluble β-d-glucan was isolated by 70% ethanol aqueous solution from Auricularia auricula-judae, coded as AAG. AAG exhibited strong inhibition against Acinar cell carcinoma (ACC) proliferation. The in vivo tests showed that AAG significantly inhibited tumor growth in a dose-dependent fashion, but not because of cytotoxicity. All the doses showed certain inhibition ratios against tumor-cell growth, while the dose of 20 mg/kg exhibited highest anti-tumor activities. Moreover, the enhancement ratios of body weight for all the doses were significantly higher than that for 5-fluorouracil (5-Fu). Fluorescence microscopy observed the apoptosis tumor cell induced by AGG sample. The results from TUNEL assay further confirmed the apoptosis in Sarcoma 180 solid tumor. Immunohistochemistry for apoptosis-related proteins Bax and Bcl-2 expression tests revealed that AAG induced S-180 tumor cell apoptosis by up-regulation of Bax and down-regulation of Bcl-2 expression. These findings demonstrated that the AAG has biological activities and could be considered as a candidate for possible anti-tumor drugs.