Enrichment of Isaria felina Culture with Selenium Enhances its in vivo Antitumor Effects on H22 Hepatoma via Decreasing the Expression of VEGF.

Abstract

The polysaccharide extract of C. sinensis, Isaria felina (IF), has antitumor effects. Selenium (Se) can improve disease prevention and reduce the toxicity of toxic elements, but the effect of Se-enriched IF on hepatoma remains unknown. To determine the organic transformation of Se and compare the antitumor effects between Se-enriched IF (IF-Se) and IF on xenograft H22 hepatoma-bearing mice. Se was added to the solid-state culture medium, and the organic Se content was detected by HPLC-ICP-MS. Forty-two Kunming mice were randomly divided into seven groups to test the antitumor effects of low- (300 mg/kg) and high- (600 mg/kg) doses of IF-Se and IF through xenograft. Huai'er granules were administered as the positive control. In addition, interleukin (IL)-2 and vascular endothelial growth factor (VEGF) expressions were measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry method. The conversion rate in the IF-Se70, IF-Se140, and IF-Se280 groups were 91.5%, 93.4%, and 89.3%, respectively. Therefore, IF-Se140 was used to carry out the subsequent experiments. The tumor inhibition rates of IF-Se were significantly higher compared with IF (P < 0.05). Moreover, the spleen coefficient, IL-2, and VEGF expression levels significantly decreased (all Ps < 0.05), and the thymus coefficient significantly increased (P < 0.05) in the high-dose IF-Se group compared with the model control group. The inhibitory effects of IF on H22 hepatoma-bearing mice were enhanced after Se enrichment. Therefore, Se-enriched IF might be a new strategy for treating hepatoma.