Optimization for production of exopolysaccharides with antitumor activity in vitro from Paecilomyces hepiali

In the present study, optimal medium for the growth of mycelia and the production of exopolysaccharides from Paecilomyces hepiali HN1 (PHEPS) in submerged culture was investigated. As a result, the maximum production of mycelia (12.98 ± 0.14 g/L) and PHEPS (5.33 ± 0.11 g/L) were achieved under the optimal medium of sucrose 46.08 g/L, yeast extract 4.71 g/L, (NH₄)₂SO₄ 5.72 g/L, KH₂PO₄ 1.70 g/L, CaCl₂ 0.50 g/L, MgSO₄ 0.50 g/L, potato extract 1% and malt extract 1%. Furthermore, the antitumor activity of PHEPS in vitro was evaluated by using three cell lines of human liver tumor HepG2 cells, breast cancer MCF-7 cells and cervical cancer Hela cells. It was found that PHEPS exhibited relative higher anti-proliferative activity against HepG2 cells than MCF-7 cells and Hela cells. At a concentration of 500 μg/mL and 72 h treatment, the inhibition rate of PHEPS on HepG2 cells reached to 62.58%. All these results suggested that PHEPS could be explored as novel natural antitumor agent with great potential application.