Antitumor activity of Se-containing tea polysaccharides against sarcoma 180 and comparison with regular tea polysaccharides and Se-yeast

Selenium (Se)-containing polysaccharide, a Se-conjugate macromolecule, generally exhibited higher antitumor activity than its regular polysaccharide. Previously, we extracted Se-containing tea polysaccharides (Se-TPS) from Se-enriched tea, and explored its structure and antioxidant activity. In this study, we investigated antitumor activity of Se-TPS on sarcoma 180 (S-180), and compared with its regular polysaccharides TPS and dietary supplement Se-yeast. In vitro antitumor activity of Se-TPS was evaluated by MTT and LDH assays, and the results indicated that Se-TPS can significantly inhibit the proliferation of S-180 in dose-dependent manner (R2 = 0.97, p < 0.0001). In S-180 cancer xenograft model in Kunming mice, Se-TPS oral administration at three doses of 50, 100 and 200 mg/kg body weight daily for 13 days resulted in significant tumor regression. At the same dose, Se-TPS exhibited significantly higher antitumor activity than TPS and Se-yeast. Importantly, Se-TPS can significantly increase the spleen and thymus indices of tumor-bearing mice, suggesting the safety and immunomodulatory activity of Se-TPS. Therefore, Se-TPS may be a desirable antitumor agent for therapeutic and immunomodulatory applications.