Radix Astragali and Tanshinone Help Carboplatin Inhibit B16 Tumor Cell Growth

Background: Excessive UV radiation causes increased melanoma incidence. Postoperation chemotherapy will destroy lymphocytes and compromise immune response. Immunodepression is also detected in patients with cancers. Previous studies suggested that polysaccharide–protein complexes manifested immunomodulatory and antitumor activities. Radix Astragali (RA) extract is a product of polysaccharide–protein complexes, which has been used in the treatment of a variety of diseases because of its low toxicity to the host. Tanshinone (TA) is a derivative of phenanthrenequinone isolated from Danshen, which is suggested to inhibit tumor growth by inducing apoptosis in tumor cells. Carboplatin (CA) is a commonly used chemotherapeutic drug in melanoma treatment. Therefore, we hypothesized that the combination of RA and TA will help CA better inhibit the B16 cell growth.Purpose: The study will test that the efficacy of growth inhibition of tumor cell produced by CA + RA + TA is better than CA + RA or CA + TA.Methods: The B16 tumor cells were injected to Swiss-Hauschka (ICR) mice subcutaneously. Twenty-four hours later, mice received CA intraperitoneally, CA + RA (RA were administered gastrically at the dosage of 10 g/kg body weight), CA + TA (TA were administered gastrically at the dosage of 0.5 g/kg body weight), or no treatment (model group). Tumor weight, volume, latency, incidence, the percentage of CD4 + and CD8 + in spleen, and natural killer (NK), and cytotoxic lymphocyte (CTL) activities were measured and compared among different groups.Results: Compared with mice treated with CA + RA, CA + TA, or CA alone, the mice treated with CA + RA + TA showed (1) significantly smaller tumor weight and tumor volume; (2) significantly longer tumor latency; (3) significantly lower tumor incidence; and (4) significantly increased percentage of CD4 + and CD8 + in spleen and increased activities of NK and CTL.Conclusion: Combination of RA and TA can help CA produce more effective inhibition on B16 cell growth.