In Vivo Antitumor Effect of Ascorbic Acid, Lysine, Proline and Green Tea Extract on Human Prostate Cancer PC-3 Xenografts in Nude Mice: Evaluation of Tumor Growth and Immunohistochemistry

Abstract

Background: Matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), Ki 67 (proliferative protein) and constituents of ECM play a critical role in angiogenesis, and are crucial in neoplastic invasion and metastasis. Based on the antitumor properties of certain nutrients, we investigated the effect of a diet containing lysine, proline, arginine, ascorbic acid and green tea extract on the growth of tumors induced by implanting human prostate cancer PC-3 cells in athymic nude mice and on the expression of MMPs, VEGF, Ki 67 and fibronectin in these tumors, as well as the production of mucin (by PAS staining). Materials and Methods: Male nude mice (n=12) were inoculated with 3×10⁶ prostate cancer PC-3 cells and randomly divided into two groups; Group A was fed a regular diet and Group B was fed a regular diet supplemented with 0.5% of the nutrient mixture (NM). Four weeks later, tumors were excised, weighed and processed for histology. Results: The results showed inhibition of tumor growth in Group B. Histological studies revealed inhibition of MMP-9 and VEGF secretion and mitosis in Group B tissues. Conclusion: Nutrient supplementation strongly suppressed the growth of tumors without any adverse effects in nude mice, suggesting strong potential as an anticancer agent.