A specific nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract has demonstrated a broad spectrum of antitumor activity against a number of cancer cell lines. In this study, our main objective was to investigate the comparative effects of NM on anticancer parameters, such as cytotoxicity, matrix metalloproteinase (MMP) secretion and Matrigel invasion in the human uterine sarcoma drug-resistant MES-SA/Dx5 and the drug-sensitive MES-SA cell lines. In addition we studied the effects of NM on P-glycoprotein (Pgp) on these cell lines. Cell proliferation was evaluated by MTT assay, MMPs by gelatinase zymography, invasion through Matrigel, morphology by H&E and Pgp expression by Western blot analysis and immunodetection using FITC-conjugated antibody and rhodamine 123 (Rh123) accumulation and efflux assays. NM exhibited antiproliferative effects on MES-SA/Dx5, by 20% at 50 and 100 µg/ml and by 36, 40 and 48% at 250, 500 and 1,000 µg/ml, respectively. By contrast, NM treatment of MES-SA cells resulted in significantly increased cytotoxicity: 40, 46, 65 and 72% at 50, 100, 500 and 1,000 µg/ml, respectively. In both cell lines, zymography demonstrated a band corresponding to MMP-2 in normal cells and MMP-9 with phorbol 12-myristate 13-acetate treatment. The two MMPs showed dose-response inhibition by NM. As shown by Western blot analysis and immunodetection, NM treatment resulted in a dose-dependent decrease in Pgp expression in the MES-SA/Dx5 cell line. The MES-SA cell line does not exhibit Pgp. NM enhanced the accumulation and efflux of the Pgp substrate, Rh123, in the MES-SA/Dx5 uterine sarcoma cell line but not in the drug-sensitive cell line, MES-SA. Therefore, it can be concluded that NM demonstrates potent anticancer effects in both the drug-resistant and sensitive cell lines and modulates Pgp, suggesting its potential therapeutic effects in drug-resistant as well as sensitive cancers.