Effects of α-tomatine and curcumin alone or in combination on the growth of PC-3 xenograft tumors and body weight of SCID mice.

<p>Male SCID mice were injected subcutaneously with PC-3 cells (2 × 10⁶ cells/0.1 ml) suspended in 50% Matrigel in RPMI medium. After about 4 weeks, mice with PC-3 xenograft tumors (0.6–1.0 cm wide and 0.6–1.0 cm long) were i.p injected with vehicle, α-tomatine (5 mg/kg body weight), curcumin (5 mg/kg body weight), and a combination of α-tomatine (5 mg/kg body weight) and curcumin (5 mg/kg body weight) once every three day for 30 days. Immunohistochemical staining of PCNA was done to determine the effect of the various treatments on tumor cell proliferation. (A) Tumor size was expressed as percent of initial tumor size. (B) The weight (g) of each tumor was measured at the end of the experiment in mice after sacrifice. (C) Body weight was expressed as percent of initial body weight. (D) Percentage of PCNA positive cells in tumors from animals treated with vehicle, α-tomatine, curcumin or the combination of α-tomatine and curcumin. Representative micrographs of PCNA immunohistochemical staining in tumors from the control group (E), the α-tomatine-treated group (F), the curcumin-treated group (G) and the combination-treated group (H) are shown. Black arrows indicate positive PCNA staining and white arrows indicate negative PCNA staining.</p

Effect of α-tomatine and curcumin on apoptosis of cultured prostate cancer cells.

<p>LNCaP, VCaP, PC-3 and RWPE-1 cells were seeded at a density of 0.2 × 10⁵ cells/ml and incubated for 24 h. The cells were then treated with α-tomatine (α-T; 1 μM) or curcumin (Cur; 5 or 10 μM) alone or in combination for 48 h. Apoptosis was determined by morphological assessment. Each value is the mean ± S.E from three experiments.</p><p>Effect of α-tomatine and curcumin on apoptosis of cultured prostate cancer cells.</p

Effects of α-tomatine and curcumin alone or in combination on the growth of cultured prostate cancer cells.

<p>Human prostate cancer cells (LNCaP, VCaP and PC-3) and non-tumorigenic prostate epithelial cells (RWPE-1) were seeded at a density of 0.2 × 10⁵ cells/ml in 35 mm tissue culture dishes and incubated for 24 h. The cells were then treated with various concentrations of α-tomatine and curcumin alone or in combination for 72 h. Viable cells was determined by the trypan blue exclusion assay. (A) Percent cell viability in the various cell lines treated with α-tomatine. (B) Percent cell viability in the various cell lines treated with curcumin. (C) Percent cell viability in the various cell lines treated with α-tomatine (1 μM) and curcumin (5 μM) alone or in combination. Each value represents mean ± S.E from three separate experiments.</p

Effect of α-tomatine and curcumin on the level of Bcl-2, phospho-Akt and phospho-ERK1/2 in PC-3 cells.

<p>The cells were seeded at a density of 1×10⁵ cells/ml of medium in 100 mm culture dishes and incubated for 24 h. The cells were then treated with α-tomatine or curcumin alone and in combination for 24 h (for analysis of phosphor-Akt and phosphor-ERK1/2) and 48 h (for analysis of Bcl-2). The levels of Bcl-2, phospho-Akt and phospho-ERK1/2 were determined by the Western blot analysis. The band density was measured and normalized for actin.</p

Inhibitory effect of α-tomatine and curcumin alone or in combination on NF-κB activation in PC-3 cells.

<p>PC-3/N cells were seeded at a density of 0.2×10⁵ cells/ml of medium in 12-well plates and incubated for 24 h. The cells were then treated with α-tomatine alone or in combination with curcumin for 24 h. The NF-κB transcriptional activity was measured by a luciferase activity assay. Each value represents mean ± S.E from three separate experiments.</p

Structures of α-tomatine and curcumin.

<p>Structures of α-tomatine and curcumin.</p