Partial
acid hydrolysis of the tetrasaccharide (
lycotetraose) side chain of the tomato glycoalkaloid α-
tomatine resulted in the formation of four products with three, two, one, and zero
carbohydrate side chains, which were separated by high-performance liquid chromatography (HPLC) and identified by thin-layer chromatography (TLC) and liquid chromatography ion-trap time-of-flight mass spectrometry (LCMS-IT-TOF). The inhibitory activities in terms of IC(50) values (concentration that inhibits 50% of the cells under the test conditions) of the parent compound and the hydrolysates, isolated by preparative HPLC, against normal human liver and lung cells and human breast, gastric, and
prostate cancer cells indicate that (a) the removal of
sugars significantly reduced the concentration-dependent cell-inhibiting effects of the test compounds, (b) PC3
prostate cancer cells were about 10 times more susceptible to inhibition by α-
tomatine than the breast and
gastric cancer cells or the normal cells, (c) the activity of α-
tomatine against the
prostate cancer cells was 200 times greater than that of the aglycone
tomatidine, and (d) the activity increased as the number of
sugars on the aglycone increased, but this was only statistically significant at p < 0.05 for the normal lung Hel299 cell line. The effect of the
alkaloids on
tumor necrosis factor α (TNF-α) was measured in RAW264.7 macrophage cells. There was a statistically significant negative correlation between the dosage of γ- and α-
tomatine and the level of TNF-α. α-
Tomatine was the most effective compound at reducing TNF-α. The dietary significance of the results and future research needs are discussed.