Protein, free amino acid, phenolic, β-carotene, and lycopene content, and antioxidative and cancer cell inhibitory effects of 12 greenhouse-grown commercial cherry tomato varieties

The content of water, free amino acids, amino acid metabolites, crude protein, the carotene pigments β-carotene and lycopene, and 9 characterized and 2 incompletely characterized individual phenolic (flavonoid) compounds of 12 greenhouse-grown cherry tomato varieties of various colors (green, yellow, orange, red, and black) was determined using HPLC and LC/MS methods. The phenolic content of the cherry tomatoes per unit weight is 3-4 times greater than reported values for large-sized tomatoes. Antioxidative effects using the ABTS and FRAP assays and cancer-cell-inhibiting effects against 2 normal (Chang liver and Hel299 lung) and 3 human cancer (lung A549; liver HepG2; and cervical HeLa) cell lines using the MTT cell viability assay were also determined. Lycopene inhibited all the cell lines, but showed strong activity against the cervical carcinoma and the lung cancer cells. The tomato extracts showed inhibition at the higher doses. The HeLa cervical carcinoma cell line was most inhibited by the pure compounds, and the HeLa or the HepG2 cells lines were the most inhibited by the tomato extracts. The results demonstrate wide-ranging differences as well as similarities in the content of nutritional and bioactive compounds in cherry tomatoes, and suggest that such knowledge can benefit consumers.