Cytotoxicity Screening of Several Tomato Extracts

Abstract

The cytotoxic effects of extracts of the tomato variety "Racimo" have been evaluated through the use of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at several concentrations. Three extracts-ethanol-water, petroleum ether, and in vitro digested tomato-exhibited in vitro cytotoxicity against the proliferation of the cultured cancer cell line HT-29. The concentration that caused 50% inhibition of cancer cell growth occurred (GI(50)) of the different extracts for HT-29 cells was 62.5 μg/mL for the petroleum ether extract and 87.0 μg/mL for the digested tomato extract. For the ethanol-water extract, it was not possible to determine this parameter at the assayed extract concentrations. These results clearly indicate that after the digestion process, the less polar substances, such as carotenoids and sterols, are bioavailable as active species against cancer cells. The GI(50) levels for tomato extracts are similar to those values reported for medicinal plants. The results of the MTT assay on nonmutagenic CCD-18 cells showed a lack of negative effect on cell growth, which indicates that tomato extracts act selectively on HT-29 tumor cells. (1)H-Nuclear magnetic resonance spectra confirmed the presence of known compounds with accepted cytotoxic activity against tumor lines (lycopene and β-carotene). The high cytotoxicity for HT-29 cells showed by the petroleum ether extract might be due to the simultaneous presence in the extract of both carotenoids and glyceryl esters of fatty acids. The results of this work clearly indicate the importance of carotenoid consumption on colon tumor proliferation and prevention, and also the importance of the dietary fats in carotenoid bioavailability.

Phytochemical composition andin vitroanti-tumour activities of selected tomato varieties

“…As expected, the total FAs in all tomato varieties was low, a result which agrees with previous reports, and thus this fact prevents it being considered that such lipids are nutritionally relevant . However, some FAs are important cytotoxic agents against colorectal cancer cells, as previously reported …”

“…To check the actions of tomato varieties on colorectal cancer cells viability, cell proliferation and cytotoxicity, fruit extracts were made by using two solvents, ethanol/water (1:1, v/v) and petroleum ether. Polarity differences allows them to extract compounds with a different ranges of solubility; thus, the biological activity of different tomato compounds was discerned depending on their hydrophilic or lipophilic characteristics . 1 H NMR analyses showed that petroleum ether extracts contained a mixture of glycerol FA esters (mainly derived of LA and OA), as well as lycopene and β ‐carotene in minor amounts, whereas the ethanol/water extract was mainly composed of carbohydrates, for instance fructose and glucose.…”

“…Different mechanisms have been identified acting on cancer prevention exercised by active compounds of tomato, such as inhibition of inflammatory processes and interference with tumour angiogenesis . Moreover, in addition to the whole fruit, tomato by‐products have shown anti‐tumour activity on HT‐29 colorectal cancer cells …”

HT29 Cell Line

“…An illustrative example is found in the study of the antiproliferative activity of the in vitro gastrointestinal digest of sea cucumber wall (Pérez-Vega et al 2013 ). Another representative study is found in the assessment of the cytotoxic activity of different extracts from "Racimo" tomato variety and simulated digests against HT29 cell growth, including also the evaluation of the selectivity of the toxic effect against cancer cells (Guil-Guerrero et al 2011 ). Other activities have been widely studied on HT29 cells or derived lines, such as immunomodulatory, antioxidant or barrier protective properties.…”

Carotenoids and total phenolic contents in plant foods commonly consumed in Korea

“…In addition, data from NHANES III indicate that for women 51-70 y, the medians for 50 th & 75 th percentiles of lutein/zeaxanthin intake were 1.7 and 2.4 mg/d, respectively [74]. Foods rich in an acyclic carotenoid, lycopene, one of the most abundant carotenoids in human blood and tissues, has been found to be associated with an inverse risk of cervical [75], prostate [76], and colon [77] cancers.…”