A team of scientists from the University of Almería (UAL) has analyzed the phytochemical compounds and the antitumor activity of arugula (Diplotaxis tenuifolia) and canon (Valerianella locusta). In vitro tests on colon cancer cells show that these plants contain bioactive compounds effective in preventing this disease.
Previous research already pointed to the beneficial effects of arugula and canon in cardiovascular diseases, diabetes and some type of cancer. However, the specific compounds responsible for this action had not been fully determined. The study, published in the journal Plant Foods for Human Nutrition, constitutes the first analysis that specifies the composition of fatty acids, phenolic compounds, carotenoids, sterols and glucosinolates of both species.
In parallel, researchers have evaluated the effects of extracts from these plants on colon cancer cells. “After a large number of tests, we have verified that there is an inhibition of growth and damage to the membranes of cancer cells. We have also grown normal colon cells, which are unaffected by such extracts at the concentrations checked. In sum, the phytochemicals of these plants act selectively against colon cancer cells but not against normal colon cells ”, explains the researcher in charge of the study, José Luis Guil Guerrero, professor of Food Technology at the UAL.
The results of toxicity against cancer cells are related to different phytochemical compounds of these plants. The study reveals that extracts from arugula induce damage to cancer cells leading to death at low concentrations. For their part, canon compounds induce a reduction in the number of tumor cells, although to a lesser degree than arugula extracts do.
Different techniques to analyze compounds
Researchers analyze the concentration of each type of phytochemical in different ways, that is, of those substances found in foods of plant origin, biologically active, that are not essential nutrients and with positive effects on health. Thus, in the case of phenolic compounds, they are determined by ultra-high-resolution liquid chromatography, a technique that allows the components of a complex mixture to be separated, identified and quantified.
For carotenoids and glucosinolates, liquid chromatography coupled to mass spectrometry was used, a technique that allows determining the structure of the molecules. It requires small amounts of sample and obtains information about the molecular weight and some characteristics of the analyte's structure. In the case of sterols and fatty acids, gas-liquid chromatography was used.
The effects of active compounds on cells are determined after extracting them with selective solvents. They are then applied in known concentrations to cell cultures. "We measure cell growth or death, using a technique called ELISA and the effect of extracts in cell cultures depends on a large number of variables, such as solvents used in the extraction, concentration and time", he details.
Ramos-Bueno RP, Rincón-Cervera MA, González-Fernández MJ, Guil-Guerrero JL. ‘Phytochemical Composition and Antitumor Activities of New Salad Greens: Rucola (Diplotaxis tenuifolia) and Corn Salad (Valerianella locusta)’. Plant Foods Hum Nutr. 2016 Jun; 71 (2): 197-203. doi: 10.1007 / s11130-016-0544-7.