In vitro plant cell cultures as sustainable alternative for the production of innovative healthy materials

One of the greatest challenges of the 21st century is to meet society's growing food needs whilst simultaneously reducing the environmental impact of agriculture. Between 60%–110% more food could be needed by 2050 due to the increasing global population, unfortunately, only 2% more agricultural land is available ultimately covering 40% of total land area. Dealing with these issues it becomes apparent that new technologies for diverse and healthy plant-based food production need to be developed. Plant cell culture technology is a new concept to consider. The use of in vitro cultures for obtaining metabolites and extracts has already and is still affecting many industries. So far, however, the use of the entire plant cell culture biomass, or its derived crude extracts, as foodstuff has not been thoroughly considered and investigated. Plant cell cultures have shown great potential for food purposes, and even if, as far as now, unlikely can cope with agriculture food derivatives, this technology can constitute an additional tool for global food production and possibly to nutraceutical/supplement industry. Because of these reasons, four plants have been investigated for the obtainment and evaluation of plant cell cultures, namely, Morus alba L., Vitis labrusca L. var. Isabella, Prunus cerasus L. var. Marasca, and Persea americana Mill. var. Hass and var. Pinkerton. Stable cell lines with excellent growth rate have been obtained for three of the four studied species within a reasonable timeframe, while for P. americana a stable cell line was established only from Hass variety, after more than two years. Preliminary untargeted HPLC-DAD analyses, together with total phenol, total flavonoid and total proanthocyanidin colorimetric assays on the cell line juices revealed different secondary metabolisms either of biomasses obtained by distinct plants, and of biomasses obtained by the same plant but exposed to diverse stimuli. The colorimetric assays done during the cell line growth cycle highlighted that in in vitro cell metabolism can change during the growth, as a result of cell activity. Data confirmed also by the antioxidant colorimetric assays. LC-MS/MS analysis has allowed to identify in M. alba and in V. vinifera cell cultures the presence of the stilbenoid class as predominant secondary metabolites, whereas in P. cerasus cell cultures several naringenin derivatives were detected. Been known that plant cell cultures are strongly influenced by environmental cues, the effect of growing in opposite conditions such as under photoperiod/dark conditions and in added hormone/without hormone media were evaluated. Differences in the morphology and slight differences in the quali-quantitative profile of material juices, highlighted the in vitro material responsiveness. Good growth rates and active secondary metabolisms were also achieved in cell suspensions maintained both under photoperiod and in dark conditions. The anti-oxidant activity on Caco-2 cells, highlighted the potential of all the suspensions, and Prunus material on solid medium. On the other hand, quite all the juices analysed revealed anti-inflammatory activity in reduction of IL-1β and THF-α in LPS stimulated Caco-2 cells. Plant culture lines also proven to be valuable nutritional source.