Inhibitory effects of wild dietary plants on lipid peroxidation and on the proliferation of human cancer cells.

Thirteen hydroalcoholic extracts of edible plants from Southern Italy were evaluated for their in vitro antioxidant and antiproliferative activity on three human cancer cell lines: breast cancer MCF-7, hepatic cancer HepG2 and colorectal cancer LoVo. After 48 h of incubation the most antiproliferative plant extract was rosemary (Rosmarinus officinalis L.) on LoVo cell line with IC50 of 16.60 µg/ml. Oregano (Origanum vulgare L. subsp. viridulum) showed a selective antiproliferative activity on hepatic cancer with IC50 of 32.59 µg/ml. All the extracts, with the exception of Diplotaxis tenuifolia (L.) DC., exerted antioxidant properties, the most active plants being dewberry (Rubus caesius L.) and "laprista" (Rumex conglomerates Murray) with IC50 of 4.91 and 5.53 µg/ml, respectively. Rumex conglomeratus contained the highest amount of flavonoids (15.5 mg/g) followed by Portulaca oleracea L. (11.8 mg/g). Rosmarinus officinalis contained the highest number of terpenes. Among them ketoursene (14.7%) and aristolone (11.3%) were found to be the major constituents. P. oleracea and Raphanus raphanistrum L. subsp. landra contained the highest number of sterols.