Chromatographic analysis, antiproliferative effect and genotoxicity of aqueous extracts of Citrus sinensis (L.) osbeck on the Allium cepa L. test system

The species Citrus sinensis (L.) Osbeck (orange) is used in folk medicine as an infusion (tea) for the treatment of nerve irritation, insomnia, spasms, whooping cough, flue, and gastrointestinal problems. The aim of this study was to evaluate the antiproliferative and genotoxic potential of aqueous extracts of C. sinensis testing by Allium cepa L., as well as to determine the components in the complex mixture (tea). Leaves from two populations of this species were used in the preparation of infusions at two concentrations: 6g.L-1 and 24g.L-1, besides using distilled water as a negative control and 9.6% glyphosate as a positive control. Six groups of four bulbs of A. cepa were used, each group corresponding to one of the treatments. The bulbs were rooted in distilled water and then transferred to the respective treatments where they remained for 24 hours (the bulbs of the negative control remained in distilled water). The rootlets were collected, fixated in ethanol-acetic acid (3:1) for 24 hours and stored in 70% alcohol. 4,000 cells were analyzed per group of bulbs, and the calculated mitotic indices were submitted to statistical analysis using the c2 test. The aqueous extracts of C. sinensis have as main components flavonoids and phenolic acids. The values of the mitotic index decreased with increasing concentration of the extracts relative to the control in water. The results indicated that the orange aqueous extracts in the studied concentrations in both populations have antiproliferative and genotoxic effects on the cell cycle of A. cepa.