Antiproliferative activity and determination of phenolic compounds in blackberry (Rubus sp.) aqueous extracts by the Allium cepa L. in vivo test system

Abstract

We aimed to evaluate the antiproliferative and genotoxic potential of aqueous extracts prepared with fresh and dry leaves of Rubus sp. on meristematic divisions of Allium cepa root tips, as well as the phenolic compounds in the extracts. Aqueous extracts were prepared by infusion of blackberry fresh leaves collected at Santa Maria municipality, Rio Grande do Sul state (RS), southern Brazil (at concentrations 20 and 60 g.L-1), and dry leaves collected at Nova Palma municipality, RS (at concentrations 10 and 30 g.L-1). Distillated water was used as negative control while 1% glyphosate solution was used as positive control. Phenolic compounds were determined by High Performance Liquid Chromatography (HPLC). We analyzed a total 4000 cells per treatment. Statistical analysis was performed using Tukey and Scott-Knott tests (p < 0.05). Both fresh- and dry-leaf aqueous extracts at both concentrations inhibited cell proliferation, showing no significant difference from one another yet showing significant difference from the control treatments. HPLC analysis revealed that dry-leaf aqueous extracts show higher total amount of phenolic compounds. Quercetin was the compound found in highest amounts in dry-leaf aqueous extracts while caffeic acid was the predominant compound in fresh-leaf aqueous extracts. Thus, we conclude that both fresh- and dry-leaf aqueous extracts of blackberry have intense antimitotic activity but no genotoxic activity in the in vivo plant test system.