Inhibitory ethanolic extract of Plantago major L. inhibitory effect on radicular meristematic growth of Allium cepa L.

Abstract

The use of natural products, such as plantain (Plantago major) extract, has generated an increase in the commercialization of substances, which in some cases are not studied for their possible toxic effects. The effect of the ethanolic extract of plantain (P. major) on root growth was studied using the standardized technique of crushing root meristematic cells of Allium cepa. Knop® commercial ethanolic extract (30 mg/mL concentration) was used. A root growth system was established under controlled conditions of temperature, oxygenation and darkness. Three groups were established (Negative Control, Experimental Group with increasing time and Group with increasing dose of 0.75 mg/mL, 1.5 mg/mL, 7.5 mg/mL, 15 mg/mL and 30 mg/mL). The optimal dose for the study was evaluated beforehand. Eighteen Allium cepa bulbs were used, with 3 bulbs for each study group. The exposure to the ethanolic extract was at 24, 48, 72, 96 and 120 h. Crushing and staining with acetochlorohydric orcein were performed. A thousand cells per plate were observed and counted. The values obtained were analyzed through of mean comparison and ANOVA test. The results were discussed and analyzed in terms of the effect of P.major on cell cycle variations and mitotic index. The results obtained indicate that the ethanolic extract of P. major at concentrations higher than 7.5 mg/ mL are cytotoxic to root meristems; and that after 48 h of exposure to the extract, cell proliferation is drastically reduced.