USE OF BIOASSAY WITH Allium cepa L. FOR THE CYTOTOXICITY ASSESSMENT OF Croton urucurana Baill

doi.org/10.29327/217514.6.12-6

Abstract

Croton urucurana Baill is a medicinal plant popularly known as Sangra d’água because when its trunk is cut, it produces resin and is a dark red color like a blood. The bark and the resin of this plant are used as a natural remedy due to anti-inflammatory, antibacterial, antiseptic, and healing properties. However, there are few studies that prove its effectiveness and safety. The use of biological assays to assess the bioactivity of a plant extract and compound has often been applied for the identification and monitoring of potentially toxic substances. This study aims to evaluate the cytotoxicity of the resin extract of medicinal plant C. urucurana through bioassay with Allium cepa (onion). The peeled onions were placed in a container with distilled water for 24 hours to stimulate the root growth. After that period, the healthy onion bulbs were selected for the experiment and were treated with six different resin concentrations (25, 50, 100, 250, 500, and 750 ppm). The test was carried out for 96 hours. The onions treated with distilled water were used as its control. At the end of the trial, the root size of the bulbs was measured, were selected ten samples for each treatment. The results showed that the extracts in the doses and exposure times evaluated, were cytotoxic and delayed the roots growth of the onions. The roots length decreased with increasing the extract concentrations. The means of treatments group are significantly different from the mean of the control (p<0.05), analyzed using Dunnett’s test. The inhibition rates were more than 50% at 250, 500, and 750 ppm with values 63, 81, and 86% respectively. In summary, the resin caused an inhibition in the Allium root growth which the intensity depends on the concentrations applied.