Cytotoxicity and genotoxicity of Vernonia condensata Baker aqueous extracts in an Allium cepa test system and C2C12 cell culture

Abstract

Vernonia condensata Baker is a medicinal species widely used by the Brazilian population for its analgesic, hepatoprotective and digestive properties. This study aimed to investigate the cytotoxic and genotoxic effects of V. condensata aqueous extracts using Allium cepa test system and in vitro micronucleus test. Fresh V. condensata leaves were collected, dried and ground, and aqueous extracts were prepared at concentrations of 1500; 3000; and 6000 µg/ml of dry extract. In the A. cepa test, ten repetitions were used per treatment. Distilled water was used as negative control and sodium azide (2M) as positive control. The onion bulbs were rooted in distilled water for 72 h and then exposed to the extracts for 24 h. The roots were collected and fixed in Carnoy’s solution (3:1) for 24 h. Smear slides were prepared of the root apical meristems and 2000 cells/concentration was analyzed, measuring the mitotic index, micronuclei frequency and mitotic abnormalities of A. cepa. In vitro cytotoxicity and genotoxicity were also performed using the murine myoblast cell line C2C12. In vivo data demonstrated that an increase in the concentration of V. condensata aqueous extracts caused cytotoxic and genotoxic effects in meristematic cells of A. cepa. A concentration of 1500 µg/ml showed no cytotoxic or genotoxic effects, while 3000 µg/ml resulted in mitotic abnormalities and a decline in the mitotic index, indicating cytotoxicity. The 6000 µg/ml aqueous extract showed cytotoxicity and genotoxicity, increasing mitotic abnormalities and micronuclei frequencies in the A. cepa test. An IC₅₀ value of 15.610 µg/mL was obtained for C2C12 cell line and the doses of 6000 µg/mL and 12000 µg/mL of Vernonia extract induced genotoxicity. The data of the present study reveals that V. condensate extract should be used with parsimony, once that it can bring unwanted side effects, which can be dangerous.