Antioxidant and allelopathic activities of Smilax brasiliensis Sprengel (Smilacaceae)

Ethanol extract and fractions obtained from leaves of Smilax brasiliensis Sprengel were examined in order to determine their total phenolic and flavonoid contents, as well as antioxidant and allelopathic activities. Analysis by thin-layer chromatography suggested the presence of rutin in the ethanol extract and in the ethyl acetate and hydroethanol fractions. In addition, chlorogenic acid was present in the ethanol extract and in the dichloromethane, ethyl acetate and hydroethanol fractions. The antioxidant activity was significantly more pronounced for the ethanol extract and fractions than that of the commercial antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT). The allelopathic effect against the seeds of Allium cepa showed promising results, predominantly with effects in growth inhibition of hypocotyls and radicles at the lower concentration tested (125 μg mL− 1). The results of this study suggest that the extract and fractions obtained from S. brasiliensis could be used as natural antioxidants and herbicides.