Dalbergia brasiliensis Vogel Extracts in vitro Antioxidant Activity and Phytotoxic Effect in Lactuca sativa and Allium cepa

Based on medicinal use of Dalbergia species, the present study aimed to evaluate D. brasiliensis leaves and barks crude extracts and fractions’ antioxidant and phytotoxic potential, employing allelopathic essays and 3 antioxidant essays: Phosphomolybdenum complex reduction, DPPH free radical scavenging and TBARS (lipid peroxidation). Concerning Phosphomolybdenum complex reduction potential, leaves chloroform fraction (LCF) and barks ethyl acetate fraction (BEAF) overcame rutin’s reduction potential in 90% and 23%. DPPH essay revealed leaves ethyl acetate fraction (LEAF) antioxidant potential (IC50 de 40,629 µg/mL), given standards ascorbic acid (IC50 = 4,503 µg/mL) and rutin (IC50 = 7,330 µg/mL) activities. TBARS essay demonstrated that leaves hexane fraction (LHF) (51%) and barks ethyl acetate fraction (BEAF) (41%) stand out when compared to BHT antioxidant activity (54%). Regarding phytotoxicity, the lowest crude extracts and fractions concentration (250 µg/mL) employed were able to inhibit L. sativa and A. cepa primary root initial growth, specially leaves hexane fraction (LHF) and leaves chloroform fraction (LCF). Dalbergia brasiliensis fractions might function as stress inhibitors in oxidant systems and alter meristem cellular division, due to present substances’ activity.