132 - Antioxidant and anticancer activities from Stryphnodendron adstringens

Abstract

Stryphnodendron adstringens is a tree species native to the Brazilian Cerrado commonly known as barbatimao or casca-da-mocidade. In traditional medicine, the stem bark of this plant are used in the treatment of several diseases. Scientifically, its antifungal, wound healing, anti-inflammatory and antidiabetic properties have already been shown. The objective of this study was assess their antioxidant activity, and anticancer effects, and chemical composition of the aqueous extract from stem bark of Stryphnodendron adstringens (SBSA). The antioxidant activity of the SBSA was assessed using two free radical scavenging methods, the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, oxidative hemolysis inhibition,and2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced lipid peroxidation inhibition in human erythrocytes. B16F10Nex-2 melanoma cells were used to assess the anticancer activity as well as the underlying mechanisms of SBSA-induced cell death. Phenolic compounds and flavonoids present in the SBSA were quantified using two colorimetric methods involving the Folin-Ciocalteu reagent and aluminum chloride complexation reaction, respectively. The concentration of phenolic compounds was 195.16 ± 0.94 mg GAE/g SBSA, and the concentration of flavonoids was 2.87 ± 0.08 mg QE/g. The SBSA showed the antioxidant activity through direct free radical scavenging as well as through oxidative hemolysis and lipid peroxidation inhibition in human erythrocytes incubated with an oxidizing agent. In addition, SBSA promoted apoptosis-induced cell death in B16F10Nex-2 by increasing the intracellular reactive oxygen species levels, inducing mitochondrial membrane potential dysfunction and activating caspase-3. Together, these data show the antioxidant and anticancer effects of the aqueous extract from stem bark of Stryphnodendron adstringens, which suggest its potential application for the treatment and/or prevention of diseases related to oxidative stress and tumor cell proliferation.