Planta Med 2011; 77 - PL71
DOI: 10.1055/s-0031-1282720

Antioxidant potential of Brazilian plants

CB Cruz 1, PR Campana 2, AF Silva 3, CG Silva 1, VL Almeida 1
  • 1Divisão de Ciências Farmacêuticas, Fundação Ezequiel Dias, Belo Horizonte, CEP 30510–010, MG, Brasil;
  • 2Divisão de Ciências Farmacêuticas, Fundação Ezequiel Dias, Belo Horizonte, CEP 30510–010, MG, Brasil; Laboratório de Fitoquímica, Faculdade de Farmácia, UFMG. Av. Antônio Carlos, 6627, Belo Horizonte, CEP 31270–090, MG, Brasil;
  • 3Empresa de Pesquisa Agropecuária de Minas Gerais – Av. José Cândido da Silveira, 1647, Belo Horizonte, CEP: 31.170–495, MG, Brasil.

Oxidative stress, the imbalance between free-radical formation and elimination, is part of the pathophysiology of many diseases1. Exogenous antioxidants, such as those from plants, can help to restore the normal redox state of tissues2. The aim of this study was to evaluate the antioxidant potential of plant species found in the Brazilian cerrado. The ethanolic extracts of different anatomical parts of 22 plant species (13 botanic families) were evaluated in vitro using two distinct approaches: the DPPH free-radical scavenging method (determination of EC50) and the β-carotene bleaching test (125; 62,5 e 31,25µg/mL), both performed in microplates and with pyrogallol and quercetin as antioxidant standards. In this study, the sample was considered active when showed EC50 <30µg/mL in the DPPH method and inhibition of 50% of β-carotene oxidation at 31.25µg/mL. All the 46 extracts evaluated showed concentration-dependent responses and 19 of them were considered active. Two species showed the best antioxidant profile: Qualea grandiflora Mart. (Volchysiaceae), with EC50 of 4.62±0.69µg/mL (leaves) and 4.94±0.34µg/mL (barks) on the DPPH method and 71.6±6.1% (leaves) and 74.7±2.38% (barks) inhibition of β-carotene oxidation at 31.25µg/mL; and Lafoensia pacari A.St.-Hil. (Lythraceae) with DPPH EC50 of 4.68±0.37µg/mL (leaves) and 4.62±0.63µg/mL (barks) and 62.4±2.9% (leaves) and 64.5±3.8% (barks) inhibition of β-carotene oxidation. These species will be further studied as a source of products for use in the prevention and treatment of diseases in which oxidants or free radicals are implicated.

Acknowledgement: Fapemig, for the financial support (FAPEMIG DEG-AUC-43/10); Prof. Braga, F.C and Prof. Castilho, R.O. for gently allowing the use of the laboratory facilities.

References: 1. Valko A et al. (2007) Int J Biochem Cell B 39: 44–84.

2. Halliwell B. (2001) Free Radical Bio Med 46: 531–542.