In vivo and in vitro antioxidant activity of Ligaria cuneifolia extracts

MARCHINI, T; MAGNANI, N; DOBRECKY, C; RICCO, R; GURNI, A; LLESUY, S; WAGNER, M; EVELSON, P

Montevideo , Uruguay

Congreso; V Meeting of the Society for Free Radical Biology and Medicine – South American Group.; 2007

Society for Free Radical Biology and Medicine – South American Group

Ligaria cuneifolia (Lc) is a hemiparasite species with anti-inflammatory and vasopressor activities, employed in Argentine folk medicine. Its pharmacological actions may be explained by the probable antioxidant activity of the phytochemical content. The aim of this work was to evaluate the in vitro and in vivo antioxidant activity of Lc extracts. We first assayed the crude, methanol, aqueous and ethyl acetate (EAF) Lc fractions with the ABTS and DPPH methods to estimate the in vitro hydrosoluble and liposoluble antioxidant capacity, respectively. All extracts tested showed significant antioxidant activities with both methods, being the EAF the one with the higher response. We then tested the EAF in in vitro assays with biological substrates and in vivo. The inhibition of the spontaneous chemiluminescence (CL) of rat brain homogenates and TBARS production in rat liver homogenates by the EAF showed, in both cases, a dose-dependent response. The EC50 values obtained from CL and TBARS were 26 mg/mL and 0.27 mg/mL of dried EAF, respectively. It is known that exposure of mouse skin to low dose UVA leads to oxidative stress, which is directly indicated by in vivo organ CL. Topical application with the EAF produced a 38% decrease in mouse skin CL after 30 min of irradiation (UVA irradiated: 42 ± 3 cps/cm2). The EAF of Lc proved to be an efficient in vitro and in vivo antioxidant. These properties may be one of the mechanisms by which Lc exerts its pharmacological actions.