Hydroxyl Radical-Scavenging Property of Secoisolariciresinol Diglucoside (SDG) Isolated from Flaxseed.
Hydroxyl Radical-Scavenging Property of Secoisolariciresinol Diglucoside (SDG) Isolated from Flaxseed.
Year: 1997
Authors: K Prasad.
Publication Name: Mol. Cell Biochem.
Publication Details: Volume 168; Number 1-2; 117.
Abstract:
Flaxseed feeding has shown beneficial effects in cancer and lupus nephritis, effects which may be due to the ability of flaxseed lignans to act as anti-oxidants and to scavenge oxygen radicals. However, information regarding the antioxidant effects of flaxseed and SDG is lacking. The objective of the present study was to assess the ability of SDG to scavenge exogenously generated hydroxyl radical (·OH) using an HPLC method. The ability of SDG to prevent ·OH-induced lipid peroxidation in a biological system (rabbit liver homogenate) was also investigated. ·OH was generated by photolysis of H202 (1.25-10.0 ?moles/ml) with ultraviolet light and was trapped with salicylic acid which was hydroxylated to produce ·OH-adduct products 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA. H202 produced a concentration-dependent ·OH as estimated by 2,3-DHBA and 2,5-DHBA. A standard curve was constructed for known concentrations of 2,3-DHBA and 2,5-DHBA against corresponding area under the peaks. This standard curve was used to measure 2,3-DHBA and 2,5-DHBA generated by UV irradiation of H202 in the presence of salicylic acid. The results showed that SDG in the concentration range of 25, 50, 100, 250, 500, 750, 1000 and 2000 mg/ml (36.4, 72.8, 145.6, 364.0, 728.0, 1092.0, 1456.0 and 2912.0 mM, respectively) produced a concentration-dependent decrease in the formation of 2,3-DHBA and 2,5-DHBA. The inhibition caused by SDG was 4 and 4.65%, respectively, with 25 mg/ml (36.4 mM) and 82 and 74%, respectively, with 2000 mg/ml (2912.0 mM). The decrease in ·OH-adduct products was due to scavenging of ·OH rather than by the scavenging of 2,3-DHBA and 2,5-DHBA. ·OH produced a marked increase in the production of malondialdehyde (MDA) in liver homogenates. SDG prevented lipid peroxidation of liver homogenates by reducing the formation of MDA in a concentration-dependent manner within the concentration range of 319.3 to 2554.4 mM. The author concluded that his data supports the ability of SDG to scavenge ·OH and therefore act as an antioxidant. The effectiveness of flaxseed lignans in the treatment of diseases such as cancer could be due to its antioxidant activity.
