Inhibitory effect of tetrahydro-beta-carboline derivatives on lipid peroxidation in vitro

We have investigated the inhibition of lipid peroxidation by beta-carboline derivatives, synthesized by Pictet-Spengler condensation of tryptophan wit h formaldehyde, acetaldehyde, pyruvic acid and pyridoxal HCl, in rat brain homogenate and liver mitochondria and microsomes. The antioxidant activity of the compounds was also evaluated by the linoleic acid autoxidation syste m. Out of the four compounds tested, one (tetrahydro beta-carboline) optima lly inhibited spontaneous and iron-induced lipid peroxidation in brain homo genate. It also inhibited lipid peroxidation induced by ferrous-ascorbate i n liver mitochondria, as well as ferrous-ADP-ascorbate and NADPH-induced li pid peroxidation in liver microsomes. In addition, this compound exhibited antioxidant activity in the linoleic acid autoxidation system and its antio xidant activity was comparable to that of the standard antioxidant viz buty lated hydroxy anisole. Its higher antioxidant activity may be attributable to its structure. Med Sci Res 27:181-184 (C) 1999 Lippincott Williams & Wil kins.