Effects Of Harmane Research Articles

Inhibition of DNA-repair and DNA-synthesis by harman in human alveolar tumor cells

The effect of the tryptophan pyrolysis product harman on colony forming ability, DNA-synthesis and DNA-repair was investigated in human alveolar tumor cells A549. Colony forming ability and overall DNA synthetic capacity decreased linearly with increasing harman concentration and reached values of 20 % and 29 % of untreated controls, respectively, at 200 μM. Harman also inhibited the repair of N-acetoxy-2-acetylaminofluorene induced DNA damage, as measured by the alkaline elution procedure. While incision of parental DNA occurred normally in the presence of harman the reconstitution of control molecular weights was strongly inhibited. These effects of harman may play a role in its co-mutagenic activity.

Effects of harman and norharman on the mutagenicity and binding to DNA of benzo[a]pyrene metabolites in vitro and on aryl hydrocarbon hydroxylase induction in cell culture

Harman and norharman, two β-carboline derivatives known to exist in certain foods and to be formed during pyrolysis of tobacco and meat, were tested for mutagenic activity in the presence of benzo[a]pyrene, mouse liver enzymes, and Salmonella typhimurium TA98 in vitro. Both harman and norharman inhibit benzo[a]pyrene mutagenicity, benzo[a]pyrene metabolism (as measured by aryl hydrocarbon hydroxylase activity), and the binding of all benzo[a]pyrene metabolites to DNA in vitro. Moreover, harman and norharman are quite toxic to cultures of hepatoma-derived H-4-II-E and Hepa-1 established cell lines and therefore were found to be very weak inducers of aryl hydrocarbon hydroxylase activity.

Enhancing effect of harman on mutagenicity in Salmonella

Enhancing effect of harman on mutagenicity in Salmonella