Fig. 1.

Treatment with proteinase K reduces the size of the active compounds in the melanin fraction of botanicals. The melanin fraction of the botanicals indicated was dissolved in 4% SDS and treated with proteinase K (black bars) or left untreated (white bars). Samples (125–150 μg) were heated at 98° C for five minutes in 1.5% SDS containing buffer and fractionated on a 16.5 % Tris-Tricine gel. Individual lanes were cut into 0.5 cm sections, extracted with octylglucoside and evaluated for activity in THP-1 human monocytes transfected with an NF-kappa B luciferase reporter plasmid. The black bars labeled C and PK represent the activity of the untreated and proteinase K treated samples respectively, before fractionation on the gel. Values are the average of duplicate determinations in a representative experiment that was repeated at least twice.