It has been shown in a previous study that
brown coal-derived potassium humate is safe and effective in suppressing contact hypersensitivity in rats. In this study
the efficacy of potassium humate on other types of inflammation was determined. Preparative TLC followed by mass spectroscopy was used in an attempt to fingerprint the product. The effects of potassium humate, at an oral dose of 60 mg/kg bodyweight, on a delayed type hypersensitivity reaction, a carrageenan-induced inflammation model and an allogeneic graft-versus-host reaction (GVHR) in rats were investigated. Paw oedema was used
as a measure of inflammation. It was found that potassium humate had no effect on the delayed type hypersensitivity reaction but significantly inhibited the increase in paw
volume of the carrageenan-induced oedema in rats which compared favourably with indomethacin treatment. Furthermore,
potassium humate inhibited the GVHR induced
in normal and cyclophosphamide-treated immune-incompetent rats. The identification of a naturally occurring compound that is safe and effective in reducing different
types of inflammation merits further evaluation in clinical trials.