A HPLC procedure has been used to examine the effect of Co-60 irradiation for
controlling microorganisms and molds on dried leaf powder of A. paniculata. Despite
the known benefits of irradiation, the radiation absorbed dose should not cause any
significant change in the content of active ingredient. Our studied revealed that the
active component is not affected by irradiation dose between 5 to 25 kGy as well as a
storage period up to 50 days after irradiation. As shown in the results, irradiated
samples A, B and C exhibited slightly decreased in contents of andrographolide after
irradiation when compared to the control samples, however, the changes were not
significant statistically. It is likely that the variations are contributed from differences
in experimental conditions, instrumental and human errors rather than from the effect
of radiation.