Abstract
In order to elucidate the action mechanism of natural products including Chinese herbs and natural foods which are now widely used for preserving health and/or medical treatments, the effect of sixteen Chinese herbs and two natural foods (AOA, GM) on active oxygen (AO) generated by human neutrophils and in xanthine-xanthine oxidase system was examined. The effects of non-heated or heated agents without dialysis and those after dialysis (which is able to separate molecular weight above 10, 000 from that below 10, 000) on AO levels were compared.
These heated agents markedly and non-heated ones moderately or slightly decreased AO levels generated in both neutrophils and xanthine-xanthine oxidase system. Of interest is that paradoxical findings were obtained from the present experiments that the capacity of these agents for reducing AO levels was not attenuated both by heat and after dialysis, seemingly suggesting that neither superoxide dismutase (SOD) nor low weight chemicals play a role in quenching AO in these agents. However, the capacity of heated ones to decrease AO was significantly attenuated after dialysis. From these results obtained, it seems likely that in non-heated products, AO quenching effect is due to high molecular weight chemicals, enzymes and that in heated ones, this effect is ascribable to the low molecular weight chemicals which are isolated to be activated for quenching AO levels by heat which may have cleaved the bonds of these chemicals linking to other chemicals in natural products. It may be possible that before heated, polymerization of these effective, low molecular weight chemicats to other chemicals inactivates their capacity for removing AO. It also seems to be due to the bondscutting effect of heat with resultant passage of the free low molecular weight, effective chemicals through the diaphromembrane that decreased AO scavenging effect of the products by dialysis after heat. It can be further suggested that these natural products tested have potent AO removing effects and that not only high molecular weight chemicals, enzymes such as SOD but also low molecular weight ones such as flavonoid which have various pharmaceutical action mechnaisms other than scavenging AO may be effectively contained in these natural products.
