Superoxide and traditional Chinese medicines.

In traditional Chinese medicinal practices, herbs are classified as 'cold', 'neutral', or 'hot'. Fluorometric analysis of herbs with 'cold' properties revealed that these herbs produce large amounts of superoxide. In contrast, herbs with 'hot' properties have scavenging activities. We believe that this electron transfer to form superoxide and the scavenging of superoxide may elucidate the phenomena of the 'yin' (represented by 'cold') and 'yang' (represented by 'hot') respectively.