Determination of reactive oxygen generated from natural medicines and their antibacterial activity

Abstract Extracts of 16 natural medicine powders ( Galla chinensis, Malloti cortex, Cassiae semen, Sophorae radix, Myricae cortex, Crataegi fructus, Gambir, Mume fructus, Geranii herba, Phellodendri cortex, Coptidis rhizoma, Swertiae herba , and Cinnamomi cortex ) were assayed for reactive oxygen concentrations using the peroxyoxalate chemiluminescent detection system. High luminescence intensity was observed in Galla chinensis, Geranii herba, Malloti cortex, Myricae cortex , and Cinnamomi cortex . Additional experiments identified the reactive oxygen species as hydrogen peroxide. Galla chinensis generated 2.4×10 −4  mol/L hydrogen peroxide from a 1 mg/mL solution. In bacterial growth tests, Galla chinensis extract had antibacterial activity against Escherichia coli , Staphylococcus aureus , Bacteroides thetaiotaomicron , Campylobacter sputorum biovar sputorum , Streptococcus salivarius thermophilus , Lactobacillus casei , and Bifidobacterium longum infantis . This antibacterial activity was decreased by the addition of catalase. It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.