Physiochemical, Clarification, and Antioxidant Properties of Aqueous Extract of Xiao-Chai-Hu-Tang as Affected by Membrane Process

摘要

Xiao-chai-hu-tang (XCHT) is a traditional Chinese herbal medicine which has been demonstrated to exhibit antioxidant and hepato-protective functions. To reduce the unpleasant dark brown color and precipitates during storage, the performances of membrane process on the clarification and antioxidant capability of XCHT was evaluated. A membrane system equipped with either a microfiltration membrane (0.45 um) or one of four ultrafiltration membranes (UK 200, UK 50, UP 20 and UK 10) was used. Our results indicated that less total solid was filtered through the membranes and thus a higher degree of clarification degree was achieved in permeates. Higher concentrations of active compounds, such as total phenolic compounds, saikosaponins, glycyrrhizin and baicalin, were detected in permeate using membranes of smaller pore-size of membranes. Antioxidant capabilities, including scavenging of free radicals, reducing power and total antioxidant activity of permeates, increased as compared to those of feed, particularly of permeates obtained with a UK 10 ultrafiltration membrane. Taken together, membrane process clarified aqueous herbal extract and selectively partitioned bioactive components in permeates, thus enhancing the feasibility of XCHT to be a commercial health drink product. Xiao-chai-hu-tang (XCHT), a traditional Chinese medicine for curing chronic hepatitis, is an aqueous extract from Bupleuri Radix, Pinelliae Tuber, Scutellariae Radix, Zizyphi Fructus, Ginseng Radix, Glycyrrhizae Radix, and Zingib-eris Rhizome. Pharmacokinetic studies show that XCHT possesses antiviral activity and hepatoprotective activity against CCl4- or H2O2-induced hepatic injury and hepatitis B virus. XCHT contains many bioactive components such as saikosaponins, glycyrrhizin, and baicalin. Those compounds were reported to exhibit antioxidant capabilities and protect liver from chemical-induced injury. Saikosaponins, a group of triterpene glycoside compounds, possess scavenging activity against reactive oxygen species and inhibit peroxidation in primary cultured rat hepatoctes. Glycyrrhizin, a triterpene glycoside, exhibits superoxide radical scavenging activity and reduces lipid peroxidation.