Antiviral Action of Combined Use of Rhizoma Polygoni Cuspidati and Radix Astragali on HSV 1 F Strain Effects of Processing on Antioxidation of Radix et Rhizoma Rhei and Rhizoma Polygoni Cuspidati Fingerprint of Rhizoma Polygoni Cuspidati Determination of Piceid in Commercial Rhizoma Polygoni Cuspidati by HPLC