In vitro Antioxidant, Antimicrobial and Anti-Herpes Simplex Virus Type 1 Activity of Phellodendron amurense Rupr. from China.

Phellodendron amurense Rupr. bark extracts were examined for antioxidant activity, antimicrobial activity and antiviral activity on herpes simplex virus type 1 (HSV-1). Ethanol extract showed higher content of both total phenolic and flavonoid than aqueous extract. In DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay, the concentration providing 50% inhibition (IC₅₀) values were 6.73 ± 0.87 mg/ml and 4.26 ± 0.59 mg/ml for aqueous and ethanol extracts respectively. Ethanol extract had a much higher antimicrobial activity than aqueous extract. Furthermore, the antiviral activity of the ethanol extract on HSV-1 was also tested. The maximum noncytotoxic concentration was 44.12 μg/ml for RC-37 cells. Plaque formation was inhibited by 74±6% when HSV-1 was pretreated with the extract prior to adsorption, whereas pretreatment of the cells with the extract, added during adsorption or after the adsorption only exhibited above 10% antiviral effect. This study has to some extent validated the medicinal potential of P. amurense bark. [ABSTRACT FROM AUTHOR]