A polysaccharide fraction from medicinal herb Prunella vulgaris downregulates the expression of herpes simplex virus antigen in Vero cells

• Published in: Journal of ethnopharmacology Vol. 93; no. 1; pp. 63 - 68
• Main Authors: Chi-Ming Chiu, Lawrence, Zhu, Wen, Eng-Choon Ooi, Vincent
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.07.2004; Elsevier
• Subjects: Animals; Antigens, Viral - biosynthesis; Antigens, Viral - immunology; Antiviral; antiviral properties; Biological and medical sciences; cell lines; Cercopithecus aethiops; Chinese medicine; Dose-Response Relationship, Drug; Down-Regulation - drug effects; Down-Regulation - physiology; Flow cytometry; Gene Expression Regulation, Viral - drug effects; Gene Expression Regulation, Viral - physiology; General pharmacology; Herpes simplex virus; Herpes simplex virus 1; Herpes simplex virus 2; Human herpesvirus 1; Human herpesvirus 2; Medical sciences; medicinal plants; Oriental traditional medicine; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; polysaccharides; Polysaccharides - isolation & purification; Polysaccharides - pharmacology; Prunella; Prunella vulgaris; Simplexvirus - drug effects; Simplexvirus - immunology; Simplexvirus - metabolism; traditional Chinese medicine; Vero Cells; viral antigens; Flow cytometry; Antiviral; Prunella vulgaris; Chinese medicine; Herpes simplex virus; Pharmacognosy; Herpesviridae; Alphaherpesvirinae; Medicinal plant; Virus; Folk medicine; Labiatae; Dicotyledones; Angiospermae; Plant origin; Spermatophyta; Herpesvirus hominis; Polysaccharide
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2004.03.024

Herpes simplex viruses (HSV) are pathogenic. With the emergence of drug-resistant strains of HSV, new antiviral agents, especially those with different modes of action, are urgently needed. Prunella vulgaris L. (Labiatae), a perennial plant commonly found in China and Europe, has long been used as a folk medicine to cure ailments. In this study, a polysaccharide fraction was prepared from Prunella vulgaris (PPV), and its effects on the expressions of HSV-1 and HSV-2 antigens in their host Vero cells were investigated with flow cytometry. The HSV antigen increased time-dependently in the infected cells, and PPV reduced its expression. The effective concentrations of PPV with 50% reductions of the HSV-1 and HSV-2 antigens were 20.6 and 20.1 μg/ml, respectively. The novelty of PPV is that it also reduces the antigen expression of acyclovir-resistant strain of HSV-1. After incubations with 25–100 μg/ml of PPV the HSV antigen-positive cells were reduced by 24.8–92.6%, respectively, showing that this polysaccharide fraction has a different mode of anti-HSV action from acyclovir. Results from this study show that PPV is effective against both the HSV-1 and HSV-2 infections, and flow cytometry offers a quantitative and highly reproducible anti-HSV drug-susceptibility assay.