title: In vitro antiviral activity of neem (Azardirachta indica L.) bark extract against herpes simplex virus type-1 infection.
abstract: Herpes simplex virus type 1 (HSV-1) causes significant health problems from periodical skin and corneal lesions to encephalitis. We report here that an aqueous extract preparation from the barks of neem plant Azardirachta indica acts as a potent entry inhibitor against HSV-1 infection into natural target cells. The neem bark extract (NBE) significantly blocked HSV-1 entry into cells at concentrations ranging from 50 to 100 microg/ml. The blocking activity of NBE was observed when the extract was pre-incubated with the virus but not with the target cells, suggesting a direct antiHSV-1 property of the neem bark. Further, virions treated with NBE failed to bind the cells which implicate a role of NBE as an attachment step blocker. Cells treated with NBE also inhibited HSV-1 glycoprotein-mediated cell-cell fusion and polykaryocytes formation suggesting an additional role of NBE at the viral fusion step. These findings open a potential new avenue for the development of NBE as a novel antiherpetic microbicide.
authors.affiliation: Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA.
authors.forename: Vaibhav
authors.initials: V
authors.lastname: Tiwari
authors.forename: Nissar A
authors.initials: NA
authors.lastname: Darmani
authors.forename: Beatrice Y J T
authors.initials: BY
authors.lastname: Yue
authors.forename: Deepak
authors.initials: D
authors.lastname: Shukla
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D031601:Azadirachta / Q000737:chemistry*; D016466:CHO Cells; D002459:Cell Fusion; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D005347:Fibroblasts; D015726:Giant Cells / Q000187:drug effects / Q000821:virology; D018259:Herpesvirus 1, Human / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000378:metabolism; D053586:Virus Internalization / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D010936:Plant Extracts; D014759:Viral Envelope Proteins; C039447:glycoprotein D, Human herpesvirus 1