Journal of Ethnopharmacology 61 (1998) 81 – 83 Short communication Effect of the extract of Annona muricata and Petunia nyctaginiflora on Herpes simplex virus P. Padma a , N.P. Pramod b , S.P. Thyagarajan b , R.L. Khosa a, * a Department of Pharmaceutics, I.T., Banaras Hindu Uniersity, Varanasi -221 005, India b Department of Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences, Uniersity of Madras, Taramani, Madras -600 113, India Received 17 August 1997; received in revised form 14 January 1998; accepted 19 January 1998 Abstract Annona muricata (Annonaceae) and Petunia nyctaginiflora (Solanaceae) were screened for their activity against Herpes simplex virus-1 (HSV-1) and clinical isolate (obtained from the human keratitis lesion). We have looked at the ability of extract(s) to inhibit the cytopathic effect of HSV-1 on vero cells as indicative of anti-HSV-1 potential. The minimum inhibitory concentration of ethanolic extract of A. muricata and aqueous extract of P. nyctaginiflora was found to be 1 mg/ml. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Annona muricata ; Petunia nyctaginiflora ; Anti-HSV-1 activity 1. Introduction Acute and recurrent infection with Herpes sim - plex virus (HSV) is a perpetual problem in both developed and developing countries. As a result of extensive research over the last two decades, a series of anti-HSV compounds have been devel- oped which include iodoxuridine, trifluridine, vi- darabine and acyclovir (ACV), the last one being more effective in the treatment of HSV-type 1 infection (Hattori et al., 1995). Continued treat- ment with ACV may result in the development of ACV-resistant mutants of HSV-1 (Sibrack et al., 1982; Erlich et al., 1989; Andrei et al., 1995) This fact, coupled with the toxicity of many of these compounds towards uninfected cells and their prohibitive costs has been the reason for an extended search for newer drugs particularly from traditional system of medicine which could be less toxic, relatively cheap and with less undesired effect. * Corresponding author. 0378-8741/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0378-8741(98)00013-0