The Alkaloid 4-Methylaaptamine Isolated from the Sponge Aaptos aaptos Impairs Herpes simplex Virus Type 1 Penetration and Immediate-Early Protein Synthesis

Abstract

We describe in this paper that the alkaloid 4-methylaaptamine, isolated from the marine sponge Aaptos aaptos, inhibited HSV-1 infection. We initially observed that 4-methylaaptamine inhibited HSV-1 replication in Vero cells in a dose-dependent manner with an EC₅₀ value of 2.4 μM. Moreover, the concentration required to inhibit HSV-1 replication was not cytotoxic, since the CC₅₀ value of 4-methylaaptamine was equal to 72 μM. Next, we found that 4-methylaaptamine sustained antiherpetic activity even when added to HSV-1-infected Vero cells at 4 h after infection, suggesting that this compound inhibits initial events during HSV-1 replication. We observed that 4-methylaaptamine impaired HSV-1 penetration without affecting viral adsorption. In addition, the tested compound could inhibit, in an MOI-dependent manner, the expression of an HSV-1 immediate-early protein, ICP27, thus preventing the inhibition of macromolecular synthesis induced by this virus. Our results warrant further investigation on the pharmacokinetics of 4-methylaaptamine and propose that this alkaloid could be considered as a potential compound for HSV-1 therapy.

Key words

Antiviral - alkaloid - in vitro - marine invertebrates

References

• 1 Roizman B, Sears A E. Fields virology, 3rd edition. Philadelphia; Lippincott-Raven Publisher 1996: 2231-95.
• 2 Spear P G. Herpes simplex virus: receptors and ligands for cell entry.  Cell Microbiol. 2004;  6 401-10.
• 3 McKnight J L, Pellett P E, Jenkins F J, Roizman B. Characterization and nucleotide sequence of two Herpes simplex virus 1 genes whose products modulate alpha-trans-inducing factor-dependent activation of alpha genes.  J Virol. 1987;  61 992-1001.
• 4 Phelan A, Clements J B. Herpes simplex virus type 1 immediate early protein IE63 shuttles between nuclear compartments and the cytoplasm.  J Gen Virol. 1997;  78 3327-31.
• 5 Whitley R. New approaches to the therapy of HSV infections.  Herpes. 2006;  13 3-5.
• 6 Abdel-Haq N, Chearskul P, Al-Tatari H, Asmar B. New antiviral agents.  Indian J Pediatr. 2006;  73 313-21.
• 7 Wang H S, Kuo M F, Huang S C, Chou M L. Choreoathetosis as an initial sign of relapsing of Herpes simplex encephalitis.  Pediatr Neurol. 1994;  11 341-5.
• 8 Corey L, Spear P G. Infections with Herpes simplex viruses (1).  N Engl J Med. 1986;  13 686-91.
• 9 De Clercq E. Antiviral drugs in current use.  J Clin Virol. 2004;  30 115-33.
• 10 Eizuru Y. Development of new antivirals for herpesviruses.  Antiviral Chem Chemother. 2003;  14 299-308.
• 11 Newman D J, Cragg G M, Snader K M. Natural products as sources of new drugs over the period 1981 - 2002.  J Nat Prod. 2003;  66 1022-37.
• 12 Khan M T, Ather A, Thompson K D, Gambari R. Extracts and molecules from medicinal plants against Herpes simplex viruses.  Antiviral Res. 2005;  67 107-19.
• 13 Bastow K F. New acridone inhibitors of human Herpes virus replication.  Curr Drug Targets Infect Disord. 2004;  4 323-30.
• 14 Barbosa J P, Pereira R C, Abrantes J L, Cirne-Santos C C, Rebello M A, Frugulhetti I C. et al . In vitro antiviral diterpenes from the Brazilian brown alga Dictyota pfaffii .  Planta Med. 2004;  70 856-60.
• 15 Cos P, Vanden Berghe D, De Bruyne T, Vlientinck A J. Plant substances as antiviral agents: An update (1997 - 2001).  Curr Org Chem. 2003;  7 1163-80.
• 16 Coutinho A F, Chanas B, Souza T ML, Frugulhetti I CPP, Epifanio R A. Anti HSV-1 alkaloids from a feeding deterrent marine sponge of the genus Aaptos .  Heterocycles. 2002;  57 1265-72.
• 17 Esquenazi D, Wigg M D, Miranda M M, Rodrigues H M, Tostes J B, Rozental S. et al . Antimicrobial and antiviral activities of polyphenolics from Cocos nucifera Linn. (Palmae) husk fiber extract.  Res Microbiol. 2002;  153 647-52.
• 18 Kuo Y C, Chen C C, Tsai W J, Ho Y H. Regulation of Herpes simplex virus type 1 replication in Vero cells by Psychotria serpens: relationship to gene expression, DNA replication, and protein synthesis.  Antiviral Res. 2001;  51 95-109.
• 19 Denizot F, Lang R. Rapid colorimetric assay for cell growth and survival. Modifications to the tetrazolium dye procedure giving improved sensitivity and reliability.  J Immunol Methods. 1986;  89 271-7.
• 20 De Logu A, Loy G, Pellerano M L, Bonsignore L, Schivo M L. Inactivation of HSV-1 and HSV-2 and prevention of cell-to-cell virus spread by Santolina insularis essential oil.  Antiviral Res. 2000;  48 177-85.
• 21 Gong Y, Matthews B, Cheung D, Tam T, Gadawski I, Leung D. et al . Evidence of dual sites of action of dendrimers: SPL-2999 inhibits both virus entry and late stages of Herpes simplex virus replication.  Antiviral Res. 2002;  55 319-29.
• 22 Nawawi A, Ma C, Nakamura N, Hattori M, Kurokawa M, Shiraki K. et al . Anti-Herpes simplex virus activity of alkaloids isolated from Stephania cepharantha .  Biol Pharm Bull. 1999;  22 268-74.
• 23 Smith R W, Malik P, Clements J B. The Herpes simplex virus ICP27 protein: a multifunctional post-transcriptional regulator of gene expression.  Biochem Soc Trans. 2005;  33 499-501.
• 24 De Souza Pereira H, Leao-Ferreira L R, Moussatche N, Teixeira V L, Cavalcanti D N, Da Costa L J. et al . Effects of diterpenes isolated from the Brazilian marine alga Dictyota menstrualis on HIV-1 reverse transcriptase.  Planta Med. 2005;  71 1019-24.
• 25 Bettega J M, Teixeira H, Bassani V L, Barardi C R, Simoes C M. Evaluation of the antiherpetic activity of standardized extracts of Achyrocline satureioides .  Phytother Res. 2004;  18 819-23.