New antiherpetic nucleoside from a Basidiomycete

Review of Whole Plant Extracts With Activity Against Herpes Simplex Viruses In Vitro and In Vivo

Herpes simplex viruses, HSV-1 and HSV-2, are highly contagious and cause lifelong, latent infections with recurrent outbreaks of oral and/or genital lesions. No cure exists for HSV-1 or HSV-2 infections, but antiviral medications are commonly used to prevent and treat outbreaks. Resistance to antivirals has begun to emerge, placing an importance on finding new and effective therapies for prophylaxis and treatment of HSV outbreaks. Botanicals may be effective HSV therapies as the constituents they contain act through a variety of mechanisms, potentially making the development of antiviral resistance more challenging. A wide variety of plants from different regions in the world have been studied for antiviral activity against HSV-1 and/or HSV-2 and showed efficacy of varying degrees. The purpose of this review is to summarize research conducted on whole plant extracts against HSV-1 and/or HSV-2 in vitro and in vivo. The majority of the research reviewed was conducted in vitro using animal cell lines, and some studies used an animal model design. Also summarized are a limited number of human trials conducted using botanical therapies on HSV lesions.

Antiviral Agents From Fungi: Diversity, Mechanisms and Potential Applications

Viral infections are amongst the most common diseases affecting people worldwide. New viruses emerge all the time and presently we have limited number of vaccines and only few antivirals to combat viral diseases. Fungi represent a vast source of bioactive molecules, which could potentially be used as antivirals in the future. Here, we have summarized the current knowledge of fungi as producers of antiviral compounds and discuss their potential applications. In particular, we have investigated how the antiviral action has been assessed and what is known about the molecular mechanisms and actual targets. Furthermore, we highlight the importance of accurate fungal species identification on antiviral and other natural products studies.

Antiviral Agents From Fungi: Diversity, Mechanisms and Potential Applications

Viral infections are amongst the most common diseases affecting people worldwide. New viruses emerge all the time and presently we have limited number of vaccines and only few antivirals to combat viral diseases. Fungi represent a vast source of bioactive molecules, which could potentially be used as antivirals in the future. Here, we have summarized the current knowledge of fungi as producers of antiviral compounds and discuss their potential applications. In particular, we have investigated how the antiviral action has been assessed and what is known about the molecular mechanisms and actual targets. Furthermore, we highlight the importance of accurate fungal species identification on antiviral and other natural products studies.

In Vivo Antitumor Activity of Clitocine, an Exocyclic Amino Nucleoside Isolated fromLepista inversa

A biologically guided fractionation from Lepista inversa (Scop.: Fr.) led to the isolation of clitocine, an exocyclic amino nucleoside. This compound and two mixtures of beta/alpha anomers (mixture A, 40:60 and mixture B, 80:20) were synthesized or isolated depending on the purification procedure. The beta anomer and clitocine mixtures A and B showed similar cytotoxic activities with IC50 values ranging from 20.5 to 42 nM in murine cancer cell lines (3LL and L1210) and from 185 to 578 nM in human cancer cell lines (DU145, K-562, MCF7, and U251). An in vivo study of mixture B was carried out on 3LL- and L1210-tumor-bearing mice. Clitocine solubilized in beta-hydroxypropylcyclodextrin and injected at concentrations of 0.5, 3, and 5 mg kg-1 did not significantly increase the survival rate and lifespan of 3LL-tumor-bearing mice. In contrast, clitocine showed antitumor activity on L1210-tumor-bearing mice with a significant increase in lifespan and a decrease in the development of ascites observed at 3 mg kg-1. The induction of apoptosis may be the basis of the antitumor activity of clitocine against L1210 as suggested by flow-cytometry analysis of cells treated in vitro.