Inhibitory Action of Natural Carrageenans on Herpes simplex Virus Infection of Mouse Astrocytes

Abstract

The effects of the carrageenans 1T1 (λ-type), 1C1 (κ/ι-type) and 1C3 (ιι/ν-type), isolated from the red seaweed Gigartina skottsbergii, on herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infection of murine astrocytes were investigated. The three compounds were effective inhibitors of virus replication, as determined by a virus yield inhibition assay, in astrocytes as well as in Vero cells. The 50% inhibitory concentration was in the range of 0.9–3.6 and 0.4–3.2 μg/ml for astrocytes and Vero cells, respectively, whereas the 90% inhibitory concentration ranged from 6.5 to 17.0 μg/ml in astrocytes and from 3.5 to 22.2 μg/ml in Vero cells. No cytotoxicity was detected at concentrations of up to 1,000 μg/ml, indicating high selectivity indices for these compounds. Inhibition of viral cytopathology and antigen expression was also detected in the presence of the carrageenans. The increase in the expression of glial fibrillary acidic protein (GFAP), an activated astrocyte marker, produced during the course of HSV-1 infection in astrocytes, was reversed in the presence of 1C1 and 1C3. By contrast, the λ-carrageenan 1T1 increased the expression of GFAP, independently of HSV-1 infection.

Carrageenan: a review

“…Carrageenan is a selective inhibitor of several enveloped viruses, including such human pathogens as human immunodeficiency virus, herpes simplex virus (HSV), human cytomegalovirus, human rhinoviruses and others (Girond et al 1991;Marchetti et al 1995;Carlucci et al 1999;Caceres et al 2000;Zacharopoulos and Phillips 1997;Stiles et al 2008). Carrageenan acts primarily by preventing the binding or the entry of virions into cells (Buck et al 2006, Grassauer et al 2008).…”

Identification of Natural Compounds with Anti-Hepatitis B Virus Activity from <i>Rheum palmatum</i> L. Ethanol Extract

“…All measurements were carried out using six separate wells for each treatment. The concentration of the agent that reduced cell viability to 50% (CC 50 ) was calculated [21,22] .…”

Herpes simplex virus: Drug resistance and new treatment options using natural products (Review)

“…Several sulfated polysaccharides have been shown to possess anti-HSV activity, and many carrageenans (found mostly in red seaweed) have been shown to be active against HSV infections. Several in vitro studies have demonstrated IC 50 values of 0.4-5.6 μg/ml for different types of carrageenans (46)(47)(48), and several in vivo mouse models have also confirmed their effectiveness. In models of intravaginal HSV-2 infection, mice exhibited signs of significant protection (30,48), and were also protected from intraperitoneal infection when carrageenan was administered immediately after infection.…”