Anti HSV-1 activity of sulphoquinovosyl diacylglycerol isolated from Spirulina platensis

Herpes simplex virus type 1 (HSV-1) causes a variety of infections in humans and can be found in many countries worldwide. Although the antiherpes drug, acyclovir, has been used very successfully, an acyclovir-resistant strain of HSV has recently been found in patients and drug toxicity has been reported with increasing use of it. As a potential alternative, it has been found that both a water soluble and a lipid extract of the microalga Spirulina platensis exhibit antiviral activity (HSV-1) in Vero cells. In this study, bioassay guided fractionation of a lipid extract from S. platensis led to the identification of sulphoquinovosyl diacylglycerol as the active antiviral agent. The chemical structure of this compound was confirmed by NMR and LC-mass spectroscopic analyses. Results from the study showed that the compound exhibited a remarkable activity against HSV-1 with an IC50 value of 6.8 mu g/ml, which was comparable to that of acyclovir (1.5 mu g/ml).