A synergestic herbal preparation of extracts of Picrorhiza Kurroa Royle or its close species of the same family such as Picrorhiza Scrophulariflora Pennel and Neopicrorhiza Scrophulariiflora and Gllycyrrhiza Glabra having medicinal values and Antiviral and Immune boosting activity against DNA virus-bacteriophage pi AT 300 �g/ml and plaque reduction assay