Antiviral and immunomodulatory effect of a lyophilized extract of Capparis spinosa L. buds

Herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) are common human pathogens that in particular cases can also cause severe problems especially in immunodeficient patients. The present paper reports the antiviral and immunomodulatory properties of a methanolic extract of C. spinosa buds (CAP), rich in flavonoids, including several quercetin and kaempferol glycosides. In particular we have investigated whether the in vitro exposure of human peripheral blood mononuclear cells (PBMCs) to CAP might inhibit the replication of HSV-2 and modulate the induction kinetics of IL-12, TNF-α IFN-γ. Our findings have shown that CAP treatment interferes with HSV-2 replication in PBMCs inhibiting the extracellular virus release upregulating their production of IL-12, IFN-γ and TNF-γ. One could speculate that CAP may contribute in improving immune surveillance of PBMCs toward virus infection by up-regulating expression of peculiar proinflammatory cytokines; it should thus be successfully employed for treatment of HSV-2 infections in immunocompromised hosts.