Antimicrobial properties of essential oils extracted from plants of the Asteraceae family against Herpes Simplex Viruses (HSV-1, HSV-2): a systematic review

Aim. To study the antimicrobial properties of essential oils extracted from plants of the Asteraceae family against Herpes Simplex Viruses type 1 and 2 (HSV-1, HSV-2). Methods. A systematic literature review was carried out in seven online repositories (ISI Web of Science, PubMed, EMBASE, Scopus, Google Scholar, CINAHL and Cochrane Library) to retrieve all relevant human and laboratory studies. All databases were screened up to May 1st, 2020. Results. After database search, 11 studies were included in this review. Retrieved evidence exclusively derived from in vitro studies conducted in laboratory models of Vero (or similar) cell lines infected with HSV-1 or HSV-2. Analyzed essential oils were obtained from Artemisia arborescens, Artemisia douglasiana, Artemisia kermanensis, Chrysanthemum trifurcatum, Eupatorium arnottianum, Eupatorium catarium, Matricaria recutita, Pulicaria vulgaris and Santolina insularis. While for Chrysanthemum trifurcatum no significant antiviral effect was detected, an inhibitory action against HSV-1 or HSV-2 was demonstrated for the other oils. The majority of antiviral effects were attributed to a direct inactivation of free virions and to the inhibition of viral penetration into host cells. Nevertheless, intracellular mechanisms of action were not fully excluded, especially for Santolina insularis. Oils obtained from Matricaria recutita and Santolina insularis also had a high Selectivity Index, thus theoretically outlining a quite safe profile for their potential uses in vivo. Discussion. Essential oils extracted from different plants of the Asteraceae family exhibit a significant antimicrobial activity against HSV-1 and HSV-2. In particular, the majority of retrieved evidence, based on in vitro studies, supports the efficacy of Artemisia spp., Matricaria recutita and Santolina insularis. Further studies on the topic are advised.