Anti-Respiratory Syncytial Virus Agents from Phytomedicine

Abstract

Although the global importance of RSV as a respiratory pathogen has been recognized for over 40 years, suitable prophylactic and therapeutic interventions have not been truly available. Vaccine development, unfortunately, has been fraught with spectacular failure and with difficult obstacles, and there are only limited therapeutic options for treatment of this disease. Currently, the only approved prophylactic options available involve the use of Palivizumab and its derivative Motivizumab (currently under trial) which are both monoclonal antibodies directed against RSV surface fusion protein. Ribavirin, a broadspectrum anti-viral agent, is the only therapeutic option employed as adjunctive therapy for the sickest patients; however, its efficacy has been called into question by multiple studies, and most institutions no longer use it. Moreover, the use of both agents has been shown to be costly and difficult to handle. Therefore, the search for novel anti-viral inhibitors of RSV has become more intensive. It could be recalled that potent anti-viral agents have previously been harnessed from medicinal plants. Since medicinal plants have consistently served as suitable lead sources for potent anti-viral agents, efforts have also been made by several investigators in developing anti-RSV compounds from phytomedicine. In this present research paper, we present a review of the past to present activities involving the discovery and development of novel and effective anti-RSV compounds from phytomedicine. First, we begin by briefly describing the problem of the global disease burden of RSV as well as efforts and approaches so far adopted to contain the viral menace. In the next section we introduce the subject of phytomedicine and anti-RSV therapeutic products originating from various reported medicinal plants. Straightforward and discreet description is made of investigations carried out by our workgroup in our attempt to develop anti-RSV compounds from medicinal plants especially Ramalina farinaceae and Aglaia ignea. Here also in this section, we present and discuss published results from other investigators regarding compounds from other medicinal plant sources. The importance of the process and techniques leading to their identification and isolation is highlighted. Attention is drawn to