Study on Effects of Compounds from Clinacanthus Nutans on Dengue Virus Type 2 Infection

Dengue viruses classified into 4 serotypes (DV1, 2, 3 and 4) are etiological agents of dengue fever (DF) and dengue hemorrhagic fever (DHF) that are arthropod-borne diseases and cause a serious global health problem. There are no specific approved drugs or vaccines for the treatment or prevention of infectious DV and there are very few compounds known to inhibit the replication of this virus. Clinacanthus nutans Lindau has long been used in Thailand as a traditional medicine for the treatment of herpes simplex virus (HSV), and varicella-zoster virus (VZV). Four chlorophyll derivatives were isolated from the chloroform extract of Clinacanthus nutans Lindau leaves by means of chromatographic techniques to give four pure compounds. Structure elucidation of the isolated compounds was carried out on the basis of spectral analyses. These compounds were investigated for anti-DV2 activity in A459 infected cell. Thus, this study aimed to investigate anti-DV2 activity from 4 compounds of C. nutans inhibitory effects of these compounds on PGE2 production in DV2 infected cells by detection of PGE2 level and COX-2 expression in cell culture.It can be concluded that chlorophyll relative compound from C. nutans exhibited immunostimulating property in A549 cells at subcytotoxic level and decreased viral load bt inhibiting DV adsorption in pre-entry step of replication and suppressed PGE2 production as well as DV replication in the tested cells. This finding may be the starting point for further study in more detail of virus compound interaction to understand the inhibitory effect of these compounds on DV infection.