The Combination of Dimorphandra gardneriana Galactomannan and Mangiferin Inhibits Herpes Simplex and Poliovirus

Background: Herpes simplex virus (HSV) and poliovirus (PV) are both agents of major concern in the public health system. It has been shown that Dimorphandra gardneriana galactomannans can be used as solubilizer vehicles in medicine manufacture. Mangiferin is the major constituent of Mangifera indica and presents multiple medicinal and biological activities. Objective: This study assayed the effect of D. gardneriana galactomannan combined with mangiferin (DgGmM) against HSV-1 and PV-1. Methods: The DgGmM cytotoxicity was evaluated by the colorimetric MTT method and the antiviral activity by plaque reduction assay, immunofluorescence and polymerase chain reaction (PCR), in HEp-2 cells. Results: The DgGmM showed a 50% cytotoxic concentration (CC50) > 2000 mu g/mL. The 50% inhibitory concentrations (IC50) for HSV-1 and PV-1 were, respectively, 287.5 mu g/mL and 206.2 mu g/mL, with selectivity indexes (SI) > 6.95 for the former and > 9.69 for the latter. The DgGmM time-of-addition protocol for HSV-1 showed a maximum inhibition at 500 mu g/mL, when added concomitantly to infection and at the time 1 h post-infection (pi). While for PV-1, for the same protocol, the greatest inhibition, was also observed concomitantly to infection at 500 mu g/mL and at the times 4 h and 8 h pi. The inhibition was also demonstrated by the decrease of fluorescent cells and/or the inhibition of specific viral genome. Conclusion: These results suggested that the DgGmM inhibited HSV-1 and PV-1 replication, with low cytotoxicity and high selectivity and, therefore, represents a potential candidate for further studies on the control of herpes and polio infections.