Anais do Congresso Paranaense de Microbiologia
Anais do III Congresso Paranaense de Microbiologia

The poliovirus, belonging to family Picornaviridae and genus Enterovirus, cause infections in human, such as poliomyelitis, disease that can severely reach the central nervous system, resulting in flaccid paralysis. This virus is composed of single-stranded RNA with positive polarity, surrounded by icosahedral capsid, but without a lipid envelope. In Brazil, such as poliomyelitis is controlled, the vaccination program was changed in August 2012, for administration of 2 doses of oral attenuated virus vaccine (OPV) and 2 doses of intramuscularly inactivated virus vaccine (IPV), in order to minimize the risk of paralysis associated with the vaccine. Although poliomyelitis is controlled in most countries, cases of the disease have been reported in Afghanistan, Pakistan, Democratic Republic of the Congo, Nigeria and Syrian Arab Republic with 22 cases of poliomyelitis from wild virus and 96 cases from vaccine virus, in the year 2017. Thus, in addition to epidemiological importance, this virus is also used for study of new antiviral agents. Natural products have been presented as a very rich source for production of new drugs, due to low toxicity, chemical diversity and possibility of acting in diverse biological target. The objective of this study was to evaluate the antiviral effect of pectin isolated from Inga spp. (PDT-S) in HEp-2 cells. The cytotoxicity of PDT-S was analyzed by colorimetric method of MTT and the antiviral activity by plaque reduction assay, using different treatment protocols (1 and 2 h before infection, at the time of infection (0h), 1 and 2 h after infection, virucidal, inhibition of adsorption and penetration) and immunofluorescence (IFI). The PDT-S presented a cytotoxic concentration of 50% (CC50) of 870 µg/mL, a inhibitory concentration of 50% (IC50) of 58 µg/mL and a selectivity index (CC50/IC50) of 15. In the highest concentration tested, 100 µg/mL, significant results were also found in adsorption inhibition test and in treatment 1 h after infection, with percentages of viral inhibition of 59.4% and 46.9%, respectively. These results suggest that PDT-S interferes in early stages of viral replication, which can also be seen by reduction of fluorescent cells in IFI, with viral inhibition of 85.71% in the highest concentration used (100 µg/mL). In conclusion, we suggest that PDT-S is a compound with promising antiviral activity for development of new antiviral drugs.