Structural characterization and antiviral activity of pectin isolated from Inga spp.

Several studies have been conducted on polysaccharides derived from natural sources, and their different biological properties have been reported. Their low toxicity and antiviral effects i.e., their action on several steps of viral replication, have been extensively examined. In this work, pectin isolated from Inga spp. fruit pulp was first characterized and evaluated using HEp-2 cells against the herpes simplex virus type 1 (HSV-1) and the poliovirus (PV). The isolated pectin (denoted as PDTS) was characterized by infrared spectroscopy, NMR and Gel permeation chromatography. The cytotoxicity was analyzed by the MTT method and antiviral activity by plaque reduction assay, immunofluorescence assay (IF) and polymerase chain reaction (PCR). The cytotoxic concentration (CC₅₀) of PDTS was 870 μg.mL^-1 and the inhibitory concentrations (IC₅₀) were 179 μg.mL^-1 and 58 μg.mL^-1 for HSV-1 and PV, respectively. Greater inhibitory effect was observed when the cells were simultaneously treated with PDTS and infected, suggesting that PDTS inhibited the initial viral replication stages, revealing its antiviral potential.