In Vitro Evaluation of Secoiridoid Glucosides from the Fruits of Ligustrum lucidum as Antiviral Agents.

TLDR

The study aimed to determine whether the antioxidant activity of Ligustrum lucidum glucosides correlates with their antiviral potency. Six secoiridoid glucosides isolated from Ligustrum lucidum fruits were tested in vitro against HSV‑1, influenza A, RSV, and parainfluenza 3 using a cytopathic effect inhibition assay. None of the compounds inhibited HSV‑1 or influenza A, but oleuropein showed strong activity against RSV and parainfluenza 3 (IC₅₀ ≈ 23 µg/ml and 12 µg/ml), while other glucosides displayed moderate activity against parainfluenza 3; antioxidant potency did not predict antiviral effects.

Abstract

Six secoiridoid glucosides, lucidumoside C (1), oleoside dimethylester (2), neonuezhenide (3), oleuropein (4), ligustroside (5) and lucidumoside A (6), isolated from the fruits of Ligustrum lucidum (Oleaceae), were examined in vitro for their activities against four strains of pathogenic viruses, namely herpes simplex type 1 virus (HSV-1), influenza type A virus (Flu A), respiratory syncytial virus (RSV) and parainfluenza type 3 virus (Para 3). Antiviral activities were evaluated by the cytopathic effect (CPE) inhibitory assay. The purpose was to check if the antioxidative potency of these glucosides correlated with their antiviral potency. Results showed that none of the glucosides had any significant activity against HSV-1 and Flu A. Oleuropein, however, showed significant antiviral activities against RSV and Para 3 with IC50 value of 23.4 and 11.7 μg/ml, respectively. Lucidumoside C, oleoside dimethylester and ligustroside showed potent or moderate antiviral activities against Para 3 with IC50 values of 15.6-20.8 μg/ml. These results also documented that the anti-oxidative potency of these secoiriodoid glucosides was not directly related to their antiviral effects.