Anti‐Herpes Simplex Virus Type 1 Activity Evaluation of Natural Derived Phloroglucinol Derivatives and Their Molecular Mechanisms Study

Abstract HSV‐1 is a common infection that can cause cold sores. In this study, the anti‐HSV‐1 virus activity of three series compounds A1 – A9 , B1 – B12 , C1 – C22 was screened by MTT assay, qRT‐PCR assay, Western blot assay and viruses’ plaque assays. The results of MTT assay disclosed that phloroglucinol derivatives C2 and C3 effectively inhibited the death of HSV‐1 infected vero cells with the CC 50 values of C2 and C3 were 72.64 μmol/L and 32.62 μmol/L in HaCaT cells, 137.6 μmol/L and 48.55 μmol/L in Hela cells. The IC 50 values of C3 in vero cells and Hela cells were 19.26 μmol/L and 22.98 μmol/L, respectively. In the qRT‐PCR experiments, it showed that C2 and C3 effectively reduced the synthesis of HSV‐1 early viral gene VP16 and late viral gene gD. The Western blot results showed that both C2 and C3 inhibited the expression of HSV‐1 gD protein in a concentration‐dependent manner. Lastly, viruses’ plaque assay results showed that C2 and C3 inhibited the production of HSV‐1 progeny virus in Hela cells and HaCaT cells in a concentration‐dependent manner. Taken together, these results suggest that C2 and C3 are promising candidate that warrants further attention in the development of anti‐HSV‐1 drugs.