Journal Article

Cell Extracts Derived from Cypress and Cedar Show Antiviral Activity against Enveloped Viruses

Itoh, Yuki, Sei, Kazunari, Hatta, Takeshi, Kawanishi, Katsuki, Amarasiri, Mohan, Furukawa, Takashi, Moroishi, Suzuha, Maehana, Shotaro, Inagaki, Ayumu

2024

Overview

The antiviral efficacy of cell-extracts (CEs) derived from cypress (Chamaecyparis obtusa (Siebold & Zucc.) Endl., C. obtusa) and cedar (Cryptomeria japonica (Thunb. ex. L.) D.Don, C. japonica) was assessed using phi6 and MS2 bacteriophages, which are widely accepted surrogate models for enveloped and non-enveloped viruses, in order to verify their potential use as antiviral agents. Our results indicate that CEs derived from C. obtusa are dominantly composed of terpinen-4-ol (18.0%), α-terpinyl acetate (10.1%), bornyl acetate (9.7%), limonene (7.1%), and γ-terpinene (6.7%), while CEs derived from C. japonica are dominantly composed of terpinen-4-ol (48.0%) and α-pinene (15.9%), which exhibited robust antiviral activity against phi6 bacteriophage. Both CEs successfully inactivated the phi6 bacteriophage below the detection limit (10 PFU/mL) within a short exposure time of 30 s (log reduction value, LRV > 4). Through exposure experiments utilizing CEs with content ratios prepared via 2-fold serial dilutions (ranging from 3.13% to 100%), we demonstrated that the antiviral effect could be sustained up to a concentration of 25% (C. obtusa LRV = 3.8, C. japonica LRV > 4.3 at a 25% CE content ratio for each species). However, CEs with content ratios below 12.5% did not produce a significant reduction in bacteriophage concentration and consequently lost their antiviral effects. Conversely, both CEs did not exhibit antiviral activity against MS2 bacteriophage, a non-enveloped virus. Our findings reveal for the first time the potential of CEs derived from C. obtusa and C. japonica for use as antiviral agents specifically targeting enveloped viruses.

• Publisher: MDPI AG,MDPI
• Subject: Acetic acid / Antiviral activity / Antiviral agents / antiviral properties / bacteriophages / Biological products / Bornyl acetate / Cellulose acetate / Chamaecyparis obtusa / cold vacuum extraction / Communication / Cryptomeria japonica / detection limit / E coli / Esters / Experiments / exposure duration / Forests / Leaves / Limonene / Phages / plant-derived cell extract / Ratios / Sesquiterpenes / species / Statistical analysis / Temperature / Terpinene / Terpinyl acetate / Viruses / α-Pinene