Litsea Species as Potential Antiviral Plant Sources

• Published in: The American journal of Chinese medicine (1979) Vol. 44; no. 2; p. 275
• Main Authors: Guan, Yifu, Wang, Dongying, Tan, Ghee T, Van Hung, Nguyen, Cuong, Nguyen Manh, Pezzuto, John M, Fong, Harry H S, Soejarto, Djaja Doel, Zhang, Hongjie
• Format: Journal Article
• Language: English
• Published: Singapore 2016
• Subjects: Anti-HIV Agents; Cell Line; Dose-Response Relationship, Drug; HIV-1 - physiology; Humans; Lignans - isolation & purification; Lignans - pharmacology; Litsea - chemistry; Phytotherapy; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; Plant Extracts - toxicity; Sesquiterpenes - isolation & purification; Sesquiterpenes - pharmacology; Sesquiterpenes - therapeutic use; Sesquiterpenes - toxicity; Structure-Activity Relationship; Virus Replication - drug effects; Litseane; Litsea; Lauraceae; Sesquiterpene Butenolide; Anti-HIV Activity; Antiviral Activity; Structure Determination
• ISSN: 0192-415X
• DOI: 10.1142/S0192415X16500166

Litsea verticillata Hance (Lauraceae), a Chinese medicine used to treat swelling caused by injury or by snake bites, was the first plant identified by our National Institutes of Health (NIH)-funded International Cooperative Biodiversity Group (ICBG) project to exhibit anti-HIV activities. From this plant, we discovered a class of 8 novel litseane compounds, prototypic sesquiterpenes, all of which demonstrated anti-HIV activities. In subsequent studies, 26 additional compounds of different structural types were identified. During our continuing investigation of this plant species, we identified two new litseanes, litseaverticillols L and M, and a new sesquiterpene butenolide, litseasesquibutenolide. Litseaverticillols L and M were found to inhibit HIV-1 replication, with an IC[Formula: see text] value of 49.6[Formula: see text][Formula: see text]M. To further determine the antiviral properties of this plant, several relatively abundant isolates, including a litseane compound, two eudesmane sesquiterpenes and three lignans, were evaluated against an additional 21 viral targets. Lignans 8 and 9 were shown to be active against the Epstein-Barr Virus (EBV), with EC[Formula: see text] values of 22.0[Formula: see text][Formula: see text]M ([Formula: see text]) and 16.2[Formula: see text][Formula: see text]M ([Formula: see text]), respectively. Since many antiviral compounds have been discovered in L. verticillata, we further prepared 38 plant extracts made from the different plant parts of 9 additional Litsea species. These extracts were evaluated for their anti-HIV and cytotoxic activities, and four of the extracts, which ranged across three different species, displayed 97-100% inhibitory effects against HIV replication without showing cytotoxicity to a panel of human cell lines at a concentration of 20 μg/mL.