Multi-target mechanisms underlying the antiviral and anti-inflammatory activities of tobacco-derived natural small molecules.

Tobacco (Nicotiana tabacum L.) is widely cultivated worldwide and is traditionally associated with adverse health effects due to cigarette consumption. However, from a phytochemical and pharmacological perspective, tobacco plants represent a rich yet underexplored reservoir of bioactive natural small molecules. Phytochemical investigations have identified more than 2,500 specialized metabolites in tobacco, including alkaloids, terpenoids, phenolic acids, and flavonoids, many of which exhibit antiviral and anti-inflammatory activities. Conventional antiviral drug development has largely followed a "one drug-one target" strategy, which is often limited by viral mutation, drug resistance, and inadequate control of virus-induced inflammation. In contrast, increasing evidence indicates that tobacco-derived natural small molecules act through multi-target and multi-stage mechanisms. These compounds can directly interfere with key steps of the viral life cycle, such as viral entry and replication, while simultaneously modulating host immune and inflammatory responses by regulating cytokine production, signaling pathways, and oxidative stress. This review summarizes the major classes of tobacco natural products with antiviral and anti-inflammatory activities, discusses their underlying mechanisms, and highlights their potential as multi-target anti-infective agents.