MEDICINAL PLANTS AS TOOLS TO CURB ANTIVIRAL RESISTANCE: A NARRATIVE REVIEW

Antiviral resistance is a predictable consequence of viral replication under drug pressure, especially when treatment is prolonged, viral load is high, adherence is incomplete, or the antiviral target tolerates escape mutations. The problem is clinically visible across HIV, influenza, herpesviruses, hepatitis viruses, cytomegalovirus, and emerging viral infections. Medicinal plants are not replacements for validated antivirals, vaccines, diagnostics, or infection-control measures. Their more realistic value is as a source of chemically diverse leads, standardized botanical products, host-directed adjuncts, and combination partners that can widen antiviral target space and reduce reliance on single viral enzymes. Plant-derived polyphenols, flavonoids, terpenoids, alkaloids, lectins, and polysaccharides have shown preclinical activity at viral entry, fusion, polymerase/protease function, neuraminidase activity, virion release, and inflammatory host pathways. However, most data remain in vitro or in silico; pharmacokinetics, toxicity, reproducibility, and clinical efficacy are often insufficiently established. A Lancet-standard research agenda should therefore prioritize authenticated plant materials, orthogonal antiviral assays, resistance-passage experiments, pharmacokinetic/pharmacodynamic modelling, herb-drug interaction studies, and randomized trials of standardized preparations only when preclinical thresholds are met. Medicinal plants can help curb antiviral resistance only if developed under the same evidence, quality, stewardship, and safety standards applied to conventional medicines. Search strategy and selection criteria This narrative review was developed from searches of PubMed/MEDLINE, Google Scholar, WHO, CDC, FDA, EMA, and publisher databases for English-language articles and guidance published from Jan 1, 2000, to May 8, 2026. Search terms included “antiviral resistance”, “HIV drug resistance”, “influenza antiviral resistance”, “medicinal plants antiviral”, “plant-derived antiviral”, “phytochemicals antiviral”, “natural products drug discovery”, “host-directed antivirals”, “baicalin oseltamivir-resistant”, “sinecatechins HPV”, “banana lectin HIV influenza”, “herb-drug interaction antiretroviral”, and “herbal medicine quality control”. Priority was given to WHO/CDC/FDA/EMA sources, peer-reviewed reviews in high-impact biomedical journals, PubMed-indexed mechanistic and preclinical studies, and clinical trials or regulatory documents for standardized botanical products. In-silico-only studies were used sparingly and not treated as clinical evidence. The review is narrative rather than systematic; therefore, no formal risk-of-bias scoring or meta-analysis was performed. Research in context Evidence before this review: Antiviral resistance is documented across major viral infections, while medicinal plants and natural products have repeatedly yielded antiviral signals in preclinical research. However, clinical translation remains limited and uneven. Added value of this review: This review reframes medicinal plants specifically as resistance-curbing tools: lead sources, adjuncts, entry inhibitors, host-directed agents, and standardized botanical products, rather than as general alternatives to antivirals. Implications of all the available evidence: Future work should prioritize resistance endpoints, pharmacokinetic plausibility, herb-drug interaction testing, quality control, and stewardship-compatible indications before clinical claims are made.