<i>Convallaria majalis</i> (Lily of the Valley): A review of its cardiac glycosides, medicinal applications, and safety profile

Convallaria majalis (Lily of the Valley) is a perennial flowering plant historically used in traditional medicine, especially for cardiovascular conditions such as heart weakness, tachycardia, and arrhythmias. Its therapeutic effects were primarily attributed to its high content of cardiac glycosides, particularly convallatoxin, which enhance cardiac contractility. However, the plant’s narrow therapeutic index presents significant toxicity risks. All parts—especially the berries and roots—are poisonous, and ingestion can result in nausea, vomiting, diarrhea. Despite its toxicity, modern research highlights the pharmacological potential of C. majalis. Convallatoxin has demonstrated anticancer effects, including inhibition of cell proliferation, induction of apoptosis, and suppression of angiogenesis in various cancers such as breast and colorectal, often independently of p53 status. Additionally, certain glycosides and flavonoids from the plant show neuroprotective and anticonvulsant properties, likely through modulation of GABAergic activity. C. majalis also exhibits notable antioxidant, anti-inflammatory, and diuretic properties, suggesting possible roles in managing chronic inflammation, oxidative stress, and fluid retention. However, the plant’s cytotoxic constituents, including specific saponins and steroidal glycosides, raise safety concerns that limit its clinical use. While topical or dermatological applications are occasionally proposed, the high toxicity of C. majalis warrants extreme caution. This review underscores the dual nature of C. majalis—a plant of considerable medicinal promise but also significant toxicological risk—highlighting the importance of further research to safely harness its bioactive compounds. Novelty of the Study: This review uniquely integrates traditional medicinal uses of Convallaria majalis with recent pharmacological and molecular research, highlighting its cardiotonic glycosides not only in cardiovascular applications but also in emerging areas such as oncology and neuroprotection. It also discusses advancements in molecular identification techniques to prevent toxic misidentification, providing a comprehensive and modernized framework for the safe and therapeutic use of C. majalis. Keywords: Convallaria majalis, cardiac glycosides, convallatoxins, neuroprotection, anticancer activity, traditional medicine, functional phytochemicals