Phenolic Profiles and Antioxidant Potential of Nymphaea and Nelumbo Species: Botanical Authentication, Redox-Modulating Mechanisms, and Translational Perspectives

Natural products are important sources of redox-active phytochemicals, but meaningful interpretation of their biological effects requires accurate botanical and chemical characterization. The vernacular label “lotus” is applied to botanically distinct taxa belonging to the genera Nymphaea (Nymphaeaceae) and Nelumbo (Nelumbonaceae), despite their substantial taxonomic and phytochemical divergence. This review critically evaluates authenticated evidence on botanical identity, phenolic and alkaloid composition, antioxidant activity, redox-modulating mechanisms, translational relevance, and safety across selected species of both genera. Particular emphasis is placed on organ-specific phytochemical specialization, the contrasting distribution of flavonoids and benzylisoquinoline alkaloids, and the limitations of comparing antioxidant activity across heterogeneous extraction and assay systems. Available mechanistic studies implicate interconnected antioxidant-response, inflammatory, metabolic, autophagy, and glucose-handling pathways, but the evidence remains predominantly preclinical. Nelumbo nucifera is substantially better characterized than Nymphaea species, especially with respect to alkaloid chemistry, pharmacology, and toxicology, whereas evidence for Nymphaea remains more fragmented and species dependent. Botanical authentication, chemical standardization, pharmacokinetic characterization, and preparation-specific safety assessment are therefore essential for meaningful translation. Overall, the therapeutic potential of Nymphaea and Nelumbo is scientifically plausible, but current evidence is insufficient for broad clinical generalization or interchangeable use of materials marketed as “lotus”.