Comparative Elemental Profiling and Differentiation Analysis of Lonicerae japonicae Flos and Lonicerae Flos Based on ICP-MS/AES and Chemometrics

Lonicerae japonicae flos (LJ), derived from Lonicera japonica Thunb., is a classic medicinal and edible plant traditionally used to clear heat, detoxify, and disperse wind-heat. It is widely consumed as a health tea or food additive and played a significant role during the COVID-19 pandemic. Its closely related species, Lonicerae flos (LFS), derived from L. macranthoides, L. hypoglauca, L. confusa, and L. fulvotomentosa, share similar functions. Distinguishing between these two is crucial to minimizing medication-related risks; however, studies on their differences in inorganic elements are currently insufficient. This study investigated the content differences in ten inorganic elements in 97 samples using inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. LJ exhibited significantly higher iron (Fe) content and considerably lower manganese (Mn) content than LFS. Fe, Mn and Na were identified as key discriminatory elements through orthogonal partial least squares-discriminant analysis, and cluster analysis based on the Fe/Mn ratio also achieved clear separation between the two groups. Network pharmacology and pathway enrichment analyses were subsequently conducted to explore the potential biological relevance of Fe- and Mn-associated differences. Additionally, molecular docking provided exploratory computational assessments of theoretical interactions between Fe/Mn and selected target proteins under simplified conditions. It is important to note that these computational results should not be interpreted as direct evidence of biological activity, since no in vitro or in vivo validation was performed. Overall, this study provides elemental profiling data to differentiate between LJ and LFS and highlights the potential value of the Fe/Mn ratio as a complementary chemical indicator for the authentication and quality evaluation of Lonicera medicinal materials.