Valorization of the industrial waste of two uncommon parts from lotus (Nelumbo nucifera Gaertn.): Insight to phytochemicals and hypolipidemic potential

Two uncommon lotus (Nelumbo nucifera Gaertn.) parts comprising petiole and seedpod are usually discarded as waste materials or byproducts due to the poorly in-depth acquaintance of their phytochemical characterizations and pharmacological properties. Untargeted metabolomic annotation, based on molecular networking, was creatively applied to characterize the metabolites of these two adjacent parts individually. The hypolipidemic activities of lotus petiole and seedpod were innovatively evaluated by measuring the lipid accumulation in palmitic acid-elicited HepG2 cells. A total of 107 components with phenols and alkaloids being the abundant classes were tentatively identified. Intriguingly, aforementioned two unfamiliar parts share the broadly similar metabolic profiling with lotus leaf, which regarded as a common material with hypolipidemic effect. Additionally, both petiole and seedpod significantly ameliorated the lipogenesis in a concentration-dependent manner, suggesting they are potential sources for hypolipidemic ingredients. Twelve representative compounds were screened for contributing the major hypolipidemic activity by modeling using random forest approaches. The systematically compositional information along with activity evaluation of lotus petiole and seedpod could be conducive to refrain from the status of waste for reasonable medicinal and/or industrial applications.