Candidate bioactive flavonoids and an optimized combination from Abelmoschus manihot (L.) flower with effects on high-glucose-associated and renal injury phenotypes in zebrafish.
Abstract
Abelmoschus manihot (L.) Medik. (AM) is traditionally used for kidney-related disorders, with its flower listed as the medicinal part in the Chinese Pharmacopoeia. However, the pharmacological basis underlying the preferential use of the flower in conditions involving glucose dysregulation and renal injury remains unclear. In this study, different AM parts and solvent extracts were evaluated in independent zebrafish models of high-glucose-associated metabolic disturbance and renal injury. HPLC fingerprinting, spectrum-effect analysis, independent pharmacological evaluation, uniform design, network pharmacology, molecular docking, and qRT-PCR were integrated to identify candidate bioactive constituents, optimize their combination, and explore potential mechanisms. Among the tested parts, AM flowers (AMF) showed the most pronounced and consistent effects on high-glucose-associated and renal injury phenotypes, with the 95% ethanol extract of AMF (AMF-95) being the most effective preparation. AMF-95 enhanced 2-NBDG uptake, reduced glucose, creatinine, and kidney injury molecule-1 levels, relieved renal edema, and improved renal histopathology. Spectrum-effect analysis revealed strong associations between eight major flavonoids, and the measured pharmacological effects, and independent pharmacological evaluation supported their bioactivity, supporting their selection as a candidate bioactive flavonoid group. An optimized constituent combination, designated combination No. 6, showed the best performance and effects comparable to those of AMF-95 under the tested experimental conditions. Network pharmacology and molecular docking predicted potential involvement of inflammation, insulin resistance, AGE-RAGE, and MAPK-related processes, with preliminary transcriptional support from whole-larvae qRT-PCR. These findings support AMF as the preferential medicinal part for high-glucose-associated and renal injury phenotypes and provide candidate flavonoids and an optimized combination for further investigation.