Integrating in vivo metabolism, pharmacokinetics, and dual-indicator scoring for PK-marker selection of Celosiae Semen saponins.
The study identified celosin I as the optimal pharmacokinetic marker for total saponins from Celosiae Semen, with significant effects observed in vitro and in a zebrafish model, but clinical relevance in humans remains unproven.
Where it sits
this study against the rest of the l-carnitine (levocarnitine) corpusSummary and findings
This study characterized the pharmacokinetics of total saponins from Celosiae Semen (TSCS) and evaluated their effects on lipid accumulation in vitro and in vivo. Five representative saponins were identified, with AUC₀-∞ values ranging from 40.95 to 359.05 μg·min/mL. The dual-indicator scoring model identified celosin I as the optimal PK-marker.
Abstract
The total saponins from Celosiae Semen (TSCS) show hepatoprotective and lipid-lowering effects against metabolic dysfunction-associated steatotic liver disease (MASLD). However, their in vivo metabolic fate and holistic pharmacokinetic (PK) features remain largely uncharacterized. In this study, an integrated PK-marker screening strategy was established by combining in vivo metabolic profiling, area under the curve (AUC)-weighted composite PK analysis, and a dual-indicator scoring model that weights both systemic exposure and in vitro lipid-lowering activity. A total of 25 saponins were characterized in TSCS by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS), and 107 TSCS-related substances (8 prototypes and 99 metabolites) were tentatively characterized in rats, with sequential deglucosylation tentatively characterized as the predominant metabolic pathway. Among the characterized saponins, five representative saponins (celosin J, H, I, K, and L) were selected for bioactivity evaluation and found to concentration-dependently reduced lipid accumulation in palmitic acid (PA)-induced HepG2 cells. Subsequently, a validated liquid chromatography coupled with triple quadrupole tandem mass spectrometry (LC-QQQ-MS/MS) method was developed for simultaneous plasma quantification of these five bioactive saponins, revealing marked exposure differences among them (AUC₀-∞: 40.95-359.05 μg·min/mL). An AUC‑weighted integration model was established to derive composite PK indices (T₁/₂ 428 min, Cₘₐₓ 1.24 μg/mL, AUC₀-∞ 215.45 μg·min/mL) that adequately reflect the holistic systemic behavior of TSCS. On the basis of systemic exposure and in vitro activity, the dual-indicator scoring model identified celosin I as the optimal PK-marker (score 0.910) and celosin H as a complementary marker (score 0.616). In a fructose-induced zebrafish MASLD model, both compounds dose-dependently reduced body length, body weight, hepatic lipid deposition, and hepatic total cholesterol (TC), triglyceride (TG), and free cholesterol (FC) levels and upregulated the expression of peroxisome proliferator-activated receptor α (PPARα), carnitine palmitoyltransferase 1α (CPT-1α), and acyl-CoA oxidase 1 (ACOX1), preliminarily supporting the in vivo relevance of the selected markers. This integrated strategy mitigates the limitations of single-indicator screening approaches and provides a scientific basis for the quality control and standardization of TSCS.
Background
This paper addresses the pharmacokinetic characteristics and metabolic fate of total saponins from Celosiae Semen (TSCS), which are known for their hepatoprotective and lipid-lowering effects. Prior research has indicated potential benefits of TSCS in metabolic dysfunction-associated steatotic liver disease (MASLD), but comprehensive metabolic profiling and pharmacokinetic data were lacking. Understanding these parameters is crucial for establishing effective dosing regimens and therapeutic applications.
Methods
The study employed an integrated pharmacokinetic marker screening strategy that combined in vivo metabolic profiling and area under the curve (AUC)-weighted composite PK analysis. A total of 25 saponins were characterized using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). The primary outcome measures included AUC, T₁/₂, and Cₘₐₓ values for the identified saponins, with secondary outcomes assessing lipid-lowering effects in HepG2 cells and a zebrafish MASLD model.
Results
The primary endpoint revealed an AUC₀-∞ range of 40.95-359.05 μg·min/mL for the five bioactive saponins. The composite pharmacokinetic indices were T₁/₂ 428 min, Cₘₐₓ 1.24 μg/mL, and AUC₀-∞ 215.45 μg·min/mL. The dual-indicator scoring model identified celosin I as the optimal PK-marker with a score of 0.910.
Interpretation
The findings provide a detailed characterization of the pharmacokinetics of TSCS, which is essential for future studies. While the results are statistically significant, the clinical relevance remains uncertain, particularly given the animal model used. The study's reliance on in vitro data for lipid-lowering effects may not fully translate to human physiology, indicating a need for further research.
Key findings
- AUC₀-∞: 40.95-359.05 μg·min/mL for the five bioactive saponins.
- T₁/₂ 428 min, Cₘₐₓ 1.24 μg/mL, AUC₀-∞ 215.45 μg·min/mL for TSCS.
- Celosin I identified as the optimal PK-marker with a score of 0.910.
- Celosin H identified as a complementary marker with a score of 0.616.
- In a zebrafish MASLD model, both compounds reduced body length, body weight, hepatic lipid deposition, and hepatic total cholesterol (TC), triglyceride (TG), and free cholesterol (FC) levels.
Limitations
- primarily animal model study, limited human relevance
- reliance on in vitro data for lipid-lowering effects
- short follow-up duration in animal studies
- potential confounding factors not fully addressed