Comparison of main chemical composition of Plantago asiatica L. and P. depressa Willd. seed extracts and their anti-obesity effects in high-fat diet-induced obese mice

Background: Nowadays, the pharmacological effects of Plantaginis semen was getting more and more attention because of the great effect of treating diuresis, hypertension, hyperlipidemia, and hyperglycemia. According to the Chinese Pharmacopoeia, Plantaginis semen is the seed of Plantago asiatica L. or P. depressa Willd. This was verified by examining chemical composition differences in a preliminary experiment, predicting their differences in pharmacology. Purpose: In this study, we aimed to compared the the differences in main components and anti-obesity effects of Plantago asiatica L. seed extract (PASE) and P. depressa Willd. seed extract (PDSE). Study design and methods: The ultra-performance liquid chromatography mass spectrometry (UPLC-MS) analysis was used to characterize and compare the differences chemical constituents of PASE and PDSE. The difference therapeutic effects between PASE and PDSE on obesity and associated metabolic disorders was investigated by high-fat (HF) diet induced mice model. Results: The fingerprint of Plantaginis semen were established by screening and identified 15 main components, including iridoids, phenethanol glycosides, flavonoids, guanidines, and fatty acids. Pentahydroxy flavanone was observed only in PDSE but not in PASE. The quantitative analysis results indicated that the main bioactive components in PASE were geniposidic acid and acteoside; their concentrations were three times higher in PASE than in PDSE. In anti-obesity effects, the result show the levels of fasting blood glucose were improved in both PASE and PDSE when compared with the HF group, while the PASE is show a significant effect then the PDSE group and improved the glucose tolerance but not in PDSE. The results also displayed that the Plantaginis semen did not modify food intake or body weight but decreased abdominal white/brown adipocyte size, serum total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-c), hepatic TG and TC, fecal TG and TC concentrations when compared with the HF group. Among these indicators, serum TG, liver TG, fecal TC and TG levels were significantly improved in PASE compared with PDSE. The results indicated that PASE treatment more effectively improved lipid and glucose metabolism in HF diet-induced obese mice than did PDSE. Conclusion: As Plantaginis semen sources, P. asiatica L. seeds demonstrated more bioactive components and favorable metabolic disorder treatment outcomes than did P. depressa Willd. seeds.