Screening and identifying cucurbitacins and cucurbitacin glycosides in Cucumis sativus using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry combined with in-source fragmentation and alkali adduct ions.

RATIONALE: Cucumber, as a popular fruit and vegetable, has tremendously contributed to providing a sufficient and high-quality food supply. However, the cucumber plant metabolites, which may possess potential benefits for human health, were rarely reported. In addition, rapid detection of these metabolites from the complex biological matrix of cucumber samples is a tremendous challenge. METHODS: A rapid detection method was established to systematically screen cucurbitacins and cucurbitacin glycosides in cucumber plants by combining high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC-Q-TOF-MS) with in-source fragmentation (ISF). Moreover, the alkali cations, including acetic acid, 0.1% LiCl, 0.1% NH4 Cl, 0.1% NaCl, and 0.1% KCl, were added to the mobile phase for improving the ion response. RESULTS: The fragmentation pathways of seven cucurbitacins and cucurbitacin glycosides were primarily investigated. The characteristic ISF ions at m/z 501.3211 and 503.3367 were identified and employed to screen 40 cucurbitacins and cucurbitacin glycosides from the complex biological matrix. Their structures were identified by their tandem mass spectrometry (MS/MS) spectra and fragmentation pathways of references. Finally, the metabolic distribution and network of cucurbitacins and cucurbitacin glycosides in cucumber plants were also proposed. CONCLUSIONS: This work marks the first systematic and comprehensive study of the metabolites in cucumber plants using HPLC-Q-TOF-MS technology, providing a template for screening and identifying the triterpenoids from other plant-derived medicines or food.

LC-MS Metabolite Profiling and the Hypoglycemic Activity of Morus alba L. Extracts.

Morus alba L. is used in traditional Chinese medicine for its anti-diabetic activity; however, the part of the hypoglycemic activity and related active metabolites are still not fully clarified. In this study, the metabolites in the M. alba roots, leaves, twigs, and fruits extracts (70% ethanol extracts) were systematically identified, and their hypoglycemic activity was evaluated by the high-fat diet/streptozotocin-induced 2 diabetes mellitus (T2D) mouse model. A total of 60 high-level compounds, including 16 polyphenols, 43 flavonoids, and one quinic acid, were identified by high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS) combined with the fragmentation pathways of standards and the self-established database. Among them, 23 metabolites were reported for the first time from this plant. In contrast to the extracts of M. alba leaves and fruits, the extracts of roots and twigs displayed significant hypoglycemic activity The glycemia was significantly reduced from 32.08 ± 1.27 to 20.88 ± 1.82 mmol/L and from 33.32 ± 1.98 to 24.74 ± 1.02 mmol/L, respectively, after 4 weeks of treatment with roots and twigs extracts. Compound 46 (morusin), which is a high-level component identified from the extracts of M. alba roots, also displayed significant activity in decreasing the blood glucose level of T2D mice reduced from 31.45 ± 1.23 to 23.45 ± 2.13 mmol/L. In addition, the extracts of roots and twigs displayed significant activity in reducing postprandial glycemia. This work marks the first comparison of the metabolites and hypoglycemic activity of M. alba roots, leaves, twigs, and fruits extracts, and provides a foundation for further development of M. alba extracts as anti-diabetic drugs.

The Aurantii Fructus Immaturus flavonoid extract alleviates inflammation and modulate gut microbiota in DSS-induced colitis mice.

Inflammatory bowel disease (IBD) is a chronic, relapsing immune-mediated disease that always leads to a progressive loss of intestinal function. Therefore, it is important to find potential therapeutic drugs. This study was conducted to elucidate the effect of Aurantii Fructus immaturus flavonoid extract (AFI, 8% neohesperidin, 10% naringin) on DSS-induced intestinal inflammation and the gut microbiome. To explore the mechanism of action by which AFI protects against intestinal inflammation, a total of 50 mice were randomly divided into 5 groups [CG (control group), MG (model group), AFI low dose, AFI middle dose, and AFI high dose] and received 2.5% DSS for 7 days. Then, mice in the AFI groups were orally administered different doses of AFI for 16 days. The results showed that, compared with the MG group, the food intake and body weight were increased in the AFI groups, but the water intake was lower. Additionally, AFI significantly alleviated DSS-induced colitis symptoms, including disease activity index (DAI), and colon pathological damage. The levels of IL-6, IL-1ß and TNF-α in serum and colon tissue were significantly decreased. The diversity and abundance of the intestinal microbiota in the AFI group were decreased. The relative abundance of Bacteroidota was increased, and the relative abundance of Firmicutes was decreased. AFI plays an important role in alleviating DSS-induced intestinal inflammation and regulating Oscillospira, Prevotellaceae and Lachnospiraceae in the intestine at low, medium and high doses, respectively. This report is a pioneer in the assessment of AFI. This study not only demonstrated the anti-inflammatory activity of AFI but also identified the microbiota regulated by different concentrations of AFI.