To clarify the effect of Dendrobium devonianum pulp (DP) on relieving constipation, the study evaluated the effect of DP on defecation function, colonic histomorphology, gastrointestinal regulatory peptides, gut microbiota composition, and short-chain fatty acid (SCFA) levels in a mouse model of slow-transit constipation induced by loperamide (LOP). The results showed that compared with the constipation group, DP intervention significantly promoted defecation in constipated mice, reducing the time to the first red fecal pellet discharge by 43.52% (P < 0.05). Additionally, it increased the number of fecal pellets, fecal water content, and colonic transit rate within 5 hours by 113.3%, 27.80%, and 193.33%, respectively, while improving fecal morphology. Histopathological analysis revealed that DP effectively alleviated constipation-induced damage to the colonic mucosal epithelium, restored villi morphology, and increased the number of goblet cells. Biochemical analysis showed that DP significantly increased the levels of excitatory gastrointestinal peptides and decreased the levels of inhibitory gastrointestinal peptides in both the serum and colon of constipated mice. Specifically, following DP intervention, the serum levels of motilin (MTL) and 5-hydroxytryptamine (5-HT) increased to 150.94% and 201.67% (P < 0.05) of the LOP group, respectively, while that of vasoactive intestinal peptide (VIP) decreased by 75.90% (P < 0.05). The colonic levels of MTL and 5-HT increased to 679.60% and 2261.09% (P < 0.05) of the LOP group, respectively, while that of VIP reduced by 59.61% (P < 0.05). 16S rRNA gene sequencing demonstrated that DP increased the Chao1, Shannon, and Simpson indices of the gut microbiota, elevated the Firmicutes/Bacteroidetes ratio, promoted the proliferation of Lactobacillus, and suppressed that of Lachnospira. Furthermore, DP significantly enhanced the levels of propionic and butyric acids in the feces of constipated mice. In conclusion, DP alleviates constipation through multiple mechanisms, including enhancing intestinal motility, repairing colonic tissue damage, balancing neuropeptide levels, optimizing gut microbiota structure, and promoting SCFA production. This study provides a scientific basis for the use of DP as a functional food for improving intestinal health and offers new insights into the application of natural products in gut function regulation.
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Open Access
Issue
This study aimed to evaluate the chemical composition, in vitro antioxidant activity, and hypoglycemic activity of extracts from the stems, leaves, and flowers of Dendrobium devonianum Paxt. (D. devonianum), to elucidate the metabolic basis underlying differences in bioactivity using metabolomics, and to provide a theoretical basis for the high-value utilization of D. devonianum resources and the development of functional foods.
Stems, leaves, and flowers of D. devonianum were extracted using varying concentrations of ethanol (0, 60%, and 100%). The content of total sugars, total phenolics, and total flavonoids were determined. Antioxidant activities including DPPH, ABTS+ radical scavenging capacities and ferric reducing antioxidant power (FRAP) were assessed, along with α-glucosidase inhibitory activity. High-performance liquid chromatography (HPLC) was employed to quantify phenolic compounds. Untargeted metabolomics, combined with partial least squares discriminant analysis (PLS-DA) and KEGG pathway enrichment analysis, was performed to compare metabolic profiles and identify key differential metabolites and pathways among the different plant parts.
Stem extracts exhibited the highest total sugar content, whereas flower extracts demonstrated significantly higher total phenolic and flavonoid contents, as well as stronger antioxidant activities, than stems and leaves. Within the same plant part, the 60% ethanol extract had the highest total flavonoid content, ABTS+ scavenging capacity, and FRAP value, while the 100% ethanol extract exhibited the highest total phenolic content and DPPH scavenging capacity. The α-glucosidase inhibitory activities of flowers and leaves were superior to those of stems. HPLC analysis identified 11 phenolic compounds, with the 60% ethanol extract containing the greatest variety and the highest concentration within the same plant part. Metabolomics identified 1 859 metabolites, of which 1 051 were differential metabolites. Metabolite classes such as lipids, organic acids, and their derivatives were significantly correlated with antioxidant and hypoglycemic activities.
The stems, leaves, and flowers of D. devonianum all possessed significant antioxidant and hypoglycemic activities, which were closely related to plant part and extraction solvent. The flowers exhibited the strongest overall bioactivity.
Open Access
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In this study, by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and double-sandwich enzyme-linked immunosorbent assay (ELISA), Juglans sigillata kernels from seven different production areas in Yunnan province were screened for their Jug r 1 contents. The preparation of Jug r 1 through ammonium sulfate precipitation, gel filtration chromatography (GFC), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was optimized and the product was identified. Its structure was characterized by circular dichroism (CD) spectroscopy. Finally, Jug r 1 content in walnut protein was measured by ELISA. The results showed that walnuts from Baoshan, which had the highest contents of total protein and Jug r 1, were used for subsequent experiments. The optimal concentration of ammonium sulfate saturation was in the range from 40% to 80%, and the optimal conditions for GFC were sample concentration of 30 mg/mL, loading volume of 4 mL, and elution flow rate of 1 mL/min. Under these conditions, the recovery of Jug r 1 was 16.58%. Mass spectrometry analysis showed that this protein had the typical characterisitcs of Jug r 1. Circular dichroism spectroscopy indicated that the secondary structure of Jug r 1 was dominated by α-helix and consisted of multiple conformations. After separation and purification by a two-step process, Jug r 1 with purity more than 96% was obtained. This study can provide a scientific basis for further research on Jug r 1 and also provide a reference for the separation and purification of allergic proteins from other nuts.
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