American ginseng (Panax quinquefolius L.) is an herbal medicine with polysaccharides as its important active ingredient. The purpose of this research was to identify the effects of the polysaccharides of P. quinquefolius (WQP) on rats with antibiotic-associated diarrhoea (AAD) induced by lincomycin hydrochloride. WQP was primarily composed of galacturonic acid, glucose, galactose, and arabinose. The yield, total sugar content, uronic acid content, and protein content were 6.71, 85.2, 31.9, and 2.1, respectively. WQP reduced the infiltration of inflammatory cells into the ileum and colon, reduced the IL-1β, IL-6, IL-17A, and TNF-α levels, increased the levels of IL-4 and IL-10 in colon tissues, improved the production of acetate and propionate, regulated the gut microbiota diversity and composition, improved the relative richness of Lactobacillus and Bacteroides, and reduced the relative richness of Blautia and Coprococcus. The results indicated that WQP can enhance the recovery of the intestinal structure in rats, reduce inflammatory cytokine levels, improve short-chain fatty acid (SCFA) levels, promote recovery of the gut microbiota and intestinal mucosal barrier, and alleviate antibiotic-related side effects such as diarrhoea and microbiota dysbiosis caused by lincomycin hydrochloride. We found that WQP can protect the intestinal barrier by increasing Occludin and Claudin-1 expression. In addition, WQP inhibited the MAPK inflammatory signaling pathway to improve the inflammatory status. This study provides a foundation for the treatment of natural polysaccharides to reduce antibiotic-related side effects.

Panax ginseng C. A. Meyer (P. ginseng) is a medicinal plant rich in bioactive components such as ginsenosides, polysaccharides, and volatile oils and is widely used in both the pharmaceutical and food industries. While the AP2/ERF gene family is well-documented to play crucial roles in plant growth, development, and defense responses, functional studies on this gene family in P. ginseng remain unreported. Our genome-wide analysis identified 318 PgAP2/ERF family members, which are classified into five subfamilies: AP2, DREB, ERF, RAV, and Soloist. Homology analysis revealed that segmental duplication serves as the primary evolutionary driver for the PgAP2/ERF gene family in P. ginseng. RT-qPCR analysis demonstrated that all PgAP2/ERF members in the DREB-A1 subgroup respond to cold stress. Specifically, we found that the DREB-A1 member PgAP2/ERF187 plays a pivotal role in the cold stress response, with its expression specifically induced by ABA. Overexpression of PgAP2/ERF187 in Arabidopsis significantly enhanced the expression of cold tolerance-related genes. Subcellular localization analysis confirmed the co-localization of PgABF and PgAP2/ERF187 in the nucleus. Combining transcription factor interaction predictions and yeast one-hybrid experiments, we propose that PgABF likely regulates PgAP2/ERF187 expression by directly binding to its promoter region. These findings unveil the potential mechanism of the “PgABF-PgAP2/ERF187” regulatory module within the ABA signaling pathway during P. ginseng’s cold stress adaptation, thereby providing novel theoretical insights into the molecular mechanisms underlying P. ginseng’s cold resistance.

Extensively applied in traditional Chinese herbal medicine, Scutellaria baicalensis Georgi is a key botanical resource. The synthesis of its main active co

Ginsenosides, the principal bioactive triterpenoid saponins of Panax ginseng C.A. Meyer, accumulate abundantly in leaves. They form a large family of secondary metabolites comprising more than 300 structurally distinct compounds, yet how leaf senescence reshapes their accumulation remains unclear. We profiled 376 saponin metabolite features across four sampling stages spanning the natural senescence progression (T1–T3) and a frost-terminated stage (T4) by ultra-performance liquid chromatography–high-resolution mass spectrometry (UPLC-HRMS), modeled temporal effects across the natural senescence gradient (T1–T3) with generalized estimating equations (GEE), analyzed the frost-terminated stage T4 as a distinct endpoint, verified senescence histologically, and analyzed stage T1–T3 transcriptomes with replicate-based statistical testing. Leaf senescence globally reshaped the saponin metabolome, with 326 of the 376 saponin features (86.7%) showing significant temporal effects across the natural senescence gradient (T1–T3). The four classical aglycone classes—protopanaxadiol (PPD), protopanaxatriol (PPT), ocotillol (OT) and oleanolic acid (OA)—followed divergent accumulation programs across the natural senescence progression (T1–T3): sustained accumulation (PPT, OT and PPD) versus a U-shaped curve (OA). At the frost-terminated stage, T4, the classes diverged sharply—PPD-type abundance fell back to the T1 level (abundance-weighted class-level T4/T3 = 0.63), whereas the other classes rose further—a frost-associated remodeling pattern rather than a continuation of the senescence program. The frost-associated PPD decline was glycosylation-dependent—low-glycosylation compounds fell far more sharply than highly glycosylated ones (median of per-compound ratios T4/T3 0.51 vs. 1.04; one-sided permutation p = 1.2 × 10⁻⁴)—and coincided with T3 induction of β-glucosidase genes (exploratory and hypothesis-level, based on two qualified T3 replicates, and requiring validation with larger replicate numbers) and histologically verified vacuolar collapse, consistent with a deglycosylation-associated catabolic mechanism. Senescence signaling was consistent with differential hormone responses (salicylic acid activation, jasmonate and ethylene attenuation), broad suppression of Ca²⁺-signaling components and WRKY/NAC-centered transcriptional control, and joint analysis suggested a dichotomous saponin–gene correlation pattern. Collectively, these results establish a temporal atlas of ginsenoside accumulation during ginseng leaf senescence, delineate the class-specific coupling of saponin secondary metabolism to the senescence program, and offer a new perspective on ginsenosides as metabolites embedded in the physiological activities of the ginseng life cycle.