Rosmarinic acid (RA) is a natural phenolic acid with multiple biological and pharmacological properties. However, its protective effect on ulcerative colitis (UC) remains uncertain. This study aims to explore the protective ability and potential mechanism of RA on UC, focusing on the intestinal barrier and homeostasis. UC mice model was established through the induction by dextran sulfate sodium (DSS) of 2.5%, and the progression of the UC after RA treatment was monitored using clinical manifestations, histopathological examination, and biochemical analysis. The mice’s composition of intestinal flora was assessed through 16S rRNA sequencing methods, while the concentrations of short-chain fatty acids (SCFAs) and bile acids (BAs) were analyzed using targeted metabolomics. The findings demonstrated that RA could prevent a decrease in body weight, reduce the scores of disease activity index (DAI), shorten colon length, and restore the claudin-1, zonula occludens-1 (ZO-1), and occludin levels in UC mice. Furthermore, RA effectively suppressed intestinal inflammation, modulated the compositin of gut microbiota, and influenced the levels of SCFAs and BAs. Hence, RA could offer therapeutic benefits for UC mice by enhancing intestinal barrier function and preserving intestinal homeostasis. Given the availability of scientific evidence, it may serve as a preventive agent or remedy for UC.

In this study, Panax notoginseng leaves (PNL) were separately fermented by Rhizopus oryzae, Neurospora crassa, Monascus and Mucor rouxianus, and changes in the contents of total saponins, total polysaccharides, total phenolics, and total flavonoids, as well as in vitro antioxidant activity and α-glucosidase inhibitory activity of PNL during the fermentation process were assessed. Additionally, the metabolite profiles of raw and fermented PNL were analyzed by ultrahigh performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The results indicated that the contents of total saponins and total polysaccharides in PNL were significantly reduced by fermentation with each of these four fungi. Interestingly, R. oryzae, N. crassa and Monascus were found to increase the content of total phenols, while Rhizopus oryzae and Mucor rouxianus increased the total flavonoid content. Fermentation for 3–5 days significantly enhanced the antioxidant activity of PNL, and the most pronounced effect was achieved with Monascus fermentation for three days, which increased the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging capacity and ferric reducing capacity by 14.30%, 5.13%, and 18.40%, respectively. Moreover, the α-glucosidase inhibitory activity of PNL initially decreased and then increased during fungal fermentation, which increased by 16.03% after Monascus fermentation for six days. By untargeted metabolomics analysis, 573 metabolites were identified from PNL. After three days of Monascus fermentation, the up-regulated metabolites were significantly less than the down-regulated ones, and the predominant up-regulated metabolites were amino acids, alkaloids, carbohydrates, lipids, phenols, flavonoids, and terpenoids. Furthermore, analysis of the 21 saponins showed that only ginsenoside F2 was significantly up-regulated, while eight other saponins were significantly down-regulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that co-factor biosynthesis, flavonoid biosynthesis, purine metabolism, and pyrimidine metabolism were the most probable metabolic pathways during the fermentation process. In conclusion, fungal fermentation, especially Monascus fermentation, can effectively improve the functional activity of P. notoginseng by metabolic alterations through various pathways. Therefore, this study provides a scientific reference for the green processing of PNL.

In order to find an excellent drying method for Panax notoginseng leaves (PNL), PNL were dried by using hot air drying (HAD), heat pump drying (HPD) or vacuum drying (VD). The contents of total saponins, polysaccharides, total phenols, total flavonoids, and monomer saponins, in vitro antioxidant activity and α-glucosidase inhibitory capacity of fresh and dried PNL were determined. By using gas chromatography-ion mobility spectrometry (GC-IMS) and non-targeted metabolomics, the volatile components and metabolites in fresh and dried PNL were identified and analyzed, respectively. The results showed that all three drying methods could significantly increase the contents of total saponins and polysaccharides in PNL, reduce the contents of total phenols and total flavonoids, but decrease the functional activities of PNL to varying degrees. Among the four samples, the HPD dried sample had the highest contents of total saponins and polysaccharides, the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and α-glucosidase inhibitory capacity, and moderately strong 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging capacity and ferric ion reducing antioxidant power (FRAP). High-performance liquid chromatography (HPLC) analysis showed that HPD treatment significantly reduced the contents of notoginsenosides Fc and Fe, while VD treatment showed the opposite effect. A total of 85 volatile components were detected, and the HPD dried sample showed the highest relative contents of alcohols and aldehydes, and the lowest relative content of ketones. In addition, there were significant differences between treatment groups. Furthermore, ultra-high performance liquid chromatography-quadrupole-orbitrap mass spectrometry (UPLC-Q-OT-MS) identified 659 metabolites in the fresh and HPD dried samples. In the positive and negative ion modes, 113 and 68 metabolites were significantly up-regulated, and 98 and 31 metabolites were significantly down-regulated, respectively. These differential metabolites predominately included lipids, lipid-like molecules, organic heterocyclic compounds, organic acids and their derivatives. Out of the 24 saponins in PNL, seven were significantly down-regulated and one was significantly up-regulated, which verified the HPLC results. Through the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of differential metabolites, it was found that the most likely metabolic pathways in HPD dried PNL included the biosynthesis of amino acids, 2-oxycarboxylic acid metabolism, and the biosynthesis of cofactors. In conclusion, HPD provided the best preservation of the chemical composition and functional activities of PNL, making it more suitable for drying PNL. Through multiple metabolite pathways, HPD could alter the composition of metabolites in PNL and affect its volatile components.

In this study, an in vitro digestive model was established to determine changes in the contents of total saponins, total phenols, polysaccharides, and total flavonoids in Panax notogiseng leaves (PNL) during simulated digestion.Meanwhile, changes in the in vitro antioxidant activity and α-glucosidase-inhibiting activity were assessed. Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was employed to further analyze the pattern of changes in 24 monomer saponins in PNL. The results showed that the contents of total saponins and total phenols were the highest at the intestinal digestion stage, reaching up to 188.32 and 17.43 mg/g, respectively. The change in polysaccharide content was insignificant during the entire digestion process. The content of total flavonoids was the highest in the oral digestion stage at 23.76 mg/g. Similarly, the antioxidant and α-glucosidase-inhibiting capacity of PNL were both the strongest in the intestinal digestion stage. The 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity, iron-reducing capacity, and α-glucosidase-inhibiting capacity all showed a trend of initial decrease and then increase and reached the highest values of 84.97%, 37.80 mg/g, and 72.5%, respectively in the intestinal digestion stage. Furthermore, the large-molecular-mass ginsenosides Rb₁, Rb₂, Rb₃, Re, and Rd were cleaved into small-molecular-mass rare saponins such as compound K, Rg₃, Rg₅, and Rk₁. In conclusion, PNL still exhibited significant functional activity after digestion. The functional activities of PNL, such as antioxidant and α-glucosidase-inhibiting activity, increased as the digestion process proceeded, reaching their highest levels in the intestinal digestion stage. This might be related to the release of active ingredients and the production of small-molecule rare saponins. This study could provide a scientific basis for applying PNL to develop functional foods.

The fermentation of lactic acid bacteria can enhance the transformation of active substances, such as polyphenols in food. This study aims to explore the effects of lactic acid bacteria fermentation on their functional activities and phenolic compounds in Dendrobium officinale (DO). Three commonly used lactic acid bacteria were first selected to ferment the DO from five regions. Then, a systematic investigation was implemented to determine the total phenolic and flavonoid contents and the antioxidant activity of DO before and after fermentation. The phenolic components and metabolite composition were finally characterized using high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that the viable cell counts gradually increased in the DO fermentation broth, as the fermentation progressed, whereas, there was a gradual decrease in the pH value. The growth rate of viable cells was highest during the first 0 to 24 h fermentation, as the decline rate of pH value. All three lactic acid bacteria enhanced the contents of total phenolic and total flavonoid, as well as the antioxidant activity of DO. The most significant enhancement was observed to ferment with Lactobacillus bulgaricus for 48 h in the DO in Wenshan City, Yunnan Province. The total phenolic and total flavonoid contents of the fermented DO were 120.67 and 23.39 mg/g, respectively, under the same condition. Additionally, the radical scavenging abilities against the cationic ABTS radical (2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (1,1-diphenyl-2-picrylhydrazyl) as well as the ferric reducing ability (FRAP) were highest at 288.51, 34.34, and 136.32 mg/g, respectively, which increased of 0.81, 2.11, and 0.52 times than before fermentation. 16 phenolic compounds were selected before and after DO fermentation using HPLC. Specifically, the content of sinapic acid increased from 0.65 to 1.14 mg/g (an increase of 75.38%), while the content of vanillic acid rose from 2.60 to 3.19 mg/g (an increase of 22.70%). However, the content of (-)-epicatechin gallate decreased from 2.92 mg/g to 0.47 mg/g (a decrease of 83.90%). Moreover, the salicylic acid was only detected in the post-fermentation samples. Non-targeted metabolomics analysis revealed that a total of 1,298 metabolites were identified from Dendrobium officinale before and after fermentation. Among them, 100 and 85 metabolites were significantly upregulated in the positive and negative ion modes, respectively, while 211 and 180 metabolites were significantly downregulated. The number of upregulated metabolites was notably lower than that of downregulated metabolites. The upregulated metabolites were primarily concentrated in the fatty acids, nucleosides, and alkaloids, whereas, the downregulated metabolites were found mainly in the flavonoids, phenolic compounds, and terpenes. It infers that these metabolites were gradually consumed or metabolically transformed during fermentation. Correlation analysis demonstrated a high correlation between antioxidant activity and phenolic compounds. Enrichment analysis of metabolic pathways was performed during Dendrobium officinale fermentation using the Kyoto Encyclopedia of Genes and Genomes (KEGG). The most likely metabolic pathways were the ABC transport pathway, biosynthesis of various secondary metabolites - part II, and metabolism of alanine, aspartate, and glutamate. In conclusion, the fermentation of lactic acid bacteria significantly improved the antioxidant activity of DO, especially Lactobacillus bulgaricus. This improvement was closely related to the transformation and release of phenolic compounds during fermentation. Dendrobium officinale can be expected to serve as the biotransformation of active components in natural products/foods.

In this study, the nutrient, amino acid and anthocyanin composition of three varieties (Rose Honey, Cloud Dance, and French Wild) of wine grape pomace from Yunnan were investigated. Subsequently, the in vitro antioxidant and hypoglycemic activities of the free, esterified and bound phenols extracted from each variety of wine grape pomace were evaluated in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activities, ferric reducing power, α-glucosidase and α-amylase inhibitory activities. Meanwhile, qualitative analysis of phenolic compounds was conducted using high performance liquid chromatography (HPLC). The results showed that the three varieties of grape pomace had similar nutrient composition, characterized by high dietary fiber content, low fat content, and abundant content and reasonable composition of essential amino acids. Overall, Rose Honey had the highest nutritional value. Furthermore, two types of anthocyanidins and 34 types of anthocyanins, primarily in the form of 3-O-glucoside, were identified in all the samples. Notably, Cloud Dance showed the highest number and amount of anthocyanidins, followed by Rose Honey. Additionally, among the three varieties of grape pomace, Rose Honey exhibited the highest total phenol content and the strongest antioxidant capacity and α-glucosidase inhibitory activity, but its α-amylase inhibitory activity was similar to that of French Wild. Regarding the different forms of phenols, the total content and in vitro antioxidant capacity of bound phenols were higher than those of free and esterified phenols, whereas the esterified phenols demonstrated higher α-amylase inhibitory activity. A total of 18 phenolic compounds were detected in the three varieties of grape pomace, with Rose Honey being found to contain a larger number of phenolic compounds (16) than the other two varieties. Moreover, the content of bound phenols was higher than those of free and esterified phenols. In conclusion, these three varieties of grape pomace possess good nutritional value and functional activities, which are suitable to be developed as functional food ingredients due to their high dietary fiber content and low fat content as well as antioxidant and hypoglycemic activity. Among these three varieties, Rose Honey has the greatest development potential. The findings of this study provide important reference for the high-value comprehensive utilization of Yunnan wine grape pomace and even for the development of the highland grape wine industry in Yunnan.