Flavor compounds in Vine Tea (Ampelopsis grossedentata) infusions

A comprehensive review of vine tea: Origin, research on Materia Medica, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Vine tea is a popular folk tea that has been consumed in China for more than 1200 years. It is often used in ethnic medicine by ethnic groups in southwest China with at least 35 aliases in 10 provinces. In coastal areas, vine tea is mostly used to treat heatstroke, aphtha, aphonia, toothache, etc. In contrast, in the southwest inland regions, vine tea is mostly used to clear away heat and toxic materials, antiphlogosis and relieving sore-throat, lowering blood pressure and lipid levels, and alleviating fatigue. Three main species have been used as the source of vine tea, Nekemias grossedentata, Nekemias cantonensis and Nekemias megalophylla. Among them, the leaves of Nekemias grossedentata were considered as new food resource in complicance with regulations, according to the Food Safety Standards published by the Monitoring and Evaluation Department of the National Health and Family Planning Commission in China.

AIM OF THE STUDY

At present, the comprehensively summary of Materia Medica on the history and source of vine tea is currently unavailable. The current article summed up the Materia Medica, species origin and pharmacological effects of all 3 major species used in vine tea to fill the knowledge gaps. We also aim to provide a reference for future research on historical textual, resource development and medicinal utilization of vine tea.

MATERIALS AND METHODS

Adhering to the literature screening methodology outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), this review encompasses 148 scholarly research papers from three database, paper ancient books, local chronicles and folklore through field investigations. We then comprehensively summarized and discussed research progresses in scientific and application studies of vine tea.

RESULTS

The historical records indicated that vine tea could have been used as early as Southern and Northern Dynasties (AC 420-589). Nekemias grossedentata, Nekemias cantonensis and Nekemias megalophylla, were used to considered as vine tea in the ethnic medicine. The main phytochemicals found in three plants are flavonoids, polyphenols and terpenoids, among which dihydromyricetin (DHM) is the most important and most studied active substance. The key words "Ampelopsis grossedentata" (Synonym of Nekemias grossedentata) and "dihydromyricetin/DHM" showed the highest frequency over the last 27 year based on the research trend analysis. And the ethnopharmacology studies drawn the main activities of vine tea are antioxidant, antibacterial, hepatoprotective, neuroprotective and anti-atherosclerosis activities.

CONCLUSIONS

This review systematically summarized and discussed vine tea from the following five aspects, history, genetic relationship, phytochemistry, research trend and ethnopharmacology. Vine tea has a long historical usage in Chinese ethnic medicine. Its outstanding therapeutic efficacies have attracted extensive attention in other places in the world at present. Nekemias cantonensis and Nekemias megalophylla are quite similar to Nekemias grossedentata in terms of many aspects. However, the current research has a narrow focus on mainly Nekemias grossedentata and DHM. We propose that future studies could be carried out to determine the synergistic effect of multi-components and multi-targets of vine tea including all 3 species to provide valuable knowledge.

Potential benefits of Rehmanniae Radix after ancient rice-steaming process in promotion of antioxidant activity in rats' health

Rice steam processed product of Rehmanniae Radix (RSRR), one of the processed products of Rehmanniae Radix (RR), is popular as an herbal medicine and food. However, the health-promoting effects and mechanisms of RSRR are still unclear. In this study, 10-week-old Sprague-Dawley female rats were treated with different processed products of RR. No organ coefficient differences were observed between RSRR and the control group, indicating that RSRR did not cause damage to the rats. Compared with other RR products, superoxide dismutase, glutathione, and catalase levels were significantly higher and malondialdehyde levels were significantly lower in the RSRR group, indicating that RSRR exerted a better antioxidant effect. Gene expression analysis showed that hemoglobin genes (Hba-a1, Hba-a2, Hbb-bs, Hbb, Hbq1b, Hbb-b1, and LOC103694857) may be potential biomarkers to evaluate the antioxidant effect of RSRR. Antioxidation-related signaling pathways in GO annotation, including cellular oxidant detoxification, hydrogen peroxide metabolic process, hemoglobin complex, and oxygen binding signaling pathways were significantly enriched, indicating these pathways may represent the antioxidant mechanism of RSRR. To explore the main active compounds primarily responsible for the antioxidant activity of RSRR, UPLC-Q-TOF-MS was used and six components (catalpol, rehmannioside A, rehmannioside D, melittoside, ajugol, and verbascoside) were identified in rat serum. Catalpol and rehmannioside A were predicted to be the major active components by network pharmacology. These results suggested that RSRR exhibits antioxidant activity and has health-promoting properties. This study provides a scientific basis for the antioxidant mechanism and clinical use of RSRR.

Natural products target glycolysis in liver disease

Mitochondrial dysfunction plays an important role in the occurrence and development of different liver diseases. Oxidative phosphorylation (OXPHOS) dysfunction and production of reactive oxygen species are closely related to mitochondrial dysfunction, forcing glycolysis to become the main source of energy metabolism of liver cells. Moreover, glycolysis is also enhanced to varying degrees in different liver diseases, especially in liver cancer. Therefore, targeting the glycolytic signaling pathway provides a new strategy for the treatment of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis associated with liver cancer. Natural products regulate many steps of glycolysis, and targeting glycolysis with natural products is a promising cancer treatment. In this review, we have mainly illustrated the relationship between glycolysis and liver disease, natural products can work by targeting key enzymes in glycolysis and their associated proteins, so understanding how natural products regulate glycolysis can help clarify the therapeutic mechanisms these drugs use to inhibit liver disease.

Study on effects of processing technology and storage on the composition of Ampelopsis grossedentata by untargeted metabolomics

Ampelopsis grossedentata is a traditional medicinal and edible plant rich in bioactive compounds. This paper focus on the white powder on the surface of A. grossedentata, and the effects of processing technology and storage time on the composition of bioactive compounds in Ampelopsis grossedentata extracts (AMP). 33 compounds in AMP were identified and 30 compounds were reported for the first time compared with standards by UHPLC-Q-Orbitrap-MS. Organic acid, phenol, and flavonoids were detected in powder samples. Through comparing the mass spectrum data of three processing samples (traditional method, fermentation and drying-only), five compounds in fermentation samples were higher than other groups, and the content of most compounds of the traditional process was decreased compared with drying-only process. For the storage time research, the powder on the surface was found to be more unstable than leaf parts after 24 h, suggesting that sealing preservation is crucial in the process after powder precipitation.

Dihydromyricetin Improves High-Fat Diet-Induced Hyperglycemia through ILC3 Activation via a SIRT3-Dependent Mechanism

SCOPE

Previous studies indicate that dihydromyricetin (DHM) effectively improved glucose homeostasis and alleviated insulin resistance in population-intervened trials, yet the underlying mechanism remains obscure.

METHODS AND RESULTS

Wild-type male mice and recombinase activating gene 1(Rag1)^-/- mice (lacking adaptive immunity lymphocytes) are fed with control, high-fat diet (HFD), or HFD+DHM diets for 8 weeks. DHM effectively protects HFD feeding mice against hyperglycemia by promoting group 3 innate lymphoid cells (ILC3s) cells proliferation and interleukin 22 (IL-22) production. Furthermore, IL-22 secretion induced by DHM increases the expression levels of the tight junction (TJs) molecules to protect the intestinal barrier integrity, thereby decreasing the level of lipopolysaccharides (LPS), an endotoxin that is involved in the regulation of chronic tissue inflammation and insulin resistance. In addition, silent mating-type information regulation 2 homolog 3 (SIRT3) deficiency results in more serious obesity and intestinal barrier damage following HFD feeding and abolished DHM-mediated increase in IL-22 expression levels of ILC3 cells in SIRT3 knockout (SIRT3KO) mice. DHM reduces metabolic stress and enhances mitochondrial respiratory capacity to promote cell proliferation and IL-22 secretion by activating SIRT3 in ILC3 cells CONCLUSIONS: DHM improves IL-22 production of ILC3 cells and subsequently inhibits intestinal barrier dysfunction to alleviate hyperglycemia partially mediated by SIRT3.

LC-ESI-QTOF/MS characterization of antimicrobial compounds with their action mode extracted from vine tea (Ampelopsis grossedentata) leaves

Vine tea (Ampelopsis grossedentata) is a tea plant cultivated south of the Chinese Yangtze River. It has anti-inflammatory properties and is used to normalize blood circulation and detoxification. The leaves of vine tea are the most abundant source of flavonoids, such as dihydromyricetin and myricetin. However, as the main bioactive flavonoid in vine tea, dihydromyricetin was the main focus of previous research. This study aimed to explore the antibacterial activities of vine tea against selected foodborne pathogens. The antimicrobial activity of vine tea extract was evaluated by the agar well diffusion method. Cell membrane integrity and bactericidal kinetics, along with physical damage to the cell membrane, were also observed. The extract was analyzed using a high-performance liquid chromatography-diode array detector (HPLC-DAD), and the results were confirmed using a modified version of a previously published method that combined liquid chromatography and electrospray-ionized quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS). Cell membrane integrity and bactericidal kinetics were determined by releasing intracellular material in suspension and monitoring it at 260 nm using an ultraviolet (UV) spectrophotometer. A scanning electron microscope (SEM) was used to detect morphological alterations and physical damage to the cell membrane. Six compounds were isolated successfully: (1) myricetin (C15H10O8), (2) myricetin 3-O-rhamnoside (C21H20O12), (3) 5,7,8,3,4-pentahydroxyisoflavone (C15H10O7), (4) dihydroquercetin (C15H12O7), (5) 6,8-dihydroxykaempferol (C15H10O8), and (6) ellagic acid glucoside (C20H16O13). Among these bioactive compounds, C15H10O7 was found to have vigorous antimicrobial activity against Bacillus cereus (AS11846) and Staphylococcus aureus (CMCCB26003). A dose-dependent bactericidal kinetics with a higher degree of absorbance at optical density 260 (OD260) was observed when the bacterial suspension was incubated with C15H10O7 for 8 h. Furthermore, a scanning electron microscope study revealed physical damage to the cell membrane. In addition, the action mode of C15H10O7 was on the cell wall of the target microorganism. Together, these results suggest that C15H10O7 has vigorous antimicrobial activity and can be used as a potent antimicrobial agent in the food processing industry.