Identification of the Hypoglycemic Active Components of Lonicera japonica Thunb. and Lonicera hypoglauca Miq. by UPLC-Q-TOF-MS

Lonicera japonica Thunb. and Lonicera hypoglauca are famous Chinese medicines used for hyperglycemia; however, the specific compounds that contributed to the hypoglycemic activity and mechanism are still unknown. In this study, the antidiabetic activity of L. japonica buds and L. hypoglauca buds, roots, stems, and leaves extracts was primarily evaluated, and the L. japonica buds and L. hypoglauca buds, roots, and stems extracts displayed significant hypoglycemic activity, especially for the buds of L. hypoglauca. A total of 72 high-level compounds, including 9 iridoid glycosides, 12 flavonoids, 34 organic acids, and 17 saponins, were identified by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) combined with the fragmentation pathways of standards from different parts of L. japonica and L. hypoglauca extracts. Among them, 19 metabolites, including 13 saponins, were reported for the first time from both medicines. Seven high-content compounds identified from L. hypoglauca buds extract were further evaluated for hypoglycemic activity. The result indicated that neochlorogenic acid, chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C displayed significant antidiabetic activity, especially for isochlorogenic acid A and isochlorogenic acid C, which demonstrated that the five chlorogenic-acid-type compounds were the active ingredients of hypoglycemic activity for L. japonica and L. hypoglauca. The potential mechanism of hypoglycemic activity for isochlorogenic acid A and isochlorogenic acid C was inhibiting the intestinal α-glucosidase activity to block the supply of glucose. This study was the first to clarify the hypoglycemic active ingredients and potential mechanism of L. japonica and L. hypoglauca, providing new insights for the comprehensive utilization of both resources and the development of hypoglycemic drugs.

Preparation, Antioxidant Activities and Bioactive Components of Kombucha Beverages from Golden-Flower Tea (Camellia petelotii) and Honeysuckle-Flower Tea (Lonicera japonica)

Kombucha is a fermented tea known for its health benefits. In this study, golden-flower tea (Camellia petelotii) and honeysuckle-flower tea (Lonicera japonica) were first used as raw materials to prepare kombucha beverages. The antioxidant activities, total phenolic contents, concentrations of bioactive components, and sensory scores of two kombucha beverages were assessed. Additionally, effects of fermentation with or without tea residues on kombucha beverages were compared. The results found that two kombucha beverages possessed strong antioxidant activities and high scores of sensory analysis. In addition, fermentation with golden-flower tea residues could remarkably enhance the antioxidant activity (maximum 2.83 times) and total phenolic contents (3.48 times), while fermentation with honeysuckle tea residues had a minor effect. Furthermore, concentrations of several bioactive compounds could be increased by fermentation with golden-flower tea residues, but fermentation with honeysuckle-flower tea residues had limited effects. Moreover, the fermentation with or without tea residues showed no significant difference on sensory scores of golden-flower tea kombucha and honeysuckle-flower tea kombucha, and golden-flower tea kombucha had higher sensory scores than honeysuckle-flower tea kombucha. Therefore, it might be a better strategy to produce golden-flower tea kombucha by fermentation with tea residues, while honeysuckle-flower tea kombucha could be prepared without tea residues.

Compound green tea (CGT) regulates lipid metabolism in high-fat diet induced mice

This work aims to study the effect of compound green tea (CGT) on liver lipid metabolism in mice based on metabolomics of liquid chromatography-mass spectrometry (LC-MS), and preliminarily identify potential biomarkers and pathways of action by using a metabonomic network database to explore the lipid-lowering effect of CGT. In this study, forty mice were randomly divided into four groups: compound tea treatment group (DH), high-fat model control group (NK), normal control group (CK) and positive drug group (YK). After a month of different interventions, the mice were weighed and the blood lipid indexes were detected. In addition, differential liver metabolites were monitored by using LC-MS. The results showed that CGT and positive drug treatment were able to decrease body weight, liver coefficient, TC, TG and LDL levels of obese mice, while increasing HDL levels. Among the 110 compounds obtained, 54 metabolites were significantly altered in the four comparisons. More importantly, 15 remarkably downregulated metabolites involved in Lysopc 16:1, Lysopc 18:1, and Lysopc 18:2 were found in the DH group when the mice were treated with CGT; meanwhile, the positive drug Xuezhikang was able to significantly downregulate 14 compounds, including (±)18-HEPE, and 6 keto-PGF1α, compared with the NK group. Besides, KEGG enrichment analysis also revealed the important metabolic pathways, such as linoleic acid metabolism, Biosynthesis of unsaturated fatty acids, and α-linolenic acid metabolism, were related to fatty acid metabolism. These results suggested that CGT could regulate the lipid metabolism in the liver of hyperlipidemia mice, and may regulate 54 potential biomarkers in mice through a related metabolic pathway to make them return to a normal state and improve the disorder of lipid metabolism.