Exploring the mechanism of citric acid for treating glucose metabolism disorder induced by hyperlipidemia.

Citric acid is a crucial organic in our daily life. The effect and mechanism of citric acid on glucose metabolism disorder induced by hyperlipidemia were explored by hyperlipidemic rat models which were established and treated with Xuezhikang and citric acid for 40 days. The results showed that citric acid significantly decreased liver index and reduced levels of triglyceride, total cholesterol and low-density lipoprotein cholesterol, while increasing high-density lipoprotein cholesterol. And citric acid observably decreased blood glucose and insulin resistance index, as well as increasing insulin sensitivity. Meanwhile, citric acid dramatically down-regulated mRNA and protein expression levels of glucose-6-phosphatase (G-6-Pase) (p < .01) and up-regulated those of glucose transporter 4 (GLUT-4) (p < .01). And significantly increased the contents of acetic, propionic and butyric acids (p < .01). These findings suggest that citric acid can regulate blood lipid levels in hyperlipidemic rats, reduce the resistance induced by hyperlipidemia, and improve insulin sensitivity. PRACTICAL APPLICATIONS: These findings suggest that citric acid can regulate blood lipid levels in hyperlipidemic rats, reduce the resistance induced by hyperlipidemia, and improve insulin sensitivity. and provide a theoretical basis for the application of citric acid in diseases related to glucose metabolism disorders.

Isolation, structural characterization, biological activity, and application of Glycyrrhiza polysaccharides: Systematic review.

Glycyrrhiza, one of the most widely used Chinese herbal medicines, is a perennial plant with good medicinal value. Polysaccharides as one of the main bioactive components of Glycyrrhiza, mainly composed of arabinose, glucose, galactose, rhamnose, mannose, xylose, and galacturonic acid in different proportions and types of glycosidic bonds. Glycyrrhiza polysaccharides (GP) have many biological activities, such as anti-oxidation, immune regulation, anti-tumor, apoptosis, anti-microbial, anti-inflammatory and regulation of intestinal flora. In this paper, relevant articles on the isolations, structural characterizations, and biological activities of GP published in the last 15 years (2006-2020) were referred to for a systematic review of the species. A total of 947 articles were searched from the database including NCBI, Science Direct, Web of Science, and How Net, and 109 of them were cited on the summarization of the past scientific researches of the polysaccharides of Glycyrrhiza genus. We hope that this work may provide new insights for further study and development of Glycyrrhiza.

Two new glucoside derivatives of truxinic and cinnamic acids from Lavandula angustifolia mill.

A phytochemical investigations on the n-butanol fraction of Lavandula angustifolia Mill. residues resulted in the isolation of ten compounds, including two new ones, 4,4'dimethoxy-2,2'di-O-ß-d-glucopyranosyl-truxinate (1) and 2-(ß-d-glucosyloxy)-trans-cinnamic acid butyl ester (2), along with eight known compounds. The structures of compounds were confirmed by NMR and HR-ESI-MS techniques and comparison with published data. The NMR data for 3 were attributed for the first time. Compound 2 was proofed to be a natural compound in plant rather than a butyl ester artifact formed by esterification reaction with butanol by comparative HPLC-DAD analysis with the ethanol extract which was obtained prior to the application of butanol. All isolated compounds were evaluated for their antioxidant and anti-hypoglycaemic activities. Among them, compounds 4 and 5 showed strong anti-oxidant activities against DPPH with IC50 values of 12.99 and 31.74 µM, respectively. Compound 5 exhibited moderate inhibitory activity against PTP1B with an IC50 value of 31.28 µM.

Isolations, characterizations and bioactivities of polysaccharides from the seeds of three species Glycyrrhiza.

In this paper, polysaccharides from the seeds of three species of genus Glycyrrhiza were extracted to investigate the physicochemical properties, structural characteristics and antioxidant activities. The polysaccharides were composed of xylose, mannose, galactose, and glucose with different molar ratio. Fourier transform infrared spectroscopy showed the presence of key functional groups of polysaccharides whereas scanning electron microscopy analysis revealed the characteristic morphology of different polysaccharides, and thermogravimetric analysis exhibited good thermal stability of all samples. The antioxidant activities of polysaccharides were evaluated in vitro. All the three polysaccharides demonstrated strong reducing power, as well as scavenging activity against DPPH, ABTS, and hydroxyl free radicals. Antioxidant assays indicated that all the polysaccharides have obvious antioxidant activities and possess a potential development and application value in food, cosmetics as well as pharmaceutical industries.

Phenolic glycosides from Lavandual angustifolia.

Four new phenolic glycosides (1-4), together with 12 known ones (5-16), were isolated from the essential oil extraction waste of Lavandula angustifolia. Their structures were unequivocally determined by extensive spectroscopic analysis (1D and 2D NMR, HR-ESI-MS, UV, and optical rotation), chemical method, and comparison with data reported in the literature. The antioxidant activities of all compounds and new compounds' influence on melanin content in B16 melanoma cells were examined, which indicated that compounds 1, 8, 13 had a certain degree of DPPH free radical scavenging activities, while only compound 2 could increase the melanin content with a dose-dependent manner.