Anti-Lipid Peroxidation, α-Glucosidase and α-Amylase Inhibitory Effects of the Extract of Capitula of Coreopsis tinctoria Nutt. and Protection Effects on High-Fat/High-Sugar and Streptozotocin-Induced Type 2 Diabetes in Mice.

Coreopsis tinctoria capitula (CTC) of the Compositae family has been used traditionally to treat various diseases in China, particularly type 2 diabetes mellitus (T2DM). This study evaluated the anti-lipid peroxidation, α-glucosidase and α-amylase inhibitory effects of CTC extracts, and analyzed its chemical composition by HPLC. Moreover, the antioxidant activity and protection effects of CTC extracts were investigated on high-fat/high-sugar and streptozotocin-induced T2DM mice. In vitro study, the ethyl acetate extract (EAE) and butanol extract (BE) of CTC exhibited anti-lipid peroxidation (IC50 : BHA>BE or EAE>ascorbic acid, p<0.05) and α-glucosidase inhibitory activity (IC50 : BE>EAE, p<0.05). In vivo, the BE at the dose of 600 mg/kg was intragastrically given to T2DM mice, which exhibited a certain extent of repair and improvement of the levels of CAT, GSH, GSH-PX , SOD, as well as plasma biomarkers, compared with those in the model group (p<0.05). These results demonstrated that CTC extracts have a positive effect to treat T2DM and it can be used for the treatment of T2DM in the future.

Structural elucidation and bioactivities of a novel arabinogalactan from Coreopsis tinctoria.

Coreopsis tinctoria is being widely cultivated in Xinjiang of China, whose consumption is known to prevent diabetes and neurodegenerative diseases. To elucidate the bioactive ingredients responsible for these benefits, the alkaline soluble crude polysaccharide (CTB) was isolated from C. tinctoria. In vitro experiments showed that the inhibition of α-amylase and α-glucosidase by CTB was 13407-fold and 906-fold higher than that by positive control, respectively. Then, a novel arabinogalactan, CTBP-1, was isolated and purified from CTB. Structural analysis showed that CTBP-1 possessed a 1,6-linked ß-d-Galp and 1,5-linked α-l-Araf backbone with branches substituted at the C-3 position of the 1,6-linked ß-d-Galp, and the side chains included 1,5-linked α-l-Araf, T-linked ß-d-Galp and T-linked α-l-Araf. The inhibitory effects of CTBP-1 on α-amylase and α-glucosidase were 2.7 and 17.9 times that of acarbose, respectively. CTBP-1 could avoid indigestion and similar side effects. In addition, CTBP-1 remarkably inhibited the release of nitric oxide (NO), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. In summary, CTBP-1 is a novel arabinogalactan with great potential as a treatment for type 2 diabetes and Alzheimer's disease.

Coreopsis Tinctoria Modulates Lipid Metabolism by Decreasing Low-Density Lipoprotein and Improving Gut Microbiota.

BACKGROUND/AIMS: The prevalence of hyperlipidemia is increasing rapidly. The role of Coreopsis tinctoria (CT) in amending lipid metabolism in hyperlipidemia patients has not been reported. This study aims to evaluate the role of CT in altering lipid metabolism in hyperlipidemia patients and to explore the possible mechanisms mediated by gut microbiota in hyperlipidemia mice models. METHODS: A retrospective analysis in 40 hyperlipidemia patients was conducted, in which 20 patients took fenofibrate and another 20 patients normatively drank water with CT. Hyperlipidemia mice models were also established. Blood biochemical tests were performed using an automatic biochemical analyzer. Liver histopathology was observed by hematoxylin and eosin staining. Ileocecal samples were collected from mice, and bacterial DNA was extracted and sequenced by MiSeq sequencing. Bacterial composition and differences were analyzed. RESULTS: In hyperlipidemia patients, CT was associated with decreased triglyceride and low-density lipoprotein (LDL) levels without liver injury. The experimental hyperlipidemia model also verified a similar result. Gut microbial richness and diversity were significantly decreased in hyperlipidemic mice, but increased after CT treatment. Bacterial communities were significantly differentiated between normal controls and hyperlipidemic mice. CT administration improved gut microbiota composition to an approximately normal status. Meanwhile, CT administration attenuated bacterial alterations at the class, order, family, and genus levels in hyperlipidemic mice. Importantly, the genera Barnesiella, Lactobacillus, and Helicobacter achieved high discriminatory power in hyperlipidemic mice relative to normal controls. CONCLUSIONS: CT can modulate blood lipid metabolism with improvement of liver function by decreasing LDL and improving gut microbiota compositions. These findings may provide novel therapeutic strategies for patients with hyperlipidemia.

Effects of the arbuscular mycorrhizal fungus Glomus mosseae on growth and metal uptake by four plant species in copper mine tailings.

A greenhouse experiment was conducted to evaluate the potential role of arbuscular mycorrhizal fungi (AMF) in encouraging revegetation of copper (Cu) mine tailings. Two native plant species, Coreopsis drummondii and Pteris vittata, together with a turf grass, Lolium perenne and a leguminous plant Trifolium repens associated with and without AMF Glomus mosseae were grown in Cu mine tailings to assess mycorrhizal effects on plant growth, mineral nutrition and metal uptake. Results indicated that symbiotic associations were successfully established between G. mosseae and all plants tested, and mycorrhizal colonization markedly increased plant dry matter yield except for L. perenne. The beneficial impacts of mycorrhizal colonization on plant growth could be largely explained by both improved P nutrition and decreased shoot Cu, As and Cd concentrations. The experiment provided evidence for the potential use of local plant species in combination with AMF for ecological restoration of metalliferous mine tailings.