Hypoglycemic effect of standardized Chrysanthemum zawadskii ethanol extract in high-fat diet/streptozotocin-induced diabetic mice and rats

Parthenolide ameliorates diabetic retinopathy by suppressing microglia-induced Müller cell gliosis and inflammation via the NF-κB signalling

Diabetic retinopathy (DR) is characterized by retinal inflammation and gliosis and the interaction between Müller cells and microglia plays a crucial role in DR pathogenesis. A sesquiterpene lactones, Parthenolide (PTL), has potent anti-inflammatory effects. This study aimed to evaluate the efficacy of PTL in ameliorating DR and the underlying mechanisms. A co-culture system of primary Müller cells and microglia under normoglycemic and hyperglycemic conditions was established. The study utilized immunofluorescent staining, Western blot analysis, ELISA, and molecular docking simulations to assess the influence of PTL on cellular interactions and NF-κB signaling modulation. Additionally, an in vivo diabetic mouse model was treated with varying doses of PTL to examine its effects on retinal pathologies, activity of Müller cells and microglia, and inflammatory responses. Co-culture with microglia exacerbated hyperglycemia-induced gliosis in Müller cells, indicated by increased GFAP expression and reduced GLAST and Kir4.1 levels. PTL treatment significantly attenuated these changes, reducing the pro-inflammatory cytokines and inhibiting microglia activation, as evidenced by decreased Iba-1 expression via suppressing NF-κB nuclear translocation. In diabetic mice, PTL demonstrated a dose-dependent protective effect against retinal damage and regulated Müller cell activation by inhibiting NF-κB activation. PTL effectively mitigates DR by suppressing microglia-induced Müller cell gliosis and inflammation, primarily via the NF-κB signaling. The findings highlight the potential of targeting Müller cell-microglia interactions in DR therapy, offering a novel approach to managing this complication. This study underscores the therapeutic promise of PTL in DR treatment, warranting further clinical exploration.

Antidiabetic Effect of Standardized Chrysanthemum rubellum Hydroethanolic Extract by Targeting α-Glucosidase and the PTP-1B Signaling Pathway for Alleviating Diabetes in Experimental Model

Objectives

The study's goal was to find out whether Chrysanthemum rubellum extract has anti-diabetic properties by concentrating on α-glucosidase and the PTP-1B signaling pathway. C. rubellum flowers were used for extraction using Methanol/water (80/20) as solvent.

Methods

LC-MS techniques was used to check the presence of phytoconstituents present in C. rubellum extract. In vitro antidiabetic activity was evaluated using α-glucosidase inhibitory activity and PTP-1B signaling pathway. On Streptozotocin (STZ)-induced rats with diabetes, the in vivo antidiabetic efficacy was assessed using a test for oral glucose tolerance.

Results

The phytoconstituents identified in the extract of C. rubellum were apigenin, diosmin, myricetin, luteolin, luteolin-7-glucoside, and Quercitrin as compound 1-6, respectively. Results showed that diosmin exhibited highest α-glucosidase inhibitory activity i.e. 90.39%. The protein level of PTP-1B was lowered and the insulin signalling activity was directly increased by compounds 1-6. The maximum blood glucose levels were seen in all groups' OGTT findings at 30 minutes following glucose delivery, followed by gradual drops. In comparison to the control group, the extract's glucose levels were 141 mg/dL at 30 minutes before falling to 104 mg/dL after 120 minutes. The current study has demonstrated, in summary, that extract with phytoconstituents reduce blood sugar levels in rats.

Conclusion

This finding suggests that extract may reduce the chance of insulin resistance and shield against disorders like hyperglycemia.

Analysis of Chemical Constituents of Chrysanthemum morifolium Extract and Its Effect on Postprandial Lipid Metabolism in Healthy Adults

Chrysanthemum extract possesses antioxidant potential and carbohydrate and fat digestive enzyme inhibitory in vitro. However, no evidence supporting chrysanthemum in modulation of postprandial lipemia and antioxidant status in humans presently exists. This study was to analyze the composition of Imperial Chrysanthemum (IC) extract and determine the effect on changes in postprandial glycemic and lipemic response and antioxidant status in adults after consumption of a high-fat (HF) meal. UHPLC-MS method was used to analyze the components of two kinds of IC extracts (IC-P/IC-E) and in vitro antioxidant activities were evaluated using 1,1-diphenyl-2-picrylhydraxyl (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Hydroxyl radical (HR) radical scavenging assays. Following a randomized design, 37 healthy adults (age, 25.2 ± 2.6 years, and BMI, 20.9 ± 1.5 kg/m2) were assigned to two groups that consumed the HF meal, or HF meal supplemented by IC extract. Blood samples were collected at fasting state and then at 0.5, 1, 2, 4, 6 and 8 h after the meal consumption. There were 12 compounds with relative content of more than 1% of the extracts, of which amino acid and derivatives, flavonoids, carboxylic acids and derivatives were the main components. Compared with IC-E, the contents of flavonoids in IC-P increased significantly (p < 0.05), and the cynaroside content exceeded 30%. In addition, IC-P showed strong free radical scavenging activity against DPPH, ABTS and HR radicals. Furthermore, according to repeated−measures ANOVA, significant differences were observed in the maximal changes for postprandial glucose, TG, T-AOC and MDA among the two groups. Postprandial glucose has significant difference between the two groups at 1 h after meal and the level in IC group was significantly lower than that in control group. No significant differences were observed in the incremental area under the curve (iAUC) among the two groups. IC significantly improved the serum antioxidant status, as characterized by increased postprandial serum T-AOC, SOD, GSH and decreased MDA. This finding suggests that IC can be used as a natural ingredient for reducing postprandial lipemia and improving the antioxidant status after consuming a HF meal.

Linarin, a Glycosylated Flavonoid, with Potential Therapeutic Attributes: A Comprehensive Review

Many flavonoids, as eminent phenolic compounds, have been commercialized and consumed as dietary supplements due to their incredible human health benefits. In the present study, a bioactive flavone glycoside linarin (LN) was designated to comprehensively overview its phytochemical and biological properties. LN has been characterized abundantly in the Cirsium, Micromeria, and Buddleja species belonging to Asteraceae, Lamiaceae, and Scrophulariaceae families, respectively. Biological assessments exhibited promising activities of LN, particularly, the remedial effects on central nervous system (CNS) disorders, whereas the remarkable sleep enhancing and sedative effects as well as AChE (acetylcholinesterase) inhibitory activity were highlighted. Of note, LN has indicated promising anti osteoblast proliferation and differentiation, thus a bone formation effect. Further biological and pharmacological assessments of LN and its optimized semi-synthetic derivatives, specifically its therapeutic characteristics on osteoarthritis and osteoporosis, might lead to uncovering potential drug candidates.

Chrysanthemi Zawadskii var. Latilobum Attenuates Obesity-Induced Skeletal Muscle Atrophy via Regulation of PRMTs in Skeletal Muscle of Mice

As obesity promotes ectopic fat accumulation in skeletal muscle, resulting in impaired skeletal muscle and mitochondria function, it is associated with skeletal muscle loss and dysfunction. This study investigated whether Chrysanthemi zawadskii var. latilobum (CZH) protected mice against obesity-induced skeletal muscle atrophy and the underlying molecular mechanisms. High-fat diet (HFD)-induced obese mice were orally administered either distilled water, low-dose CZH (125 mg/kg), or high-dose CZH (250 mg/kg) for 8 w. CZH reduced obesity-induced increases in inflammatory cytokines levels and skeletal muscle atrophy, which is induced by expression of atrophic genes such as muscle RING-finger protein 1 and muscle atrophy F-box. CZH also improved muscle function according to treadmill running results and increased the muscle fiber size in skeletal muscle. Furthermore, CZH upregulated mRNA and protein levels of protein arginine methyltransferases (PRMT)1 and PRMT7, which subsequently attenuated mitochondrial dysfunction in the skeletal muscle of obese mice. We also observed that CZH significantly decreased PRMT6 mRNA and protein expression, which resulted in decreased muscle atrophy. These results suggest that CZH ameliorated obesity-induced skeletal muscle atrophy in mice via regulation of PRMTs in skeletal muscle.

Dendrobium officinale polysaccharide ameliorates diabetic hepatic glucose metabolism via glucagon-mediated signaling pathways and modifying liver-glycogen structure

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium officinale polysaccharide (DOP) is the main active ingredient of Dendrobium officinale Kimura & Migo, which is a precious traditional Chinese medicine and often used in treatment of hepatitis, diabetes, obesity and rheumatoid arthritis.

AIM OF THE STUDY

DOP exhibits significant hypoglycemic activity, while its mechanism remains unclear. The present study aims to investigate the hypoglycemic mechanisms of DOP based on the glucagon-mediated signaling pathways and the liver glycogen structure, which catalyze hepatic glucose metabolism, and provide new knowledge about the antidiabetic mechanism of DOP and further evidence for its clinical use for diabetes.

MATERIALS AND METHODS

DOP were obtained from the dry stems of Dendrobium officinale by water extraction and alcohol precipitation method. T2DM mice model was established by high-fat diet combined with streptozotocin. Liver histopathological changes were observed by H&E and PAS straining. Pancreatic histology was studied by H&E staining and immunofluorescence analysis. The levels of glucagon and insulin were detected by Elisa Kit and the hepatic glycogen content was detected by GOPOD. The expressions of the hepatic glycogen-related metabolism enzymes, hepatic gluconeogenesis enzymes, and the related protein in cAMP-PKA and Akt/FoxO1 signaling pathways were detected by western blots. Liver glycogen was extracted from the liver tissues by sucrose density gradient centrifugation, and size exclusion chromatography (SEC) was used to analyze the structure of liver glycogen.

RESULTS

DOP could significantly affect the glucagon-mediated signaling pathways, cAMP-PKA and Akt/FoxO1, to further promote hepatic glycogen synthesis, inhibit hepatic glycogen degradation and hepatic gluconeogenesis. Moreover, DOP could reverse the instability of the liver glycogen structure and thus probably suppressed glycogen degradation. Thus, DOP finally would ameliorate hepatic glucose metabolism via glucagon-mediated signaling pathways and modifying liver-glycogen structure in diabetic mice.

CONCLUSIONS

The hypoglycemic mechanism of DOP might be associated with the regulation of glucagon-mediated hepatic glycogen metabolism and gluconeogenesis, and of liver glycogen structure, contributing to improved hepatic glucose metabolism in diabetic mice.