Protective effect of umbelliferone on high-fructose diet-induced insulin resistance and oxidative stress in rats

Liver-Targeting Composite Nanocarrier Delivery System Based on Chitosan Nanoparticles and Phospholipid Complexes

Liver fibrosis is mainly caused by excessive accumulation of extracellular matrix and structural changes in the liver, ultimately leading to cirrhosis if left untreated. Reducing hyaluronan synthesis by inhibiting hyaluronic acid deposition or regulating the expression of hyaluronic synthase can ameliorate liver fibrosis symptoms. In this study, we aimed to improve the bioavailability and liver-targeting capacity of hydroxymethyl coumarin (4-MU) using a newly developed phospholipid complex chitosan nanoparticle (4-MU PC/CNP) optimized using the Box-Behnken design. The composite nanocarrier delivery system was formulated using solvent evaporation technology, and formulation and process parameters were evaluated. Furthermore, 4-MU PC/CNPs and their pharmacokinetics were characterized. The established 4-MU PC/CNPs had an average particle size of 153.07 ± 0.29 nm, a polydispersity index value of 0.383, and a positive zeta potential of ∼35.4 mV. Compared with 4-MUs, 4-MU PC/CNPs exhibited significantly improved water solubility, faster plasma clearance and tissue distribution, and better liver targeting. Pharmacokinetic analysis showed that the oral bioavailability of 4-MU in 4-MU PC/CNPs was significantly higher than that of simple 4-MU. In conclusion, 4-MU PC improved drug lipid (oil-water distribution coefficient of 1.31 ± 0.03) and water solubilities (2.05 times the drug substance). 4-MU PC/CNPs significantly improved 4-MU oral bioavailability, representing a promising approach for enhancing drug solubility. This study demonstrates that the targeting parameters of 4-MU PC/CNPs in the liver were all greater than 1, indicating that they specifically targeted the liver, thereby potentially alleviating liver fibrosis.

Response surface methodology optimization and HPLC-ESI-QTOF-MS/MS analysis on ultrasonic-assisted extraction of phenolic compounds from okra (Abelmoschus esculentus) and their antioxidant activity

Okra (Abelmoschus esculentus) has attracted a growing attention for its nutritional and medicinal values, while few studies focused on systemic study of okra polyphenols (OP). In order to obtain the maximum extracted efficiency, response surface methodology was used to optimize ultrasonic-assisted extraction conditions. The maximum TPC was 7.02 mg GAE/g dw under the condition of solid-liquid ratio 1:25, ethanol concentration 70 %, 40 min, and 142 W at 46 °C. Then 27 compounds in OP were identified by HPLC-ESI-QTOF-MS/MS, among which 7-hydroxycoumarin, scopoletin, luteolin and et al were firstly identified from okra. Furthermore, OP exhibited antioxidant activity in reducing power (FRAP, 9.77 mM Fe²⁺/g OP) and radical scavenging (DPPH, IC₅₀ 19.31 µg/mL; SARC, IC₅₀ 210.81 µg/ml). Moreover, OP significantly inhibited cell apoptosis and ROS generation, and alleviated oxidative damage in t-BHP induced HUVECs. Overall, our findings could provide perspective for further potential employments of okra as functional food.

Moringa, Rosemary and Purslane Leaves Extracts Alleviate Metabolic Syndrome in Rats Induced by High Fat-High Fructose Diet

<b>Background and Objective:</b> Metabolic syndrome is a cluster of metabolic abnormalities characterized by obesity, insulin resistance and dyslipidemia. This study aimed to investigate the impact of moringa, rosemary and purslane leave water extracts on metabolic syndrome in rats. <b>Materials and Methods:</b> Phenolic compounds in the plant leaves water extracts were determined by HPLC. Fifty adult male albino rats Sprague-Dawley strain were equally divided into five groups, group (1) Normal rats fed on the balanced diet, group (2) Metabolic syndrome rats fed on High Fat-High Fructose Diet (HF-HFD). The other three groups were fed on HF-HFD and orally administered 200 mg kg<sup></sup><sup>1</sup> b.wt. daily of the tested plant's leaves water extracts, respectively, for 12 weeks. Some anthropometric measurements (BMI, Lee index and adiposity index), biochemical parameters such as glucose hemostasis parameters (glucose, Insulin, HOMA-IR and GLP-1), lipids profile (TAGs, TC, LDL-C, HDL-C, free fatty acids, Apo-B and Apo A1), adipokines (leptin and adiponectin), some inflammatory markers (TNF-α and IL-6) and oxidative stress markers (PCC, NO and MDA), some anti-oxidant markers (GSH, CAT and TAOC) as well as, the gene expression level of endothelial nitric oxide synthase were determined. <b>Results:</b> The results revealed that feeding rats with HF-HFD for 12 weeks significantly increased anthropometric measurements, some inflammatory markers and oxidative stress markers and worsen glucose hemostasis parameters, lipids profile, adipokines and endothelial function as compared to the normal group. Moreover, co-administration of the tested plant's extracts at the tested dose to HF-HFD fed rats reduced the development of indicators of metabolic syndrome when compared to the metabolic syndrome group. <b>Conclusion:</b> The administered plant leaves water extracts at the tested dose could improve the features of metabolic syndrome. Rosemary leaves water extract has more effect in comparison with the other extracts.

Umbelliferone Ameliorates Complete Freund Adjuvant-Induced Arthritis via Reduction of NF-κB Signaling Pathway in Osteoclast Differentiation

Osteoclasts, bone-resorbing somatic cells, are directly responsible for bone destruction during rheumatoid arthritis. Complete Freund adjuvant (CFA) is a widely used animal model using rodents for studying rheumatoid arthritis (RA), which effectively manifests serious cartilage destruction and progressive bone erosion, affecting synovial joints and serious joint dysfunction. It was considered that joint injury in RA is induced through systemic inflammation pathway. Umbelliferone (UF), a coumarin derivative of Agele marmilosa, possesses anti-inflammatory activity. In the current study, we scrutinize the effect of umbelliferone on CFA-induced arthritis model and explore the possible mechanism on bone destruction. Intradermal administration of CFA (0.05 mL) was to induce RA manifestations in the experimental rats and the same oral administration of UF was received. The anti-arthritic activity of UF was determined by its inhibitory activity on various biochemical markers, viz., pro-inflammatory, inflammatory, antioxidant enzymes, and hematological parameters elevated during RA condition. We also estimated the mRNA expression of osteoclast parameters. Obtained result disclosed significant reduction in the paw edema and increment of the body weight after UF administration. UF reduce the inflammatory mediatory such as COX-2, PGE₂, NF-kB, and VEGF; pro-inflammatory cytokines include TNF-α, IL-1β, IL-6, IL-10, and IL-17 significantly. Moreover, UF treatment significantly reduced the osteoclast number via modulating the RANKL/RANK/OPG ratio. Furthermore, administration of umbelliferone significantly (P < 0.001) suppressed the NF-κB and VEGF. Collectively, our results indicated the novel role of umbelliferone in osteoclastogenesis and proved that umbelliferone is a modern therapeutic tool as a natural agent for treating arthritis and other autoimmune disorders with bone degradation.

The impact of sugar-sweetened beverage intake on rat cardiac function

Aims

Although there is evidence linking sugar-sweetened beverage (SSB) intake with the development of cardio-metabolic diseases, the underlying mechanisms remain unclear. The current study therefore evaluated the effects of SSB consumption by establishing a unique in-house in vivo experimental model.

Main methods

Male Wistar rats were divided into two groups: a) one consuming a popular local SSB (SSB- Jive), and b) a control group (Control-water) for a period of three and six months (n = 6 per group), respectively. Rats were gavaged on a daily basis with an experimental dosage amounting to half a glass per day (in human terms) (SSB vs. water). Cardiac function was assessed at baseline (echocardiography) and following ex vivo ischemia-reperfusion of the isolated perfused working rat heart. Oral glucose tolerance tests and mitochondrial respiratory analyses were also performed. In addition, the role of non-oxidative glucose pathways (NOGPs), i.e. the polyol pathway, hexosamine biosynthetic pathway (HBP) and PKC were assessed.

Key findings

These data show that SSB intake: a) resulted in increased weight gain, but did not elicit major effects in terms of insulin resistance and cardiac function after three and six months, respectively; b) triggered myocardial NOGP activation after three months with a reversion after six months; and c) resulted in some impairment in mitochondrial respiratory capacity in response to fatty acid substrate supply after six months.

Significance

SSB intake did not result in cardiac dysfunction or insulin resistance. However, early changes at the molecular level may increase risk in the longer term.

Tartary buckwheat flavonoids ameliorate high fructose-induced insulin resistance and oxidative stress associated with the insulin signaling and Nrf2/HO-1 pathways in mice

The present study was conducted to explore the effects of a purified tartary buckwheat flavonoid fraction (TBF) on insulin resistance and hepatic oxidative stress in mice fed high fructose in drinking water (20%) for 8 weeks. The results indicated that continuous administration of TBF dose-dependently improved the insulin sensitivity and glucose intolerance in high fructose-fed mice. TBF treatment also reversed the reduced level of insulin action on the phosphorylation of insulin receptor substrate-1 (IRS-1), protein kinase B (Akt) and phosphatidylinositol 3-kinase (PI3K), as well as the translocation of glucose transporter type 4 (GLUT4) in the insulin-resistant liver. Furthermore, TBF was found to exert high antioxidant capacity as it acts as a shield against oxidative stress induced by high fructose by restoring the antioxidant status, and modulating nuclear factor E2 related factor 2 (Nrf2) translocation to the nucleus with subsequently up-regulated antioxidative enzyme protein expression. Histopathological examinations revealed that impaired pancreatic/hepatic tissues were effectively restored in high fructose-fed mice following TBF treatment. Our results show that TBF intake is effective in preventing the conversion of high fructose-induced insulin resistance and hepatic oxidative stress in mice by improving the insulin signaling molecules and the Nrf2 signal pathway in the liver.

Hydroxycitric acid ameliorates high-fructose-induced redox imbalance and activation of stress sensitive kinases in male Wistar rats

BACKGROUND

Excess fructose consumption causes dyslipidemia, oxidative stress, and various complications. Hydroxycitric acid (HCA), one of the principal components of the fruit Garcinia cambogia, has been shown to possess antiobesity properties. The objective was to investigate the effects of HCA on redox imbalance and activation of stress sensitive kinases in high fructose-fed rats.

METHODS

Male Wistar rats (n=40) were randomly divided into four groups with 10 rats in each group. The rats were fed with either standard rodent diet or 60% fructose diet and administered with HCA at a dose of 400 mg/kg body wt/day for 10 weeks. Body weight was measured once a week, and food intake was noted daily. At the end of the study, lipid profile and oxidative stress parameters were estimated. Expressions of stress sensitive kinases were analyzed in liver homogenates.

RESULTS

Fructose-fed rats displayed elevated body weight, higher levels of plasma total cholesterol (TC), triacylglycerol (TAG), non-high-density lipoprotein cholesterol (non HDL-C), malondialdehyde (MDA), total oxidant status (TOS), oxidative stress index (OSI), lower levels of HDL-C, glutathione (GSH), glutathione peroxidase (GPx), and total antioxidant status (TAS). Fructose feeding caused higher phosphorylation of stress sensitive kinases ERK ½ and p38. Administration with HCA lowered body weight, food intake, TAG, non-HDL-C, MDA, TOS, and OSI and elevated GSH, GPx, and TAS levels. Reduced phosphorylation of ERK ½ and p38 mitogen-activated protein kinase (MAPK) was observed upon HCA treatment.

CONCLUSIONS

Thus, HCA improved fructose induced redox imbalance and activation of stress sensitive kinases through its hypolipidemic effects.

Virgin coconut oil maintains redox status and improves glycemic conditions in high fructose fed rats

Virgin Coconut Oil (VCO), extracted from fresh coconut kernel possess similar fatty acid composition to that of Copra Oil (CO), a product of dried kernel. Although CO forms the predominant dietary constituent in south India, VCO is being promoted for healthy life due to its constituent antioxidant molecules. High fructose containing CO is an established model for insulin resistance and steatohepatitis in rodents. In this study, replacement of CO with VCO in high fructose diet markedly improved the glucose metabolism and dyslipidemia. The animals fed VCO diet had only 17 % increase in blood glucose level compared to CO fed animals (46 %). Increased level of GSH and antioxidant enzyme activities in VCO fed rats indicate improved hepatic redox status. Reduced lipid peroxidation and carbonyl adducts in VCO fed rats well corroborate with the histopathological findings that hepatic damage and steatosis were comparatively reduced than the CO fed animals. These results suggest that VCO could be an efficient nutraceutical in preventing the development of diet induced insulin resistance and associated complications possibly through its antioxidant efficacy.

NFAT inhibitor tributylhexadecylphosphoniumbromide, ameliorates high fructose induced insulin resistance and nephropathy

High fructose diet (HFrD)-induced insulin resistance (IR) has been reported to be associated with an increase in albuminuria, glomerular hypertrophy and inflammation in kidney. However, the molecular mechanisms associated with high fructose-induced IR and renal dysfunction are still unclear. In the present study, we have investigated the role of nuclear factor of activated T-cell (NFAT) and its inhibitor, Tributylhexadecylphosphoniumbromide (THPB) in high fructose-induced IR and renal injury. NFAT inhibition by THPB treatment significantly improved HFrD-induced insulin resistance. Treatment with THPB markedly reduced high fructose diet-induced protein expression of NFATc4, PTEN and also alleviated expression of inflammatory markers in kidneys of HFrD rats. Further, THPB treatment not only improved acute ANG II responses but also repressed the processes of renal fibrosis, ECM accumulation, foot process effacement and renal apoptosis in HFrD rats. Taken together, we for the first time provide evidence that HFrD -induced insulin resistance and renal injury is associated with dysregulated NFATc4/PTEN signalling and THPB prevents this dysregulation through inhibition of NFATc4. Thus, targeting NFATc4 can be a novel therapeutic approach for preventing HFrD induced- IR and renal injury.