Pretreatment with quercetin prevents changes in lymphocytes E-NTPDase/E-ADA activities and cytokines secretion in hyperlipidemic rats

Berberine attenuates inflammation and oxidative stress and modulates lymphocyte E-NTPDase in acute hyperlipidemia

Hyperlipidemia is a common clinically encountered health condition worldwide that promotes the development and progression of cardiovascular diseases, including atherosclerosis. Berberine (BBR) is a natural product with acknowledged anti-inflammatory, antioxidant, and metabolic effects. This study evaluated the effect of BBR on lipid alterations, oxidative stress, and inflammatory response in rats with acute hyperlipidemia induced by poloxamer-407 (P-407). Rats were pretreated with BBR (25 and 50 mg/kg) for 14 days and acute hyperlipidemia was induced by a single dose of P-407 (500 mg/kg). BBR ameliorated hypercholesterolemia, hypertriglyceridemia, and plasma lipoproteins in P-407-adminsitered rats. Plasma lipoprotein lipase (LPL) activity was decreased, and hepatic 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase activity was enhanced in hyperlipidemic rats. The expression of low-density lipoprotein receptor (LDL-R) and ATP-binding cassette transporter 1 (ABCA1) was downregulated in hyperlipidemic rats. BBR enhanced LPL activity, upregulated LDL-R, and ABCA1, and suppressed HMG-CoA reductase in P-407-administered rats. Pretreatment with BBR ameliorated lipid peroxidation, nitric oxide (NO), pro-inflammatory mediators (interleukin [IL]-6, IL-1β, tumor necrosis factor [TNF]-α, interferon-γ, IL-4 and IL-18) and enhanced antioxidants. In addition, BBR suppressed lymphocyte ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) and ecto-adenosine deaminase (E-ADA) as well as NO and TNF-α release by macrophages isolated from normal and hyperlipidemic rats. In silico investigations revealed the binding affinity of BBR toward LPL, HMG-CoA reductase, LDL-R, PSK9, ABCA1, and E-NTPDase. In conclusion, BBR effectively prevented acute hyperlipidemia and its associated inflammatory responses by modulating LPL, cholesterolgenesis, cytokine release, and lymphocyte E-NTPDase and E-ADA. Therefore, BBR is an effective and safe natural compound that might be employed as an adjuvant against hyperlipidemia and its associated inflammation.

Role of purinergic signalling in obesity-associated end-organ damage: focus on the effects of natural plant extracts

Obesity has become one of the major public health problems in both the developing and developed countries. Recent studies have suggested that the purinergic signalling is involved in obesity-associated end-organ damage through purine P1 and P2 receptors. In the search for new components for the treatments of obesity, we and other researchers have found much evidence that natural plant extracts may be promising novel therapeutic approaches by modulating purinergic signalling. In this review, we summarize a critical role of purinergic signalling in modulating obesity-associated end-organ damage, such as overhigh appetite, myocardial ischemia, inflammation, atherosclerosis, non-alcoholic fatty liver disease (NAFLD), hepatic steatosis and renal inflammation. Moreover, we focus on the potential roles of several natural plant extracts, including quercetin, resveratrol/trans-resveratrol, caffeine, evodiamine and puerarin, in alleviating obesity-associated end-organ damage via purinergic signalling. We hope that the current knowledge of the potential roles of natural plant extracts in regulating purinergic signalling would provide new ideas for the treatment of obesity and obesity-associated end-organ damage.

Rutin and Quercetin Decrease Cholesterol in HepG2 Cells but Not Plasma Cholesterol in Hamsters by Oral Administration

Rutin (R) and quercetin (Q) are two widespread dietary flavonoids. Previous studies regarding the plasma cholesterol-lowering activity of R and Q generated inconsistent results. The present study was therefore carried out to investigate the effects of R and Q on cholesterol metabolism in both HepG2 cells and hypercholesterolemia hamsters. Results from HepG2 cell experiments demonstrate that both R and Q decreased cholesterol at doses of 5 and 10 µM. R and Q up-regulated both the mRNA and protein expression of sterol regulatory element binding protein 2 (SREBP2), low-density lipoprotein receptor (LDLR), and liver X receptor alpha (LXRα). The immunofluorescence study revealed that R and Q increased the LDLR expression, while only Q improved LDL-C uptake in HepG2 cells. Results from hypercholesterolemia hamsters fed diets containing R (5.5 g/kg diet) and Q (2.5 g/kg diet) for 8 weeks demonstrate that both R and Q had no effect on plasma total cholesterol. In the liver, only Q reduced cholesterol significantly. The discrepancy between the in vitro and in vivo studies was probably due to a poor bioavailability of flavonoids in the intestine. It was therefore concluded that R and Q were effective in reducing cholesterol in HepG2 cells in vitro, whereas in vivo, the oral administration of the two flavonoids had little effect on plasma cholesterol in hamsters.

Rosuvastatin suppresses cytokine production and lung inflammation in asthmatic, hyperlipidemic and asthmatic-hyperlipidemic rat models

BACKGROUND

Given the role that T lymphocytes play on the pathogenesis of allergic asthma, drugs targeting Th2 and Th17 cells may be a hopeful therapeutic strategy. This study aimed to evaluate the effect of rosuvastatin treatment on cytokine production and lung inflammation in allergic asthma.

METHODS

The animals were assigned into control (C), asthmatic (A), hyperlipidemic (H), asthmatic-hyperlipidemic (AH), rosuvastatin (40 mg/kg/day intraperitoneally, for 3 weeks)-treated asthmatic (AR), rosuvastatin-treated hyperlipidemic (HR) and rosuvastatin-treated asthmatic-hyperlipidemic (AHR) groups (n = 6 in each group). The levels of IL-4, IFN-γ and IL-17, total and differential WBC counts in bronchoalveolar lavage fluid (BALF), Th1/Th2 balance, and pathological changes were evaluated.

RESULTS

The BALF level of IL-4 in A, H and AH groups, and IL-17A in A and AH groups were significantly higher than that in C group (p < 0.05 to p < 0.001). IFN-γ level and Th1/Th2 balance (IFN‑γ/IL-4 ratio) in A and AH groups were significantly decreased (p < 0.05 to p < 0.01). Inflammatory cells infiltration, muscle hypertrophy and emphysema were also observed in A and AH groups. The BALF levels of IL-4 in AR, HR and AHR groups, IFN-γ level in HR group, and IL-17A level in AR and AHR groups showed a significant improvement compared to that of A, H and AH groups (p < 0.05 to p < 0.001). Rosuvastatin treatment increased Th1/Th2 balance in all treated groups (p < 0.05 to p < 0.01), decreased total WBC counts, neutrophilia, eosinophilia and lung inflammation in AR and AHR groups, and improved muscle hypertrophy and emphysema in AHR group.

CONCLUSIONS

Rosuvastatin treatment improved lung pathological changes by suppression of Th2 and Th17-mediated cytokines which was unrelated to its lipid-lowering activity. Therefore, rosuvastatin might be a candidate immunomodulatory drug for treatment of patients with allergic asthma.