The effect of citrus flavonoids on the redox state of alimentary-induced fatty liver in rats

Age Is Just a Number: Progress and Obstacles in the Discovery of New Candidate Drugs for Sarcopenia

Sarcopenia is a disease characterized by the progressive loss of skeletal muscle mass and function that occurs with aging. The progression of sarcopenia is correlated with the onset of physical disability, the inability to live independently, and increased mortality. Due to global increases in lifespan and demographic aging in developed countries, sarcopenia has become a major socioeconomic burden. Clinical therapies for sarcopenia are based on physical therapy and nutritional support, although these may suffer from low adherence and variable outcomes. There are currently no clinically approved drugs for sarcopenia. Consequently, there is a large amount of pre-clinical research focusing on discovering new candidate drugs and novel targets. In this review, recent progress in this research will be discussed, along with the challenges that may preclude successful translational research in the clinic. The types of drugs examined include mitochondria-targeting compounds, anti-diabetes agents, small molecules that target non-coding RNAs, protein therapeutics, natural products, and repositioning candidates. In light of the large number of drugs and targets being reported, it can be envisioned that clinically approved pharmaceuticals to prevent the progression or even mitigate sarcopenia may be within reach.

Diosmin Mitigates Cyclophosphamide Induced Premature Ovarian Insufficiency in Rat Model

The current study was designed to investigate the protective role of diosmin against cyclophosphamide-induced premature ovarian insufficiency (POI). Female Swiss albino rats received a single intraperitoneal dose of cyclophosphamide (200 mg/kg) followed by 8 mg/kg/day for the next 15 consecutive days either alone or in combination with oral diosmin at 50 or 100 mg/kg. Histopathological examination of ovarian tissues, hormonal assays for follicle stimulating hormone (FSH), estradiol (E2), and anti-Mullerian hormone (AMH), assessment of the oxidative stress status, as well as measurement of the relative expression of miRNA-145 and its target genes [vascular endothelial growth factor B (VEGF-B) and regulator of cell cycle (RGC32)] were performed. Diosmin treatment ameliorated the levels of E2, AMH, and oxidative stress markers. Additionally, both low and high diosmin doses significantly reduced the histopathological alterations and nearly preserved the normal ovarian reserve. MiRNA-145 expression was upregulated after treatment with diosmin high dose. miRNA-145 target genes were over-expressed after both low and high diosmin administration. Based on our findings, diosmin has a dose-dependent protective effect against cyclophosphamide-induced ovarian toxicity in rats.

Citrus flavonoids and their antioxidant evaluation

The antioxidant ability is the link and bridge connecting a variety of biological activities. Citrus flavonoids play an essential role in regulating oxidative stress and are an important source of daily intake of antioxidant supplements. Many studies have shown that citrus flavonoids promote health through antioxidation. In this review, the biosynthesis, composition and distribution of citrus flavonoids were concluded. The detection methods of antioxidant capacity of citrus flavonoids were divided into four categories: chemical, cellular, animal and clinical antioxidant capacity evaluation systems. The modeling methods, applicable scenarios, and their relative merits were compared based on these four systems. The antioxidant functions of citrus flavonoids under different evaluation systems were also discussed, especially the regulation of the Nrf2-antioxidases pathway. Some shortcomings in the current research were pointed out, and some suggestions for progress were put forward.

Metabolism and pharmacological activities of the natural health-benefiting compound diosmin

Diosmin is a famous natural flavonoid for treating chronic venous insufficiency and varicose veins.

Quercetin stimulates mitochondrial apoptosis dependent on activation of endoplasmic reticulum stress in hepatic stellate cells

CONTEXT

Activation of hepatic stellate cells (HSCs) is a hallmark of liver fibrosis. Quercetin has benefits for liver fibrosis, but the mechanisms are unknown.

OBJECTIVE

We investigated the quercetin effect on HSC survival and the role of endoplasmic reticulum stress (ERS).

MATERIALS AND METHODS

Rat HSCs and LO2 hepatocytes were treated with quercetin (0.5-120 μM) for 24 h. Quercetin (10-40 μM) effects on apoptosis for 24 h were analyzed by flow cytometry and TUNEL staining. Quercetin (10-40 μM) effects on the expression of Bcl-2, caspase-9, caspase-3, PARP-1, PERK, IRE1, ATF6, calnexin and CHOP for 24 h were analyzed by Western blot. Quercetin (10-40 μM) effects on mRNA expression of calnexin and CHOP for 24 h were analyzed by Real-time PCR.

RESULTS

Quercetin at concentrations greater than 20 μM significantly inhibited HSC proliferation (IC₅₀ 27.2 μM), but did not affect hepatocyte growth until 80 μM (IC₅₀ 68.5 μM). Quercetin stimulated HSC apoptosis and the apoptotic rate reached 40% at a concentration of 40 μM (EC₅₀ 51.6 μM). Quercetin induced downregulation of Bcl-2 and upregulation of Bax, and increased cytochrome C in the cytoplasm in HSCs. The cleaved forms of caspase-9, caspase-3 and PARP-1 were also increased by quercetin. Furthermore, quercetin elevated mRNA and protein expression of calnexin and CHOP in HSCs but not in hepatocytes. Quercetin also increased phosphorylation of PERK and IRE1 and ATF6 cleavage. However, ERS inhibitor salubrinal significantly abrogated quercetin induction of HSC apoptosis.

CONCLUSION

Quercetin activated ERS pathway in HSCs leading to apoptosis. We characterized an ERS-mediated mechanism for quercetin as a promising antifibrotic agent.

The Possible Role of Flavonoids in the Prevention of Diabetic Complications

Type 2 diabetes mellitus is a disease that affects many metabolic pathways. It is associated with insulin resistance, impaired insulin signaling, β-cell dysfunction, abnormal glucose levels, altered lipid metabolism, sub-clinical inflammation and increased oxidative stress. These and other unknown mechanisms lead to micro- and macro-complications, such as neuropathy, retinopathy, nephropathy and cardiovascular disease. Based on several in vitro animal models and some human studies, flavonoids appear to play a role in many of the metabolic processes involved in type 2 diabetes mellitus. In this review, we seek to highlight the most recent papers focusing on the relationship between flavonoids and main diabetic complications.

A flavonoid fraction purified from Rutaceae aurantiae (Daflon(R)) inhibiting AGE formation, reduces urinary albumin clearance and corrects hypoalbuminemia in normotensive and hypertensive diabetic rats

AIM

Advanced glycation endproducts (AGEs) have been shown to contribute to alteration of glomerular permselectivity to proteins in diabetes. Oxidative stress is required for AGE formation. Therefore we studied the effect of an antioxidant micronized purified flavonoid fraction (MPFF, Daflon(R) 500 mg), on urinary albumin clearance in diabetic rats.

METHODS

Hyperglycaemia was induced by streptozotocin 55 mg/kg IM at days 0 and 7 in normotensive Wistar rats (NWR, diabetes duration 5 months) or hypertensive Wistar Kyoto rats (SHR, diabetes duration 2 months). MPFF was administered at 300 mg/kg/day, from day -2 until sacrifice.

RESULTS

After 5 months of diabetes in NWR, MPFF reduced albumin clearance from 729±92 to 392±60 nl/min/kg, p<0.01, and restored albuminemia from 20.4±0.9 to 24.0±1 g/l, p<0.05; albumin fractional clearance was significantly diminished in the flavonoid-treated diabetic rats (0.360±0.037‰ versus 1.335±0.430‰ in the diabetic controls, p<0.001); MPFF did not significantly modify blood glucose and plasma fructosamine levels. After 2 months of diabetes in SHR, MPFF reduced albumin clearance from 243±121 to 101±47 nl/min/kg, p<0.05, and restored albuminemia from 21.1±1.6 to 26.7±2.2 g/l (p<0.05); MPFF also decreased plasma fluorescence characteristic of AGEs (p<0.02). Besides hesperetin, a main metabolite of MPFF recovered in plasma, inhibited in vitro the formation of the crosslinking AGE pentosidine in collagen incubated with high glucose (p<0.001).

CONCLUSION

Our results confirm the role of glycoxidative stress in diabetic nephropathy. MPFF might be useful as complementary treatment for preventing diabetic microangiopathy.

Calculation of melatonin and resveratrol effects on steatosis hepatis using soft computing methods

In this work, beneficial effects of melatonin and resveratrol drugs on liver damage in rats, induced by application of acute and chronic carbon tetrachloride (CCl4) have been examined. The study consists of three main stages: (1) DATA ACQUISITION: light microscopic images were obtained from 60 rats separated into 10 groups after the preparation of liver tissue samples for histological examination. Rats in first five experimental groups for the four-day and the other five groups for twenty-day were examined. (2) Data processing: by the help of histograms of oriented gradient (HOG) method, obtaining low-dimensional image features (color, shape and texture) and classifying five different group characteristics by using these features with artificial neural networks (ANNs), and support vector machines (SVMs) have been provided. (3) Calculation of drug effectiveness: firstly to determine the differences between group characteristics of rats, a pilot group has been selected (diseased group-CCl4), and the responses of ANN and SVM trained by HOG features have been calculated. As a result of ANN, it has been seen that melatonin and resveratrol drugs have %65.62-%75.12 positive effects at the end of the fourth day, %84.12-%98.89 positive effects on healing steatosis hepatis at the end of the twentieth day respectively and as a result of SVM, it has been seen that melatonin and resveratrol drugs have %62.5-%68.75 positive effects at the end of the fourth day, %45.12-%60.89 positive effects on healing steatosis hepatis at the end of the twentieth day respectively.

The genetic epidemiology of nonalcoholic fatty liver disease: toward a personalized medicine

The understanding of the genetic bases of complex diseases such as nonalcoholic fatty liver disease opens new opportunities and challenges. This article explores new tools designed toward moving genomic data into clinical medicine, providing putative answers to more practical questions.