Anti-hyperlipidemic properties of CM108 (a flavone derivative) in vitro and in vivo

Metal complexes of flavonoids: their synthesis, characterization and enhanced antioxidant and anticancer activities

Flavonoids are polyphenolic compounds of natural origin. They are extensively studied within drug discovery programs due to their wide ranging biological activities such as antimicrobial, antioxidant, antitumor, neuroprotective and cardioprotective properties. The ability of flavonoids to coordinate with metal atoms has provided new leads for drug discovery programs, with better pharmacological activities and clinical profiles than the parent flavonoids. In this review, the enhanced antioxidant and anticancer activities of flavonoid metal complexes versus the parent flavonoids are discussed. Possible mechanisms of action for the metal complexes, such as DNA binding and apoptosis induction, are also presented alongside an overview of the synthesis of the metal complexes, and the different techniques used for their characterization.

Association of Dietary Flavonoid Intake with Prevalence of Type 2 Diabetes Mellitus and Cardiovascular Disease Risk Factors in Korean Women Aged ≥30 Years

The purpose of this study was to investigate the association between dietary flavonoid intake and the prevalence of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) risk factors among Korean women aged ≥30 y. This study used data collected from the 2007-2012 Korean National Health and Nutrition Examination Survey. We excluded subjects who had energy intake <500 kcal or ≥5,000 kcal, were diagnosed with chronic disease, were taking medication, or were pregnant or lactating. The final subjects included 7,963 women, and they were divided into 2 groups, the normal fasting glucose (NFG) group (n=7,738) and the T2DM group (n=225). The intake of flavonoids was estimated on the basis of the flavonoid database. After adjustment for confounding factors, the mean intakes of fruits, anthocyanidins, and flavones were significantly lower in the T2DM group than in the NFG group. In multiple regression analysis, the dietary flavone intake was negatively associated with systolic blood pressure, triglyceride, TG/HDL-cholesterol, and homesostatic model assessment of insulin resistance. Daily intake of flavones above the 25th percentile was associated with a lower prevalence of T2DM compared with intake below the 25th percentile (OR=0.593, 95% confidence interval (CI): 0.414-0.847). These study results showed that dietary flavone intake may have some beneficial effects in reducing CVD risks and prevalence of T2DM in Korean women.

Facile synthesis of acacetin and its derivatives

Acacetin, a O-methylated bioflavonoid isolated from the traditional Chinese medicine Xuelianhua (Saussurea tridactyla), is a promising orally effective atrium-selective antiarrhythmic agent for the treatment of atrial fibrillation (AF). Here we describe an efficient two-component method for the synthesis of acacetin and its derivatives.

Realistic intake of a flavanol-rich soluble cocoa product increases HDL-cholesterol without inducing anthropometric changes in healthy and moderately hypercholesterolemic subjects

To assess whether antioxidant, anti-inflammatory and other cardio-protective effects attributed to cocoa are achieved when regularly consuming moderate amounts of a flavanol-rich soluble cocoa product, a non-randomized, controlled, crossover, free-living study was carried out in healthy (n = 24; 25.9 ± 5.6 years) and moderately hypercholesterolemic (200-240 mg dL(-1); n = 20; 30.0 ± 10.3 years) volunteers. Participants consumed two servings per day (7.5 g per serving) of a soluble cocoa product (providing 45.3 mg flavanols per day) in milk, which was compared with consuming only milk during a 4 week period. The effects on systolic and diastolic blood pressure and heart rate were determined, as well as on serum lipid and lipoprotein profiles, interleukins (IL)-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), vascular (VCAM-1) and intercellular cell adhesion molecules (ICAM-1), serum malondialdehyde (MDA), carbonyl groups (CG), ferric reducing/antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and free radical scavenging capacity (ABTS). During the study, the volunteers' diets and physical activity were also evaluated, as well as any changes in weight, skin folds, circumferences and related anthropometric parameters. Cocoa and certain polyphenol-rich fruits and vegetables and their derivatives were restricted. After consuming the cocoa product positive effects were observed such as an increase in serum HDL-C (p < 0.001) and dietary fiber intake (p = 0.050), whereas IL-10 decreased (p = 0.022). Other cardiovascular-related biomarkers and anthropometric parameters were unaffected. We have therefore concluded that regular consumption of this cocoa product in a Spanish-Mediterranean diet may protect against cardiovascular disease in healthy and hypercholesterolemic subjects without producing any weight gain or other anthropometric changes.

Flavones: an important scaffold for medicinal chemistry

Flavones have antioxidant, anti-proliferative, anti-tumor, anti-microbial, estrogenic, acetyl cholinesterase, anti-inflammatory activities and are also used in cancer, cardiovascular disease, neurodegenerative disorders, etc. Also, flavonoids are found to have an effect on several mammalian enzymes like protein kinases that regulate multiple cell signaling pathways and alterations in multiple cellular signaling pathways are frequently found in many diseases. Flavones have been an indispensable anchor for the development of new therapeutic agents. The majority of metabolic diseases are speculated to originate from oxidative stress, and it is therefore significant that recent studies have shown the positive effect of flavones on diseases related to oxidative stress. Due to the wide range of biological activities of flavones, their structure-activity relationships have generated interest among medicinal chemists. The outstanding development of flavones derivatives in diverse diseases in very short span of time proves its magnitude for medicinal chemistry research. The present review gives detail about the structural requirement of flavone derivatives for various pharmacological activities. This information may provide an opportunity to scientists of medicinal chemistry discipline to design selective, optimize as well as poly-functional flavone derivatives for the treatment of multi-factorial diseases.

Hesperetin upregulates ABCA1 expression and promotes cholesterol efflux from THP-1 macrophages

ABCA1, a member of the ATP-binding cassette transporter family, regulates high-density lipoprotein (HDL) metabolism and cholesterol transport. Its expression is upregulated mainly by the activation of the liver X receptor (LXR). Since ABCA1 plays a pivotal role in cholesterol and HDL metabolism, identification of a compound capable of increasing its expression may be beneficial for the prevention and therapy of atherosclerosis. Firefly luciferase reporter assays were developed for human ABCA1 promoters and LXR enhancers, and an in-house phytochemical library was screened. It was found that a citrus flavonoid, hesperetin (1), increased ABCA1 promoter and LXR enhancer activities in THP-1 macrophages. It was also found that this flavonoid promoted PPAR-enhancing activity. In accordance with these findings, 1 increased mRNA and protein expression of ABCA1 and consequently upregulated ApoA-I-mediated cholesterol efflux. These results provide evidence that 1 promotes ApoA-I-mediated cholesterol efflux from macrophages by increasing ABCA1 expression through the activation of LXRα and PPARγ.

Cacao polyphenols influence the regulation of apolipoprotein in HepG2 and Caco2 cells

Cocoa powder is rich in polyphenols, such as catechins and procyanidins, and has been shown to inhibit low-density lipoprotein (LDL) oxidation and atherogenesis in a variety of models. Human studies have also shown daily intake of cocoa increases plasma high-density lipoprotein (HDL) and decreases LDL levels. However, the mechanisms responsible for these effects of cocoa on cholesterol metabolism have yet to be fully elucidated. The present study investigated the effects of cacao polyphenols on the production of apolipoproteins A1 and B in human hepatoma HepG2 and intestinal Caco2 cell lines. The cultured HepG2 cells or Caco2 cells were incubated for 24 h in the presence of cacao polyphenols such as (-)-epicatechin, (+)-catechin, procyanidin B2, procyanidin C1, and cinnamtannin A2. The concentration of apolipoproteins in the cell culture media was quantified using an enzyme-linked immunoassay, and the mRNA expression was quantified by RT-PCR. Cacao polyphenols increased apolipoprotein A1 protein levels and mRNA expression, even though apolipoprotein B protein and the mRNA expression were slightly decreased in both HepG2 cells and Caco2 cells. In addition, cacao polyphenols increased sterol regulatory element binding proteins (SREBPs) and activated LDL receptors in HepG2 cells. These results suggest that cacao polyphenols may increase the production of mature form SREBPs and LDL receptor activity, thereby increasing ApoA1 and decreasing ApoB levels. These results elucidate a novel mechanism by which HDL cholesterol levels become elevated with daily cocoa intake.

Hypolipidaemic mechanisms of action of CM108 (a flavone derivative) in hyperlipidaemic rats

In the present study, the molecular mechanisms by which CM108, a flavone derivative, improves lipid profiles were investigated further. Hyperlipidaemia was induced by oral administration of high cholesterol and fat. After 4 weeks of treatment, the lipid levels in the serum, liver and faeces were measured and the liver genes involved in lipid metabolism were analysed to explore the molecular mechanisms of lowering lipids. CM108 modulated lipid profiles, including elevating the level of high-density lipoprotein cholesterol (HDL-C; 40%) and reducing serum levels of triglyceride (10%), total cholesterol (10%) and low-density lipoprotein cholesterol (26%). Levels of triglyceride and total cholesterol in the liver were reduced by 18% and 24%, respectively. Increased HDL-C level was attributed to the synergic effects of CM108 in increasing levels of ATP-binding cassette transporter (ABC)A1, apolipoprotein AI and apolipoprotein AII in the liver. Intriguingly, CM108 induced genes, including fatty acid transport protein, acyl-CoA synthetase and lipoprotein lipase that are important for more efficient fatty acid β-oxidation, thereby reducing serum and liver triglyceride levels. In addition, induction of ABCG5, ABCG8 and cholesterol 7α-hydroxylase contributed to cholesterol metabolism, leading to decreases in serum and liver cholesterol levels. Thus, the genes involved in lipid metabolism were systemically modulated by CM108, which contributed to the improvement of lipid profiles in hyperlipidaemic rats.

7-Hydroxy-benzopyran-4-one derivatives: a novel pharmacophore of peroxisome proliferator-activated receptor alpha and -gamma (PPARalpha and gamma) dual agonists

Design, synthesis, and in vitro bioevaluation of a new class of potential dual PPARalpha and gamma agonists discovered through a structure-driven design paradigm are described. The 7-hydroxy-benzopyran-4-one moiety (includes flavones, flavanones, and isoflavones) is the key pharmacophore of these novel molecules, exhibiting similarity to the core structure of both fibrates and thiazolidinediones. New lead PPAR ligands were identified from "natraceuticals" and synthetic analogues. In total, 77 molecules, including chalcones, flavones, flavanones, isoflavones, and pyrazole derivatives, were screened and structure-activity relationship studies of the dual agonists undertaken. Compounds 68, 70, 72, and 76 were identified as novel and potent dual PPARalpha and gamma agonists. These novel molecules may have the potential to be the future leads in PPAR-related disorders, including type II diabetes mellitus and metabolic syndrome.

Hypoglycaemic and hypolipidaemic effects of Withania somnifera root and leaf extracts on alloxan-induced diabetic rats

Withania somnifera is an important medicinal plant, which is used in traditional medicine to cure many diseases. Flavonoids were determined in the extracts of W. somnifera root (WSREt) and leaf (WSLEt). The amounts of total flavonoids found in WSREt and WSLEt were 530 and 520 mg/100 g dry weight (DW), respectively. Hypoglycaemic and hypolipidaemic effects of WSREt and WSLEt were also investigated in alloxan-induced diabetic rats. WSREt and WSLEt and the standard drug glibenclamide were orally administered daily to diabetic rats for eight weeks. After the treatment period, urine sugar, blood glucose, haemoglobin (Hb), glycosylated haemoglobin (HbA1C), liver glycogen, serum and tissues lipids, serum and tissues proteins, liver glucose-6-phosphatase (G6P) and serum enzymes like aspartate transaminase (AST), alanine transaminase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) levels were determined. The levels of urine sugar, blood glucose, HbA1C, G6P, AST, ALT, ACP, ALP, serum lipids except high density lipoprotein-bound cholesterol (HDL-c) and tissues like liver, kidney and heart lipids were significantly (p < 0.05) increased, however Hb, total protein, albumin, albumin:globulin (A:G) ratio, tissues protein and glycogen were significantly (p < 0.05) decreased in alloxan-induced diabetic rats. Treatment of the diabetic rats with WSREt, WSLEt and glibenclamide restored the changes of the above parameters to their normal level after eight weeks of treatment, indicating that WSREt and WSLEt possess hypoglycaemic and hypolipidaemic activities in alloxan-induced diabetes mellitus (DM) rats.