Hypotensive and lipid regulatory actions of 4-hydroxyderricin, a chalcone from Angelica keiskei, in stroke-prone spontaneously hypertensive rats

Randomised, double-blind, parallel group comparison of Ashitaba (Angelica Keiskei) chalcone effects on visceral fat areas and waist circumference of overweight persons

This randomised, placebo-controlled, double-blind, parallel-group study aimed to determine whether encapsulated Ashitaba chalcone (16 mg comprising 10.1 mg 4-hydroxyderricin and 5.9 mg xanthoangelol) could reduce obesity in 17 men and 25 women with a body mass index (BMI) of 25 to < 30. Participants ingested capsules containing either the chalcone or a placebo daily for 12 weeks. The primary endpoint was changes in visceral fat areas determined by computed tomography (CT) at baseline, and at 8 and 12 weeks later. The primary endpoint, abdominal visceral fat area, was significantly reduced in the chalcone, compared with a placebo group 12 weeks after screening (p < 0.05). The secondary endpoint, waist circumference, was significantly decreased in the chalcone, compared with the placebo group at weeks 8 and 12 (p < 0.05 at week 8; p < 0.01 at week 12). Therefore, Ashitaba chalcone has anti-obesity benefits for overweight men and women.

Chalcone Scaffolds, Bioprecursors of Flavonoids: Chemistry, Bioactivities, and Pharmacokinetics

Chalcones are secondary metabolites belonging to the flavonoid (C6-C3-C6 system) family that are ubiquitous in edible and medicinal plants, and they are bioprecursors of plant flavonoids. Chalcones and their natural derivatives are important intermediates of the flavonoid biosynthetic pathway. Plants containing chalcones have been used in traditional medicines since antiquity. Chalcones are basically α,β-unsaturated ketones that exert great diversity in pharmacological activities such as antioxidant, anticancer, antimicrobial, antiviral, antitubercular, antiplasmodial, antileishmanial, immunosuppressive, anti-inflammatory, and so on. This review provides an insight into the chemistry, biosynthesis, and occurrence of chalcones from natural sources, particularly dietary and medicinal plants. Furthermore, the pharmacological, pharmacokinetics, and toxicological aspects of naturally occurring chalcone derivatives are also discussed herein. In view of having tremendous pharmacological potential, chalcone scaffolds/chalcone derivatives and bioflavonoids after subtle chemical modification could serve as a reliable platform for natural products-based drug discovery toward promising drug lead molecules/drug candidates.

4-Hydroxyderricin Promotes Apoptosis and Cell Cycle Arrest through Regulating PI3K/AKT/mTOR Pathway in Hepatocellular Cells

4-hydroxyderricin (4-HD), as a natural flavonoid compound derived from Angelica keiskei, has largely unknown inhibition and mechanisms on liver cancer. Herein, we investigated the inhibitory effects of 4-HD on hepatocellular carcinoma (HCC) cells and clarified the potential mechanisms by exploring apoptosis and cell cycle arrest mediated via the PI3K/AKT/mTOR signaling pathway. Our results show that 4-HD treatment dramatically decreased the survival rate and activities of HepG2 and Huh7 cells. The protein expressions of apoptosis-related genes significantly increased, while those related to the cell cycle were decreased by 4-HD. 4-HD also down-regulated PI3K, p-PI3K, p-AKT, and p-mTOR protein expression. Moreover, PI3K inhibitor (LY294002) enhanced the promoting effect of 4-HD on apoptosis and cell cycle arrest in HCC cells. Consequently, we demonstrate that 4-HD can suppress the proliferation of HCC cells by promoting the PI3K/AKT/mTOR signaling pathway mediated apoptosis and cell cycle arrest.

Inhibitory effects of tangeretin and trans-ethyl caffeate on the HMG-CoA reductase activity: Potential agents for reducing cholesterol levels

One of the pathways to reduce cholesterol production in the liver is through the inhibition of HMG-Coa reductase (HMGCR) by current drugs, statins. However, these have side effects if consumed in prolonged periods. Tangeretin and trans-ethyl caffeate as alternative drugs in reducing hypercholesterolemia and preventing atherosclerosis have never been reported. Their effects on inhibiting HMGCR activity were investigated through enzymatic method (in vitro and in vivo). The toxicity property was analyzed on the Serum Glutamate Oxalate Transaminase (SGOT)/Serum Glutamate Piruvate Transaminase (SGPT) levels and rat liver histology. The results showed that both compounds inhibited HMGCR activity significantly compare to the control simvastatin (p < 0.05). Tangeretin which showed very good activity in inhibiting HMGCR (83.8 of % inhibition, equal to simvastatin) was selected and used for anti-hypercholesterolemia in vivo assessment. Furthermore, tangeretin was shown to effectively reduced Total Cholesterol (TC) and Low Density Lipoprotein (LDL), and increased High Density Lipoprotein (HDL) levels significantly compared to the simvastatin group (p < 0.05). Tangeretin group was also proven to inhibit HMGCR rat liver activity significantly compare to the control simvastatin (p < 0.05). The toxicity study on the SGOT/SGPT levels and liver histology revealed that there were no side effects after administration by tangeretin. Results found that both tangeretin and trans-ethyl caffeate are potent candidates as anti-hypercholesterolemia agent in vitro. In addition, tangeretin was also shown to be safe and suitable as an alternative treatment for controlling hypercholesterolemia in vivo as well as have potency for preventing atherosclerosis.

Simultaneous Optimization of Ultrasound-Assisted Extraction for Flavonoids and Antioxidant Activity of Angelica keiskei Using Response Surface Methodology (RSM)

Angelica keiskei Koidzumi (A. keiskei), as a Japanese edible herbal plant, enjoys a variety of biological activities due to the presence of numerous active compounds, especially flavonoids. This study aims for the optimization of ultrasound-assisted extraction (UAE) for flavonoids in A. keiskei and their antioxidant activity by using the response surface methodology (RSM). Single-factor experiments and a four-factor three-level Box-Behnken design (BBD) were performed to explore the effects of the following parameters on flavonoid extraction and antioxidant activity evaluation: ultrasonic temperature (X1), ultrasonic time (X2), ethanol concentration (X3) and liquid-solid ratio (X4). The optimum conditions of the combination of total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity (DPPH-RSC) and ferric-reducing antioxidant power (FRAP) were as follows: X1 = 80 °C, X2 = 4 min, X3 = 78%, X4 = 35 mL/g, respectively. The experimental results provide a theoretical basis for the extensive utilization of A. keiskei and flavonoids extraction from A. keiskei as a potential source of antioxidants.

Minor phenolics from Angelica keiskei and their proliferative effects on Hep3B cells

A new coumarin, (-)-cis-(3'R,4'R)-4'-O-angeloylkhellactone-3'-O-β-d-glucopyranoside (1) and two new chalcones, 3'-[(2E)-5-carboxy-3-methyl-2-pentenyl]-4,2',4'-trihydroxychalcone (4) and (±)-4,2',4'-trihydroxy-3'-{2-hydroxy-2-[tetrahydro-2-methyl-5-(1-methylethenyl)-2-furanyl]ethyl}chalcone (5) were isolated from the aerial parts of Angelica keiskei (Umbelliferae), together with six known compounds: (R)-O-isobutyroyllomatin (2), 3'-O-methylvaginol (3), (-)-jejuchalcone F (6), isoliquiritigenin (7), davidigenin (8), and (±)-liquiritigenin (9). The structures of the new compounds were determined by interpretation of their spectroscopic data including 1D and 2D NMR data. All known compounds (2, 3, and 6-9) were isolated as constituents of A. keiskei for the first time. To identify novel hepatocyte proliferation inducer for liver regeneration, 1-9 were evaluated for their cell proliferative effects using a Hep3B human hepatoma cell line. All isolates exhibited cell proliferative effects compared to untreated control (DMSO). Cytoprotective effects against oxidative stress induced by glucose oxidase were also examined on Hep3B cells and mouse fibroblast NIH3T3 cells and all compounds showed significant dose-dependent protection against oxidative stress.

Angelica keiskei, an emerging medicinal herb with various bioactive constituents and biological activities

Angelica keiskei (Miq.) Koidz. (Umbelliferae) has traditionally been used to treat dysuria, dyschezia, and dysgalactia as well as to restore vitality. Recently, the aerial parts of A. keiskei have been consumed as a health food. Various flavonoids, coumarins, phenolics, acetylenes, sesquiterpene, diterpene, and triterpenes were identified as the constituents of A. keiskei. The crude extracts and pure constituents were proven to inhibit tumor growth and ameliorate inflammation, obesity, diabetics, hypertension, and ulcer. The extract also showed anti-thrombotic, anti-oxidative, anti-hyperlipidemic, anti-viral, and anti-bacterial activities. This valuable herb needs to be further studied and developed not only to treat these human diseases but also to improve human health. Currently A. keiskei is commercialized as a health food and additives in health drinks. This article presents a comprehensive review of A. keiskei and its potential place in the improvement of human health.

Therapeutic potential of chalcones as cardiovascular agents

Cardiovascular diseases are the leading cause of death affecting 17.3 million people across the globe and are estimated to affect 23.3 million people by year 2030. In recent years, about 7.3 million people died due to coronary heart disease, 9.4 million deaths due to high blood pressure and 6.2 million due to stroke, where obesity and atherosclerotic progression remain the chief pathological factors. The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates to inhibit various cardiovascular, hematological and anti-obesity targets like angiotensin converting enzyme (ACE), cholesteryl ester transfer protein (CETP), diacylglycerol acyltransferase (DGAT), acyl-coenzyme A: cholesterol acyltransferase (ACAT), pancreatic lipase (PL), lipoprotein lipase (LPL), calcium (Ca(2+))/potassium (K(+)) channel, COX-1, TXA2 and TXB2. In this review, a comprehensive study of chalcones, their therapeutic targets, structure activity relationships (SARs), mechanisms of actions (MOAs) have been discussed. Chemically diverse chalcone scaffolds, their derivatives including structural manipulation of both aryl rings, replacement with heteroaryl scaffold(s) and hybridization through conjugation with other pharmacologically active scaffold have been highlighted. Chalcones which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-hypertensive, anti-anginal, anti-arrhythmic and cardioprotective agents. With the knowledge of these molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective chalcone derivatives as potential cardiovascular agents.

Separation of two major chalcones from Angelica keiskei by high-speed counter-current chromatography

Angelica keiskei (Shin-sun cho) is an edible higher plant with the beneficial preventive effects on cancer, hypertension, and coronary heart disease. Two bioactive chalcones of Shin-sun cho, xanthoangelol (1) and 4-hydroxyderricin (2), were separated simultaneously by using high-speed counter-current chromatography with a two-phase solvent system composed of n-hexane-EtOAc-MeOH-H2O (9:5:9:4). Only nonconsuming processes, solvent fractionations and Sephadex LH-20 column chromatography, were conducted as presteps. Xanthoangelol (1, 35.9 mg, 99.9 % purity at 254 and 365 nm) and 4-hydroxyderricin (2, 4.4 mg, 98.7 % purity at 254 nm and 98.8 % purity at 365 nm) were successfully purified from 70 mg of the processed extract from A. keiskei. The structures of two compounds were confirmed by (1)H- and (13)C-NMR analysis.

Xanthoangelol and 4-Hydroxyderricin Are the Major Active Principles of the Inhibitory Activities against Monoamine Oxidases on Angelica keiskei K

Monoamine oxidase inhibitors (MAOI) have been widely used as antidepressants. Recently, there has been renewed interest in MAO inhibitors. The activity-guided fractionation of extracts from Angelica keiskei Koidzumi (A. keiskei K.) led to the isolation of two prenylated chalcones, xanthoangelol and 4-hydroxyderricin and a flavonoid, cynaroside. These three isolated compounds are the major active ingredients of A. keiskei K. to inhibit the MAOs and DBH activities. Xanthoangelol is a nonselective MAO inhibitor, and a potent dopamine β-hydroxylase (DBH) inhibitor. IC₅₀ values of xanthoangelol to MAO-A and MAO-B were calculated to be 43.4 μM, and 43.9 μM. These values were very similar to iproniazid, which is a nonselective MAO inhibitor used as a drug against depression. The IC₅₀ values of iproniazid were 37 μM, and 42.5 μM in our parallel examination. Moreover, IC₅₀ value of xanthoangelol to DBH was calculated 0.52 μM. 4-Hydroxyderricin is a potent selective MAO-B inhibitor and also mildly inhibits DBH activity. The IC₅₀ value of 4-hydroxyderricin to MAO-B was calculated to be 3.43 μM and this value was higher than that of deprenyl (0.046 μM) used as a positive control for selective MAO-B inhibitor in our test. Cynaroside is a most potent DBH inhibitor. The IC₅₀ value of cynaroside to DBH was calculated at 0.0410 μM. Results of this study suggest that the two prenylated chalcones, xanthoangelol and 4-hydroxyderricin isolated from A. keiskei K., are expected for potent candidates for development of combined antidepressant drug. A. keiskei K. will be an excellent new bio-functional food material that has the combined antidepressant effect.

Probing antioxidant activity of 2'-hydroxychalcones: crystal and molecular structures, in vitro antiproliferative studies and in vivo effects on glucose regulation

In order to better understand the antioxidant behavior of a series of polyphenolic 2'-hydroxychalcones, we describe the results of several chemical and biological studies, in vitro and in vivo. Single crystal X-ray methods elucidated their molecular structures and important intermolecular interactions such as H-bonding and molecular stacking in the crystal structures that contribute to our knowledge in explaining antioxidant activity. The results of experiments using the 1,1-diphenyl-2-dipicrylhydrazyl (DPPH) UV-vis spectroscopic method indicate that a hydroxyl group in position 5' induces the highest antioxidant activity. Consequently, 2,2',5'-trihydroxychalcone was selected for further study in vitro towards ROS scavenging in L-6 myoblasts and THP-1 human monocytes, where it shows an excellent antioxidant activity in a concentration range lower than that reported by most studies of related molecules. In addition, this chalcone shows a very selective activity: it inhibits the proliferation of leukemic cells, but it does not affect the normal L-6 myoblasts and human fibroblasts. In studying 2,2',5'-trihydroxychalcone's effect on weight gain and serum glucose and insulin levels in Zucker fatty (fa(-)/fa(-)) rats we found that supplementing the diet with a 10 mg/kg dose of this chalcone (3 times weekly) blunted the increase in glucose that co-occurs with weight gain over the 6-week treatment period. It is concluded that 2,2',5'-trihydroxychalcone has the potential to serve as a protective agent for some debilitating diseases.

Phenols, Alkaloids and Terpenes from Medicinal Plants with Antihypertensive and Vasorelaxant Activities. A Review of Natural Products as Leads to Potential Therapeutic Agents

Numerous studies support the cardiovascular effects of medicinal plants. This review examines plants whose antihypertensive and vasorelaxant effects have been scientifically validated. Our study selected only chemically characterized plants whose mode of action had already been investigated. The aim of the paper is to provide a quick way to identify medicinal plants and their constituents with antihypertensive and vasorelaxant activities.

Phloridzin reduces blood glucose levels and improves lipids metabolism in streptozotocin-induced diabetic rats

Phloridzin is the specific and competitive inhibition of sodium/glucose cotransporters in the intestine (SGLT1) and kidney (SGLT2). This property which could be useful in the management of postprandial hyperglycemia in diabetes and related disorders. Phloridzin is one of the dihydrochalcones typically contained in apples and in apple-derived products. The effect of phloridzin orally doses 5, 10, 20 and 40 mg/kg body weight on diabetes was tested in a streptozotocin-induced rat model of diabetes type 1. From beneficial effect of this compound is significant reduction of blood glucose levels and improve dyslipidemia in diabetic rats. As a well-known consequence of becoming diabetic, urine volume and water intake were significantly increased. Administration of phloridzin reduced urine volume and water intake in a dose-dependent manner. Phloretin decreases of food consumption, as well as a marked lowering in the weight. In conclusion, this compound could be proposed as an antihyperglycemic and antihyperlipidemic agent in diabetes and potential therapeutic in obesity.

The role of chalcones in suppression of NF-κB-mediated inflammation and cancer

Although consumption of fruits, vegetables, spices, cereals and pulses has been associated with lower incidence of cancer and other chronic diseases, how these dietary agents and their active ingredients minimize these diseases, is not fully understood. Whether it is oranges, kawa, hops, water-lilly, locorice, wax apple or mulberry, they are all connected by a group of aromatic ketones, called chalcones (1,3-diaryl-2-propen-1-ones). Some of the most significant chalcones identified from these plants include flavokawin, butein, xanthoangelol, 4-hydroxyderricin, cardamonin, 2',4'-dihydroxychalcone, isoliquiritigenin, isosalipurposide, and naringenin chalcone. These chalcones have been linked with immunomodulation, antibacterial, antifungal, antiviral, anti-inflammatory, antioxidant, anticancer, and antidiabetic activities. The current review, however, deals with the role of various chalcones in inflammation that controls both the immune system and tumorigenesis. Inflammatory pathways have been shown to mediate the survival, proliferation, invasion, angiogenesis and metastasis of tumors. How these chalcones modulate inflammatory pathways, tumorigenesis and immune system is the focus of this review.

BENEFICIAL EFFECT OF XANTHOANGELOL, A CHALCONE COMPOUND FROM ANGELICA KEISKEI, ON LIPID METABOLISM IN STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

1. Recently, we reported that 4-hydroxyderricin, one of the major chalcones in Angelica keiskei extract (ethyl acetate extract from the yellow liquid of stems), exerted hypotensive and lipid regulatory actions in stroke-prone spontaneously hypertensive rats (SHRSP). In the present study, we isolated xanthoangelol, another major chalcone in A. keiskei extract, and examined the effect of dietary xanthoangelol on blood pressure and lipid metabolism in SHRSP. 2. Six-week-old male SHRSP were fed diets containing 0.02% or 0.1% xanthoangelol (0.02 and 0.10 Xan, respectively) for 7 weeks, with free access to the diet and water. There were no significant changes in daily food intake, bodyweight or systolic blood pressure throughout the experimental period. Serum total cholesterol levels tended to decrease in the two experimental groups (albeit not significantly), which was due to a dose-dependent decrease in the cholesterol content of the low-density lipoprotein (LDL) fraction. These results suggest that dietary xanthoangelol decreases serum LDL levels. 3. In the liver, significant dose-dependent decreases in relative liver liver weight and total triglyceride content were seen in the 0.02 and 0.10 Xan groups. In addition, a significant decrease in total cholesterol content was found in the 0.10 Xan group, which may be due to an elevation of faecal cholesterol excretion in addition to the decrease in liver weight. 4. Investigation of the hepatic mRNA expression of proteins involved in lipid metabolism indicated that there was a significant increase in peroxisome proliferator-activated receptor (PPAR) alpha mRNA expression associated with the tendency for increases in acyl-coenzyme A (CoA) synthetase and acyl-CoA oxidase mRNA expression in the 0.10 Xan group, which may be responsible, at least in part, for the decrease in hepatic triglyceride content in the xanthoangelol-treated rats. In addition, a significant increase in LDL receptor mRNA expression in the 0.10 Xan group may be responsible, at least in part, for the decrease in serum LDL levels in the xanthoangelol-treated rats. 5. In conclusion, dietary xanthoangelol results in a reduction of serum LDL levels and decreases in total cholesterol and triglyceride contents in the liver of SHRSP. These beneficial effects are more effective following consumption of diet containing 0.10% xanthoangelol.

Beneficial effect of laserpitin, a coumarin compound fromAngelica keiskei, on lipid metabolism in stroke‐prone spontaneously hypertensive rats

Recently, we found that 4-hydroxyderricin, one of the major chalcones in Angelica keiskei extract (an ethyl acetate extract from the yellow liquid of stems), suppressed increases in systolic blood pressure and reduced both serum very low-density lipoprotein levels and liver triglyceride content in stroke-prone spontaneously hypertensive rats (SHRSP). In the present study, we have isolated laserpitin, a characteristic coumarin, from the A. keiskei extract and examined the effect of dietary laserpitin on blood pressure and lipid metabolism in SHRSP. Six-week-old male SHRSP were fed diets containing 0.1% laserpitin for 7 weeks with free access to the diet and water. Bodyweight gain was reduced by dietary laserpitin after 4 weeks through to 7 weeks without any significant change in daily food intake. Serum total cholesterol, phospholipid and apolipoprotein (apo) E levels were significantly increased, which was due to significant increases in cholesterol, phospholipid and apoE contents in the low- and high-density lipoprotein (LDL and HDL, respectively) fractions. These results suggest that dietary laserpitin increases serum apoE-HDL levels. In the liver, significant decreases in relative liver weight and triglyceride content were found after treatment with laserpitin for 7 weeks. An investigation of hepatic mRNA expression of proteins involved in lipid metabolism indicated that a significant decrease in hepatic triglyceride lipase may be responsible for the increase in serum HDL levels and also indicated that a marked decrease in adipocyte determination and differentiation factor 1 may be responsible, at least in part, for the decrease in hepatic triglyceride content. In conclusion, dietary laserpitin produces increases in serum HDL levels, especially apoE-HDL, and decreases in the hepatic triglyceride content in SHRSP.