Artery relaxation by chalcones isolated from the roots of Angelica keiskei

Vasorelaxant effects of biochemical constituents of various medicinal plants and their benefits in diabetes

Endothelial function plays a pivotal role in cardiovascular health, and dysfunction in this context diminishes vasorelaxation concomitant with endothelial activity. The nitric oxide-cyclic guanosine monophosphate pathway, prostacyclin-cyclic adenosine monophosphate pathway, inhibition of phosphodiesterase, and the opening of potassium channels, coupled with the reduction of calcium levels in the cell, constitute critical mechanisms governing vasorelaxation. Cardiovascular disease stands as a significant contributor to morbidity and mortality among individuals with diabetes, with adults afflicted by diabetes exhibiting a heightened cardiovascular risk compared to their non-diabetic counterparts. A plethora of medicinal plants, characterized by potent pharmacological effects and minimal side effects, holds promise in addressing these concerns. In this review, we delineate various medicinal plants and their respective biochemical constituents, showcasing concurrent vasorelaxant and anti-diabetic activities.

Exploring the Targets of Novel Corona Virus and Docking-based Screening of Potential Natural Inhibitors to Combat COVID-19

There is a need to explore natural compounds against COVID-19 due to their multitargeted actions against various targets of nCoV. They act on multiple sites rather than single targets against several diseases. Thus, there is a possibility that natural resources can be repurposed to combat COVID-19. However, the biochemical mechanisms of these inhibitors were not known. To reveal the mode of anti-nCoV action, structure-based docking plays a major role. The present study is an attempt to explore various potential targets of SARS-CoV-2 and the structure-based screening of various potential natural inhibitors to combat the novel coronavirus.

Vasorelaxant Effect of Novel Nitric Oxide-Hydrogen Sulfide Donor Chalcone in Isolated Rat Aorta: Involvement of cGMP Mediated sGC and Potassium Channel Activation

BACKGROUND AND OBJECTIVE

Recently, nitric oxide (NO) and hydrogen sulfide (H2S) donating moieties were extensively studied for their role in the vasculature as they are responsible for many cellular and pathophysiological functioning. The objective of the present study is to evaluate novel NO and H2S donating chalcone moieties on isolated rat aorta for vasorelaxation, and to investigate the probable mechanism of action.

METHODS

To extend our knowledge of vasorelaxation by NO and H2S donor drugs, here we investigated the vasorelaxing activity of novel NO and H2S donating chalcone moieties on isolated rat aorta. The mechanism of vasorelaxation by these molecules was investigated by performing in vitro cGMP mediated sGC activation assay and using Tetraethylammonium chloride (TEA) as a potassium channel blocker and Methylene blue as NO blocker.

RESULTS

Both NO and H2S donating chalcone moieties were found to be potent vasorelaxant. The compound G4 and G5 produce the highest vasorelaxation with 3.716 and 3.789 M of pEC50, respectively. After the addition of TEA, G4 and G5 showed 2.772 and 2.796 M of pEC50, respectively. The compounds Ca1, Ca2, and D7 produced significant activation and release of cGMP mediated sGC which was 1.677, 1.769 and 1.768 M of pEC50, respectively.

CONCLUSION

The vasorelaxation by NO-donating chalcones was blocked by Methylene blue but it did not show any effect on H2S donating chalcones. The vasorelaxing potency of NO-donating molecules was observed to be less affected by the addition of TEA but H2S donors showed a decrease in both efficacy and potency. The cGMP release was more in the case of NO-donating molecules. The tested compounds were found potent for relaxing vasculature of rat aorta.

Secondary Metabolites of Plants as Modulators of Endothelium Functions

According to the World Health Organization, cardiovascular diseases are the main cause of death worldwide. They may be caused by various factors or combinations of factors. Frequently, endothelial dysfunction is involved in either development of the disorder or results from it. On the other hand, the endothelium may be disordered for other reasons, e.g., due to infection, such as COVID-19. The understanding of the role and significance of the endothelium in the body has changed significantly over time—from a simple physical barrier to a complex system encompassing local and systemic regulation of numerous processes in the body. Endothelium disorders may arise from impairment of one or more signaling pathways affecting dilator or constrictor activity, including nitric oxide–cyclic guanosine monophosphate activation, prostacyclin–cyclic adenosine monophosphate activation, phosphodiesterase inhibition, and potassium channel activation or intracellular calcium level inhibition. In this review, plants are summarized as sources of biologically active substances affecting the endothelium. This paper compares individual substances and mechanisms that are known to affect the endothelium, and which subsequently may cause the development of cardiovascular disorders.

[Research on Analysis of Final Diagnosis and Prognostic Factors, and Development of New Therapeutic Drugs for Malignant Tumors (Especially Malignant Pediatric Tumors)]

Outcomes of treatment for malignant pediatric tumors including leukemia are improving by conventional multimodal treatment with strong chemotherapy, surgical resection, radiotherapy, and bone marrow transplantation. However, patients with advanced neuroblastoma, metastatic Ewing's sarcoma family of tumor (ESFT), and metastatic osteosarcoma continue to have an extremely poor prognosis. Therefore novel therapeutic strategies are urgently needed to improve their survival. Apoptotic cell death is a key mechanism for normal cellular homeostasis. Intact apoptotic mechanisms are pivotal for embryonic development, tissue remodeling, immune regulation, and tumor regression. Genetic aberrations disrupting programmed cell death often underpin tumorigenesis and drug resistance. Moreover, it has been suggested that apoptosis or cell differentiation proceeds to spontaneous regression in early stage neuroblastoma. Therefore apoptosis or cell differentiation is a critical event in this cancer. We extracted many compounds from natural plants (Angelica keiskei, Alpinia officiarum, Lycaria puchury-major, Brassica rapa) or synthesized cyclophane pyridine, indirubin derivatives, vitamin K3 derivatives, burchellin derivatives, and GANT61, and examined their effects on apoptosis, cell differentiation, and cell cycle in neuroblastoma and ESFT cell lines compared with normal cells. Some compounds were very effective against these tumor cells. These results suggest that they may be applicable as an efficacious and safe drug for the treatment of malignant pediatric tumors.

New flavonoid-based compound synthesis strategy for antihypertensive drug development

Hypertension is one of the leading causes of mortality in relation to the cardiovascular conditions and easily the most overlooked and poorly managed disease in mankind. With well over 200 drugs available in the market globally, there is still an urgency to search for antihypertensive alternatives due to the subpar efficacy and unwarranted side effects of the current choices. Present studies reported over 250 types of plant-derived compounds were being investigated for potential pharmacological effects on the vasculature in the last 3 decades. There were numerous literatures that claimed various compounds exhibiting vasorelaxant properties to a certain extent with low numbers of these compounds being successfully adapted into the current medicinal practice for treatment of hypertension. The issue is the scarcity of reviews that summarizes the discovery of this field and the lack of thorough comparison of these compounds to identify which of these vasodilators should be the next face of hypertension management. Thus, this review is aiming towards identifying the relationship between a major class of plant-derived compounds, flavonoid's activity as a vasodilator with their signalling pathways and their structural characteristics according to their vasorelaxant properties. Interestingly, we found that both nitric oxide and voltage-operated calcium channels pathways, and two of the flavonoid's structural characteristics play crucial roles in eliciting strong vasorelaxant effects. We have faith that the insights of this review will serve as a reference for those researching similar topics in the future and potentially lead to the development of more promising antihypertensive alternative.

Investigation of anti-inflammatory, nitric oxide donating, vasorelaxation and ulcerogenic activities of 1, 3-diphenylprop-2-en-1-one derivatives in animal models

The main aim of this work is to find out novel chemical moieties with potent anti-inflammatory and vasorelaxant activities with reduced gastric toxicities. For fulfilling the above aim, here we investigated novel chalcones (1, 3-diphenylprop-2-en-1-one derivatives) with nitric oxide (NO) and hydrogen sulphide (H₂ S) donating potency for anti-inflammatory activity by carrageenan-induced rat paw oedema. These molecules then further evaluated for in-vitro NO-releasing potency and vasorelaxation effect on isolated adult goat aortic tissue. The promising molecules were further screened for ulcerogenic activity in the rat model. The tested compounds produced % inhibition in paw oedema ranging from 29.16% to 79.69% and standard drug Diclofenac sodium produced 85.30% reduction in paw oedema after 5 hours. Out of this dataset, compounds AI1, AI7, Ca1, B2, B10, D2, and E8 showed 73.01%, 79.69%, 75.02%, 75.46%, 74.35%, 73.9% and 74.35% reduction in paw oedema respectively, which is approximately 80%-90% to that of standard Diclofenac sodium. The compound Ca1 was found to release 0.870 ± 0.025 mol/mol of NO and standard Glyceryl trinitrate (GTN) was found to release 0.983 ± 0.063 mol/mol of NO. The compound Ca1 produced 950.2 μmol/L of EC₅₀ whereas standard GTN produced 975.8 μmol/L of EC₅₀ for aortic smooth relaxation. The compounds Ca1 produced 0.1117 of ulcer index which is far less than that of standard Diclofenac sodium (1.148). The potent lead molecules were further evaluated to understand the mechanism of vasorelaxation by using specific antagonists or blockers of NO and H₂ S.

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.

Chalcones from Angelica keiskei: Evaluation of Their Heat Shock Protein Inducing Activities

Five new chalcones, 4,2',4'-trihydroxy-3'-[(2E,5E)-7-methoxy-3,7-dimethyl-2,5-octadienyl]chalcone (1), (±)-4,2',4'-trihydroxy-3'-[(2E)-6-hydroxy-7-methoxy-3,7-dimethyl-2-octenyl]chalcone (2), 4,2',4'-trihydroxy-3'-[(2E)-3-methyl-5-(1,3-dioxolan-2-yl)-2-pentenyl]chalcone (3), 2',3'-furano-4-hydroxy-4'-methoxychalcone (4), and (±)-4-hydroxy-2',3'-(2,3-dihydro-2-methoxyfurano)-4'-methoxychalcone (5), were isolated from the aerial parts of Angelica keiskei Koidzumi together with eight known chalcones, 6-13, which were identified as (±)-4,2',4'-trihydroxy-3'-[(6E)-2-hydroxy-7-methyl-3-methylene-6-octenyl]chalcone (6), xanthoangelol (7), xanthoangelol F (8), xanthoangelol G (9), 4-hydroxyderricin (10), xanthoangelol D (11), xanthoangelol E (12), and xanthoangelol H (13), respectively. Chalcones 1-13 were evaluated for their promoter activity on heat shock protein 25 (hsp25, murine form of human hsp27). Compounds 1 and 6 activated the hsp25 promoter by 21.9- and 29.2-fold of untreated control at 10 μM, respectively. Further protein expression patterns of heat shock factor 1 (HSF1), HSP70, and HSP27 by 1 and 6 were examined. Compound 6 increased the expression of HSF1, HSP70, and HSP27 by 4.3-, 1.5-, and 4.6-fold of untreated control, respectively, without any significant cellular cytotoxicities, whereas 1 did not induce any expression of these proteins. As a result, 6 seems to be a prospective HSP inducer.

Two chalcones, 4-hydroxyderricin and xanthoangelol, stimulate GLUT4-dependent glucose uptake through the LKB1/AMP-activated protein kinase signaling pathway in 3T3-L1 adipocytes

4-Hydroxyderricin (4HD) and xanthoangelol (XAG) are major components of n-hexane/ethyl acetate (5:1) extract of the yellow-colored stem juice of Angelica keiskei. 4-Hydroxyderricin and XAG have been reported to increase glucose transporter 4 (GLUT4)-dependent glucose uptake in 3T3-L1 adipocytes, but the detailed mechanism of this phenomenon remains unknown. This present study was aimed at clarifying the detailed mechanism by which 4HD and XAG increase GLUT4-dependent glucose uptake in 3T3-L1 adipocytes. Both 4HD and XAG increased glucose uptake and GLUT4 translocation to the plasma membrane. 4-Hydroxyderricin and XAG also stimulated the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK) and its downstream target acetyl-CoA carboxylase. In addition, phosphorylation of liver kinase B1 (LKB1), which acts upstream of AMPK, was also increased by 4HD and XAG treatment. Small interfering RNA knockdown of LKB1 attenuated 4HD- and XAG-stimulated AMPK phosphorylation and suppressed glucose uptake. These findings demonstrate that 4HD and XAG can increase GLUT4-dependent glucose uptake through the LKB1/AMPK signaling pathway in 3T3-L1 adipocytes.

Study on structural and spectral properties of isobavachalcone and 4-hydroxyderricin by computational method

Isobavachalcone and 4-hydroxyderricin, two major chalcone constituents isolated from the roots of Angelica keiskei KOIDZUMI, exhibit numerous biological activities. Quantum chemical methods have been employed to investigate their structural and spectral properties. The ground state structures were optimized using density functional B3LYP method with 6-311G (d, p) basis set in both gas and solvent phases. Based on the optimized geometries, the harmonic vibrational frequency, the (1)H and (13)C nuclear magnetic resonance (NMR) chemical shift using the GIAO method were calculated at the same level of theory, with the aim of verifying the experimental values. Results reveal that B3LYP has been a good method to study their vibrational spectroscopic and NMR spectral properties of the two chalcones. The electronic absorption spectra were calculated using the time-dependent density functional theory (TDDFT) method. The solvent polarity effects were considered and calculated using the polarizable continuum model (PCM). Results also show that substitutions of different electron donating groups can alter the absorption properties and shift the spectra to a higher wavelength region.

Vasodilator compounds derived from plants and their mechanisms of action

The present paper reviews vasodilator compounds isolated from plants that were reported in the past 22 years (1990 to 2012) and the different mechanisms of action involved in their vasodilator effects. The search for reports was conducted in a comprehensive manner, intending to encompass those metabolites with a vasodilator effect whose mechanism of action involved both vascular endothelium and arterial smooth muscle. The results obtained from our bibliographic search showed that over half of the isolated compounds have a mechanism of action involving the endothelium. Most of these bioactive metabolites cause vasodilation either by activating the nitric oxide/cGMP pathway or by blocking voltage-dependent calcium channels. Moreover, it was found that many compounds induced vasodilation by more than one mechanism. This review confirms that secondary metabolites, which include a significant group of compounds with extensive chemical diversity, are a valuable source of new pharmaceuticals useful for the treatment and prevention of cardiovascular 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.

Identification of PPARgamma partial agonists of natural origin (II): in silico prediction in natural extracts with known antidiabetic activity

Background

Natural extracts have played an important role in the prevention and treatment of diseases and are important sources for drug discovery. However, to be effectively used in these processes, natural extracts must be characterized through the identification of their active compounds and their modes of action.

Methodology/Principal Findings

From an initial set of 29,779 natural products that are annotated with their natural source and using a previously developed virtual screening procedure (carefully validated experimentally), we have predicted as potential peroxisome proliferators-activated receptor gamma (PPARγ) partial agonists 12 molecules from 11 extracts known to have antidiabetic activity. Six of these molecules are similar to molecules with described antidiabetic activity but whose mechanism of action is unknown. Therefore, it is plausible that these 12 molecules could be the bioactive molecules responsible, at least in part, for the antidiabetic activity of the extracts containing them. In addition, we have also identified as potential PPARγ partial agonists 10 molecules from 16 plants with undescribed antidiabetic activity but that are related (i.e., they are from the same genus) to plants with known antidiabetic properties. None of the 22 molecules that we predict as PPARγ partial agonists show chemical similarity with a group of 211 known PPARγ partial agonists obtained from the literature.

Conclusions/Significance

Our results provide a new hypothesis about the active molecules of natural extracts with antidiabetic properties and their mode of action. We also suggest plants with undescribed antidiabetic activity that may contain PPARγ partial agonists. These plants represent a new source of potential antidiabetic extracts. Consequently, our work opens the door to the discovery of new antidiabetic extracts and molecules that can be of use, for instance, in the design of new antidiabetic drugs or functional foods focused towards the prevention/treatment of type 2 Diabetes Mellitus.

Isobavachalcone suppresses expression of inducible nitric oxide synthase induced by Toll-like receptor agonists

Toll-like receptors (TLRs) play an important role by recognizing many pathogen-associated molecular patterns and inducing innate immunity. Dysregulated activation of TLR signaling pathways induces the activation of various transcription factors such as nuclear factor-κB, leading to the induction of pro-inflammatory gene products such as inducible nitric oxide synthase (iNOS). The present study investigated the effect of isobavachalcone (IBC), a natural chalcone component of Angelica keiskei, on inflammation by modulating iNOS expression induced by TLR agonists in murine macrophages. IBC suppressed iNOS expression induced by macrophage-activating lipopeptide 2-kDa, polyriboinosinic polyribocytidylic acid, or lipopolysaccharide. These results indicate the potential of IBC as a potent anti-inflammatory drug.

The Inhibitory Effects of Representative Chalcones Contained in Angelica keiskei on Melanin Biosynthesis in B16 Melanoma Cells

In our effort to find new whitening agents, we evaluated the effects of representative chalcones [4-hydroxyderricin (1), xanthoangelol (2), xanthoangelol H (3), deoxyxanthoangelol H (4), and deoxydihydroxanthoangelol H (5)] contained in the stem of Angelica keiskei on tyrosinase and melanin formation in B16 melanoma cells. In addition, the antioxidant effects of these chalcones in ORAC and DPPH assays were also determined. Interestingly, all chalcones (1–5) inhibit melanin formation in B16 melanoma cells, with low cytotoxicity.

Xanthoangelols isolated from Angelica keiskei inhibit inflammatory-induced plasminogen activator inhibitor 1 (PAI-1) production

The folk medicine Angelica keiskei (Ashitaba) exhibits antitumor, antioxidant and antidiabetic activities and it has recently attracted attention as a health food. Ashitaba is thought to have antithrombotic properties, but this has not yet been scientifically proven. The elevation of plasma plasminogen activator inhibitor 1 (PAI-1), an inhibitor of fibrinolysis results in a predisposition to the risk of thrombosis. The present study showed that Ashitaba exudates injected intraperitoneally and orally administered over long-term suppressed the lipopolysaccharide (LPS) induced PAI-1 increase in mouse plasma. We also found that xanthoangelol, xanthoangelols B and D, the components of Ashitaba exudates, significantly inhibited TNFα-induced PAI-1 production from human umbilical vein endothelial cells (HUVECs). These findings suggest that Ashitaba can decrease elevated PAI-1 production, and that daily consumption of Ashitaba product might maintain anticoagulant status by inhibiting elevations in PAI-1 under inflammatory conditions.

Isobavachalcone, a chalcone constituent of Angelica keiskei, induces apoptosis in neuroblastoma

Six chalcones from Angelica keiskei KOIDZUMI (Ashitaba in Japanese) and two chalcones from Humulus lupulus L. (hop) were examined for their cytotoxicity in two human neuroblastoma cell lines (IMR-32 and NB-39) and normal cells (primary culture of rat cerebellar granule cells) by [3-(4,5)-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. All chalcones exhibited cytotoxicity against neuroblastoma cells, and two of them (isobavachalcone and xanthoangelol H) had no effect on normal cells even at high concentration (10(-4) M) exposure. Typical morphologic features of apoptosis, including cell shrinkage, chromatin condensation, nuclear fragmentation and formation of apoptotic bodies, were observed in isobavachalcone-treated cells by Hoechst 33342 staining. Western blot analysis showed that isobavachalcone significantly reduced pro-caspase-3 and pro-caspase-9, and subsequently increased the level of cleaved caspase-3 and cleaved caspase-9 in both neuroblastoma cell lines. Moreover, Bax was markedly induced by isobavachalcone application. These results suggest that isobavachalcone induces apoptotic cell death in neuroblastoma via the mitochondrial pathway and has no cytotoxicity against normal cells. Therefore, isobavachalcone may be applicable as an efficacious and safe drug for the treatment of neuroblastoma.

Bioactive peroxides as potential therapeutic agents

Present review describes research on more than 280 natural anticancer agents isolated from terrestrial and marine sources and synthetic biologically active peroxides. Intensive searches for new classes of pharmacologically potent agents produced by terrestrial and marine organisms have resulted in the discovery of dozens of compounds possessing high cytotoxic, antibacterial, antimalarial, and other activities as an important source of leads for drug discovery.

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.

A systematic review of mechanisms by which natural products of plant origin evoke vasodilatation

This article reviews the body of work aimed at elucidating the mechanisms of action by which natural products of plant origin exert a vasodilatory effect at the level of the vasculature. The search was restricted to 4 mechanisms: the nitric oxide system and (or) reactive oxygen species, the eicosanoid system, potassium channel function, and calcium channel function. The National Library of Medicine database was searched using "PubMed" without restriction to language. The search generated 266 references on 15 November 2005. Most studies were in vitro in nature and of these, most involved studies in the rat aorta. Many of the natural products evoked vasodilatation through an endothelium-dependent mechanism. The vasodilatation was attenuated or abolished by a nitric oxide synthase inhibitor and, in some of these studies, by an inhibitor of guanylate cyclase. A few studies reported a cyclooxygenase component, but most found no effect of the cyclooxygenase inhibitor, indomethacin. The vasorelaxation evoked by several natural products was attenuated by various potassium channel blocking agents, suggesting that some natural products exerted their effect either directly or indirectly through activation of potassium channels. Finally, a significant number of natural products evoked vasodilatation either through blockade of calcium channels or by inhibiting the release of calcium from intracellular stores. Many natural products evoked vasodilatation through multiple mechanisms. The information in this review on mechanisms of action should facilitate good clinical practice by increasing the predictive capabilities of the practitioner, notably the ability to predict adverse effects and interactions among medications. The knowledge should also help to provide leads to the ultimate goal of developing new therapeutic medications.

Effects of Dietary Angelica keiskei on Serum and Liver Lipid Profiles, and Body Fat Accumulations in Rats

Angelica keiskei (Ashitaba) is a perennial plant belonging to the Umbelliferae family. Recently, much attention has been focused on Ashitaba products as a so-called health food for the breakdown of cellulite among various physiological benefits of Ashitaba. The current study was carried out to investigate the physiological efficacy of dietary Ashitaba on serum and liver lipid profiles and body fat accumulation in rats. Rats were fed a high-fat diet with various amounts of Ashitaba for 28 d. Perirenal adipose tissue weights of rats fed the x 10 (170 mg/100 g BW) Ashitaba diet were significantly higher (p < 0.05) than those of the control group. Serum triacylglycerol concentrations of rats fed the x 100 (1,700 mg/100 g BW) Ashitaba diet were significantly higher (p < 0.05) than those of the x 1 (17 mg/100 g BW) group. Fecal weights and bile acid excretions of rats fed the x 10 or x 100 Ashitaba diet were significantly higher (p < 0.05) than those of the control group. However, there were no significant differences in the body weight gain, epididymal adipose tissue weight, serum cholesterol or liver lipid concentrations or other biochemical profiles in the serum. Furthermore, even the excessive ingestion of Ashitaba had no significant pathological impact on the liver or kidney. These results indicate that the large intake of Ashitaba products may supply dietary fiber and thus improve gastrointestinal condition through the increased excretion of feces containing high level of bile acids, although even excessive intake of Ashitaba for a short period of 28 d did not show any impact on the decrease in body fat or modification of lipid profiles in this study.

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.

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

1. Previously, we found that Angelica keiskei extract (ethyl acetate extract from the yellow liquid of stems) elevated serum high-density lipoprotein (HDL) levels and reduced liver triglyceride content in stroke-prone spontaneously hypertensive rats (SHRSP). To identify the active substance in A. keiskei extract, we examined the effect of 4-hydroxyderricin, a characteristic chalcone isolated from the yellow liquid of stems, on blood pressure and lipid metabolism in SHRSP. 2. Six-week-old male SHRSP were fed diets containing 0.07% 4-hydroxyderricin for 7 weeks with free access to the diet and water. Elevation of systolic blood pressure was significantly suppressed after 7 weeks treatment. Serum very low-density lipoprotein (VLDL) levels were significantly reduced, without any effect on HDL levels, and were associated with a significant decrease in the serum concentration of free fatty acids. 3. In the liver, significant decreases in relative liver weight and triglyceride content were found after treatment with 4-hydroxyderricin for 7 weeks. 4. An investigation of hepatic mRNA expression of proteins involved in lipid metabolism indicated that a significant decrease in microsomal triglyceride transferprotein may be responsible for the decrease in serum VLDL levels and that significant decreases in adipocyte determination and differentiation factor 1 and fatty acid synthase may be responsible for the decrease in hepatic triglyceride content. 5. In conclusion, dietary 4-hydroxyderricin produces suppression of the elevation of systolic blood pressure, reduction of serum VLDL levels and a decrease in hepatic triglyceride content in SHRSP.

Xanthoangelol D Isolated from the Roots of Angelica keiskei Inhibits Endothelin-1 Production through the Suppression of Nuclear Factor-.KAPPA.B

Transcription factor nuclear factor-kappa B (NF-kappaB) has been demonstrated to be important in regulating various gene expressions such as cytokines, adhesion molecules, and endothelin-1 (ET-1) in vascular endothelial cells. In the present study, we show the effects of xanthoangelol, xanthoangelol D, E, and F, which isolated from the root of Angelica keiskei KOIDZUMI (Umbelliferae), on NF-kappaB activation and ET-1 gene expression in cultured porcine aortic endothelial cells (PAECs). Treatments of xanthoangelol D but not xanthoangelol, xanthoangelol E and F markedly suppressed both of basal and tumor necrosis factor-alpha (TNF-alpha)-induced NF-kappaB activation in PAECs. To clarify the mechanism of xanthoangelol D-induced suppression on NF-kappaB activation, we evaluated the effects of xanthoangelol D on phosphorylation and degradation of IkappaBalpha, an inhibitory protein bound to NF-kappaB, and obtained evidence that xanthoangelol D selectively suppresses the phosphorylation of IkappaBalpha rather than the degradation of phosphorylated IkappaBalpha. In addition, xanthoangelol D significantly attenuated basal and TNF-alpha-induced prepro ET-1 mRNA expression in PAECs. These results suggest that xanthoangelol D may be useful for the treatment of various vascular diseases involved NF-kappaB activation.

Xanthoangelol, a Major Chalcone Constituent of Angelica keiskei, Induces Apoptosis in Neuroblastoma and Leukemia Cells

Xanthoangelol, a major chalcone constituent of the stem exudates of Angelica keiskei, was evaluated for cell toxicity and apoptosis-inducing activity in human neuroblastoma (IMR-32) and leukemia (Jurkat) cells. Xanthoangelol concentration-dependently reduced the survival rates of both cell lines as revealed by the trypan blue exclusion test. Early apoptosis induced by 4 h incubation with xanthoangelol was detected using flow cytometry after double-staining with annexin V and propidium iodide (PI). Western blot analysis showed that xanthoangelol markedly reduced the level of precursor caspase-3 and increased the level of cleaved caspase-3, but Bax and Bcl-2 proteins were not affected. These results suggest that xanthoangelol induces apoptotic cell death by activatation of caspase-3 in neuroblastoma and leukemia cells through a mechanism that does not involve Bax/Bcl-2 signal transduction. Therefore, xanthoangelol may be applicable as an effective drug for treatment of neuroblastoma and leukemia.

Effects of dietary Angelica keiskei on lipid metabolism in stroke-prone spontaneously hypertensive rats

1. The effect of dietary Angelica keiskei on lipid metabolism was examined in stroke-prone spontaneously hypertensive rats (SHRSP). 2. Six-week-old male SHRSP were fed diets containing 0.2% A. keiskei extract (ethyl acetate extract from the yellow liquid of stems) for 6 weeks with free access to the diet and water. 3. Elevation of systolic blood pressure tended to be suppressed on and after 2 weeks; however, this effect was not statistically significant. 4. Serum levels of cholesterol and phospholipid in SHRSP were significantly elevated after treatment with A. keiskei extract and this effect was accompanied by significant increases in serum apolipoprotein (Apo) A-I and ApoE concentrations. These changes in the serum were due to increases in high-density lipoprotein (HDL) containing ApoA-I and ApoE. 5. In the liver, significant decreases in relative weight and triglyceride content were observed in SHRSP after treatment with A. keiskei extract. An investigation of mRNA expression of enzymes involved in hepatic triglyceride metabolism indicated a decreased level of hepatic Acyl-coenzyme A synthetase mRNA expression. 6. In conclusion, dietary A. keiskei produces elevation of serum HDL levels and a reduction of liver triglyceride levels in SHRSP.

Analgesic and antiinflammatory effects of chalcones isolated from Myracrodruon urundeuva allemão

The present work showed analgesic and antiinflammatory activities from a fraction containing three dimeric chalcones (chalcone enriched fraction - CEF), isolated from the stem-bark ethyl acetate extract of Myracrodruon urundeuva Allemao (Anacardiaceae). M. urundeuva is a popular medicinal plant used widely in Northeast Brazil, mainly as a topical female genital tract antiinflammatory. We observed that the CEF (5 and 10 mg/kg body wt., i.p. or p.o.) inhibited acetic acid-induced abdominal contractions in mice. In the formalin test, the CEF (5 and 10 mg/kg body wt.) was more effective intraperitoneally and inhibited predominantly the second phase of response. Naloxone reversed this effect, indicating an involvement of the opioid system. The CEF (10 and 20 mg/kg body wt.) also increased the reaction time to thermal stimuli in the hot-plate test in mice, after i.p. but not after p.o. administration. In the carrageenan-induced paw edema test in mice, the CEF (20 and 40 mg/kg body wt.) decreased paw volume significantly, after i.p. administration 2-4 hours after carrageenan injection. The CEF (40 mg/kg body wt.) was also active orally during the same period of time. The present work is the first report on peripheral and central analgesic effects and antiinflammatory activity of natural dimeric chalcones.