Cnidicin, a coumarin, from the root of Angelica koreana, inhibits the degranulation of mast cell and the NO generation in RAW 264.7 cells

Anti-Obesity and Anti-Diabetic Effects of Ostericum koreanum (Ganghwal) Extract

"Ganghwal" is a widely used herbal medicine in Republic of Korea, but it has not been reported as a treatment strategy for obesity and diabetes within adipocytes. In this study, we determined that Ostericum koreanum extract (OKE) exerts an anti-obesity effect by inhibiting adipogenesis and an anti-diabetic effect by increasing the expression of genes related to glucose uptake in adipocytes and inhibiting α-glucosidase activity. 3T3-L1 preadipocytes were differentiated for 8 days in methylisobutylxanthine, dexamethasone, and insulin medium, and the effect of OKE was confirmed by the addition of 50 and 100 µg/mL of OKE during the differentiation process. This resulted in a reduction in lipid accumulation and the expression of PPARγ (Peroxisome proliferator-activated receptor γ) and C/EBPα (CCAAT enhancer binding protein α). Significant activation of AMPK (AMP-activated protein kinase), increased expression of GLUT4 (Glucose Transporter Type 4), and inhibition of α-glucosidase activity were also observed. These findings provide the basis for the anti-obesity and anti-diabetic effects of OKE. In addition, OKE has a significant antioxidant effect. This study presents OKE as a potential natural product-derived material for the treatment of patients with metabolic diseases such as obesity- and obesity-induced diabetes.

A specific UDP-glucosyltransferase catalyzes the formation of triptophenolide glucoside from Tripterygium wilfordii Hook. f

Tripterygium wilfordii Hook. f. is a perennial woody vine member of the Celastraceae family. As a traditional Chinese medicine, it contains complex chemical components and exerts various pharmacological activities. In the present study, we identified a glucosyltransferase, TwUGT1, that can catalyze the synthesis of an abietane-type diterpene glucoside, namely, triptophenolide14-O-beta-D-glucopyranoside, and investigated the pharmacological activity of triptophenolide glucoside in diverse cancer cells. Triptophenolide glucoside exhibited significant inhibitory effects on U87-MG, U251, C6, MCF-7, HeLa, K562, and RBL-2H3 cells as determined by pharmacological analysis. The triptophenolide glucoside content of T. wilfordii was analyzed using Agilent Technologies 6490 Triple Quad LC/MS. The glucosyltransferase TwUGT1 belongs to subfamily 88 and group E in family 1. Molecular docking and site-directed mutagenesis of TwUGT1 revealed that the His30, Asp132, Phe134, Thr154, Ala370, Leu376, Gly382, His387, Glu395 and Gln412 residues play crucial roles in the catalytic activity of triptophenolide 14-O-glucosyltransferase. In addition, TwUGT1 was also capable of glucosylating phenolic hydroxyl groups, such as those in liquiritigenin, pinocembrin, 4-methylumbelliferone, phloretin, and rhapontigenin.

Effects of drying methods on contents of bioactive compounds and antioxidant activities of Angelica dahurica

Baizhi (Angelica dahurica) has been widely used as a traditional Chinese herbal medicine, functional food and cosmetic product ingredient, mostly because of the high furanocoumarin compounds in roots. Because the fresh root is perishable, drying techniques are needed to maintain a higher-quality product. Freeze-drying is the best method but energy-consuming and costly. The aim of this study was to analyze the quality (antioxidant and furanocoumarin content) of Baizhi roots after freeze-drying (the control) and in-the-shade, 40 and 70 °C drying. Antioxidant activity was revealed by 2,2-diphenyl-1-picrylhydrazyl and Fe2+ chelating assay, and the content of six furanocoumarin compounds, including xanthotoxin, bergapten, oxypeucedanin, imperatorin, phellopterin and isoimperatorin, was analyzed by liquid chromatography. Antioxidant activity was greater in roots with in-the-shade, 40 and 70 °C drying than freeze-drying. The furanocoumarin content pattern was similar with 70 °C drying and freeze-drying. A. dahurica roots dried at 70 °C may be an alternative method for maintaining high quality.

Influence of harvest stage on the pharmacological effect of Angelica dahurica

BACKGROUND

Baizhi (Angelica dahurica) has been widely used as a traditional Chinese herbal medicine, functional food and cosmetic product ingredient, mostly because of the high furanocoumarin compounds in roots. The cropping system of Baizhi with its unique summer dormancy feature, is easily affected by the transition of its growth stages. The aim of this study was to analyze the quantity (size, form and dry weight [DW]) and quality (antioxidant and furanocoumarin content) of taproot and lateral root from three growth stages of Baizhi; vegetative (V-stage), summer dormancy (S-stage) and bolting stage (B-stage).

RESULTS

Root length and diameter were lower at V-stage than the other two stages, and S-stage had higher lateral root to total root ratio. However, the highest root DW was observed at S-stage. Antioxidant activity was revealed by 2,2-diphenyl-L-picrylhydrazyl and Fe²⁺ chelating assay, and the content of six furanocoumarin compounds, including xanthotoxin, bergapten, oxypeucedanin, imperatorin, phellopterin and isoimperatorin, was analyzed by liquid chromatography. Although the antioxidant activity was less at S-stage than the other stages, furanocoumarin contents showed little variation.

CONCLUSION

Considering the high DW and stable furanocoumarin composition, S-stage is the best harvest stage than the other stages because of its richer total pharmacological content.

Suppression of IgE-mediated mast cell activation and mouse anaphylaxis via inhibition of Syk activation by 8-formyl-7-hydroxy-4-methylcoumarin, 4μ8C

Mast cells trigger IgE-mediated allergic reactions by releasing various allergic mediators. 8-Formyl-7-hydroxy-4-methylcoumarin, also called 4μ8C, was originally known as an inositol-requiring enzyme 1 (IRE1) suppressant, but no study has examined its relationship with mast cells and allergic diseases. Therefore, the purpose of this study was to determine whether 4μ8C is effective in suppressing allergic reactions in mast cells and in IgE-mediated allergic animal model. 4μ8C suppressed the degranulation of IgE-mediated mast cells (IC₅₀=3.2μM) and the production of cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4) in a dose-dependent manner. 4μ8C also suppressed passive cutaneous anaphylaxis (PCA) in mice (ED₅₀=25.1mg/kg). In an experiment on mast cell signaling pathways stimulated by antigen, the phosphorylation and activation of Syk was decreased by 4μ8C, and phosphorylation of downstream signaling molecules, such as linker for activated T cells (LAT), Akt, and the three MAP kinases, ERK, p38, and JNK, were suppressed. Mechanistic studies showed that 4μ8C inhibited the activity of Lyn and Fyn in vitro. Based on the results of those experiments, the suppressor mechanism of allergic reaction by 4μ8C involved reduced activity of Lyn and Fyn, which is pivotal in an IgE-mediated signaling pathway. In summary, for the first time, this study shows that 4μ8C inhibits Lyn and Fyn, thus suppressing allergic reaction by reducing the degranulation and the production of inflammatory cytokines. This suggests that 4μ8C can be used as a new medicinal candidate to control allergic diseases such as seasonal allergies and atopic dermatitis.

Prenylfuranocoumarin-HMGA-flavonol glucoside conjugates and other constituents of the fruit peels of Citrus hystrix and their anticholinesterase activity

Sixteen compounds including dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid conjugates and dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid/1-O-flavonyl-β-d-glucopyranoside conjugates, together with other dihydroxyprenylfuranocoumarins conjugates, were isolated from the ethyl acetate extract of the fruit peels of Citrus hystrix. Some of the isolates were evaluated for their cholinesterase inhibitory activity, but only one compound possessing a 3-O-β-d-glucopyranosyl-3,5,7,4'-tetrahydroxy-6,8,3'-trimethoxyflavonol nucleus in the prenylfuranocoumarin-HMGA conjugate showed strong activity.

Citrusosides A-D and furanocoumarins with cholinesterase inhibitory activity from the fruit peels of Citrus hystrix

Four new compounds, citrusosides A-D (1-4), and 15 known compounds were isolated from the hexanes and CH(2)Cl(2) extracts of the peels of Citrus hystrix fruits. Compound 1 is a 1-O-isopropyl-6-O-β-D-glucopyranosyl ester of 5'',9''-dimethyl-2'',8''-decadienoic acid. Compounds 2-4 possess a 1-O-isopropyl-β-D-glucopyranosyl and a dihydroxyprenylfuranocoumarin moiety conjugated to the 3-hydroxy-3-methylglutaric acid as diesters. Several furanocoumarins were evaluated for their cholinesterase inhibitory activity. (R)-(+)-6'-Hydroxy-7'-methoxybergamottin, (R)-(+)-6',7'-dihydroxybergamottin, and (+)-isoimparatorin showed IC(50) values of 11.2 ± 0.1, 15.4 ± 0.3, and 23 ± 0.2 μM, respectively. Bioassay results indicated that the presence of a dioxygenated geranyl chain in the test compounds is crucial for the inhibitory activity.

Antiproliferative effect of furanocoumarins from the root of Angelica dahurica on cultured human tumor cell lines

A bioassay-guided fractionation of the root extract of Angelica dahurica (Umbelliferae) led to the isolation of six furanocoumarins as active ingredients responsible for the antitumoral property. The hexane soluble part of the extract demonstrated a significant inhibition on the proliferation of cultured human tumor cells such as A549 (non small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nervous system) and HCT-15 (colon) in vitro, whereas the remaining water soluble part exhibited poor inhibition. Intensive investigation of the hexane soluble part of the extract yielded six furanocoumarins, i.e. isoimperatorin, cnidicin, imperatorin, oxypeucedanin, byakangelicol, oxypeucedanin hydrate, all of which exhibited a significant inhibition on cell proliferation in a dose-dependent manner.

Agents protecting against sepsis from the roots of Angelica dahurica

In the course of isolating agents preventing sepsis from the EtOAc extract of the roots of Angelica dahurica, four known furanocoumarins, isoimperatorin (1), oxypeucedanin (2), (+/-)-byakangelicin (3), and (+)-oxypeucedanin hydrate (4), were isolated as active compounds based on the in vivo assay model of sepsis induced by lipopolysaccharide (LPS) and D-galactosamine (D-GalN). Among them, 3 showed the highest survival rate (100% with a dose of 30 mg/kg versus 20% for the control experiment) and decreased the plasma levels of tumor necrosis factor-alpha and alanine aminotransferase in mice adminstered LPS/D-GalN.

Molecular mechanisms of inhibitory activities of tanshinones on Lipopolysaccharide-lnduced nitric oxide generation in RAW 264.7 cells

The effects of four tanshinones isolated from Tanshen (the root of Salvia miltiorrhiza Bunge, Labiatae) were tested for their inhibition of nitric oxide production in macrophage cells, and the underlying molecular mechanisms studied. Of the four tanshinones used, 15, 16-dihydrotanshinone-I, tanshinone-IIA and cryptotanshinone, but not tanshinone I, demonstrated significant inhibition of the LPS-induced nitric oxide production in RAW 264.7 cells, with calculated IC50 values of 5, 8, and 1.5 microM, respectively. Tanshinones exerted inhibitory activities on the LPS-induced nitric oxide production only when applied concurrently with LPS, and tanshinone-IIA and cryptotanshinone were found to inhibit LPS-induced NF-kappaB mobilization and extracellular-regulated kinase (ERK) activation, respectively. These results suggest that tanshinones inhibit LPS-induced nitric oxide generation by interfering with the initial stage of LPS-induced expression of certain genes. NF-kappaB and ERK could be the molecular targets for tanshinones for the inhibition of LPS-induced nitric oxide production in macrophage cells.