Essential Oils from the Leaves, Stem, and Roots of Blumea lanceolaria (Roxb.) Druce in Vietnam: Determination of Chemical Composition, and In Vitro, In Vivo, and In Silico Studies on Anti-Inflammatory Activity.

Blumea lanceolaria (Roxb.) Druce, a flowering plant, is used for treating cancer and inflammatory diseases. In this study, we determined the chemical composition of the EOs extracted from the leaves (LBEO), stem (SBEO), and roots (RBEO) of B. lanceolaria and analyzed their anti-inflammation potential. Overall, 30 compounds representing 99.12%, 98.44%, and 96.89% of total EO constituents of the leaves, stem, and roots, respectively, were identified using GC-MS. ELISA, Western blotting, and qRT-PCR studies showed that LBEO, SBEO, and RBEO inhibited multiple steps in the inflammatory responses in the RAW 264.7 cell model, including NO production; TNF-α, IL-6, iNOS, and COX-2 transcription and translation; and phosphorylation of IκBα and p65 of the NF-κB pathway. In the carrageenan-induced paw edema model, all three EOs inhibited paw edema at both early and delayed phases. Molecular docking studies indicated that the main components of B. lanceolaria EOs (BEOs) targeted and inhibited major components of inflammation-related pathways, including the arachidonic acid metabolic pathway, NF-κB pathway, and MAPK pathway. We present the first study to characterize the chemical composition of BEOs and confirm their potent anti-inflammatory effects in in vitro, in vivo, and in silico analysis. These results can facilitate the development of effective anti-inflammatory drugs with limited side effects in the future.

Cytotoxic components from the leaves of Erythrophleum fordii induce human acute leukemia cell apoptosis through caspase 3 activation and PARP cleavage.

Cassaine diterpenoids as erythrofordins A-C (1-3), pseudo-erythrosuamin (4), and erythrofordin U (5) isolated from the leaves of Vietnamese Erythrophleum fordii Oliver were tested cytotoxic activity against human leukemia cancer cells. The results showed that these metabolites exhibited dose-dependent cytotoxicity against human leukemia HL-60 and KG cells with IC50 values ranging from 15.2 ± 1.5 to 42.2 ± 3.6 µM. Treatment with erythrofordin B led to the apoptosis of HL-60 and KG cells due to the activation of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). Erythrofordin B significantly increased Bak protein expression, but downregulated the anti-apoptotic protein Bcl-2, in HL-60 cells. In silico results demonstrated that erythrofordin B can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of -7.36 and -10.76 kcal/mol, respectively. These results indicated that the leaves of Vietnamese E. fordii, which contain cassaine diterpenoids, can induce the apoptosis of human leukemia cancer cells.

Antioxidant and Cell Proliferation Properties of the Vietnamese Traditional Medicinal Plant Peltophorum pterocarpum.

Peltophorum pterocarpum is regarded as one of the most important medicinal plants in the traditional medicine system of Vietnam. However, scientific evidence for the antioxidant effects against lipid peroxidation and the potential effects in cancer of this plant are lacking. In our experiments, 70% ethanolic extracts of P. pterocarpum leaves (LPP) and stem bark (SPP) were evaluated for their low-density lipoprotein (LDL) oxidation and cytotoxic activity against cancer cell lines. Both LPP and SPP inhibited Cu2+-mediated LDL by increasing the lag time of conjugated diene formation and inhibiting the generation of thiobarbituric acid reactive substances (TBARS) in a dose-dependent manner. In cancer cells, LPP and SPP triggered the most potent cytotoxic effects against human leukemia cells, CRF-SBA and HL-60, with half-maximal inhibitory concentration (IC50) values ranging from 118.5 to 157.2 µg/mL. SPP exhibited significant cytotoxicity against MIA PACA2, A549, and KG cell lines with IC50 values of 167.5, 244.1 and 255.0 µg/mL, respectively. Meanwhile, LPP showed cytotoxic activity against KG with an IC50 value of 228.1 µg/mL. SPP mediated cytotoxicity in HL-60 and CCRF-SBA cells through the activation of the apoptosis pathway, including the activation of caspases 3, and 9 and poly (ADP-ribose) polymerase (PARP). These results suggested that SPP may prevent the development and progression of atherosclerosis and leukemia in humans.

Cassaine Diterpenoid Amide from Stem Bark of Erythrophleum fordii Suppresses Cytotoxic and Induces Apoptosis of Human Leukemia Cells.

Cassaine diterpenoids amides from the stem bark of Vietnamese Erythrophleum fordii Oliver were screened for their cytotoxic activity against human cancer cells. The cell proliferation assay results showed that, among the active compounds, 3ß-acetyl-nor-erythrophlamide (3AEP) exhibited the most potential cytotoxicity against human leukemia HL-60 and KG cells with IC50 values of 12.0 ± 1.2 and 18.1 ± 2.7 µM, respectively. Treatment of 3AEP resulted in the apoptosis of HL-60 cells via the activation of caspase 3, and poly (ADP-ribose) polymerase (PARP). Molecular docking in silico results showed that the 3AEP can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of -7.51 and -9.63 kcal/mol respectively. These results indicated that the stem bark of Vietnamese E. fordii and its cassaine diterpenoid amides may be useful in the apoptosis induction of human leukemia cancer cells.

Strong and Selective Inhibitory Effects of the Biflavonoid Selamariscina A against CYP2C8 and CYP2C9 Enzyme Activities in Human Liver Microsomes.

Like flavonoids, biflavonoids, dimeric flavonoids, and polyphenolic plant secondary metabolites have antioxidant, antibacterial, antiviral, anti-inflammatory, and anti-cancer properties. However, there is limited data on their effects on cytochrome P450 (P450) and uridine 5'-diphosphoglucuronosyl transferase (UGT) enzyme activities. In this study we evaluate the inhibitory potential of five biflavonoids against nine P450 activities (P450s1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A) in human liver microsomes (HLMs) using cocktail incubation and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The most strongly inhibited P450 activity was CYP2C8-mediated amodiaquine N-dealkylation with IC50 ranges of 0.019~0.123 µM. In addition, the biflavonoids-selamariscina A, amentoflavone, robustaflavone, cupressuflavone, and taiwaniaflavone-noncompetitively inhibited CYP2C8 activity with respective Ki values of 0.018, 0.083, 0.084, 0.103, and 0.142 µM. As selamariscina A showed the strongest effects, we then evaluated it against six UGT isoforms, where it showed weaker inhibition (UGTs1A1, 1A3, 1A4, 1A6, 1A9, and 2B7, IC50 1.7 µM). Returning to the P450 activities, selamariscina A inhibited CYP2C9-mediated diclofenac hydroxylation and tolbutamide hydroxylation with respective Ki values of 0.032 and 0.065 µM in a competitive and noncompetitive manner. However, it only weakly inhibited CYP1A2, CYP2B6, and CYP3A with respective Ki values of 3.1, 7.9, and 4.5 µM. We conclude that selamariscina A has selective and strong inhibitory effects on the CYP2C8 and CYP2C9 isoforms. This information might be useful in predicting herb-drug interaction potential between biflavonoids and co-administered drugs mainly metabolized by CYP2C8 and CYP2C9. In addition, selamariscina A might be used as a strong CYP2C8 and CYP2C9 inhibitor in P450 reaction-phenotyping studies to identify drug-metabolizing enzymes responsible for the metabolism of new chemicals.

Inhibitory Effect of Selaginellins from Selaginella tamariscina (Beauv.) Spring against Cytochrome P450 and Uridine 5'-Diphosphoglucuronosyltransferase Isoforms on Human Liver Microsomes.

Selaginella tamariscina (Beauv.) has been used for traditional herbal medicine for treatment of cancer, hepatitis, and diabetes in the Orient. Numerous bioactive compounds including alkaloids, flavonoids, lignans, and selaginellins have been identified in this medicinal plant. Among them, selaginellins having a quinone methide unit and an alkylphenol moiety have been known to possess anticancer, antidiabetic, and neuroprotective activity. Although there have been studies on the biological activities of selaginellins, their modulatory potential of cytochrome P450 (P450) and uridine 5'-diphosphoglucuronosyltransferase (UGT) activities have not been previously evaluated. In this study, we investigated the drug interaction potential of two selaginellins on ten P450 isoforms (CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 2J2 and 3A) and six UGT isoforms (UGT1A1, 1A3, 1A4, 1A6, 1A9 and 2B7) using human liver microsomes and liquid chromatography-tandem mass spectrometry. Selaginellin and selaginellin M had high inhibitory potential for CYP2C8-mediated amodiaquine O-demethylation with IC50 values of 0.5 and 0.9 µM, respectively. Selaginellin and selaginellin M also showed medium inhibitory potential against CYP2C9, CYP2J2, UGT1A1, and UGT1A3 (1 µM < IC50 < 5 µM). These two selaginellins had low inhibitory potential against CYP1A2, CYP2A6, CYP2E1, and UGT1A6 (IC50 > 25 µM). This information might be helpful to predict possible drug interaction potential of between selaginellins and co-administered drugs.

PTP1B, α-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L.

Two new flavonoids, bismilachinone (11) and smilachinin (14), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1-16 were evaluated at the molecular level. Among them, compounds 4, 7, and 10 showed moderate DPP-IV inhibitory activities with IC50 values of 20.81, 33.12, and 32.93 µM, respectively. Compounds 3, 4, 6, 11, 12, and 16 showed strong PTP1B inhibitory activities, with respective IC50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 µM compared with the IC50 value for the positive control (ursolic acid: IC50 = 1.21 µM). Compounds 2-7, 11, 12, 15, and 16 showed potent α-glucosidase inhibitory activities, with respective IC50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 µM. The positive control, acarbose, displayed an IC50 value of 175.84 µM. In the kinetic study for the PTP1B enzyme, compounds 6, 11, and 12 displayed competitive inhibition with Ki values of 3.20, 8.56, and 5.86 µM, respectively. Compounds 3, 4, and 16 showed noncompetitive inhibition with Ki values of 18.75, 5.95, and 22.86 µM, respectively. Molecular docking study for the competitive inhibitors (6, 11, and 12) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity.

Anti-inflammatory terpenylated coumarins from the leaves of Zanthoxylum schinifolium with α-glucosidase inhibitory activity.

Nine terpenylated coumarins, namely 7-[(E)-3',7'-dimethyl-6'-oxo-2',7'-octadienyl]oxy-coumarin (1), schinilenol (2), schinindiol (3), collinin (4), 7-[(E)-7'-hydroxy-3',7'-dimethy-locta-2',5'-dienyloxy]-coumarin (5), 8-methoxyanisocoumarin (6), 7-(6'R-hydroxy-3',7'-dimethyl-2'E,7'-octadienyloxy)coumarin (7), (E)-4-methyl-6-(coumarin-7'-yloxy)hex-4-enal (8), and aurapten (9), along with a 4-quinolone alkaloid (10) and integrifoliodiol (11), were isolated from the leaves of Zanthoxylum schinifolium. Of the isolates, compounds 4 and 7 potentially inhibited NO production in lipopolysaccharide (LPS)-stimulated macrophage RAW264.7 cells, with IC50 values of 5.9 ± 0.8 and 18.2 ± 1.8 µM, respectively. Furthermore, compounds 4 and 7 dose-dependently reduced the LPS-induced iNOS expression. Moreover, pre-incubation of cells with 4 and 7 significantly suppressed LPS-induced COX-2 protein expression. In addition, compounds 4, 7, 8, and 10 showed strong α-glucosidase inhibitory effects, with IC50 values of 92.1 ± 0.7, 90.6 ± 0.9, 78.2 ± 0.2, and 82.4 ± 0.8 µM, respectively. Compounds 1, 5, and 11 displayed moderate effects with IC50 values of 161.6 ± 0.3, 164.4 ± 1.1, and 155.4 ± 0.9 µM, while acarbose, a positive control, possessed an IC50 value of 121.5 ± 1.0 µM. This is the first investigation on the α-glucosidase inhibitory effect of components from Zanthoxylum schinifolium. Further studies should be made on active compounds.

Isolation of benzoic and cinnamic acid derivatives from the grains of Sorghum bicolor and their inhibition of lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells.

Two new caffeoylglycerols, (hwanggeumchal A-B, 9-10), together with eight known derivatives (1-8) were isolated from the grains of Sorghum bicolor (L.) Moench var. hwanggeumchal. Their chemical structures were established mainly by 1D and 2D NMR techniques and MS data analysis. Amongst those, methyl 3,4-dihydroxybenzoate (2), 3,4,5-trihydroxycinnamate (3), methyl 3,4-dihydroxycinnamate (5), caffeoylglycolic acid methyl ester (7) and 1-O-caffeoylglycerol (8) displayed potential inhibitory effects against LPS-induced NO production in macrophage RAW264.7 cells with IC50 values of 11.9, 2.9, 27.1, 29.0 and 18.5µM, respectively. Furthermore, these compounds dose-dependently reduced the LPS-induced iNOS expression. In addition, pre-incubation of cells with compounds 2, 3 and 5 significantly suppressed LPS-induced COX-2 protein expression. SAR investigation revealed that compounds with a methyl ester (COOCH3) group possessed stronger activity. Our obtained data suggest that S. bicolor and its caffeoylglyceride-enrich extracts may be applied as supplemental and/or functional foods having a beneficial effect against inflammation.

New prenylated isoflavonoids as protein tyrosine phosphatase 1B (PTP1B) inhibitors from Erythrina addisoniae.

Bioassay-guided fractionation of the EtOAc extract of the root of Erythrina addisoniae (Leguminosae) resulted in the isolation of four new (1-4), along with 2 known prenylated isoflavonoids (5-6). The structures of the isolates were assigned on the basis of spectroscopic data analysis, focusing on interpretation of 1D and 2D NMR, and MS data. All the isolates were evaluated for their inhibitory effects on protein tyrosine phosphatase 1B (PTP1B), as well as their growth inhibition on MCF7, adriamycin-resistant MCF7 (MCF7/ADR), and MDA-MB-231 breast cancer cell lines. Compounds which exhibited PTP1B inhibitory activity (IC(50) values ranging from 4.6 ± 0.3 to 24.2 ± 2.1 µM) showed potential cytotoxic activity (IC(50) values ranging from 3.97 ± 0.17 to 11.4 ± 1.9 µM). Taken together, our data suggest that prenylated isoflavonoids, especially the isoflavone-type skeleton could be considered as new lead compounds against breast cancer via PTP1B inhibition.

Nectandrin B activates endothelial nitric-oxide synthase phosphorylation in endothelial cells: role of the AMP-activated protein kinase/estrogen receptor α/phosphatidylinositol 3-kinase/Akt pathway.

We revealed previously that nectandrin B isolated from Myristica fragrans (nutmeg, Myristicaceae) functions as a potent AMP-activated protein kinase (AMPK) activator and showed its antiobesity effect. In this study, we investigated whether nectandrin B affects phosphorylation of endothelial nitric-oxide synthase (eNOS) in human endothelial cells. Nectandrin B increased the phosphorylation of eNOS and nitric oxide (NO) production in a concentration-dependent manner and maximal effect was found at 10 µg/ml. Nectandrin B activates AMPK, presumably via Ca(2+)/calmodulin kinase II activation and nectandrin B-stimulated eNOS phosphorylation was reversed by AMPK inhibition. Both the enzyme activity of phosphatidylinositol 3-kinase (PI3K) and the estrogen receptor (ER)-dependent reporter gene transcription were enhanced by nectandrin B. ERα inhibition by specific antagonist or small interfering siRNA (siRNA) suppressed nectandrin B-mediated eNOS phosphorylation. Moreover, AMPK inhibition significantly reversed the activation of ER-dependent transcription and PI3K activation in response to nectandrin B. Nectandrin B evoked endothelium-dependent relaxation in rat aortic rings, and this was blocked by inhibition of AMPK, ER, or PI3K. These results suggest that potent AMPK activator nectandrin B enhances NO production via eNOS phosphorylation in endothelial cells and ERα-dependent PI3K activity is required.

SIRT1 inhibitory diterpenoids from the Vietnamese medicinal plant Croton tonkinensis.

Silent information regulator two ortholog 1 (SIRT1) is a member of the sirtuin deacetylase family of enzymes that removes acetyl groups from the lysine residues in histones and other proteins. It has been suggested that SIRT1 inhibitors might be beneficial in the treatment of cancer and neurodegenerative diseases. Bioassay-guided fractionation of the MeOH extract of the leaves of CROTON TONKINENSIS resulted in the isolation of a new ENT-kaurane diterpenoid (1) along with 11 known compounds (2- 12). The structure of the new compound 1 was determined to be ENT-11 alpha-acetoxy-7 beta-hydroxykaur-16-en-15-one based on spectroscopic analyses. Compounds 3, 4, 6- 9, 11, and 12 exhibited SIRT1 inhibitory activity in an IN VITRO assay, with IC (50) values ranging from 16.08 +/- 0.11 to 44.34 +/- 2.32 microM. This is the first report showing the potential of ENT-kaurane diterpenoids as a new class of natural SIRT1 inhibitors.

Crotonkinensins A and B, diterpenoids from the Vietnamese medicinal plant Croton tonkinensis.

Two new diterpenoids, crotonkinensins A (1) and B (2), were isolated from the leaves of the Vietnamese endemic medicinal plant Croton tonkinensis. Their structures were determined to be 7alpha,10alpha-epoxy-14beta-hydroxygrayanane-1(5),16(17)-dien-2,15-dione (1) and 7alpha,10alpha-epoxy-14beta-hydroxygrayanane-1(2),16(17)-dien-15-one (2) by spectroscopic analysis. Compounds 1 and 2 showed strong anti-inflammatory effects on the LPS-induced COX-2 promoter activity and COX-2 expression in Raw 264.7 cells.

Cytotoxic and PTP1B inhibitory activities from Erythrina abyssinica.

Bioassay-guided fractionation of the EtOAc extract of the stem bark of Erythrina abyssinica (Leguminosae) resulted in the isolation of three new (1-3), along with 12 known (4-15) pterocarpan derivatives. Their chemical structures were determined by physicochemical and spectroscopic data analysis (IR, UV, [alpha](D), CD, 1D and 2D NMR, and MS data). All the isolates were evaluated for their inhibitory effects on protein tyrosine phosphatase-1B (PTP1B), as well as their growth inhibition on MCF7, tamoxifen-resistant MCF7 (MCF7/TAMR), adriamycin-resistant MCF7 (MCF7/ADR) and MDA-MB-231 breast cancer cell lines. Compounds which exhibited PTP1B inhibitory activity (IC(50) values ranging from 4.2+/-0.2 to 19.3+/-0.3 microM) showed strong cytotoxic activity (IC(50) values from 5.6+/-0.7 to 28.0+/-0.2 microM). Our data suggested that pterocarpans could be considered as new anticancer materials by PTP1B inhibition.