Synthesis, biological evaluation, and correlation of cytotoxicity versus redox potential of 1,4-naphthoquinone derivatives.

A series of 1,4-naphthoquinone derivatives of lawsone (1), 6-hydroxy-1,4-naphthoquinone (2), and juglone (3) were synthesized by alkylation, acylation, and sulfonylation reactions. The yields of lawsone derivatives 1a-1k (type A), 6-hydroxy-1,4-naphthoquinone derivatives 2a-2j (type B), and juglone derivatives 3a-3h (type C) were 52-99%, 53-96%, and 28-95%, respectively. All compounds were tested in vitro for the cytotoxicity against human oral epidermoid carcinoma (KB) and cervix epithelioid carcinoma (HeLa) cells and their structure-activity relationship was studied. Compound 3c was found to be most potent in KB cell line (IC50 = 1.39 µM). Some compounds were evaluated for DNA topoisomerase I inhibition. Compounds 2c, 3, 3a, and 3d showed topoisomerase inhibition activity with IC50 values of 8.3-91 µM. Standard redox potentials (E°) of all naphthoquinones in phosphate buffer at pH 7.2 were examined by means of cyclic voltammetry. A definite correlation has been found between the redox potentials and inhibitory effects of type A compounds.

Diterpenoids and Bisnorditerpenoids from Blumea aromatica.

Three new labdane-type diterpenoids, 6α-O-isovalerylnidorellol (1), (12S)-blumdane (2), and (12R)-epiblumdane (3), and three new bisnorditerpenoids, 6α-O-(3-methyl-2-butenoyl)sterebin A (5), 6α-O-angeloylsterebin A (6), and 6α-O-isovalerylsterebin A (7), plus 17 known compounds were isolated from Blumea aromatica. Their structures of the new compounds were proposed by detailed spectroscopic analysis. The absolute configuration at C-12 of blumdane (2) was determined by the modified Mosher's method. The anti-inflammatory and anti-immunosuppressive effects of these isolated compounds were assessed. Compounds 9, 16, and 23 (at 40 µM) showed a slight suppression of TNF-α production, but no or little effect on the expression of PD-L1 in granulocytic myeloid-derived suppressor cells was observed for all test compounds.

The Cyanthin Diterpenoid and Sesterterpene Constituents of Hericium erinaceus Mycelium Ameliorate Alzheimer's Disease-Related Pathologies in APP/PS1 Transgenic Mice.

Hericium erinaceus was used in traditional Chinese medicine for physiologically beneficial medicines. Recently, it has become a candidate in causing positive brain health-related activities. We previously reported that Hericium erinaceus mycelium ameliorates Alzheimer's disease (AD)-related pathologies. To reveal the role of the cyanthin diterpenoid and sesterterpene constituents on this effects, erinacine A and S were isolated and their effects on attenuating AD-related pathology in APPswe/PS1dE9 transgenic mice were investigated. A 30 day short-term administration of erinacine A and S were performed to explore the effect of each erinacine on AD-related pathology including amyloid ß production and degradation, plaque formation, plaque growth, glial activation and neurogenesis deterioration. Our results indicated the benefit effects of both erinacine A and S in cerebrum of APPswe/PS1dE9 mice, including: (1) attenuating cerebral plaque loading by inhibiting plaque growth; (2) diminishing the activation of glial cells; (3) raising the level of insulin degrading enzyme; and (4) promoting hippocampal neurogenesis. Moreover, erinacine A reduced the level of insoluble amyloid ß and C-terminal fragment of amyloid precursor protein which was not mediated by erinacine S. We further performed a long term administration of erinacine A and found that erinacine A recovered the impairment in the tasks including burrowing, nesting, and Morris water maze. Our data pointed out that although both erinacine A and S reduce AD pathology via reducing amyloid deposition and promoting neurogenesis, erinacine A can also inhibit amyloid ß production and is worth to be further developed for AD therapeutic use.

Anti-inflammatory and Antiosteoporosis Flavonoids from the Rhizomes of Helminthostachys zeylanica.

Chemical investigation of the rhizomes of Helminthostachys zeylanica led to the isolation of eight new flavonoids including six cyclized geranylflavonoids, ugonins V-X (1-3), (10R,11S)-ugonin N (4), (10R,11S)-ugonin S (5), and ugonin Y (6), as well as two quercetin glucosides, quercetin-4'-O-ß-d-glucopyranosyl-(1→2)-ß-d-glucopyranoside (7) and quercetin-3-O-ß-d-glucopyranosyl-4'-O-ß-d-glucopyranosyl-(1→2)-ß-d-glucopyranoside (8). The structures of these compounds were established by spectroscopic analyses and acid hydrolysis of the sugar moiety. Among the isolated compounds, 1, 2, 5, 6, ugonins J-S (9-13), ugonstilbene A (14), and ugonin L (23) were evaluated for their anti-inflammatory activity on lipopolysaccharide-induced nitric oxide (NO) production in microglial cells. Except for 1, 5, and 13, all other compounds inhibited NO production with IC50 values of 6.2-10.1 µM and were more potent than the positive control, pyrrolidine dithiocarbamate. Compounds 1, 2, 5, 6, and 10-13 were tested for antiosteoporotic activities, and ugonin K (10) exhibited the highest inhibitory activity against RANKL-induced osteoclast differentiation in RAW264.7 cells with an IC50 value of 1.8 ± 0.2 µM.

Meroterpenoids and Chalcone-Lignoids from the Roots of Mimosa diplotricha.

Six new meroterpenoids, diplomeroterpenoids A-F (1-6), two new chalcone-lignoids, diplochalcolins A and B (7, 8), and 13 known compounds were isolated from the root extract of Mimosa diplotricha. Diplomeroterpenoids A-F consist of a 4H-chromen-4-one and a diterpenoid unit, and their absolute configurations were determined by X-ray crystallographic analysis. Compounds 1-3 and 5 showed potent inhibitory activity on protein farnesyl transferase, with IC50 values from 5.0 to 8.5 µM. Compound 1 showed antiproliferative activity against human hepatoblastoma HepG2 cells with a GI50 value of approximately 8.6 µM.

Erinacine S, a Rare Sesterterpene from the Mycelia of Hericium erinaceus.

A new sesterterpene, erinacine S, and one cyathane diterpene xyloside, erinacine A, were isolated from the ethanol extract of the mycelia of Hericium erinaceus. Their structures were elucidated by spectroscopic and X-ray analysis. A 30-day oral course of erinacines A and S attenuated Aß plaque burden in the brains of 5-month-old female APP/PS1 transgenic mice. Moreover, erinacines A and S significantly increased the level of insulin-degrading enzyme in cerebral cortex.

Wild Bitter Melon Leaf Extract Inhibits Porphyromonas gingivalis-Induced Inflammation: Identification of Active Compounds through Bioassay-Guided Isolation.

Porphyromonas gingivalis has been identified as one of the major periodontal pathogens. Activity-directed fractionation and purification processes were employed to identify the anti-inflammatory active compounds using heat-killed P. gingivalis-stimulated human monocytic THP-1 cells in vitro. Five major fractions were collected from the ethanol/ethyl acetate extract of wild bitter melon (Momordica charantia Linn. var. abbreviata Ser.) leaves and evaluated for their anti-inflammatory activity against P. gingivalis. Among the test fractions, Fraction 5 effectively decreased heat-killed P. gingivalis-induced interleukin (IL)-8 and was subjected to separation and purification by using chromatographic techniques. Two cucurbitane triterpenoids were isolated from the active fraction and identified as 5ß,19-epoxycucurbita-6,23-diene-3ß,19,25-triol (1) and 3ß,7ß,25-trihydroxycucurbita-5,23-dien-19-al (2) by comparing spectral data. Treatments of both compounds in vitro potently suppressed P. gingivalis-induced IL-8, IL-6, and IL-1ß levels and the activation of mitogen-activated protein kinase (MAPK) in THP-1 cells. Both compounds effectively inhibited the mRNA levels of IL-6, tumor necrosis factor (TNF)-α, and cyclooxygenase (COX)-2 in P. gingivalis-stimulated gingival tissue of mice. These findings imply that 5ß,19-epoxycucurbita-6,23-diene-3ß,19,25-triol and 3ß,7ß,25-trihydroxycucurbita-5,23-dien-19-al could be used for the development of novel therapeutic approaches against P. gingivalis infections.

The Effect of Oxidation on Berberine-Mediated CYP1 Inhibition: Oxidation Behavior and Metabolite-Mediated Inhibition.

The protoberberine alkaloid berberine carries methylenedioxy moiety and exerts a variety of pharmacological effects, such as anti-inflammation and lipid-lowering effects. Berberine causes potent CYP1B1 inhibition, whereas CYP1A2 shows resistance to the inhibition. To reveal the influence of oxidative metabolism on CYP1 inhibition by berberine, berberine oxidation and the metabolite-mediated inhibition were determined. After NADPH-fortified preincubation of berberine with P450, the inhibition of CYP1A1 and CYP1B1 variants (CYP1B1.1, CYP1B1.3, and CYP1B1.4) by berberine was not enhanced, and CYP1A2 remained resistant. Demethyleneberberine was identified as the most abundant metabolite of CYP1A1- and CYP1B1-catalyzed oxidations, and thalifendine was generated at a relatively low rate. CYP1A1-catalyzed berberine oxidation had the highest maximal velocity (V max) and exhibited positive cooperativity, suggesting the assistance of substrate binding when the first substrate was present. In contrast, the demethylenation by CYP1B1 showed the property of substrate inhibition. CYP1B1-catalyzed berberine oxidation had low K m values, but it had V max values less than 8% of those of CYP1A1. The dissociation constants generated from the binding spectrum and fluorescence quenching suggested that the low K m values of CYP1B1-catalyzed oxidation might include more than the rate constants describing berberine binding. The natural protoberberine/berberine fmetabolites with methylenedioxy ring-opening (palmatine, jatrorrhizine, and demethyleneberberine) and the demethylation (thalifendine and berberrubine) caused weak CYP1 inhibition. These results demonstrated that berberine was not efficiently oxidized by CYP1B1, and metabolism-dependent irreversible inactivation was minimal. Metabolites of berberine caused a relatively weak inhibition of CYP1.

Antioxidant and Anti-Inflammatory Phenolic Glycosides from Clematis tashiroi.

From the 95% EtOH extract of dried aerial parts of Clematis tashiroi, eight new and four known phenolic (caffeic acid, coumaric acid, ferrulic acid) glycosides were isolated and characterized. The structures of the new isolates (clematisides A-H) were elucidated by spectroscopic data interpretation as trans-4-O-(6-O-trans-caffeoyl-ß-D- glucopyranosyl)-9-O-ß-D-glucopyranosyl caffeic acid (1), trans-4-O-(6-O-trans-feruloyl-ß-D-glucopyranosyll)-9-O-ß-D-glucopyranosyl caffeic acid (2), trans-4-O-(6-O-trans-p-coumaroyl-ß-D-glucopyranosyl)-9-O-ß-D-glucopyranosyl caffeic acid (3), trans-4-O-(6-O-trans-caffeoyl-ß-D-glucopyranosyl)-9-O-ß-D-glucopyranosyl p-coumaric acid (4), trans-3-O-(6-O-trans-caffeoyl-ß-D-glucopyranosyl)-9-O-ß-D-glucopyranosyl caffeic acid (5), trans-3-O-(6-O-trans-p-coumaroyl-ß-D-glucopyranosyl)-9-O-ß-D-glucopyranosyl caffeic acid (6), 6-(3',4'-dihydroxystyryl)-2-pyrone-4-O-(6-O-trans-caffeoyl)-ß-D-glucopyranoside (7), and 6-(3',4'-dihydroxystyryl)-2-pyrone-4-O-{6-O-[4-O-(6-O-trans-caffeoyl)-ß-D-glucopyranosyl]-trans-caffeoyl}-ß-D-glucopyranoside (8), respectively. In a DPPH radical-scavenging test, compounds 1, 7, and 8 showed more potent antioxidant activity than that of the positive control, vitamin E. In addition, compound 7 also showed inhibitory activity in an antinitric oxide release assay.

Dicentrine Analogue-Induced G2/M Arrest and Apoptosis through Inhibition of Topoisomerase II Activity in Human Cancer Cells.

Lindera megaphylla has been traditionally used as an antineoplastic and wound healing remedy. We previously demonstrated the antitumor effects of D-dicentrine, a natural aporphine alkaloid from the root of L. megaphylla. To generate analogues, series of phenanthrene alkaloids from D-dicentrine were synthesized by degradation with ethyl chloroformate in pyridine, base hydrolysis, and N-alkylation. In this study, we demonstrated that one of the synthesized D-dicentrine analogues (here after designated as analogue 1) exhibited more potent cytotoxic effects than D-dicentrine in colon adenocarcinoma, hepatoma, leukemia, and epidermoid carcinoma cells. We performed cell cycle and apoptotic analysis by flow cytometry, an apoptotic DNA detection ELISA assay, and topoisomerase II activity by the kinetoplast DNA concatenation assay for studying their cytotoxic mechanisms. We found that both D-dicentrine and analogue 1 induced apoptosis and G2/M arrest in HL-60 leukemia cells. The percentage of apoptotic cells induced by analogue 1 was 4.5-fold higher than that induced by D-dicentrine as evident from measuring the amount of histone-bound DNA fragments. Moreover, we found that analogue 1 was 28-fold more potent than D-dicentrine for inhibition of topoisomerase II activity by the kinetoplast DNA concatenation assay. Our findings indicate that D-dicentrine analogue 1 is very promising as a potential antitumor agent for future study.

Three New Sesquiterpene Aryl Esters from the Mycelium of Armillaria mellea.

Three new sesquiterpene aryl esters and eight known compounds were isolated from the EtOH extract of the mycelium of Armillaria mellea. The structures of new compounds were established by analysis of their spectroscopic data. Some of the isolates showed cytotoxicity to a variety of cancer cell lines, including MCF-7, H460, HT-29, and CEM.

Lignans from the aerial parts of Saururus chinensis: isolation, structural characterization, and their effects on platelet aggregation.

Five new diaryldimethylbutane lignans, saurulignans A-E (1-5), four new tetrahydrofuran lignans, saurufurins A-D (6-9), and one arylnaphthalene lignan, saurunarin (10), were isolated from Saururus chinensis, along with 18 known compounds. Lignan 5 showed significant inhibition of ADP-induced aggregation with an IC50 value of 9.8 µM and AA-induced aggregation with an IC50 value of 14.0 µM. Compound 19 showed significant activity to inhibit PAF-induced aggregation with an IC50 value of 9.1 µM. In addition, five isolated compounds could induce platelet aggregation. These results suggest that secondary metabolites in S. chinensis have bidirectional regulation on blood clotting and anticlotting effects.

The contribution of neutrophils to bacteriophage clearance and pharmacokinetics in vivo.

With the increasing prevalence of antimicrobial-resistant bacterial infections, there is great interest in using lytic bacteriophages (phages) to treat such infections. However, the factors that govern bacteriophage pharmacokinetics in vivo remain poorly understood. Here, we have examined the contribution of neutrophils, the most abundant phagocytes in the body, to the pharmacokinetics of intravenously administered bacteriophage in uninfected mice. A single dose of LPS-5, an antipseudomonal bacteriophage recently used in human clinical trials, was administered intravenously to both wild-type BALB/c and neutropenic ICR mice. Phage concentrations were assessed in peripheral blood and spleen at 0.5, 1, 2, 4, 8, 12, and 24 hours after administration by plaque assay and qPCR. We observed that the phage clearance is only minimally affected by neutropenia. Indeed, the half-life of phages in blood in BALB/c and ICR mice is 3.45 and 3.66 hours, respectively. These data suggest that neutrophil-mediated phagocytosis is not a major determinant of phage clearance. Conversely, we observed a substantial discrepancy in circulating phage levels over time when measured by qPCR versus plaque assay, suggesting that substantial functional inactivation of circulating phages occurs over time. These data indicate that circulating factors, but not neutrophils, inactivate intravenously administered phages.

BPR0C305, an orally active microtubule-disrupting anticancer agent.

BPR0C305 is a novel N-substituted indolyl glyoxylamide previously reported with in-vitro cytotoxic activity against a panel of human cancer cells including P-gp-expressing multiple drug-resistant cell sublines. The present study further examined the underlying molecular mechanism of anticancer action and evaluated the in-vivo antitumor activities of BPR0C305. BPR0C305 is a novel synthetic small indole derivative that demonstrates in-vitro activities against human cancer cell growth by inhibiting tubulin polymerization, disrupting cellular microtubule assembly, and causing cell cycle arrest at the G2/M phase. It is also orally active against leukemia and solid tumor growths in mouse models. Findings of these pharmacological and pharmacokinetic studies suggest that BPR0C305 is a promising lead compound for further preclinical developments.

Cytotoxic apigenin derivatives from Chrysopogon aciculatis.

Four new apigenin derivatives, 7-de-O-methylaciculatin, 8-C-ß-D-boivinopyranosylapigenin, aciculatinone, and 4'-O-glucosylaciculatin, along with eight known compounds, apigenin-8-carbaldehyde, kaempferol, tricin, taxifolin, 6,7,4'-trihydroxyflavone, trans-oxyresveratrol, aciculatin, and luteolin-7-sulfate, were isolated from an ethanolic extract of Chrysopogon aciculatis. Their chemical structures were elucidated by spectroscopic methods. Among the known compounds, the natural occurrence of apigenin-8-carbaldehyde and luteolin-7-sulfate is demonstrated for the first time. Some of the isolates were evaluated for cytotoxic activity against human cancer cell lines including MCF-7, H460, HT-29, and CEM.

A phenolic derivative and two diacetylenes from Symphyotrichum subulatum.

A pytochemical study on the constituents of the roots of Symphyotrichum subulatum led to the isolation of three new compounds including two diacetylenes, asterynes A (1) and B (2), and (E)-4-(3-acetoxyprop-1-enyl)-2-methoxyphenyl (S)-2-methylbutanoate (3) along with twelve known compounds. Their structures were elucidated with spectroscopic analyses. Compound 3 showed anti-inflammatory activity on LPS-induced NO production with an EC50 value of 15.0 µM.

Effects of armepavine against hepatic fibrosis induced by thioacetamide in rats.

The aim of this study was to investigate if armepavine (Arm, C19H23O3N) could exert inhibitory effects against hepatic fibrosis in rats. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with tumour necrosis factor-α (TNF-α) to evaluate the inhibitory effects of Arm. Rats were injected with thioacetamide (TAA; 300 mg/kg, intraperitoneally) thrice a week for 4 weeks to induce hepatic fibrosis, with Arm (3 or 10 mg/kg) given by gavage twice a day. Liver sections were taken for western blotting, fibrosis scoring and immunofluorescence staining. Arm (1-10 µm) concentration-dependently attenuated TNF-α-stimulated: (i) protein expressions of α-smooth muscle actin (α-SMA), collagen type I and angiopoietin-1; (ii) H2O2 production; and (iii) NF-κB, JunD and C/EBPß (cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding protein-ß (EBPß)) nuclear translocations in HSC-T6 cells. In vivo Arm treatment significantly reduced plasma aspartate transaminase and alanine transaminase levels, hepatic α-SMA expression and collagen contents, and fibrosis scores of TAA-injected rats. Moreover, Arm treatment decreased α-SMA- and NF-κB-positive cells in immunohistochemical staining, and mRNA expression levels of IL-6, TGF-ß1, TIMP-1, col1α2, iNOS and ICAM-1 genes, but up-regulated the metallothionein gene in the livers of TAA-injected rats. Our results indicated that Arm exerted both in vitro and in vivo antifibrotic effects in rats, with inhibition of NF-κB, JunD and C/EBPß pathways.

Antioxidant and anti-nitric oxide components from Quercus glauca.

From the ethanolic extract of Quercus glauca, two new lignans, (+)-5'-methoxyisolariciresinol-9'-O-α-L-rhamnopyranoside (1) and (7R,8S)-dihydrodehydrodiconiferyl alcohol 4-ß-D-xyloside (2), along with fourteen known compounds including four lignanoids (3-6), five triterpenoids (7-11), two flavonoids (12, 13), two aromatics (14, 15), and one steroid (16) were isolated. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. Moreover, compounds 9 and 14 strongly inhibited nitric oxide (NO) production with IC50 values of 8.25 and 14.04 µM, respectively, and compounds 1, 4-6, 14, and 15 showed moderate antioxidant activities.

Antimicrobial isothiocyanates from the seeds of Moringa oleifera Lam.

4-(alpha-L-Rhamnosyloxy)benzyl isothiocyanate (1) and 4-(4'-O-acetyl-alpha-L-rhamnosyloxy)-benzyl isothiocyanate (2) isolated from Moringa oleifera seeds were screened for their antibacterial activities against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Pseudomonas aeruginosa, and for their antifungal activities against Candida albicans, Trichophyton rubrum, and Epidermophyton floccosum using the disk diffusion method. Isothiocyanates 1 and 2 were found active at the lowest inhibitory concentration of 1 mg/ml against all Gram-positive bacteria tested (S. aureus, S. epidermidis, B. subtilis) and against the dermatophytic fungi E. floccosum and T. rubrum. Statistically significant differences were found between the mean inhibition zones (IZ) of 1 and 2 and the standard drugs, ofloxacin and clotrimazole. The minimum inhibitory concentration (MIC) values confirmed the good antimicrobial activity of 1 and 2 against S. aureus, good to moderate activity against S. epidermidis, moderate activity against B. subtilis, and weak activity against E. floccosum and T. rubrum. The in vitro bactericidal effect of 1 and 2 against the Gram-positive bacterial strains tested is suggested by MBC:MIC ratios of 2:1.

Effect of repeated Shengmai-San administration on nifedipine pharmacokinetics and the risk/benefit under co-treatment.

Herbal interactions with nifedipine/felodipine through cytochrome P450 (CYP) 3A inhibition is significant in humans. Shengmai-San (SMS), a three-herbal formula of Chinese medicine, is commonly prescribed in Asia populations for cardiovascular disorders. This study aimed to elucidate the impact of SMS on nifedipine/felodipine treatment by the findings from rat pharmacokinetic study of nifedipine to the retrospective cohort study of patients with hypertension. The 3-week SMS treatment increased the systemic exposure to nifedipine by nearly two-fold and decreased nifedipine clearance by 39% in rats. Among the ingredients of SMS component herbs, schisandrin B, schisantherin A, and methylophiopogonanone A, inhibited the nifedipine oxidation (NFO) activities of rat hepatic and intestinal microsomes, as well as human CYP3A4. Methylophiopogonanone A was identified as a time-dependent inhibitor of CYP3A4. After 1:5 propensity score matching, 4,894 patients with nifedipine/felodipine use were analyzed. In patients receiving nifedipine/felodipine, the subgroup with concurrent SMS treatment had a higher incidence of headache (92.70 per 1,000 personyears) than the subgroup without SMS treatment (51.10 per 1,000 person-years). There was a positive association between headache incidence and cumulative doses of SMS (1-60 g SMS: hazard ratio (HR): 1.39; 95% confidence interval (CI): 1.11-1.74; >60 g SMS: HR: 1.97; 95% CI: 1.62-2.39; p < 0.0001). However, patients who had higher cumulative SMS doses had a lower risk of all-cause mortality (1-60 g SMS: HR: 0.67; 95% CI: 0.47-0.94; >60 g SMS: HR: 0.54; 95% CI: 0.37-0.79; p = 0.001). Results demonstrated increased rat plasma nifedipine levels after 3-week SMS treatment and increased headache incidence should be noted in nifedipine/felodipine-treated patients with prolonged SMS administration.