Cerebral white matter burden is linked to cognitive function in patients undergoing hemodialysis

INTRODUCTION

Chronic kidney disease is related to neurodegeneration and structural changes in the brain which might lead to cognitive decline. The Fazekas scale used for assessing white matter hyperintensities (WMHs) was associated with poor cognitive performance. Therefore, this study investigated the associations between the mini-mental status examination (MMSE), Montreal cognitive assessment (MoCA), cognitive abilities screening instrument (CASI), and Fazekas scale in patients under hemodialysis (HD).

METHODS

The periventricular (PV) WMHs and deep WMHs (DWMHs) in brain magnetic resonance images of 59 patients under dialysis were graded using the Fazekas scale. Three cognition function tests were also performed, then multivariable ordinal regression and logistic regression were used to identify the associations between cognitive performance and the Fazekas scale.

RESULTS

There were inverse associations between the three cognitive function tests across the Fazekas scale of PVWMHs (p = .037, .006, and .008 for MMSE, MoCA, and CASI, respectively), but the associations were attenuated in the DWMHs group. In CASI, significant differences were identified in short-term memory, mental manipulation, abstract thinking, language, spatial construction, and name fluency in the PVWMHs group. However, DWMHs were only significantly correlated with abstract thinking and short-term memory.

CONCLUSION

An inverse correlation existed between the Fazekas scale, predominantly in PVWMHs, and cognition in patients undergoing HD. The PVWMHs were associated with cognitive performance assessed by MMSE, MoCA, and CASI, as well as with subdomains of CASI such as memory, language and name fluency in patients undergoing HD.

Dramatic band gap reduction incurred by dopant coordination rearrangement in Co-doped nanocrystals of CeO2

A dramatic band gap narrowing of 1.61 eV has been observed in Co-doped nanocrystals of CeO₂ (ceria), as a result of thermal annealing, without changing the ceria crystal structure and the Co concentration. As demonstrated by x-ray absorption fine structures, thermal annealing incurs an oxygen coordination rearrangement around Co atoms from an octahedral coordination to a square-planar coordination. First principle calculation using density functional theory reveals two stable oxygen coordination types surrounding Co, consistent with the experimental observation. The band gap values calculated for the two stable coordination types differ dramatically, reproducing the experimentally observed band gap narrowing. These prominent effects due to local structure rearrangement around dopant atoms can lead to unprecedented methods for band gap engineering in doped nanocrystal oxides.

Unconventional interplay between heterovalent dopant elements: Switch-and-modulator band-gap engineering in (Y, Co)-Codoped CeO2 nanocrystals

We report the experimental observation and theoretical explanation of an unconventional interplay between divalent Co and trivalent Y dopants, both of which incur oxygen vacancies in the CeO₂ host that has predominantly tetravalent Ce cations. The Co dopant atoms were experimentally found to act as a switch that turns on the dormant effect of Y-modulated band-gap reduction. As revealed by density functional theory (DFT) calculations with structures verified by synchrotron-radiation x-ray measurements, a Co 3d band that hybridizes with Ce 4f band was lowered due to reduced O 2p repulsion arising from oxygen vacancies incurred by Y doping and therefore gave rise to the observed band-gap narrowing effect. Such switch-and-modulator scheme for band-gap engineering in nanocrystal materials can lead to important applications in environmental protection and solar energy harvesting technologies.

Stevens-Johnson syndrome and toxic epidermal necrolysis in patients with malignancies

BACKGROUND

Malignancy is known to be associated with an increased mortality rate in patients with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). However, risk factors contributing to the poor prognosis of patients with SJS/TEN with malignancies remain undefined.

OBJECTIVES

To explore the potential involvement of malignancy and its related factors contributing to the poor outcome of SJS/TEN, in a retrospective study.

METHODS

In total 517 patients with SJS/TEN were enrolled. Forty-seven who sustained various types of malignancies were analysed for numerous malignancy-related factors, including cancer types, clinical stages and chemotherapies given or not before the onset of SJS/TEN.

RESULTS

We found that the mortality rate of patients with SJS/TEN with malignancies was higher than that of patients without malignancies (32%, 15/47 vs. 8·5%, 40/470, respectively) (P < 0·001). The use of phenytoin was significantly higher in the malignancy group. The presence of hepatocellular carcinoma (80%, four of five; P < 0·001; odds ratio 43) and colorectal cancer (67%, two of three; P = 0·022; odds ratio 21·5) significantly increased the death rate of patients with SJS/TEN, whereas lung cancer and urothelial carcinoma did not. Patients who had received ongoing or recent chemotherapy showed higher mortality than those without chemotherapy (P = 0·022; odds ratio 4·95). Furthermore, among the 47 patients with SJS/TEN with malignancies, lower serum albumin, haemoglobin and platelet count were detected in the deceased patients than in the surviving patients before the onset of SJS/TEN.

CONCLUSIONS

Our results suggest that several factors related to malignancies, such as specific cancer types, chemotherapy and malnutrition, may contribute to poor prognosis in patients with malignancies developing SJS/TEN.

Meta-analysis of the effectiveness of esomeprazole in gastroesophageal reflux disease and Helicobacter pylori infection

WHAT IS KNOWN AND OBJECTIVE

Proton pump inhibitors (PPIs) are one of the most widely used classes of drugs. However, the quantum clinical benefit of newer and more expensive PPIs over the older generation PPIs remains uncertain. This meta-analysis sought to assess the clinical and safety profiles of esomeprazole versus omeprazole at pharmacologically equivalent doses in healing gastroesophageal reflux disease (GERD), peptic ulcer disease and eradicating Helicobacter pylori (H. pylori) infection.

METHODS

PubMed and the Cochrane Library were searched for randomized controlled trials comparing esomeprazole with omeprazole at all doses up to February 2015. Trials were assessed by two reviewers for eligibility according to predefined study inclusion criteria. Meta-analysis was conducted using a random effects model, and heterogeneity in the estimated effects was investigated using meta-regression. Sensitivity analysis was performed to test the robustness of the findings.

RESULTS AND DISCUSSION

Fifteen trials were included and none of which compared esomeprazole with omeprazole in peptic ulcer disease. The included studies had not evaluated esomeprazole 20 mg versus omeprazole 40 mg. In GERD, esomeprazole 40 mg (relative risk (RR) = 1·07; 95% confidence interval (CI) 1·02 to 1·12) and 20 mg (RR=1·04; 95% CI 1·01 to 1·08) significantly improved esophagitis healing when compared with omeprazole 20 mg at week 8. The corresponding numbers needed to treat were 17 and 30, respectively. No significant difference was observed between esomeprazole 20 mg and omeprazole 20 mg at week 4. In H. pylori eradication, there was no difference in the treatment effects between esomeprazole 20 mg and omeprazole 20 mg (RR = 1·01;95% CI 0·96 to 1·05). Their safety profiles were comparable.

WHAT IS NEW AND CONCLUSION

Esomeprazole demonstrated better esophagitis healing rate in patients with GERD than omeprazole at week 8. However, this clinical advantage diminished when both drugs were given at the same doses at week 4. Superiority of esomeprazole was not observed in the H. pylori eradication rates.

CORRELATION BETWEEN C-erbB-2 WITH GASTRIC MUCOSAL ATYPICAL HYPERPLASIA AND GASTRIC CARCINOMA

C-erbB-2 is a cancer gene originating from cells. The high-expression and amplification of C-erbB-2 and its protein products (P185) are found in a wide variety of tumors. The abnormal expression of C-erbB-2 has great influence on the occurrence and development of gastric carcinoma. This paper aimed to analyze the expression of C-erbB-2 in the tissues of gastric carcinoma, gastric mucosal atypical hyperplasia and gastritis, and discuss its role in the occurrence and development of gastric carcinoma. The morphological differences and connections among simple intestinal metaplasia (SIM), atypical intestinal metaplasia (AIM) and dysplasia in intestinal metaplasia through hematoxylin and eosin (HE) staining were studied. Three groups were set to detect the expression condition of C-erbB-2 by immunohistochemical method (IHC). The result showed that C-erbB-2 had no significant difference in AIM and gastric carcinoma, that is, AIM was closely related to gastric carcinoma. The positive expression was demonstrated of C-erbB-2 products (P185) in medium and gastric mucosa dysplasia tissues and was 29.41% and 66.67%, respectively, while it was 25%, 50% and 77.78% in high, medium and low differentiation of gastric carcinoma. It can be seen that there was a significant difference between them (P<0.05), and the expression degree was significantly enhanced (P<0.05); the expression degree in high differentiation gastric cancer tissue was significantly higher than the middle and low differentiation gastric cancer tissue. It was concluded that C-erbB-2 played an important role in the pathogenic mechanism of gastric carcinoma, and it might act on the later period of the gastric carcinoma, which provides objective reference index for the diagnosis and prognosis of gastric carcinoma and meanwhile provides instructional theoretical reference for the application of targeted drugs in the clinical treatment of gastric carcinoma.

Alkaloids of the wood of Cryptocarya chinensis

Four new pavine alkaloids, (+)-eschscholtzidine-N-oxide (1), (-)-12-hydroxycrychine (2), (-)-12-hydroxy-O-methylcaryachine (3), and (-)-N-demethylcrychine (4), and four new proaporphine alkaloids, isocryprochine (5), prooxocryptochine (6), isoamuronine (7), and (+)-8,9-dihydrostepharine (8), together with nine known compounds were isolated from an ethanol extract of the wood of Cryptocarya chinensis. Their structures were elucidated by spectral analysis (NMR and MS), and the structures of 2 and 5 were confirmed by X-ray crystallography.

Alkaloids from the leaves of Cryptocarya chinensis Hemsl

Investigation of the leaves of Cryptocarya chinensis resulted in the isolation of three new alkaloids, named (-)-isocaryachine-N-oxide, isoboldine-beta-N-oxide, and 1-hydroxycryprochine, together with seven known compounds. Their structures were elucidated by spectral analysis. The structures of (-)-isocaryachine-N-oxide and 1-hydroxycryprochine were further confirmed by X-ray techniques.

Constituents of the root bark of Severinia buxifolia collected in Hainan

Two new tetranortriterpenoids, 7-isovaleroylcycloseverinolide (1) and 7-isovaleroylcycloepiatalantin (2), together with 28 known compounds, were isolated and characterized from the root bark of Severinia buxifolia collected in Hainan. The structures of 1 and 2 were elucidated on the basis of spectral evidence including 2D NMR and X-ray techniques. The cytotoxicity of several acridone alkaloid isolates (3-8) was evaluated against a small tumor cell panel.

Cytotoxicity of Ganoderma lucidum triterpenes

Two new triterpenoids, lucidenic acid N (1) and methyl lucidenate F (2), together with four known compounds, lucidenic acid A, lucidenolactone, lucidenic acid C, and ganoderic acid E, were isolated from the dried fruiting bodies of Ganoderma lucidum. Their structures were elucidated by spectral and chemical transformation studies. Among them, lucidenic acid N (1), lucidenic acid A, and ganoderic acid E showed significant cytotoxic activity against Hep G2, Hep G2,2,15, and P-388 tumor cells.

Cinnamophilin as a novel antiperoxidative cytoprotectant and free radical scavenger

The antioxidant properties of cinnamophilin were evaluated by studying its ability to react with relevant reactive oxygen species, and its protective effect on cultured cells and biomacromolecules under oxidative stress. Cinnamophilin concentration-dependently suppressed non-enzymatic iron-induced lipid peroxidation in rat brain homogenates with an IC50 value of 8.0+/-0.7 microM and iron ion/ADP/ascorbate-initiated rat liver mitochondrial lipid peroxidation with an IC50 value of 17.7+/-0.2 microM. It also exerted an inhibitory activity on NADPH-dependent microsomal lipid peroxidation with an IC50 value of 3.4+/-0.1 microM without affecting microsomal electron transport of NADPH-cytochrome P-450 reductase. Both 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azo-bis(2-amidinopropane) dihydrochloride-derived peroxyl radical tests demonstrated that cinnamophilin possessed marked free radical scavenging capacity. Cinnamophilin significantly protected cultured rat aortic smooth muscle cells (A7r5) against alloxan/iron ion/H2O2-induced damage resulting in cytoplasmic membranous disturbance and mitochondrial potential decay. By the way, cinnamophilin inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity and thiobarbituric acid-reactive substance formation in a concentration-dependent manner. On the other hand, it was reactive toward superoxide anions generated by the xanthine/xanthine oxidase system and the aortic segment from aged spontaneously hypertensive rat. Furthermore, cinnamophilin exerted a divergent effect on the respiratory burst of human neutrophil by different stimulators. Our results show that cinnamophilin acts as a novel antioxidant and cytoprotectant against oxidative damage.

New constituents and antiplatelet aggregation and anti-HIV principles of Artemisia capillaris

Five new constituents including a flavonoid, artemisidin A (1), and four coumarins, artemicapins A (2), B (3), C (4) and D (5), together with 70 known compounds (6-75), have been isolated and characterized from the aerial part of Artemisia capillaris. The structures of these compounds were determined from spectral analyses and/or chemical evidence. Among them, 15 compounds (3, 6, 10, 18. 30-32, 38-41, 44, 45, 51, and 55) showed antiplatelet aggregation activity and three compounds (10, 17, and 51) demonstrated significant activity against HIV replication in H9 lymphocytic cells.

Constituents of the roots and stems of Aristolochia mollissima

Five new sesquiterpenes, mandolins R (1), S (2), U (3), W (4), and X (5), together with 39 known compounds, were isolated from the dried roots and stems of Aristolochia mollissima. Their structures were determined by spectroscopic methods.

Constituents from the stem and root of Aristolochia kaempferi

Three new phenanthrene derivatives, aristoliukine-C, aristofolin-E and aristolochic acid-Ia methyl ester, and one new sesquiterpene, madolin-P, together with 58 known compounds were isolated from the stem and root of Aristolochia kaempferi. The structures of these compounds were determined by spectral analysis. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.

The constituents of the root and stem of Aristolochia cucurbitifolia Hayata and their biological activity

Four new compounds, three phenanthrene derivatives, aristolochic acid-III methyl ester (1), cepharanone C (2), and sodium 7-hydroxyl-8-methoxyaristolate (3), and the benzoate derivative, sodium 3,4-dimethoxybenzoate (4), together with 53 known compounds were isolated and characterized from the fresh root and stem of Aristolochia cucurbitifolia. Their structures were elucidated by spectral analyses and chemical transformations. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.

Constituents from the leaves of Aristolochia elegans

One new biphenyl ether, aristogin C (1), and two new porphyrins, aristophylls A (2) and B (3), as well as 11 known compounds, were isolated from the leaves of Aristolochia elegans. Their structures were elucidated according to the spectroscopic (NMR and MS) analyses or by comparison with literature values.

The constituents of the root and stem of Aristolochia heterophylla Hemsl

Seven new compounds, sodium aristolochate-VII (1), aristolactam-CIV (2), madolin-I (3), -J (4), -K (5), -L (6) and -M (7) together with 71 known compounds were isolated and characterized from the fresh root and stem of Aristolochia heterophylla Hemsl. Their structures were determined by spectral methods. Compound 8 was revised as aromadendrane-4beta, 10beta-diol by spectral data and single-crystal X-ray analysis.

Chemical constituents of Glycosmis citrifolia (Willd.) Lindl. Structures of four new acridones and three new quinolone alkaloids

The structures of two new dimeric acridone alkaloids, glycobismine-D (1) and -E (2), having a novel linkage as binary acridones, three monomeric acridones, glycocitrine-IV (3), -V (4), and -VI (5), and three quinolone alkaloids, glycocitlone-A (6), -B (7), and -C (8) from Glycosmis citrifolia (Willd.) Lindl. (Rutaceae) have been elucidated by spectrometric studies.

Acridone alkaloids from the root bark of Severinia buxifolia in Hainan

Eight new acridone alkaloids, buxifoliadines-A--H together with nine known acridone compounds, were isolated and characterized from the root bark of Severinia buxifolia which was collected in Hainan province, China. Their structures were determined by spectroscopic methods. The relationship between acridone alkaloids with collecting area is discussed. The 13C-NMR spectra of the prenyl substituents at C-2 and/or C-4 of N-unsubstituted acridone alkaloids are also discussed.

Schistosoma japonicum infection presenting with colon perforation: case report

Colon perforation can be caused by a variety of entities, including iatrogenic trauma, tumors, ischemia, inflammatory bowel disease, and steroid use. Parasitic infection rarely leads to colon perforation. Secondary peritonitis results from mixed microorganism infection, including enterococci, enteric bacilli, and anaerobes. A combination of an optimal antibiotic regimen and surgical intervention is of paramount importance. Nevertheless, intra-abdominal infections usually have a high mortality rate. Schistosomiasis occurs worldwide. S. japonicum infection is endemic in Asia. The most common complications of gastrointestinal schistosomiasis are periportal fibrosis, intestinal polyposis, and bowel stricture. Rarely, schistosomiasis results in colon perforation. The diagnosis of schistosome infections is based on ova in stool or tissue specimens, and/or immunologic diagnostic tests. The most effective anti-schistosomiasis agent is praziquantel. Herein, we describe an unusual case of colon perforation associated with Schistosoma japonicum infection, which resulted in severe peritonitis and led to the patient's death.

Ionic mechanisms for the antiarrhythmic action of cinnamophilin in rat heart

We investigated the electrophysiological effect and antiarrhythmic potential of cinnamophilin (Cinn), a thromboxane A(2) antagonist isolated from Cinnamomum philippinense, on rat cardiac tissues. Action potential and ionic currents in single rat ventricular cells were examined by current clamp or voltage clamp in a whole-cell configuration. In 9 episodes of ischemia-reperfusion arrhythmia, 10 microM Cinn converted 6 of them to normal sinus rhythm. Cinn suppressed the maximal rate of rise of the action potential upstroke (V(max)) and prolonged the action potential duration at 50% repolarization (APD(50)). Voltage clamp study showed that the suppression of V(max) by Cinn was associated with an inhibition of sodium inward current (I(Na), IC(50) = 10.0 +/- 0.4 microM). At 30 microM, V(1/2) for the steady-state inactivation curve of I(Na) was shifted from -84.1 +/- 0.2 to -93.0 +/- 0.5 mV. Cinn also reduced calcium inward current (I(Ca)) dose-dependently with an IC(50) value of 9.5 +/- 0.3 microM. Cinn (10 microM) reduced the I(Ca) with a negative shift of V(1/2) for the steady-state inactivation curve of I(Ca) from -32.2 +/- 0.3 to -50.7 +/- 0.4 mV. The prolongation of APD(50) was associated with an inhibition of the integral of potassium outward current with IC(50) values between 4.8 and 7.1 microM. At 10 microM, Cinn reduced I(Na) without a negative shift of its voltage-dependent steady-state inactivation curves. The inhibition of transient outward current (I(to)) by Cinn (3-30 microM) was associated with an acceleration of its time constant of inactivation and negative shift of its potential-dependent steady-state inactivation curves. The equilibrium dissociation constant (K(d)) of Cinn to inhibit open state I(to) channels, as calculated from the time constant of developing block, was 18.3 microM. The time constant of recovery of I(to) from inactivation state was unaffected by Cinn. The rate constant for the relief from the depolarization-dependent block of I(to) was calculated to be 23. 9 ms. As compared with its effect on I(to), Cinn exerted about half the potency to block I(Na) and I(Ca). These results indicate that the inhibition of I(Na), I(Ca) and I(to) may contribute to the antiarrhythmic activity of Cinn against ischemia-reperfusion arrhythmia.

Sesquiterpene esters of aristolochic acid from the root and stem of Aristolochia heterophylla

Three novel sesquiterpene esters of aristolochic acid, aristoloterpenate-II (2), -III (3), and-IV (4), together with known aristoloterpenate-I (1), were isolated and characterized from the root and stem of Aristolochia heterophylla. Their structures were elucidated by spectroscopic methods. The absolute configuration of these compounds at C-4' was determined as R by circular dichroic studies. These compounds showed cytotoxicity against hepatoma G2, 2, 2, 15 cells.

The bakkenolides from the root of Petasites formosanus and their cytotoxicity

Thirty-two new bakkenolides, bakkenolides-Db (1)--Dh(7), -Fa(8), -Fb(9), -I(10)--M(14), -Na(15), -Nb(16), -O(17)--T(22), -Ua (23), -Ub(24), -V(25)--X(27), -Ya(28), -Yb(29), -Za(30), -Zb(31) and -III(32), from the roots of Petasites formosanus together with thirty known compounds were isolated. The structures were characterized by spectral analysis. The locations, C-1 and/or C-9 of bakkenolide skeleton, of the substituents, such as acetoxy, isobutyroyloxy and isovaleroyloxy groups, can be determined by the chemical shifts of their signals and the H-1 and/H-9 in the 1H-NMR spectra. The cytotoxicity was also discussed.

Differential effects of IL-2 and IL-15 on the death and survival of activated TCR gamma delta+ intestinal intraepithelial lymphocytes

TCR gamma delta+ cells are enriched in the intestine mucosa and constitute approximately half of the intestinal intraepithelial lymphocytes (iIEL) in mice. They are likely activated by self and foreign Ags in situ, but little is known about how the activated gamma delta iIEL are regulated. In the iIEL compartment, IL-2 is produced by activated TCR alpha beta+ iIEL, and IL-15 message is detected in iIEL and in the epithelial cells. We found surface expression of IL-2 as well as IL-15Rs on activated gamma delta iIEL, and examined the effects of IL-2 and IL-15 on the survival and death of gamma delta iIEL during secondary stimulation through TCR. We found that both cytokines supported growth of the restimulated gamma delta iIEL, but exerted different effects on their survival. A significant higher number of live cells were recovered from the gamma delta iIEL cultures restimulated in IL-15 than in IL-2. Quantitation of apoptotic cells showed more cell death in the IL-2 group than in the IL-15 group. The cell death was associated with restimulation through TCR and was not caused by insufficient growth factor, thus representing activation-induced cell death. Western blot analyses found no difference in the levels of Bcl-2 and Bax proteins between the two groups. However, the level of Bcl-xL protein diminished with time in the IL-2 group whereas the level was sustained in the IL-15 group, which may contribute to the pro-survival effect of IL-15. These results demonstrated that the survival of activated gamma delta iIEL is differentially regulated by IL-2 and IL-15.

Terpenoids of Syzygium formosanum

A new natural product, 4-epifriedelin (1), and 12 known terpenoids have been isolated from the leaves of Syzygium formosanum. The known compounds include caryophyllene oxide, friedelin, canophyllal, glutinol, alpha-terpineol, phytol, betulinic acid, uvaol, lupeol, betulin, ursolic acid, and oleanolic acid. All of these compounds are reported for the first time from S. formosanum.

Four aristolochic acid esters of rearranged ent-elemane sesquiterpenes from aristolochia heterophylla

Four aristolochic acid esters of ent-elemane type sesquiterpene having a new carbon skeleton, aristophyllides A (1), B (2), C (3), and D (4), were isolated from the stems and roots of Aristolochia heterophylla. The esters were characterized by NMR and MS methods and included is a study of absolute configurations using the CD exciton chirality method.

Rhinacanthin-Q, a naphthoquinone from Rhinacanthus nasutus and its biological activity

The continuing investigation of the root of Rhinacanthus nasutus afforded a 1,4-naphthoquinone ester, rhinacanthin-Q, accompanied by twenty-four known compounds. The structure was elucidated on the basis of spectroscopic analyses. The cytotoxicity and antiplatelet effect of this compound was also discussed.

Synthesis and cytotoxicity of acetyl-4H,9H-naphtho[2,3-b]thiophene-4,9-diones

Several new acetyl-4H,9H-naphtho[2,3-b]thiophene-4,9-diones were synthesized and evaluated for in vitro cytotoxicity by NCI against seven cancer cell types. 2,7-Diacetyl naphtho[2,3-b]thiophene-4,9-dione (9) showed significant cytotoxicity against leukemia cells with log GI50 values of -7.61 against SR cells and -7.18 against MOLT-4 cells. 3-Acetyl-naphtho[2,3-b]thiophene-4,9-dione (6) also demonstrated potent cytotoxicity in the latter cell line with log GI50 < -8.

Beta-carotene reduces the ductular (oval) cell reaction in the liver of Wistar rats submitted to the resistant hepatocyte model of carcinogenesis

The morphology of livers of Wistar rats treated with beta-carotene (BC), vitamin A (VA, retinol acetate) or corn oil (CO, controls) and submitted to the resistant hepatocyte model of carcinogenesis was studied. Preneoplastic lesions (PNL) were smaller and less numerous in the BC group. The latter group also presented fewer placental glutathione-S-transferase (GST-P) positive and hematoxylin and eosin (H&E) distinguishable PNL, with smaller mean areas and smaller mean areas of the liver occupied by PNL. Clear cell foci predominated in BC livers. In picrosirius-stained liver sections, fibrosis, whether or not accompanying the bile ductular cells, surrounded only 16.67% of PNL in the BC group, as compared to 35.71% in the VA group and 87.72% in the CO group. Moreover, the ductular cell reaction was smaller in the BC group. Smooth muscle actin-positive cells surrounded some PNL, mostly in CO rats, and less frequently in the VA and BC groups. Examination by transmission electron microscopy (TEM) showed that cells with nuclei similar to those of perisinusoidal cells, devoid of cytoplasmic fat globules, probably represented myofibroblasts derived from Ito cells and accompanied the ductular cell reaction. On the basis of these results, we suggest that BC reduced not only the PNL but also the ductular (oval) cell reaction in this experimental model.

Naphthoquinone esters from the root of Rhinacanthus nasutus

Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.

Bakkenolide G, a natural PAF-receptor antagonist

Because platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) participates in many physiopathological responses, including inflammatory reaction, endotoxic shock, allergic diseases and platelet aggregation, PAF-receptor antagonists are important in the treatment of these diseases. A biologically active compound, bakkenolide G, extracted from the plant Petasites formosanus selectively and concentration-dependently inhibited PAF-induced platelet aggregation and ATP release. The IC50 of bakkenolide G for PAF (2 ng mL(-1))-induced platelet aggregation was 5.6 +/- 0.9 microM. Bakkenolide G also concentration-dependently inhibited PAF-induced intracellular signal transductions, including thromboxane B2 formation, and increased intra-cellular calcium concentration and phosphoinositide breakdown without affecting those caused by thrombin (0.1 units mL(-1)), collagen (10 microg mL(-1)), arachidonic acid (100 microM) and U46619 (1 microM). Bakkenolide G shifted the concentration-response curves of PAF-induced platelet aggregation parallel to the right; the Schild plot slope and the pA2 value were 1.31 +/- 0.31 and 6.21 +/- 0.75, respectively. Moreover, bakkenolide G concentration-dependently competed with [3H]PAF binding to platelets, with an IC50 value of 2.5 +/- 0.4 microM. These data strongly indicate that bakkenolide G is a specific PAF-receptor antagonist as an antiplatelet aggregatory agent.

Cytotoxic and antiplatelet aggregation principles from Aglaia elliptifolia

Two related 1H-2,3,3a,8b-tetrahydrocyclopenta[b]benzofurans, aglafolin (1a) and rocaglamide (2), isolated from the stems of Aglaia elliptifolia, showed significant cytotoxicity in six cancer cell lines. Aglafolin (1a) was also found to completely block platelet aggregation caused by arachidonic acid and platelet-activating factor at 100 microM and 2 ng/mL, respectively.

Bioactive alkaloids from Illigera luzonensis

Using antiplatelet aggregation as a guide to fractionation, seven aporphines, actinodaphnine (1), N-methylactinodaphnine (2), launobine (3), dicentrine (4), O-methylbulbocapnine (5), hernovine (7), and bulbocapnine (9), and two oxoaporphines, dicentrinone (6) and liriodenine (8), were isolated from the stems of Illigera luzonensis. Among them, compounds 2, 4, 5, 8, and 9 were isolated for the first time from this species. Moreover, compounds 1-5, and 8 showed significant antiplatelet aggregation and compounds 1 and 6 exhibited significant vasorelaxant activities, respectively.