Blood-brain barrier dysfunction in mice induced by lipopolysaccharide is attenuated by dapsone

Blood-brain barrier (BBB) dysfunction is a key event in the development of many central nervous system (CNS) diseases, such as septic encephalopathy and stroke. 4,4'-Diaminodiphenylsulfone (DDS, Dapsone) has displayed neuroprotective effect, but whether DDS has protective role on BBB integrity is not clear. This study was designed to examine the effect of DDS on lipopolysaccharide (LPS)-induced BBB disruption and oxidative stress in brain vessels. Using in vivo multiphoton imaging, we found that DDS administration significantly restored BBB integrity compromised by LPS. DDS also increased the expression of tight junction proteins occludin, zona occludens-1 (ZO-1) and claudin-5 in brain vessels. Level of reactive oxygen species (ROS) was reduced by DDS treatment, which may due to decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and NOX2 expression. Our results showed that LPS-induced BBB dysfunction could be attenuated by DDS, indicated that DDS has a therapeutic potential for treating CNS infection and other BBB related diseases.

Two Natural ent-kauranoids as Novel Wnt Signaling Inhibitors

Constitutively active Wnt signaling frequently occurs in most colon cancers. Therefore, inhibitors of Wnt signaling pathway could provide rational therapeutic effects for colorectal malignancy. Within this paper, we identified two inhibitors of Wnt signaling pathway, rabdoternin B and maoecrystal I from a natural ent-kauranoid library by a dual-luciferase reporter gene assay. The two compounds inhibited Wnt signaling pathway in a concentration-dependent manner and exhibited selective cytotoxicity toward a number of colon carcinoma cell lines SW480, HCT116, and HT29, with only weak cytotoxicity towards the normal colonic epithelial cell line CCD-841-CoN. Rabdoternin B and maoecrystal I treatment induced G2/M phase arrest efficiently in SW480 cells as revealed by flow cytometry analysis. A further study found that maoecrystal I decreased the expression of Wnt signaling target genes, including c-myc, cyclin D1, survivin and Axin2 in colon cancer cells. Collectively our data suggests that rabdoternin B and maoecrystal I are novel inhibitors of canonical Wnt signaling pathway and may possess potentials for colon cancer therapy.

Horsfiequinones A-F, dimeric diarylpropanoids from Horsfieldia tetratepala

A new diarylpropanoid, horsfiequinone A (1), and five new dimeric diarylpropanoids with 1,4-p-benzoquinone residue, horsfiequinones B-F (2-6), along with a known compound, combrequinone B (7), were isolated from Horsfieldia tetratepala. Their structures were elucidated by means of spectroscopic analysis. Horsfiequinones B-F (2-6), isolated as enantiomer mixtures with unequal proportions, were verified by analysis on a chiral OD-H HPLC column. Cytotoxicity evaluation against five human tumor lines showed selective inhibitory effects on HL-60 for several compounds tested with IC50 values ranging from 3.18 ± 0.67 to 6.61 ± 0.08 µM.

Cytotoxic ent-kaurane diterpenoids from Isodon wikstroemioides

Phytochemical investigation of EtOAc extracts of the aerial parts of Isodon wikstroemioides afforded 18 new ent-kaurane diterpenoids (wikstroemioidins E-V, 1-18), along with 17 known analogues (19-35). The absolute configurations of 1 and 16 were confirmed by single-crystal X-ray diffraction analysis. The isolates were screened against five human tumor cell lines; compounds 3, 4, 9, 11-13, 23, 25-28, and 33 exhibited significant cytotoxic activity against all five, with IC50 values ranging from 0.4 to 5.1 μM. In addition, 17 of the isolates strongly inhibited nitric oxide production in LPS-activated RAW264.7 macrophages.

Enmein-type 6,7-seco-ent-kauranoids from Isodon sculponeatus

Fourteen enmein-type 6,7-seco-ent-kaurane diterpenoids, seven new ones (sculponins M-S, 1-7) and seven known compounds (8-14), were isolated from the aerial parts of Isodon sculponeatus . Compound 1 is the first example of an ent-kauranoid, possessing a 11,12-epoxy group, and compounds 6 and 7 have a rare 3,6-epoxy group. The structures were established primarily by NMR and MS methods, and the absolute configurations of 1, 3, and 6 were determined by single-crystal X-ray diffraction. Compound 14 showed significant cytotoxic activity against five human tumor lines, with IC50 values ranging from 1.0 to 3.5 μM, and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with an IC50 value of 2.2 μM.

[Detection of endotoxin activity in water environment and analysis of influence factors for TAL assay]

Endotoxins, derived from cell walls of most Gram-negative bacteria and some cyanobacteria, are common pyrogen and highly immunogenic molecules, and related to many diseases. In this paper, a detection method for endotoxin activity in water environment using kinetic-turbid assay of Tachypleus Amebocyte Lysate (TAL) was established, the influence of pH and salts on TAL assay was investigated. Results showed that it was favorable for TAL assay in the pH range of 6.0-8.4, at low pHs, inhibition results were observed and opposite results were obtained at high pHs. The pH should be adjusted by Tris-HCl (pH = 7.4) buffer before the endotoxin detection. No significant interference was shown in the detection of water containing NaCl, Na2SO4, CaCl2, MgCl2 and KCl with a concentration of less than 50 mg x L(-1), however, the inhibition occurred at the concentration up to 1000-10,000 mg x L(-1). Only 2. 5 mg x L(-1) of FeCl, Fe2(SO4)3, AlCl3 and Al2 (SO4)3 caused significant inhibition. Endotoxin activities of ultrapure water, tap water and recreational water were detected by TAL assay, and their endotoxin activities were < 0.06 EU x mL(-1), 0.46 EU x mL(-1) and 432. 68 EU x mL(-1), respectively.

Inhibition of cystathionine β-synthase is associated with glucocorticoids over-secretion in psychological stress-induced hyperhomocystinemia rat liver

Hyperhomocysteinemia (HHcy), a pathological condition characterized by an increase in plasma concentration of total homocysteine (Hcy), is recognized as a risk factor for several diseases. The transsulfuration pathway is the main metabolic fate of Hcy utilization, which requires the activity of cystathionine β-synthase (CBS). Our results showed the development of HHcy induced by psychological stress was mainly derived from a reduction of CBS activity in the liver, which was accompanied by a significant decrease in its mRNA level. It suggested that the hepatic CBS enzyme regulated by stress at the level of transcription would have a profound effect on circulating Hcy levels. The expression of Sp3, a negative factor for cbs transcription, obviously increased in hepatocytes nuclei of stressed rats, but Sp1 was not altered. It indicated that Sp3 was the key point of variations in cbs transcription caused by stress. Meanwhile, we detected that augmented plasma Hcy concentrations correlated with glucocordicoids (GCs) over-secretion in response to stress, and CBS mRNA levels were markedly lowered in GCs-treated rat hepatocytes. Further results found that glucocorticoids receptor (GR) expression in hepatocyte nuclei of stress rats and GR nuclear translocation ratio was increased, and the same results were proved by experiments in vitro, i.e., GR nuclear translocation and Sp3 expression was remarkably increased in GCs-treated hepatocytes. Moreover, results from ChIP suggested GCs enhanced the binding of GR to the regulatory region of the Sp3 promoter. These results indicated that GCs inhibit CBS transcription by up-regulating Sp3 in psychological stress-induced HHcy.

Four new diterpenoids from Isodon eriocalyx var. laxiflora

Four new diterpenoids, laxiflorins S-V (1–4), bearing four different types, and one known compound, laxiflorin O (5), were isolated from Isodon eriocalyx var. laxiflora. Compound 1 was the first example of ent-kauranoids bearing a unique C₂₄ carbon framework and compound 4 was the first example of 3,4-seco-ent-abietane diterpenoids from the Isodon genus. Their structures were determined by spectroscopic methods (UV, IR, MS, NMR).

Bioactive ent-kaurane diterpenoids from Isodon rosthornii

Isorosthin A (1), the first 20-nor-enmein-type diterpenoid, and 15 new ent-kauranoids, isorosthins B-P (2-16), along with 22 known analogues were isolated from the aerial parts of Isodon rosthornii. The structures of 1-16 were elucidated by means of spectroscopic analysis. The relative configuration of 2 and the absolute configuration of 3 were determined by single-crystal X-ray diffraction. Cytotoxicity evaluation against five human tumor lines showed inhibitory effects by several of the compounds tested. Furthermore, 12 of the isolates exhibited inhibitory activity against nitric oxide production in LPS-activated RAW264.7 macrophages.

Angioarchitectural characteristics associated with complications of embolization in supratentorial brain arteriovenous malformation

BACKGROUND AND PURPOSE

Embolization is an important therapeutic technique in brain arteriovenous malformations; however, little has been reported on the factors contributing to complications. We retrospectively reviewed a large series of supratentorial brain AVMs to identify the angioarchitectural characteristics that might be associated with the complications of embolization and poor clinical outcomes.

MATERIALS AND METHODS

The clinical and angiographic features of 130 consecutive patients with supratentorial brain AVMs embolized with ethylene-vinyl alcohol copolymer in our hospital from 2005-2008 were retrospectively reviewed. None of these patients had prior embolization. Complications were classified as transient neurologic deficits, persistent neurologic deficits, and death. Univariate and multivariate analyses were conducted to assess the angiographic features in patients with and without complications.

RESULTS

Twenty-three complications occurred in 130 embolization procedures, 13 (10%) were transient neurologic deficits (9 ischemic and 4 hemorrhagic), 9 (6.92%) were persistent neurologic deficits (7 ischemic and 2 hemorrhagic), and 1 death occurred. By univariate analyses, eloquent cortex (OR, 2.57; 95% CI, 1.08-3.42) and exclusive deep venous drainage (OR, 4.56; 95% CI, 1.28-9.67) were correlated with procedural complications. The impaction of eloquent cortical location (P = .001) and exclusive deep venous drainage (P = .035) on complications were also demonstrated by multivariate analysis. Eloquent cortex mainly resulted in permanent ischemic neurologic deficit; occlusion of drainage vein was significantly correlated with periprocedural hemorrhage in supratentorial brain AVMs with subtotal and partial embolization.

CONCLUSIONS

In a retrospective study on supratentorial brain AVMs with first-time embolization, 6.92% of patients had permanent neurologic deficit or death. Eloquent cortical location and exclusive deep venous drainage were associated with complications.