Determination of oxygen extraction fraction using magnetic resonance imaging in canine models with internal carotid artery occlusion.

Perfusion of the penumbra tissue below the flow threshold for functional disturbance but above that for the maintenance of morphological integrity is the target for therapy in acute ischaemic stroke. The measurement of the oxygen extraction fraction (OEF) may provide a direct assessment of tissue viability, so that irreversible tissue damage and penumbra can be reliably identified. By using an asymmetric spin echo single-shot echo planar imaging (ASE-SSEPI) sequence, the quantitative OEF was obtained in the ischaemic brain tissues of canine models with internal carotid artery occlusion. TTC staining, which delineated the regions of infarct and penumbra, was used for defining the corresponding regions on OEF maps. The threshold of the OEF to discriminate the infarct cores and penumbral tissues was then determined according to the OEF values at different times. With repeated-measures ANOVA, the OEF of the infarcted regions was found to be time dependent. An OEF greater than 0.48 best predicted cortical infarction at 1.5 hr, with an area under the receiving operating characteristic curve of 0.968, a sensitivity of 97.5%, and a specificity of 92.5%. Our results may be helpful in the evaluation of tissue viability during stroke events.

New phenanthrene glycosides from Dioscorea opposita.

Two new phenanthrene glycosides, dioscopposide A and dioscopposide B (1 and 2), were isolated from the rhizomes of Dioscorea opposita. Their structures were determined primarily on the basis of 1D and 2D NMR techniques, MS studies, and chemical methods. All the isolates were evaluated for their inhibitory effects on the lipopolysaccharide-induced nitric oxide production using murine macrophage RAW 264.7 cells. The IC50 values of dioscopposide A and dioscopposide B were 5.8 and 7.2 µM, respectively.

Three new triterpene glycosides from Ilex asprella.

Three new sulfated triterpene glycosides, asprellanosides C-E (1-3), were isolated from the roots of Ilex asprella. Their structures were elucidated as 3ß-[(2-O-sulfo-ß-d-xylopyranosyl)oxy]urs-12,19(29)-diene-28-oic acid 28-ß-d-glucopyranoside (1), 3ß-[(2-O-sulfo-ß-d-xylopyranosyl)oxy]urs-12,19-diene-28-oic acid 28-ß-d-glucopyranoside (2), and 3ß-[(2-O-sulfo-ß-d-xylopyranosyl)oxy]urs-12,19-diene-28-oic acid (3) on the basis of the spectral and chemical methods.

The membrane permeability of Astragali Radix-derived formononetin and calycosin is increased by Angelicae Sinensis Radix in Caco-2 cells: a synergistic action of an ancient herbal decoction Danggui Buxue Tang.

Danggui Buxue Tang (DBT), a herbal decoction contains Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), has been used as a health food supplement in treating menopausal irregularity in women for more than 800 years in China. Several lines of evidence indicate that the synergistic actions of AR and ASR in this herbal decoction leading to a better pharmacological effect of DBT. Here, the role of different herbs in directing the transport of active ingredients of DBT was determined. A validated RRLC-QQQ-MS/MS method was applied to determinate the permeability of ingredients across the Caco-2 cell monolayer. AR-derived chemicals, including astragaloside IV, calycosin and formononetin, as well as ASR-derived chemicals, including ferulic acid and ligustilide, were determined by RRLC-QQQ-MS/MS. The pharmacokinetic results showed that the membrane permeabilities of calycosin and formononetin, two of the major flavonoids in AR, could be markedly increased in the presence of ASR extract: this induction effect could be mediated by ferulic acid deriving from ASR. In contrast, the extract of AR showed no effect on the chemical permeability. The current results suggested that the ingredients of ASR (such as ferulic acid) could enhance the membrane permeability of AR-derived formononetin and calycosin in cultured Caco-2 cells. The possibility of herb-drug synergy within DBT was proposed here.

Salidroside stimulates the accumulation of HIF-1α protein resulted in the induction of EPO expression: a signaling via blocking the degradation pathway in kidney and liver cells.

Rhodiolae Crenulatae Radix et Rhizoma (Rhodiola), the root and rhizome of Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba, has been used as a traditional Chinese medicine (TCM) to increase the body resistance to mountain sickness in preventing hypoxia; however, the functional ingredient responsible for this adaptogenic effect has not been revealed. Here, we have identified salidroside, a glycoside predominantly found in Rhodiola, is the chemical in providing such anti-hypoxia effect. Cultured human embryonic kidney fibroblast (HEK293T) and human hepatocellular carcinoma (HepG2) were used to reveal the mechanism of this hematopoietic function mediated by salidroside. The application of salidroside in cultures induced the expression of erythropoietin (EPO) mRNA from its transcription regulatory element hypoxia response element (HRE), located on EPO gene. The application of salidroside stimulated the accumulation of hypoxia-inducible factor-1α (HIF-1α) protein, but not HIF-2α protein: the salidroside-induced HIF-1α protein was via the reduction of HIF-1α degradation but not the mRNA induction. The increased HIF-1α could account for the activation of EPO gene. These results supported the notion that hematopoietic function of Rhodiola was triggered, at least partially, by salidroside.

New aliphatic nitro-compounds from Indigofera carlesii.

An investigation of aliphatic nitro-compounds in Indigofera carlesii resulted in the identification of two blended novel compounds: 2-O-acryl-3,6-di-O-(3-nitropropanoyl)-alpha-d-glucopyranose and 6-O-acryl-2,3-di-O-(3-nitropropanoyl)-alpha-d-glucopyranose. The structures of the new compounds were elucidated on basis of spectral analysis.

A nobel cyanogenic glycoside from Semiaquilegia adoxoides.

Phytochemical investigation of Semiaquilegia adoxoides was initiated in view of its common usage in traditional Chinese medicine and the scarcity of previous phytochemical studies. Fractionation of an ethanol extract from the roots of this plant led to the isolation and identification of a novel cyanogenic glycoside, 2-(beta-D-glucopyranosyloxy)-4-hydroxybenzeneacetonitrile (1). The structure of 1 was elucidated on the basis of IR, FAB-MS, 1D and 2D NMR spectral analysis.

[Progress in the biotechnology of legume forage plants].

As important forage crops,legume forage plants can play an important role in improving natural environment, maintenins water and soil. With development of molecular biology and improvement of plant transformation techniques,molecular breeding of legume forage plants by biotechnology is possible. This review summarized recent progress on improvement of several forage crops,including improvement of nutrient quality, increase of biomass,enhancement of the assimilation and efficient absorb of nutrient element, and enhancement of abiotic and biotic stress resistance.