Beneficial effect of the short-chain fatty acid propionate on vascular calcification through intestinal microbiota remodelling.

BACKGROUND: Vascular calcification is a major cause of the high morbidity and mortality of cardiovascular diseases and is closely associated with the intestinal microbiota. Short-chain fatty acids (SCFAs) are derived from the intestinal microbiota and can also regulate intestinal microbiota homeostasis. However, it remains unclear whether exogenous supplementation with propionate, a SCFA, can ameliorate vascular calcification by regulating the intestinal microbiota. This study was conducted to explore the roles of propionate and the intestinal microbiota in the process of vascular calcification. METHODS: In total, 92 patients were enrolled consecutively as the observational cohort to analyse the relationship between SCFAs and vascular calcification in both blood and faecal samples. A rat model of vascular calcification was induced by vitamin D3 and nicotine (VDN) to validate the effect of propionate. Differences in the intestinal microbiota were analysed by 16S ribosomal RNA gene sequencing. Faecal microbiota transplantation and Akkermansia muciniphila transplantation experiments were performed to evaluate the functions of the intestinal microbiota. RESULTS: The results of the observational cohort study revealed that the levels of SCFAs (particularly propionate) in both blood and faecal samples independently correlated negatively with calcification scores (P < 0.01). To verify the activities of propionate, it was provided to VDN-treated rats, and oral or rectal propionate delivery reshaped the intestinal microbiota, resulted in elevated SCFA production, improved intestinal barrier function and alleviated inflammation, ultimately ameliorating vascular calcification. Furthermore, we demonstrated that transplantation of the propionate-modulated intestinal microbiota induced beneficial outcomes similar to those with oral or rectal propionate administration. Interestingly, linear discriminant analysis (LDA) effect size (LEfSe) revealed that oral or rectal propionate administration and propionate-modulated intestinal microbiota transplantation both enriched primarily Akkermansia. Subsequently, we demonstrated that Akkermansia supplementation could ameliorate VDN-induced vascular calcification in rats. CONCLUSIONS: Propionate can significantly ameliorate vascular calcification in VDN-treated rats, and this effect is mediated by intestinal microbiota remodelling. The findings in our study indicate that the intestinal tract-vessel axis is a promising target for alleviating vascular calcification. Video Abstract.

Neuroprotection of hydroxysafflor yellow A in experimental cerebral ischemia/reperfusion injury via metabolic inhibition of phenylalanine and mitochondrial biogenesis.

Stroke is the second most frequent cause of mortality, resulting in a huge societal burden worldwide. Timely reperfusion is the most effective therapy; however, it is difficult to prevent ischemia/reperfusion (I/R) injury. In traditional Chinese medicine, hydroxysafflor yellow A (HSYA) has been widely used for the treatment of cerebrovascular disease and as a protective therapy against I/R injury. Evidence has demonstrated that HSYA could reduce the levels of reactive oxygen species and suppress cellular apoptosis; however, whether HSYA alters the metabolic profile as its underlying mechanism for neuroprotection remains unknown. In the present study, using a metabolomic screening, phenylalanine was identified to significantly increase in an experimental model of mouse cerebral I/R injury. Notably, western blotting and qPCR analysis were conducted to test the expression level of apoptosis­associated factors, and HSYA was identified to be able to protect neuronal cells by reducing phenylalanine level associated with I/R injury. Additionally, these findings were confirmed in primary mouse neurons and PC12 cells exposed to oxygen and glucose deprivation/reoxygenation (OGD/R) stress. Of note, HSYA was observed to regulate the mRNA expression of key metabolic enzymes, phenylalanine hydroxylase, tyrosine aminotransferase and aspartate aminotransferase, which are responsible for phenylalanine metabolism. Furthermore, by performing mitochondrial labeling and JC­1 fluorescence assay, HSYA was identified to promote mitochondrial function and biogenesis suppressed by OGD/R. The findings of the present study demonstrated that I/R injury could increase the levels of phenylalanine, and HSYA may inhibit phenylalanine synthesis to enhance mitochondrial function and biogenesis for neuroprotection. The present study proposed a novel metabolite biomarker for cerebral I/R injury and the evaluated the efficacy of HSYA as a potential therapeutic treatment I/R injury.

Z-Guggulsterone attenuates astrocytes-mediated neuroinflammation after ischemia by inhibiting toll-like receptor 4 pathway.

Inflammatory damage plays a pivotal role in ischemic stroke pathogenesis and may represent one of the therapeutic targets. Z-Guggulsterone (Z-GS), an active component derived from myrrh, has been used to treat various diseases. The traditional uses suggest that myrrh is a good candidate for anti-inflammatory damage. This study was to investigate the anti-inflammatory and neuroprotective effects of Z-GS following cerebral ischemic injury, as well as the exact mechanisms behind them. Rat middle cerebral artery occlusion (MCAO) model and in vitro astrocytes oxygen-glucose deprivation (OGD) model were adopted to simulate ischemic stroke. Z-GS (30 or 60 mg/kg) was administered intraperitoneally immediately after reperfusion, while astrocytes were maintained in 30 or 60 µM Z-GS before OGD treatment. The results indicated that Z-GS significantly alleviated neurological deficits, infarct volume and histopathological damage in vivo, and increased the astrocytes viability in vitro. Moreover, the treatment of Z-GS inhibited the astrocytes activation and down-regulated the mRNA levels of pro-inflammatory cytokines. Furthermore, the activated TLR4-NF-κB signaling pathways induced by MCAO or OGD were significantly suppressed by Z-GS treatment, which was achieved via inhibiting the phosphorylation of JNK. Our results demonstrated that Z-GS exerted neuroprotective and anti-inflammatory properties through preventing activation of TLR4-mediated pathway in the activated astrocytes after ischemia injury. Therefore, Z-GS could be considered as a promising candidate for the treatment of ischemic stroke.

Two novel terpenoids from the cultured Perovskia atriplicifolia.

Two new terpenoids, named biperovskatone B (1) and 1α- hydroxyl demethylsalvicanol quinine (2), were isolated from the cultured Perovskia atriplicifolia. Their structures were elucidated by comprehensive analyses of the MS, IR, 1D and 2D NMR spectra. Compound 1 was a novel diterpenoid dimer, containing two different rearranged 9(10 → 20)-abeoabietane type diterpenoid fragments. Compound 2 was a new icetexane diterpenoid with characteristic ortho-quinone carbonyl groups. Both compounds were assayed for their anti-HBV activity in vitro. Results suggested compounds 1 and 2 showed noticeable anti- anti-HBV activity, inhibiting the replication of HBV DNA with IC50 values of 10.78 and 8.61 µM, respectively.

Ultra Performance Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry-Based Metabonomics Reveal Protective Effect of Terminalia chebula Extract on Ischemic Stroke Rats.

Terminalia chebula (TC), a kind of Combretaceae, is a widely used herb in India and East Asia to treat cerebrovascular diseases. However, the potential mechanism of the neuroprotective effects of TC at the metabonomics level is still not clear. The present study focused on the effects of TC on metabonomics in a stroke model. Rats were divided randomly into sham, model, and TC groups. Rats in the TC group were intragastrically administered with TC for 7 days after a middle cerebral artery occlusion (MCAO) operation. The sham and the model groups received vehicle for the same length of time. Subsequently, the neuroprotective effects of TC were examined by evaluation of neurological defects, assessment of infarct volume, and identification of biochemical indicators for antioxidant and anti-inflammatory activities. Further, metabonomics technology was employed to evaluate the endogenous metabolites profiling systematically. Consist with the results of biochemical and histopathological assays, pattern recognition analysis showed a clear separation of the model group and the sham group, indicating the recovery impact of TC on the MCAO rats. Moreover, 12 potential biomarkers were identified in the MCAO model group, involving energy (lactic acid, succinic acid, and fumarate), amino acids (leucine, alanine, and phenylalanine), and glycerophospholipid (PC [16:0/20:4], PC [20:4/20:4], LysoPC [18:0], and LysoPC [16:0]) metabolism, as well as other types of metabolism (arachidonic acid and palmitoylcarnitine). Notably, it was found that metabolite levels of TC group were partially reversed to normal. In conclusion, TC could ameliorate MCAO in rats by affecting energy metabolism (glycolysis and the TCA cycle), amino acid metabolism, glycerophospholipid metabolism, and other types of metabolism.

Two new biphenyls from the stems of Garcinia tetralata.

Two new biphenyls (1 and 2) and three known xanthones (3-5) were isolated from the ethanol extract of the stems of Garcinia tetralata. Structural elucidations of 1-2 were elucidated by spectroscopic methods including extensive 1D- and 2D-nuclear magnetic resonance spectroscopy techniques. Compounds 1-2 showed anti-rotavirus activities with SI above 10.

Differential gene expression profiles between two subtypes of ischemic stroke with blood stasis syndromes.

Ischemic stroke is a cerebrovascular thrombotic disease with high morbidity and mortality. Qi deficiency blood stasis (QDBS) and Yin deficiency blood stasis (YDBS) are the two major subtypes of ischemic stroke according to the theories of traditional Chinese medicine. This study was conducted to distinguish these two syndromes at transcriptomics level and explore the underlying mechanisms. Male rats were randomly divided into three groups: sham group, QDBS/MCAO group and YDBS/MCAO group. Morphological changes were assessed after 24 h of reperfusion. Microarray analysis with circulating mRNA was then performed to identify differential gene expression profile, gene ontology and pathway enrichment analyses were carried out to predict the gene function, gene co-expression and pathway networks were constructed to identify the hub biomarkers, which were further validated by western blotting and Tunel staining analysis. Three subsets of dysregulated genes were acquired, including 445 QDBS-specific genes, 490 YDBS-specific genes and 1676 blood stasis common genes. Our work reveals for the first time that T cell receptor, MAPK and apoptosis pathway were identified as the hub pathways based on the pathway networks, while Nfκb1, Egfr and Casp3 were recognized as the hub genes by co-expression networks. This research helps contribute to a clearer understanding of the pathological characteristics of ischemic stroke with QDBS and YDBS syndrome, the proposed biomarkers might provide insight into the accurate diagnose and proper treatment for ischemic stroke with blood stasis syndrome.

[Chemical constituents from Perovskia atriplicifolia].

An investigation on the chemical constituents of the 90% EtOH extract of Perovskia atriplicifolia led to the isolation of fifteen compounds from the EtOAc fraction. Based on the detailed spectral analysis (MS, 1D and 2D NMR), as well as comparison with the literatures, the structures of compounds 1-15 were determined as cirsimaritin (1), salvigenin (2), syringaldehyde (3), vinyl caffeate (4), 2α, 3α-dihydroxyolean-12-en-28-oicacid (5), 2α, 3α-dihydroxyurs-12-en-28-oicacid (6), niga-ichigoside F1 (2α, 3ß, 19α, 23- tetrahydroxyurs - 12-en-28-oicacid- O-ß-D- glucopyranoside, 7), sericoside (8), 4-epi-niga-ichigoside F1 (2α, 3ß, 19α, 24-tetrahydroxyurs-12-en-28-oicacid O-ß-D-glucopyranoside, 9), 2α, 3ß, 24-trihydroxyolean-12-en-28-oicacid O-ß-D-glucopyranosyl-(1 --> 2) - ß-D-glucopyranoside (10), pruvuloside A (11), asteryunnanoside A [2α, 3ß, 23-trihydroxyolean-12-en-28-oicacid O-ß-D-glucopyranosyl-(1 --> 2)-ß- D- glucopyranoside,12], rosmarinic acid methyl ester (13), ß-sitosterol (14), and daucosterol (15), respectively. Compounds 1-13 were isolated from the Perovskia genus for the first time. All the compounds were obtained from P. atriplicifolia for the first time.

Modulation of exogenous selenium in cadmium-induced changes in antioxidative metabolism, cadmium uptake, and photosynthetic performance in the 2 tobacco genotypes differing in cadmium tolerance.

Hydroponic experiments were conducted using cadmium (Cd)-sensitive (cv Guiyan 1) and Cd-tolerant (Yunyan 2) tobacco cultivars to evaluate cultivar differences in response to Cd toxicity in the presence of selenium (Se). The results showed that addition of 3 µM Se in 50 µM Cd solution markedly reduced Cd accumulation in plants, alleviated Cd-induced growth inhibition, and increased nitrogen and chlorophyll contents as well as photosynthetic performance (i.e., net photosynthetic rate, stomatal conductance, and transpiration rate). External Se dramatically depressed Cd-induced O2 (•-) , H2 O2 , and malondialdehyde accumulation, especially in the sensitive cultivar. Selenium significantly elevated Cd-depressed activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, glutathione-peroxidase, and glutathione reductase in the both cultivars after 7-d treatments. Meanwhile, Se counteracted Cd-induced alterations in certain nutrient elements; for example, it significantly increased Zn and Ca concentrations and reduced Mg concentration in both cultivars. Furthermore, Se significantly elevated Cd-depressed H(+) -K(+) -adenosine triphosphatase (ATPase), Na(+) -K(+) -ATPase, and Ca(2+) -Mg(2+) -ATPase activities. The beneficial effect of Se under Cd stress may be related mainly to the increased ATPase activity and reduced Cd uptake and reactive oxygen species accumulation, thus reducing the negative consequences of oxidative stress caused by Cd toxicity.

The effect of staggered administration of zinc sulfate on the pharmacokinetics of oral cephalexin.

AIMS: To investigate the effect of zinc sulfate on pharmacokinetics of cephalexin when administered concurrently or at strategically spaced dosing times designed to avoid the potential interaction in healthy volunteers. METHODS: In this study, all subjects (n= 12) were randomized to receive the following four treatments, separated by a wash-out period of 7 days: cephalexin 500mg alone, concomitantly with zinc 250mg, 3h after zinc 250mg or 3h before zinc 250mg. RESULTS: All subjects completed the study safely. Zinc supplements administered concurrently with cephalexin significantly decreased the peak serum concentration (C(max) ), area under the plasma concentration-time curve from zero to infinity (AUC(0-∞) ) and the time for which the plasma concentration of the drug remained above the minimal inhibitory concentration of the pathogenic organism (T > MIC) of cephalexin [mean percentage decrease (95% confidence intervals) of 31.05% (22.09-40.01%), 27.40% (18.33-36.47%) and 22.33% (12.51-32.16%), respectively; P < 0.05] compared with administration of cephalexin alone. Also, administration of zinc 3h before cephalexin decreased the C(max) , AUC(0-∞) and T > MIC of the drug compared with administration of cephalexin alone [mean percentage decrease (95% confidence intervals) of 11.48% (3.40-19.55%), 18.12% (9.63-26.60%) and 23.75% (14.30-33.20%), respectively; P < 0.05]. In contrast, the pharmacokinetics of cephalexin was not notably altered by administration of zinc 3h after cephalexin dosing (P > 0.05). CONCLUSIONS: The significant interaction between zinc and cephalexin might affect the clinical outcome of cephalexin therapy. The dosing recommendation is that zinc sulfate can be safely administered 3h after a cephalexin dose.