Hepatoprotective activity of Cassia fistula leaf extract.

Hepatoprotective activity of the n-heptane extract of Cassia fistula leaves was investigated by inducing hepatotoxicity with paracetamol in rats. The extract at a dose of 400 mg/kg body wt. exhibited orally, significant protective effect by lowering the serum levels of transaminases (SGOT and SGPT), bilirubin and alkaline phosphatase (ALP). The effects produced were comparable to that of a standard hepatoprotective agent.     

Growth Substances Separated from the Fruits of Cassia fistula

The growth substances of the seeds of Cassia fistula were studied and the changes in the relative levels in the endosperm and embryo (plus cotyledons) with development of the seed were noted. Indoleacetic acid was found to be the major auxin component of the seed almost throughout its growth and development, while acidic inhibitors possibly belonging to β-complex were also noted in bioassay tests. The main source of the IAA in the seed is the endosperm, although measurable amounts are also present in the embryo. While this IAA activity in the endosperm is detectable till maturity of the fruit, it decreases relatively in the embryo to fall to insignificance at maturity of the seed. However, there is indication of the binding of such IAA in the embryo or the cotyledon, which can be released by alkaline hydrolysis but not before the seeds are matured. No such bound auxin could be detected in the endosperm. The inhibitors, on the other hand, are more prominent in the embryo than in the endosperm, particularly with ageing of the fruit. The possible significance of these changes in the growth factors has been discussed in relation to the age of the seed and the development of the embryo inside it.     

Rheological Properties of Aqueous Dispersions of Xanthan Gum Containing Different Chloride Salts Are Impacted by both Sizes and Net Electric Charges of the Cations

Xanthan gum (XG) is one of the most effective thickener agents used worldwide. In foods products, one of the factors affecting its physical properties is the ionic strength of the medium. Though it is well known that XG rheological properties in aqueous media depend on both type and concentration of electrolytes, correlations between such dispersion properties and molecular aspects of dispersed XG chains are still to be more deeply studied. Thus, in the present study, aqueous XG dispersions [200 mg?(100 mL)^?1] added of Na, K, Mg or Ca chlorides (ionic strength 50 mM or 100 mM) were rheologically characterized, and the corresponding results were explained based on different physicochemical analyses. Comparing to the control (unsalted XG dispersion), KCl and CaCl₂ tended to produce a more drastic decrease of apparent viscosities of XG dispersions than NaCl and MgCl₂. In dynamic-oscillatory assays, the predominance of elastic character over viscous character was more evident for XG dispersions containing KCl and CaCl₂, in particular at frequencies > 0.1 Hz. XG dispersions containing KCl or CaCl₂ also presented smaller pH and |ζ-potentials| values, as well as greater densities and average hydrodynamic diameters of dispersed XG chains, when compared to respective counterparts containing NaCl or MgCl₂. As the decreasing order of the cations radii is K⁺?>?Ca²⁺ ≈ Na⁺?>?Mg²⁺, our results allowed deducing that not only the net electric charges of the cations, but also their sizes, should be considered when analyzing the effect of chloride salts on rheological properties of XG aqueous dispersions, according to the desired for this hydrocolloid (weak thickener, strong thickener or pro-gelling agent).     

Chromones from the stems of Cassia fistula and their anti-tobacco mosaic virus activities

Three new chromones, 5-methoxy-2,2-dimethyl-7-(2-oxopropyl)-2,3-dihydrochromen-4-one (1), 5-methoxy-2,2-dimethyl-8-(2-oxopropyl)-2,3-dihydrochromen-4-one (2), and 1-(3,4-dihydro-5-methoxy-2,2-dimethyl-2H-chromen-7-yl)propan-2-one (3), together with four known chromones (4–7) were isolated from the stems of Cassia fistula. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compounds 1–5 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 5 exhibited high anti-TMV activity with inhibition rate of 30.8% at a concentration of 20 μM. The other compounds also exhibited potential anti-TMV activities with inhibition rates in the range of 15.6–22.1% at the same concentration.     

Antifeedant and larvicidal activities of Rhein isolated from the flowers of Cassia fistula L.

Antifeedant and larvicidal activities of rhein (1,8-dihydroxyanthraquinone-3-carboxylic acid) isolated from the ethyl acetate extract of Cassia fistula flower were studied against lepidopteron pests Spodoptera litura and Helicoverpa armigera. Significant antifeedant activity was observed against H. armigera (76.13%) at 1000 ppm concentration. Rhein exhibited larvicidal activity against H. armigera (67.5), S. litura (36.25%) and the LC₅₀ values was 606.50 ppm for H. armigera and 1192.55 ppm for S.litura. The survived larvae produced malformed adults.     

Flavonoids from the bark and stems of Cassia fistula and their anti-tobacco mosaic virus activities

Two new flavonoids, fistulaflavonoids B and C (1–2), together with five known flavonoids (3–7) were isolated from the bark and stems of Cassia fistula. Their structures were determined by means of HRESIMS, extensive 1D and 2D NMR spectroscopic studies and chemical evidences. The anti-tobacco mosaic virus (anti-TMV) activity of the isolated flavonoids was also evaluated. The results showed that compounds 1 and 2 showed high anti-TMV activity with inhibition rate of 28.5% and 31.3%, which is higher than that of Ningnanmycin (24.7%). Compounds 4–7 showed modest anti-TMV activity with inhibition rate of 18.5%, 22.7%, 16.4%, and 15.3%, respectively.     

Effect of Cassia fistula Linn. leaf extract on diethylnitrosamine induced hepatic injury in rats

The hepatoprotective and antioxidant effect of Cassia fistula Linn. leaf extract on liver injury induced by diethylnitrosamine (DEN) was investigated. Wistar rats weighing 200+/-10g were administered a single dose of DEN (200mg/kg b.w., i.p.) and left for 30 days. For hepatoprotective studies, ethanolic leaf extract (ELE) of C. fistula Linn. (500mg/kg b.w., p.o.) was administered daily for 30 days. AST, ALT, ALP, LDH, gamma-GT and bilirubin were estimated in serum and liver tissue. Lipid peroxidation (LPO), SOD and CAT were also estimated in liver tissue as markers of oxidative stress. DEN induced hepatotoxicity in all the treated animals were evident by elevated serum ALT, AST, ALP and bilirubin levels and a simultaneous fall in their levels in the liver tissue after 30 days. Induction of oxidative stress in the liver was evidenced by increased LPO and fall in the activities of SOD and CAT. ELE administration for 30 days prevented the DEN induced hepatic injury and oxidative stress. In conclusion, it was observed that ELE of C. fistula Linn. protects the liver against DEN induced hepatic injury in rats.     

Molecular docking analysis of tetracyclic triterpenoids from Cassia fistula L. with targets for diabetes mellitus

It is of interest to develop effective drugs for diabetes mellitus. We document the molecular docking analysis data of tetra-cyclic-tri-terpenoids from Cassia fistula L. with targets for diabetes mellitus.     

Anti-inflammatory activity of rhein isolated from the flowers of Cassia fistula L. and possible underlying mechanisms

Objective

Anti-inflammatory activity of rhein in animal models with potential mechanism of actions.

决明子萌发过程中抗氧化活性变化研究

以决明干燥种子和不同萌发期决明子芽的干粉为材料,采用超声波提取法提取醇溶成分和水溶成分,通过总抗氧化活性、还原力、清除羟自由基活性和清除DPPH自由基活性的测定,研究决明子萌发过程中抗氧化活性的变化规律,为决明子的合理开发和有效利用提供理论依据.结果表明:(1)决明子和不同萌发期决明子芽干粉醇提物和水提物均具有抗氧化活性.(2)在决明子萌发过程中,醇提物的总抗氧化活性呈先下降后上升再下降的趋势,还原力、清除DPPH·活性、清除·OH活性均呈先上升后下降的趋势.在种子萌发后第7天,醇提物的抗氧化活性均高于干燥种子.(3)在决明子萌发过程中,水提物的总抗氧化活性和清除DPPH·活性呈下降趋势,还原力呈先下降后上升再下降的趋势,清除·OH活性呈先上升后下降的趋势.     

Effect of pretreatment of Cassia fistula Linn. leaf extract against subacute CCl4 induced hepatotoxicity in rats

CCl4 alone treatment (0.lml of liquid paraffin/100g body weight, ip) for 7 days followed by 0.l ml of CCl4 (in liquid parafiin/100g body weight, ip) from day 8 till day 14, caused a 16 fold increase in lipid peroxidation and a 50% reduction in catalase and glutathione reductase in liver tissue of rats accompanied by an increase in the activities of transaminases. alkaline phosphatase, lactate dehydrogenase and gamma - glutamyl transpeptidase in serum as compared to liquid paraffin treated control. Pretreatment of ethanolic leaf extract of C. fistula (500mg/kg body weight/day for 7 days) followed by CCl4 treatment (0.1 ml/100g body weight from day 8 till day 14) completely reversed back lipid peroxidation and the activities of catalase and glutathione reductase in the liver tissue towards normalcy. This treatment also reversed the elevated levels of the enzymes in the serum. Ethanolic leaf extract alone treatment did not produce any change in all the parameters studied. The results suggest antioxidant and hepatoprotective properties of C. fistula during its pretreatment against CCl4 induced hepatotoxicity.     

Doped Copper Phthalocyanine via an Aqueous Solution Process for Normal and Inverted Perovskite Solar Cells

Great efforts toward developing novel and efficient hole‐transporting materials are needed to further improve the device efficiency and enhance the cell stability of perovskite solar cells (PSCs). The poor film conductivity and the low carrier mobility of organic small‐molecule‐based hole‐transporting materials restrict their application in PSCs. This study develops an efficient and stable hole‐transporting material, tetrafluorotetracyanoquinodimethane (F₄‐TCNQ)‐doped copper phthalocyanine‐3,4′,4′′,4′′′‐tetra‐sulfonated acid tetra sodium salt (TS‐CuPc) via a solution process, in planar structure PSCs. The p‐type‐doped TS‐CuPc film demonstrates improved film conductivity and hole mobility owing to the strong electron affinity of F₄‐TCNQ. By the F₄‐TCNQ tailoring, the composite film gives the highest occupied molecular orbital level as high as 5.3 eV, which is beneficial for hole extraction. In addition, the aqueous solution processed TS‐CuPc:F₄‐TCNQ precursor is almost neutral with good stability for avoiding the electrode erosion. As a result, the fabricated PSCs employing TS‐CuPc:F₄‐TCNQ as the hole‐transporting material exhibit a power conversion efficiency of 16.14% in a p–i–n structure and 20.16% in an n–i–p structure, respectively. The developed organic small molecule of TS‐CuPc provides the diversification of hole‐transporting materials in planar PSCs.     

乙醇-磷酸氢二钾双水相体系萃取L-精氨酸

采用乙醇-磷酸氢二钾(K2HPO4)双水相体系萃取L-精氨酸。实验考察了乙醇浓度、K2HPO4浓度、pH、萃取温度对萃取分离L-精氨酸的影响。结果表明,L-精氨酸在该双水相体系的分配系数K随体系乙醇浓度、K2HPO4浓度的增大、萃取温度的升高而增大,随着体系pH的增大而减小;L-精氨酸在该双水相体系的萃取率随体系乙醇浓度和pH的增大而减小,随着体系K2HPO4浓度增大、萃取温度的升高而增大。     

Protective effect of Cassia fistula Linn. on diethylnitrosamine induced hepatocellular damage and oxidative stress in ethanol pretreated rats

Diethylnitrosamine (DEN), found in many commonly consumed foods, is widely reported to induce cancer in animals and humans. The aim of the present study was to investigate the hepatoprotective and antioxidant activities of the leaf extract of the medicinal plant Cassia fistula Linn. against diethylnitrosamine induced liver injury in ethanol pretreated rats. Albino Wistar rats, pretreated with ethanol for 15 days, were administered a single dose of DEN. Thirty days after DEN administration, hepatotocellular damage was observed histologically, along with elevated levels of serum AST, ALT, ALP, LDH, γ-GT and bilirubin and a simultaneous fall in the levels of the marker enzymes in the liver tissue. Liver oxidative stress was confirmed by elevated levels of lipid peroxidation (LPO) and a decrease in enzymic and non-enzymic antioxidants activities. Oral administration of the ethanolic leaf extract (ELE) of Cassia fistula for 30 days to ethanol + DEN treated rats significantly improved the above alterations in the markers of hepatotoxicity and oxidative stress, resulting in the reversal of most of the parameters studied and were comparable to the standard hepatoprotective drug silymarin.     

Symbols as Self-emergent Entities in an Optimization Process of Feature Extraction and Predictions

In the mammalian cortex the early sensory processing can be characterized as feature extraction resulting in local and analogue low-level representations. As a direct consequence, these map directly to the environment, but interpretation under natural conditions is ambiguous. In contrast, high-level representations for cognitive processing, e.g. language, require symbolic representations characterized by expression and syntax. The representations are binary, structured and disambiguated. However, do these fundamental functional distinctions translate into a fundamental distinction of the respective brain areas and their anatomical and physiological properties? Here we argue that the distinction between early sensory processing and higher cognitive functions may not be based on structural differences of cortical areas; instead similar learning principles acting on input signals with different statistics give rise to the observed variations of function. Firstly, we give an account of present research describing neuronal properties at early stages of sensory systems as a consequence of an optimization process over the set of natural stimuli. Secondly, addressing a stage following early visual processing we suggest to extend the unsupervised learning scheme by including predictive processes. These contain the widely used objective of temporal coherence as a special case and are a powerful approach to resolve ambiguities. Furthermore, in combination with a prior on the bandwidth of information exchange between units it leads to a condensation of information. Thirdly, as a crucial step, not only are predictive units optimized, but the selectivity of the feature extractors are adapted to allow optimal predictability. Thus, over and beyond making useful predictions, we propose that the predictability of a stimulus be in itself a selection criterion for further processing. In a hierarchical system the combined optimization process leads to entities that represent condensed pieces of knowledge and that are not analogue anymore. Instead, these entities work as arguments in a framework of transformations that realize predictions. Thus, the criteria of predictability and condensation in an optimization of sensory representations relate directly to the two defining properties of symbols of expression and syntax. In this paper, we sketch an unsupervised learning process that gradually transforms analogue local representations into discrete binary representations by means of four hypotheses. We propose that in this optimization process acting in a hierarchical system, entities emerge at, higher levels that fulfil the criteria defining symbols, instantiating qualitatively different representations at similarly structured low and high levels.     

Divalent Metal Ion-Catalyzed Pyrophosphate Bond Formation in Aqueous Solution. Synthesis of Nucleotides Containing Polyphosphate

Abstract

Nucleotides containing polyphosphate were prepared from nucleoside-5′-phosphorimidazolide and nucleotides or phosphoryl compounds by divalent metal ion catalyst such as Mn², Cd²⁺ or Mg²⁺ in aqueous solution.