Repellent,larvicidal and adulticidal activities of essential oil from Dai medicinal plant Zingiber cassumunar against Aedes albopictus

Zingiber cassumunar is an important plant used in traditional medicine and as a natural mosquito repellent. However, the compounds responsible for the repellent activity of the plant are still unknown. The aim of the study is to identify the components of Z. cassumunar essential oil that show repellent activity against Aedes albopictus. We also evaluated the larvicidal and adulticidal activities of Z. cassumunar essential oil against Ae. albopictus. In-cage mosquito repellent experiments showed that Z. cassumunar essential oil possessed moderate repellent activity with a minimum effective dose (MED) of 0.16 ± 0.01 mg/cm², compared to reference standard N,N-diethyl-3-methylbenzamide (DEET, 0.03 ± 0.01 mg/cm²). Bioassay-guided fractionation identified the major active compound of Z. cassumunar essential oil as (−)-terpinen-4-ol (1) (MED: 0.19 ± 0 mg/cm²). We also found that Z. cassumunar essential oil showed moderate larvicidal activity against first instar larvae of Ae. albopictus with a LC₅₀ (50% lethal concentration) of 44.9 μg/L after 24 h. Fumigation bioassays showed that Z. cassumunar essential oil exhibits moderate adulticidal activity against Ae. albopictus with a LC₅₀ of 5.44%, while (−)-terpinen-4-ol showed significant adulticidal activity with a LC₅₀ of 2.10% after 24 h. This study verifies that the Z. cassumunar essential oil has mosquito repellent activity, and that (−)-terpinen-4-ol is mainly responsible for this activity. Furthermore, this study provides scientific support for the folk usage of Z. cassumunar essential oil as mosquito repellent and indicates that Z. cassumunar essential oil and (−)-terpinen-4-ol can be used as plant-derived repellents and insecticides for mosquito control.     

Translocation of Sugars in Cucurbita melopepo IV. Effects of Temperature Change

A study has been made of the temperature control of translocation localized to regions of the stem, petiole and hypocotyl of Cucurbita melopepo. The basipetal and acropetal movement of translocated ¹⁴C-labeled compounds in the phloem tissue, measured over a 45-minute period, was almost completely inhibited at 0°. At 10° a partial inhibition occurred while an extremely variable degree of inhibition occurred at 15°. Above 15° to 35° temperature ceased to be a limiting factor in the movement of ¹⁴C-labeled compounds. At 45° partial inhibition was observed while at 55° there was an almost complete cessation. The localized temperature treatment of the plant parts did not disturb the rate of ¹⁴CO₂ assimilation or the export of ¹⁴C compounds by the leaf blade. Translocated compounds unable to pass a temperature inhibited zone were diverted toward other importing regions of the plant. The similarity of the translocation response to temperature change in the various organs of the plant indicated a uniform mechanism throughout the plant controlling movement of the major proportion of the translocated compounds. The temperature characteristics of the mechanism were found to closely parallel those of protoplasmic streaming in chill-sensitive plants.     

Characteristics of a membrane-associated lipoxygenase in tomato fruit

Microsomal membranes isolated from the pericarp of maturegreen tomato (Lycopersicon esculentum) fruit rapidly metabolize exogenous radiolabeled linoleic acid into fatty acid oxidation products at 22°C. The reaction is strongly inhibited by n-propyl gallate, an inhibitor of lipoxygenase. The membranes also rapidly metabolize 16:0/18:2^* phosphatidylcholine into radiolabeled oxidation products that comigrate on TLC plates with those formed from free linoleic acid. At 30°C, the formation of fatty acid oxidation products from 16:0/18:2^* phosphatidylcholine is slower, and there is an initial accumulation of radiolabeled linoleic acid that is not evident at 22°C, which can be attributed to the action of lipolytic acyl hydrolase. Radiolabeled phosphatidic acid and diacylglycerol are also formed during metabolism of 16:0/18:2^* phosphatidylcholine by the microsomal membranes, and there is no breakdown of either linoleic acid or phosphatidylcholine by heat-denatured membranes. When Triton X-100 treated membranes were used, the same patterns of metabolite formation from radiolabeled linoleic acid and 16:0/18:2^* phosphatidylcholine were observed. Thus, the enzymes mediating the breakdown of these radiolabeled compounds appear to be tightly associated with the membranes. Collectively, the data indicate that there is a lipoxygenase associated with microsomal membranes from tomato fruit that utilizes free fatty acid substrate released from phospholipids. The microsomal lipoxygenase is strongly active over a pH range of 4.5 to 8.0, comprises approximately 38% of the total (microsomal plus soluble) lipoxygenase activity in the tissue, has an apparent K_m of 0.52 millimolar and an apparent V_max of 0.186 millimoles per minute per milligram of protein. The membranous enzyme also cross-reacts with polyclonal antibodies raised against soybean lipoxygenase-1 and has an apparent molecular mass of 100 kilodaltons.     

The metabolism of [2-14C]indole in the rat

1. [2-¹⁴C]Indole has been synthesized from [¹⁴C]formate and o-toluidine via N[¹⁴C]-formyltoluidine. 2. When fed to rats, the ¹⁴C of [¹⁴C]indole (dose 70–80mg./kg. body wt.) is fairly rapidly excreted, and in 2 days an average of 81% appears in the urine, 11% in the faeces and 2·4% as carbon dioxide in the expired air. 3. Radioactivity is excreted in the urine as indoxyl sulphate (50% of the dose), indoxyl glucuronide (11%), oxindole (1·4%), isatin (5·8%), 5-hydroxyoxindole conjugates (3·1%), N-formylanthranilic acid (0·5%) and unchanged indole (0·07%). The faeces contain indoxyl sulphate (0·4% of the dose) and indole (0·2%), but the major metabolites have not been identified. 4. Fed to rats with biliary cannulae an average of 5·6% of a dose of [¹⁴C]indole (20–60mg./kg. body wt.) is excreted in the bile in 2 days. Radioactivity is present as indoxyl sulphate (0·8% dose) and 5-hydroxyoxindole conjugates (0·6%). 5. Rats further metabolize indoxyl into N-formylanthranilic acid and anthranilic acid, and oxindole into 5-hydroxyoxindole. 6. With rat-liver microsomes plus supernatant under aerobic conditions, indole gives indoxyl, oxindole, possibly isatin, N-formylanthranilic acid and anthranilic acid, but under anaerobic conditions gives only oxindole. Similarly, under aerobic conditions, oxindole gives 5-hydroxyoxindole, anthranilic acid and o-aminophenylacetic acid. 7. Indole is metabolized by two pathways, one via indoxyl to isatin, N-formylanthranilic acid and anthranilic acid, and the other via oxindole to 5-hydroxyoxindole and possibly to o-aminophenylacetic and anthranilic acid. 8. The following new compounds are described: 4-hydroxy-2-nitrophenylacetic acid, 3-, 4- and 5-benzyloxy-2-nitrophenylacetic acid, 5- and 7-hydroxyoxindole and 5-aminoacridine indoxyl sulphate.     

Mechanisms of lipid peroxide formation in animal tissues

1. Homogenates of rat liver, spleen, heart and kidney form lipid peroxides when incubated in vitro and actively catalyse peroxide formation in emulsions of linoleic acid or linolenic acid. 2. In liver, catalytic activity is distributed throughout the nuclear, mitochondrial and microsomal fractions and is present in the 100000g supernatant. Activity is weak in the nuclear fraction. 3. Dilute (0·5%, w/v) homogenates catalyse peroxidation over the range pH5·0–8·0 but concentrated (5%, w/v) homogenates inhibit peroxidation and destroy peroxide if the solution is more alkaline than pH7·0. 4. Ascorbic acid increases the rate of peroxidation of unsaturated fatty acids catalysed by whole homogenates of liver, heart, kidney and spleen at pH6·0 but not at pH7·4. 5. Catalysis of peroxidation of unsaturated fatty acids by the mitochondrial and microsomal fractions of liver is inhibited by ascorbic acid at pH7·4 but the activity of the supernatant fraction is enhanced. 6. Inorganic iron or ferritin are active catalysts in the presence of ascorbic acid. 7. Lipid peroxide formation in linoleic acid or linolenic acid emulsions catalysed by tissue homogenates is partially inhibited by EDTA but stimulated by o-phenanthroline. 8. Cysteine or glutathione (1mm) inhibits peroxide formation catalysed by whole homogenates, mitochondria or haemoprotein. Inhibition increases with increase of pH.     

Biosynthesis and Characterization of Polyhydroxyalkanoates Copolymers Produced by Pseudomonas putida Bet001 Isolated from Palm Oil Mill Effluent

The biosynthesis and characterization of medium chain length poly-3-hydroxyalkanoates (mcl-PHA) produced by Pseudomonas putida Bet001 isolated from palm oil mill effluent was studied. The biosynthesis of mcl-PHA in this newly isolated microorganism follows a growth-associated trend. Mcl-PHA accumulation ranging from 49.7 to 68.9% on cell dry weight (CDW) basis were observed when fatty acids ranging from octanoic acid (C_8∶0) to oleic acid (C_18∶1) were used as sole carbon and energy source. Molecular weight of the polymer was found to be ranging from 55.7 to 77.7 kDa. Depending on the type of fatty acid used, the ¹H NMR and GCMSMS analyses of the chiral polymer showed a composition of even and odd carbon atom chain with monomer length of C4 to C14 with C8 and C10 as the principal monomers. No unsaturated monomer was detected. Thermo-chemical analyses showed the accumulated PHA to be semi-crystalline polymer with good thermal stability, having a thermal degradation temperature (T _d) of 264.6 to 318.8 (±0.2) ^oC, melting temperature (T _m) of 43. (±0.2) ^oC, glass transition temperature (T _g) of −1.0 (±0.2) ^oC and apparent melting enthalpy of fusion (ΔH _f) of 100.9 (±0.1) J g⁻¹.     

Chemical compositions by using LC–MS/MS and GC–MS and antioxidant activities of methanolic extracts from leaf and flower parts of Scabiosa columbaria subsp. columbaria var. columbaria L.

The members of the Scabiosa genus are one of the traditional medicinal plants used in the treatment of many diseases, in particular the treatment of scabies. In this study, it was aimed to determine antioxidant activities and chemical composition of methanolic extracts of leaves and flowers of Scabiosa columbaria subsp. columbaria var. columbaria. The phenolic contents of both parts of the plant were analyzed by LC–MS/MS. A total of 6 phenolic compounds were determined and chlorogenic acid was the major compound in both flower and leaf parts of the plants, with 5936.052 µg/g and 8021.666 µg/g, respectively. 6 different methods were used to determine the antioxidant activity of the plant parts. Both leaf and flower parts of the plant showed high antioxidant activity in all tested methods and the antioxidant activity values of the leaf part were measured higher than those of the flower part for four tests. The methanol extracts of the plant parts was analyzed with GC–MS and number of the essential oil compounds in the leaf and flower parts were determined as 17 and 13, respectively. Linalool compound was also found to be common in both parts of the plant. The major compounds of the essential oils were identified as 4-Octadecenal (30.01%) in the flower and carvone (35.44%) in the leaf. In addition, terpene derivatives was determined as 90.32% of the highest essential oil group in the leaf, while this value was determined as 1.42% in the flower. For the flower, aromatics were determined as the main component group with 21.31%.     

Elemental Composition (C, N, P) and Cell Volume of Exponentially Growing and Nutrient-Limited Bacterioplankton

Marine bacterioplankton were isolated and grown in batch cultures until their growth became limited by organic carbon (C), nitrogen (N), or phosphorus (P). Samples were taken from the cultures at both the exponential and stationary phases. The elemental composition of individual bacterial cells was analyzed by X-ray microanalysis with an electron microscope. The cell size was also measured. The elemental content was highest in exponentially growing cells (149 ± 8 fg of C cell⁻¹, 35 ± 2 fg of N cell⁻¹, and 12 ± 1 fg of P cell⁻¹; average of all isolates ± standard error). The lowest C content was found in C-limited cells (39 ± 3 fg of C cell⁻¹), the lowest N content in C- and P-limited cells (12 ± 1 and 12 ± 2 fg of N cell⁻¹, respectively), and the lowest P content in P-limited cells (2.3 ± 0.6 fg of P cell⁻¹). The atomic C:N ratios varied among treatments between 3.8 ± 0.1 and 9.5 ± 1.0 (average ± standard error), the C:P ratios between 35 ± 2 and 178 ± 28, and the N:P ratios between 6.7 ± 0.3 and 18 ± 3. The carbon-volume ratios showed large variation among isolates due to different types of nutrient limitation (from 51± 4 to 241 ± 38 fg of C μm⁻¹; average of individual isolates and treatments ± standard error). The results show that different growth conditions and differences in the bacterial community may explain some of the variability of previously reported elemental and carbon-volume ratios.     

In Vivo Cell Wall Loosening by Hydroxyl Radicals during Cress Seed Germination and Elongation Growth

Loosening of cell walls is an important developmental process in key stages of the plant life cycle, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical (^·OH)-mediated cell wall loosening during plant seed germination and seedling growth. We used electron paramagnetic resonance spectroscopy to show that ^·OH is generated in the cell wall during radicle elongation and weakening of the endosperm of cress (Lepidium sativum; Brassicaceae) seeds. Endosperm weakening precedes radicle emergence, as demonstrated by direct biomechanical measurements. By ³H fingerprinting, we showed that wall polysaccharides are oxidized in vivo by the developmentally regulated action of apoplastic ^·OH in radicles and endosperm caps: the production and action of ^·OH increased during endosperm weakening and radicle elongation and were inhibited by the germination-inhibiting hormone abscisic acid. Both effects were reversed by gibberellin. Distinct and tissue-specific target sites of ^·OH attack on polysaccharides were evident. In vivo ^·OH attack on cell wall polysaccharides were evident not only in germinating seeds but also in elongating maize (Zea mays; Poaceae) seedling coleoptiles. We conclude that plant cell wall loosening by ^·OH is a controlled action of this type of reactive oxygen species.     

Dietary Medium Chain Fatty Acid Supplementation Leads to Reduced VLDL Lipolysis and Uptake Rates in Comparison to Linoleic Acid Supplementation

Dietary medium chain fatty acids (MCFA) and linoleic acid follow different metabolic routes, and linoleic acid activates PPAR receptors. Both these mechanisms may modify lipoprotein and fatty acid metabolism after dietary intervention. Our objective was to investigate how dietary MCFA and linoleic acid supplementation and body fat distribution affect the fasting lipoprotein subclass profile, lipoprotein kinetics, and postprandial fatty acid kinetics. In a randomized double blind cross-over trial, 12 male subjects (age 51±7 years; BMI 28.5±0.8 kg/m²), were divided into 2 groups according to waist-hip ratio. They were supplemented with 60 grams/day MCFA (mainly C8:0, C10:0) or linoleic acid for three weeks, with a wash-out period of six weeks in between. Lipoprotein subclasses were measured using HPLC. Lipoprotein and fatty acid metabolism were studied using a combination of several stable isotope tracers. Lipoprotein and tracer data were analyzed using computational modeling. Lipoprotein subclass concentrations in the VLDL and LDL range were significantly higher after MCFA than after linoleic acid intervention. In addition, LDL subclass concentrations were higher in lower body obese individuals. Differences in VLDL metabolism were found to occur in lipoprotein lipolysis and uptake, not production; MCFAs were elongated intensively, in contrast to linoleic acid. Dietary MCFA supplementation led to a less favorable lipoprotein profile than linoleic acid supplementation. These differences were not due to elevated VLDL production, but rather to lower lipolysis and uptake rates.     

Phytochemical Profiles and Antioxidant Activities in Six Species of Ramie Leaves

Increased consumption of vegetables or plant food has been associated with decreased risk of developing major chronic diseases, such as cancers, diabetes, cardiovascular diseases, and age-related functional decline. Ramie leaves are rich in phenolics and flavonoids, which have been suggested for human health benefits. Phenolic contents, flavonoid contents, phenolic compounds, and anti-cancer properties in six species of ramie leaves were analyzed by Folin-reagent method, sodium borohydride/chloranil-based assay (SBC), HPLC method and antiproliferation, cytoxicity, respectively. Antioxidant activities were measured through peroxyl radical scavenging capacity (PSC) method, oxygen radical absorbance capacity (ORAC) method, and cellular antioxidant activity (CAA). Research indicated that Boehmeria penduliflora contained the highest total phenolic content (2313.7±27.28 mg GAE/100 g FW), and flavonoid content (1682.4±27.70 mg CAE/100 g FW). Boehmeria tricuspis showed the highest PSC value (9574.8±117.63 µM vit. C equiv./100 g FW), while Boehmeria penduliflora indicated the highest ORAC value (330.44±16.88 µmol Trolox equiv./g FW). The antioxidant activities were correlated with phenolic contents and flavonoid contents. Boehmeria tricuspis had the highest antiproliferative capacity with the lowest EC₅₀ (4.11±0.19 mg/mL). The results for the analyzed ramie for CAA were significantly different from each other (p<0.05), Boehmeria tricuspis had the highest CAA value (133.63±7.10 µmol QE/100 g). Benzoic acid, 4-coumaric acid, caffeic acid, and ferulic acid were the dominant phenolic ingredients in the ramie leaves according to HPLC analysis. Our research is the first report to study the phytochemical profiles and antioxidant activities in different species of ramie leaves for their health benefit.     

The Structure of the Karrikin-Insensitive Protein (KAI2) in Arabidopsis thaliana

KARRIKIN INSENSITIVE 2 (KAI2) is an α/β hydrolase involved in seed germination and seedling development. It is essential for plant responses to karrikins, a class of butenolide compounds derived from burnt plant material that are structurally similar to strigolactone plant hormones. The mechanistic basis for the function of KAI2 in plant development remains unclear. We have determined the crystal structure of Arabidopsis thaliana KAI2 in space groups P2₁ 2₁ 2₁ (a  = 63.57 Å, b  = 66.26 Å, c  = 78.25 Å) and P2₁ (a  = 50.20 Å, b  = 56.04 Å, c  = 52.43 Å, β  = 116.12°) to 1.55 and 2.11 Å respectively. The catalytic residues are positioned within a large hydrophobic pocket similar to that of DAD2, a protein required for strigolactone response in Petunia hybrida. KAI2 possesses a second solvent-accessible pocket, adjacent to the active site cavity, which offers the possibility of allosteric regulation. The structure of KAI2 is consistent with its designation as a serine hydrolase, as well as previous data implicating the protein in karrikin and strigolactone signalling.     

Design and green synthesis of novel quinolinone derivatives of potential anti-breast cancer activity against MCF-7 cell line targeting multi-receptor tyrosine kinases

A new set of 4,6,7,8-tetrahydroquinolin-5(1H)-ones were designed as cytotoxic agents against breast cancer cell line (MCF-7) and synthesised under ultrasonic irradiation using chitosan decorated copper nanoparticles (CS/CuNPs) catalyst. The new compounds 4b, 4j, 4k, and 4e exhibited the most potent cytotoxic activity of IC₅₀ values (0.002 − 0.004 µM) comparing to Staurosporine of IC₅₀; 0.005 μM. The latter derivatives exhibited a promising safety profile against the normal human WI38 cells of IC₅₀ range 0.0149 − 0.048 µM. Furthermore, the most promising cytotoxic compounds 4b, 4j were evaluated as multi-targeting agents against the RTK protein kinases; EGFR, HER-2, PDGFR-β, and VEGFR-2. Compound 4j showed promising inhibitory activity against HER-2 and PDGFR-β of IC₅₀ values 0.17 × 10⁻³, 0.07 × 10⁻³ µM in comparison with the reference drug sorafenib of IC₅₀; 0.28 × 10⁻³, 0.13 × 10⁻³ µM, respectively. In addition, 4j induced apoptotic effect and cell cycle arrest at G2/M phase preventing the mitotic cycle in MCF-7 cells.     

Active cytokinins: photoaffinity labeling agents to detect binding

Four series of azidopurines have been synthesized and tested for cytokinin activity in the tobacco callus bioassay: 2- and 8-azido-N⁶-benzyladenines, -N⁶-(Δ²-isopentenyl)adenines, and -zeatins, and N⁶-(2- and 4-azidobenzyl)adenines. The compounds having 2-azido substitution on the adenine ring are as active as the corresponding parent compounds, while those with 8-azido substitution are about 10 or more times as active. The 8-azidozeatin, which is the most active cytokinin observed, exhibited higher than minimal detectable activity at 1.2 × 10⁻⁵ micromolar, the lowest concentration tested. The shape of the growth curve indicates that even a concentration as low as 5 × 10⁻⁶ micromolar would probably be effective. By comparison, the lowest active concentration ever reported for zeatin has been 5 × 10⁻⁵ micromolar, representing a sensitivity rarely attained.     

High Fat Feeding Induces Hepatic Fatty Acid Elongation in Mice

Background

High-fat diets promote hepatic lipid accumulation. Paradoxically, these diets also induce lipogenic gene expression in rodent liver. Whether high expression of these genes actually results in an increased flux through the de novo lipogenic pathway in vivo has not been demonstrated.

Methodology/Principal Findings

To interrogate this apparent paradox, we have quantified de novo lipogenesis in C57Bl/6J mice fed either chow, a high-fat or a n-3 polyunsaturated fatty acid (PUFA)-enriched high-fat diet. A novel approach based on mass isotopomer distribution analysis (MIDA) following 1-¹³C acetate infusion was applied to simultaneously determine de novo lipogenesis, fatty acid elongation as well as cholesterol synthesis. Furthermore, we measured very low density lipoprotein-triglyceride (VLDL-TG) production rates. High-fat feeding promoted hepatic lipid accumulation and induced the expression of lipogenic and cholesterogenic genes compared to chow-fed mice: induction of gene expression was found to translate into increased oleate synthesis. Interestingly, this higher lipogenic flux (+74 µg/g/h for oleic acid) in mice fed the high-fat diet was mainly due to an increased hepatic elongation of unlabeled palmitate (+66 µg/g/h) rather than to elongation of de novo synthesized palmitate. In addition, fractional cholesterol synthesis was increased, i.e. 5.8±0.4% vs. 8.1±0.6% for control and high fat-fed animals, respectively. Hepatic VLDL-TG production was not affected by high-fat feeding. Partial replacement of saturated fat by fish oil completely reversed the lipogenic effects of high-fat feeding: hepatic lipogenic and cholesterogenic gene expression levels as well as fatty acid and cholesterol synthesis rates were normalized.

Conclusions/Significance

High-fat feeding induces hepatic fatty acid synthesis in mice, by chain elongation and subsequent desaturation rather than de novo synthesis, while VLDL-TG output remains unaffected. Suppression of lipogenic fluxes by fish oil prevents from high fat diet-induced hepatic steatosis in mice.     

Recombinant production and biochemical characterization of a hyperthermostable α-glucan/maltodextrin phosphorylase from Pyrococcusfuriosus

Alpha-glucan phosphorylase catalyzes the reversible cleavage of α-1-4-linked glucose polymers into α-D-glucose-1-phosphate. We report the recombinant production of an α-glucan/maltodextrin phosphorylase (PF1535) from a hyperthermophilic archaeon, Pyrococcus furiosus, and the first detailed biochemical characterization of this enzyme from any archaeal source using a mass-spectrometry-based assay. The apparent 98 kDa recombinant enzyme was active over a broad range of temperatures and pH, with optimal activity at 80 °C and pH 6.5–7. This archaeal protein retained its complete activity after 24 h at 80 °C in Tris-HCl buffer. Unlike other previously reported phosphorylases, the Ni-affinity column purified enzyme showed broad substrate specificity in both the synthesis and degradation of maltooligosaccharides. In the synthetic direction of the enzymatic reaction, the lowest oligosaccharide required for the chain elongation was maltose. In the degradative direction, the archaeal enzyme can produce glucose-1-phosphate from maltotriose or longer maltooligosaccharides including both glycogen and starch. The specific activity of the enzyme at 80 °C in the presence of 10 mM maltoheptaose and at 10 mg ml^–1 glycogen concentration was 52 U mg^–1 and 31 U mg^–1, respectively. The apparent Michaelis constant and maximum velocity for inorganic phosphate were 31 ± 2 mM and 0.60 ± 0.02 mM min^–1 µg^–1, respectively. An initial velocity study of the enzymatic reaction indicated a sequential bi-bi catalytic mechanism. Unlike the more widely studied mammalian glycogen phosphorylase, the Pyrococcus enzyme is active in the absence of added AMP.     

Pharmacological PPARα Activation Markedly Alters Plasma Turnover of the Amino Acids Glycine,Serine and Arginine in the Rat

The current study extends previously reported PPARα agonist WY 14,643 (30 µmol/kg/day for 4 weeks) effects on circulating amino acid concentrations in rats fed a 48% saturated fat diet. Steady-state tracer experiments were used to examine in vivo kinetic mechanisms underlying altered plasma serine, glycine and arginine levels. Urinary urea and creatinine excretion were measured to assess whole-body amino acid catabolism. WY 14,643 treated animals demonstrated reduced efficiency to convert food consumed to body weight gain while liver weight was increased compared to controls. WY 14,643 raised total amino acid concentration (38%), largely explained by glycine, serine and threonine increases. ³H-glycine, ¹⁴C-serine and ¹⁴C-arginine tracer studies revealed elevated rates of appearance (R_a) for glycine (45.5±5.8 versus 17.4±2.7 µmol/kg/min) and serine (21.0±1.4 versus 12.0±1.0) in WY 14,643 versus control. Arginine was substantially decreased (−62%) in plasma with estimated R_a reduced from 3.1±0.3 to 1.2±0.2 µmol/kg/min in control versus WY 14,643. Nitrogen excretion over 24 hours was unaltered. Hepatic arginase activity was substantially decreased by WY 14,643 treatment. In conclusion, PPARα agonism potently alters metabolism of several specific amino acids in the rat. The changes in circulating levels of serine, glycine and arginine reflected altered fluxes into the plasma rather than changes in clearance or catabolism. This suggests that PPARα has an important role in modulating serine, glycine and arginine de novo synthesis.     

In vitro anti-inflammatory and wound healing properties of Andrographis echioides and Andrographis paniculata

Andrographis echioides (L.) is an annual herbaceous plant in the family Acanthaceae. Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. They are sometimes called "free-radical scavengers. Therefore, it is of interest to analyse the anti-inflammatory and antioxidant properties of Andrographis echioides and Andrographis paniculata. Protease inhibitor activity was done by bovine serum albumin was added to 100µl of plant sample with increase in concentrations (100-500µg/ml). Invitro antioxidant activity was done by DPPH free radical scavenging assay. 200 µL of 0.1 mM DPPH prepared in methanol was added to 100 µL of the plant extract with increase in concentration. Based on the results from the present study, it can be concluded that A.echioides is found to be a good natural antioxidant source and A. paniculata is found to be a good anti-inflammatory source. However, both the plant A.echioides and A.paniculata have these properties. Data shows that both A.echioides and A. paniculata have potential anti-inflammatory and antioxidant activity which could be due to the presence of bioactive compounds present in the plant extracts.     

Synthesis of hydroxy fatty acids from linoleic acid by human blood platelets

The metabolism of linoleic acid by washed human platelets was investigated. 1.¹⁴C linoleic acid was converted to 1.¹⁴C hydroxy octadecadienoic acids (HODES) at about the same rate with which 1.¹⁴C 12-HETE was produced from 1.¹⁴C arachidonic acid. The total radioactivity in HODEs was distributed among two isomers: 13-HODE (85%) and 9-HODE (15%) as defined by GC-MS. The production of HODES by intact washed platelets was inhibited by indomethacin (IC50:5×10⁻⁷M) which suggest that hydroxy fatty acids were produced by PGH-synthase. By contrast, the production of HODEs by platelet cytosolic fractions was not modified under indomethacin treatment but completely abolished by NDGA (10⁻³M) and inhibited by the platelet lipoxygenase inhibitors 15-HETE (2.10⁻⁵M) and baicalein (10⁻⁵M). Platelets thus contain two different active systems which may convert linoleic acid to hydroxy fatty acids. Since these compounds remained essentially associated with the platelets, their presence may significantly participate in the mechanisms of platelet activation.