OLEANOLIC ACID, A PROSPECTIVE PROTECTIVE AGENT AGAINST BRAIN ENERGY METABOLISM AND OXIDATIVE DYSFUNCTIONS FOLLOWING HEXAVALENT CHROMIUM EXPOSURE IN MICE

Objective: Effect of oleanolic acid against hexavalent chromium-induced altered brain energy metabolism associated with oxidative stress was evaluated in the present study. Methods: Swiss albino mice were divided into three groups, Control (n=6), chromium-treated (n=6), and oleanolic acid (OA) supplemented (n=6). The chromium treated group was orally administered with K2Cr2O7 for 30 days at a dose of 10 mg/kg b.w/day. OA supplementation was given at a dose of 5 mg/kg bw/day for the past 14 days of chromium treatment. Control group received the vehicle only. After the treatment, whole brain was removed for examining the parameters such as pyruvic acid, free amino nitrogen, tissue protein, TCA cycle enzyme activities, NADH dehydrogenase function, and oxidative stress markers. Results: Significant decrease in cerebral pyruvic acid content associated with suppressed malate dehydrogenase and succinate dehydrogenase activities were observed. The NADH dehydrogenase activity was inhibited owing to enhanced accumulation of chromium in cerebral tissue. Depletion of proteins and increased free amino acid nitrogen were accompanied with inhibited cathepsin, pronase and trypsin activities, and increased transaminase function. In addition, GSH content was decreased along with increased lipid peroxidation, oxidized GSSG content, TG/GSSG ratio, carbonylated protein content, and tissue free hydroxyl radical formation. Superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase were also inhibited by hexavalent chromium. Oleanolic acid supplementation was found to have significant protective effect against brain metabolic and oxidative dysfunctions. Conclusion: The present study elucidated therapeutic efficacy of oleanolic acid against hexavalent chromium toxicity in brain tissue of mice.

Effect of thermal treatment on physicochemical, phytochemical, and microbiological characteristics of brown Spanish onion paste

Onion paste is a commercially used processed product that reduces cooking time. Industrial processing of onion paste involves various treatments that affect the overall nutritional profile of the final product. In this study, effect of various thermal treatment conditions was evaluated, with temperature and time ranging between 70 and 90°C for 8 to 22 min, respectively. Changes in quercetin, pyruvic acid, and quality characteristics of fresh onion paste were investigated. A negative linear trend was observed in quercetin, pyruvic acid, viscosity, ascorbic acid, and total plate count, with an increase in temperature and time. An interactive and combined effect of time and tem-perature showed a positive linear relationship with color difference. For all the quality parameters investigated in this study, thermal treatment at 87°C for 15 min was found to be optimum for development of shelf-stable onion paste. Quercetin and pyruvic acid content were found to be 2.587±0.03 g kg–1 and 0.086±0.004 µmol kg–1, respectively. Optimum conditions depicted better retention of principal compounds as compared to the other experimental conditions and exhibited safer quality product as compared to the untreated sample.Industrial relevance: Brown Spanish onion is a perishable produce due to high moisture content. In order to reduce its postharvest losses at domestic and commercial levels, optimized processing parameters for the production of onion paste can be economically beneficial, and it is a highly acclaimed product for consumer usage.

Pyruvic acid, an efficient catalyst in SO₃ hydrolysis and effective clustering agent in sulfuric acid-based new particle formation

The role of pyruvic acid (PA), one of the most abundant α-keto carboxylic acids in the atmosphere, was investigated both in the SO3 hydrolysis reaction to form sulfuric acid (SA) and in SA-based aerosol particle formation using quantum chemical calculations and a cluster dynamics model. We found that the PA-catalyzed SO3 hydrolysis is a thermodynamically driven transformation process, proceeding with a negative Gibbs free energy barrier, ca. −1 kcal mol−1 at 298 K, ~6.50 kcal mol−1 lower than that in the water-catalyzed SO3 hydrolysis. Results indicated that the PA-catalyzed reaction can potentially compete with the water-catalyzed SO3 reaction in SA production, especially in dry and polluted areas, where it is found to be ~two orders of magnitude more efficient that the water-catalyzed reaction. Given the effective stabilization of the PA-catalyzed SO3 hydrolysis product as SA•PA cluster, we proceeded to examine the PA clustering efficiency in sulfuric acid-pyruvic acid-ammonia (SA-PA-NH3) system. Our thermodynamic data used in the Atmospheric Cluster Dynamics Code indicated that under relevant tropospheric temperatures and concentrations of SA (106 cm3), PA (1010 cm3) and NH3 (1011 and 5 × 1011 cm3), of the PA-containing clusters, only clusters with one PA molecule, namely (SA)2•PA•(NH3)2, can participate to the particle formation, contributing by ~100 % to the net flux to aerosol particle formation at 238 K, exclusively. At higher temperatures (258 K and 278 K), however, the net flux to the particle formation is dominated by pure SA-NH3 clusters, while PA would rather evaporate from the clusters at high temperatures and not contribute to the particle formation. The enhancing effect of PA of examined by evaluating the ratio of the ternary SA-PA-NH3 cluster formation rate to binary SA-NH3 cluster formation rate. Our results show that while the enhancement factor of PA to the particle formation rate is almost insensitive to investigated temperatures and concentrations, it can be as high as 4.7 × 102 at 238 K and [NH3] = 1.3 × 1011 molecule cm−3. This indicates that PA may actively participate in aerosol formation, only in cold regions of the troposphere and highly NH3-polluted environments. The inclusion of this mechanism in aerosol models may definitely reduce uncertainties that prevail in modeling the aerosol impact on climate.

Water-Mediated Green Synthesis of Benzimidazoles Using Pyruvic Acid: A Comparable Study of Ultra-sonication versus Conventional Heating

: An efficient and green protocol has been introduced for the synthesis of benzimidazole derivatives using a pyruvic acid catalyst in the presence of water. Pyruvic acid catalyses the reaction of aromatic aldehydes with o-phenylenediamine efficiently, and products were obtained in good to excellent yields under sonication (50 oC) or under conventional heating (50 oC). The advantages of this synthetic methodology are the use of eco-friendly, commercially cheap, biodegradable catalyst, metal-free and Lewis acid-free mild reaction conditions with excellent yields, short reaction times, and compatible with a wide range of electronically diverse substrates. Pyruvic acid in water as a catalyst under ultrasound irradiation can be a better alternative to synthesize benzimidazole derivatives than some of the traditional methods.

Effect of diet-induced hypercholesterolemia on metabolic processes in the heart, liver, and pancreas in rats

Aim. To analyze the biochemical changes in the cells of the heart muscle, liver and pancreas, as well as to establish their pathogenetic significance in diet-induced experimental hypercholesterolemia. Methods. The study was conducted on 65 outbred male rats. During the experiment, the animals were divided into groups: the first (control, n=30) animals that were kept on a general vivarium diet; the second (experimental, n=35) animals with diet-induced hypercholesterolemia for three months by keeping on a special diet. At the end of the experiment, the concentrations of pyruvic acid, lactate, reduced glutathione, the activity of glutathione reductase, and glutathione peroxidase were determined in the tissues by using biochemical methods. The Student's t-test was used for the experimental data of the samples after normality testing. Results. The analysis of energy metabolism indicators in animals with hypercholesterolemia relative to the control group revealed a lower level of pyruvic acid in the heart muscle (0.290.03 mmol/mg protein; p 0.05) and liver (0.250.02 mmol/mg protein; p 0.001). A significantly higher lactate level was recorded in all tissues, most pronounced in the liver (6.730.6 mmol/mg protein; p 0.001). The results obtained indicate the predominance of the anaerobic glycolysis in the tissues and the accumulation of incomplete-oxidation products. The study of the key glutathione-linked enzymes in animals with hypercholesterolemia relative to the control showed a lower activity of glutathione reductase in the pancreas 0.520.05 mmol/mg protein/min (p 0.001), as well as its higher activity in the liver 0.2970.03 mmol/mg protein/min (p 0.001) and heart 13.581.4 mmol/mg protein/min (p 0.001). The activity of glutathione peroxidase and reduced glutathione in all organs remained practically unchanged, or the differences were insignificant. This trend indicates a violation of the antioxidant defense system and oxidative stress. Conclusion. Changes in the metabolic link of adaptive-compensatory responses in the cells of the heart muscle, liver, and, most pronounced in the pancreas, indicate the role of the pancreas as a target organ in the pathogenesis of diet-induced hypercholesterolemia.

Comparison of the effectiveness of non invasive and invasive therapy in the removal of viral warts of the foot skin

The aim of this review was to compare the effectiveness of natural and invasive therapy in the removal of viral warts of the foot skin. A research was conducted based on 25 studies on wart removal with salicylic acid, pyruvic acid and formic acid, retinoids, 5-fluorouracil, phenol, occlusion, lasers: CO2, KTP, Nd:Yag, Er:Yag, pulse-dye, cryotherapy, electrocoagulation and surgical method. When comparing natural and invasive treatments, similar effectiveness was concluded, and the presented studies did not show any advantage one over the other.

Impact of pyruvic acid photolysis on acetaldehyde and peroxy radical formation in the boreal forest: theoretical calculations and model results

Based on the first measurements of gas-phase pyruvic acid (CH3C(O)C(O)OH) in the boreal forest, we derive effective emission rates of pyruvic acid and compare them with monoterpene emission rates over the diel cycle. Using a data-constrained box model, we determine the impact of pyruvic acid photolysis on the formation of acetaldehyde (CH3CHO) and the peroxy radicals CH3C(O)O2 and HO2 during an autumn campaign in the boreal forest. The results are dependent on the quantum yield (φ) and mechanism of the photodissociation of pyruvic acid and the fate of a likely major product, methylhydroxy carbene (CH3COH). With the box model, we investigate two different scenarios in which we follow the present IUPAC (IUPAC Task Group on Atmospheric Chemical Kinetic Data Evaluation, 2021) recommendations with φ = 0.2 (at 1 bar of air), and the main photolysis products (60 %) are acetaldehyde + CO2 with 35 % C–C bond fission to form HOCO and CH3CO (scenario A). In the second scenario (B), the formation of vibrationally hot CH3COH (and CO2) represents the main dissociation pathway at longer wavelengths (∼ 75 %) with a ∼ 25 % contribution from C–C bond fission to form HOCO and CH3CO (at shorter wavelengths). In scenario 2 we vary φ between 0.2 and 1 and, based on the results of our theoretical calculations, allow the thermalized CH3COH to react with O2 (forming peroxy radicals) and to undergo acid-catalysed isomerization to CH3CHO. When constraining the pyruvic acid to measured mixing ratios and independent of the model scenario, we find that the photolysis of pyruvic acid is the dominant source of CH3CHO with a contribution between ∼ 70 % and 90 % to the total production rate. We find that the photolysis of pyruvic acid is also a major source of the acetylperoxy radical, with contributions varying between ∼ 20 % and 60 % dependent on the choice of φ and the products formed. HO2 production rates are also enhanced, mainly via the formation of CH3O2. The elevated production rates of CH3C(O)O2 and HO2 and concentration of CH3CHO result in significant increases in the modelled mixing ratios of CH3C(O)OOH, CH3OOH, HCHO, and H2O2.

Jasmonic Acid-Dependent MYC Transcription Factors Bind to a Tandem G-Box Motif in the YUCCA8 and YUCCA9 Promoters to Regulate Biotic Stress Responses

The indole-3-pyruvic acid pathway is the main route for auxin biosynthesis in higher plants. Tryptophan aminotransferases (TAA1/TAR) and members of the YUCCA family of flavin-containing monooxygenases catalyze the conversion of l-tryptophan via indole-3-pyruvic acid to indole-3-acetic acid (IAA). It has been described that jasmonic acid (JA) locally produced in response to mechanical wounding triggers the de novo formation of IAA through the induction of two YUCCA genes, YUC8 and YUC9. Here, we report the direct involvement of a small number of basic helix-loop-helix transcription factors of the MYC family in this process. We show that the JA-mediated regulation of the expression of the YUC8 and YUC9 genes depends on the abundance of MYC2, MYC3, and MYC4. In support of this observation, seedlings of myc knockout mutants displayed a strongly reduced response to JA-mediated IAA formation. Furthermore, transactivation assays provided experimental evidence for the binding of MYC transcription factors to a particular tandem G-box motif abundant in the promoter regions of YUC8 and YUC9, but not in the promoters of the other YUCCA isogenes. Moreover, we demonstrate that plants that constitutively overexpress YUC8 and YUC9 show less damage after spider mite infestation, thereby underlining the role of auxin in plant responses to biotic stress signals.