Chemical profiling and biological evaluation of Nepeta baytopii extracts and essential oil: An endemic plant from Turkey

Nepeta baytopii is a poorly studied, endemic Nepeta species (Lamiaceae) of Turkey. For the first time, the biological activities (antioxidant, enzyme inhibition, and cytotoxicity properties) of the hexane, ethyl acetate, methanol, water/methanol, and water extracts and essential oil prepared from N. baytopii aerial parts were assessed. Hydro-methanol (41.25 mg gallic acid equivalent (GAE)/g) and water extracts (50.30 mg GAE/g), respectively showed the highest radical scavenging (94.40 and 129.22 mg Trolox equivalent (TE)/g, for 2,2-diphenyl-1-picrylhydrazyl radical and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid radical scavenging assays) and reducing (229.37 and 129.55 mg TE/g, for ferric-reducing antioxidant power and cupric-reducing antioxidant capacity assays) capacities in vitro. An interestingly high inhibition was observed for ethyl acetate extract against butyrylcholinesterase (10.85 mg galantamine equivalent/g). The methanol extract showed high cytotoxicity (31.7%) against HepG2 cells. Caryophyllene oxide was identified in high concentrations in the essential oil (39.3%). Luteolin and apigenin and their derivatives were identified from the methanol and water extracts. The results obtained from this study highlighted that the abundance of highly bioactive compounds from Nepeta baytopii ensures the multiple biological activities of the tested extracts, and this suggests a potential use in the pharmaceutical and nutraceutical fields, and therefore should be investigated further.info:eu-repo/semantics/publishedVersio

Glyceraldehyde-3-phosphate Dehydrogenase and Fructose-1, 6-bisphosphatase of the Enteric Pathogens C. jejuni and H. pylori

Campylobacter jejuni and Helicobacter pylori are pathogens which cause gastrointestinal diseases and are therefore of significant importance. However, their metabolism and physiology is relatively poorly understood. It had been noted that the genome of these pathogens lack open reading frames for some glycolytic enzymes. Notably, both pathogens lack the gene encoding phosphofructokinase (6-PFK) and thus regulation of the complementary gluconeogenic enzyme fructose-1,6-bisphosphatase (FBPase) might be different to that in the majority of organisms which retain 6-PFK. In order to further understand the metabolism of C. jejuni and H. pylori, the structure and function of FBPase and the key gluconeogenic/glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was investigated. Specifically, the regulation of FBPase in both pathogens was investigated using kinetic and biophysical techniques. The results suggested that the enzymes are insensitive to AMP inhibition, unlike mammalian and E. coli FBPases. The FBPases were also insensitive to the other compounds of glycolytic and gluconeogenic pathways. The essentiality of fbp in C. jejuni was also tested and confirmed with gene complementation methodology. The essentiality and difference in regulation of these enzymes suggests they have potential as drug targets. The crystal structures of C. jejuni GAPDH (cjGAPDH) with bound NAD+ and NADP+ showed dual coenzyme specificity, revealing similarities with plant GAPDHs and suggesting a gluconeogenic role. The mechanism of inhibition of cjGAPDH was investigated further through covalent modification of the active site cysteine by iodoacetamide, this blocked NAD(P)+ binding. A competitive inhibitor-bound structure of cjGAPDH, in which the coenzyme was replaced by ADP, was also solved. Comparison of the crystal structures of cjGAPDH-ADP and cjGAPDH-NAD(P)+ complexes highlighted specific conformational changes linked to interactions with the ribose 2’-phosphate. The interactions of this 2’-phosphate might also be utilised to inform the design of lead compounds for inhibitory drug development

Chrysin mitigates diclofenac-induced hepatotoxicity by modulating oxidative stress, apoptosis, autophagy and endoplasmic reticulum stress in rats

Diclofenac (DF) is a non-steroidal anti-inflammatory drug (NSAID) generally prescribed for the treatment of pain. In spite of the widespread use of DF, hepatotoxicity has been reported after its administration. The current study discloses new evidence as regards of the curative effects of chrysin (CHR) on DF-induced hepatotoxicity by regulating oxidative stress, apoptosis, autophagy, and endoplasmic reticulum (ER) stress. Methods: The animals were separated into five different groups. Group-I was in control. Group-II received CHR-only (50 mg/kg bw, p.o.) on all 5 days. Group-III received DF-only (50 mg/kg bw, i.p.) on 4th and 5th day. Group-IV received DF (50 mg/kg bw) + CHR (25 mg/kg, bw) and group-V received DF (50 mg/kg, bw) + CHR (50 mg/kg, bw) for 5 days. Results: DF injection was associated with increased MDA while reduced GSH level, activities of superoxide dismutase, glutathione peroxidase, and catalase and mRNA levels of HO-1 and Nrf2 in the liver. DF injection caused apoptosis and autophagy in the liver by up-regulating caspase-3, Bax, LC3A, and LC3B levels and down-regulating Bcl-2. DF also caused ER stress by increasing mRNA transcript levels of ATF-6, IRE1, PERK, and GRP78. Additionally, it was observed that DF administration up-regulated MMP2 and MMP9. However, treatment with CHR at a dose of 25 and 50 mg/kg considerably ameliorated oxidative stress, apoptosis, autophagy, and ER stress in liver tissue. Conclusion: Overall, the data of this study indicate that liver damage associated with DF toxicity could be ameliorated by CHR administration

Crystal structures of a dual coenzyme specific glyceraldehyde-3-phosphate dehydrogenase from the enteric pathogen Campylobacter jejuni

Campylobacter jejuni is a pathogenic bacteria that causes gastrointestinal disorders and is thus of great importance. Phosphorylating Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a ubiquitous cellular enzyme that has a well-defined role in glycolysis and other pathways where it catalyses the oxidative phosphorylation of glyceraldehyde 3-phosphate (2-hydroxy-3-oxopropyl dihydrogen phosphate) to 1,3-Bisphosphoglycerate ((2-Hydroxy-3-phosphonooxy-propanoyloxy)phosphonic acid). The C. jejuni genome encodes a single GAPDH enzyme (CjGAPDH) which displays dual (NAD/NADP) coenzyme specificity. NAD-specific GAPDHs are given the EC classification of 1.2.1.12, whereas NADP-specific GAPDHs are classed as 1.2.1.13. GAPDH's with dual specificity are in the class 1.2.1.59. Here we present the X-ray crystal structure of this enzyme (at 2.25 Å), this comprises superimposed structures of NAD- and NADP- complexes showing the structural adaptation that allows this dual specificity, and we consider this in the context of the pathogen's metabolism. There are no previous reports of EC 1.2.1.59 structures that compare the binding of the two co-enzymes. Furthermore, we also report the structure (at 2.05 Å) of the enzyme complexed with the nucleoside ADP and consider this with respect to the reported “moonlighting” activities of GAPDH

Melatonin and vitamin E alleviate homocysteine‐induced oxidative injury and apoptosis in endothelial cells

A relationship exists between hyperhomocysteinemia and cardiovascular diseases, although the underlying mechanisms are still incompletely defined. One possibility involves a homocysteine (Hcy)-induced increased oxidative stress. Melatonin (Mel) and vitamin E (vitE) are important anti-oxidants. The main purpose of this study was (1) to compare the effect of treatments with Mel, vitE or both, on Hcy-induced apoptosis in human umbilical vein endothelial cells (HUVECs), and (2) to investigate the underlying mechanisms. Cell proliferation assay was carried out by Water Soluble Tetrazolium-1 (WST-1) assay kit. Apoptotic index was calculated by TUNEL Assay. Anti-oxidant parameters were studied by measurement of reactive oxygen species (ROS) and lipid peroxidation (LPO) levels. mRNA and protein expression levels of apoptotic and anti-apoptotic genes and proteins were studied by quantitative real time polymerase chain reaction (qRT-PCR) and Western blotting experiments respectively. The results showed that treatments with Mel, vitE or Mel + vitE suppressed Hcy-induced cell death, with a higher efficiency for the Mel and Mel + vitE treatments. Our results suggests that the mechanisms by which these anti-oxidants protected endothelial cells include the decrease in ROS and LPO levels, an increase in cell migration, the downregulation of pro-apoptotic proteins Cas 3, Cas 9, Cyt C and Bax and the upregulation of anti-apoptotic protein Bcl 2. Collectively, these results revealed the protective role of vitE and Mel against Hcy-induced cell apoptosis, which may add insight into therapeutic approaches to Hcy-induced damages

Neuroprotective effects of 18 beta-glycyrrhetinic acid against bisphenol A-induced neurotoxicity in rats: involvement of neuronal apoptosis, endoplasmic reticulum stress and JAK1/STAT1 signaling pathway

The exposure to bisphenol A (BPA) is inevitable owing to its common use in the production of polycarbonate plastics. Studies to reduce side effects are gaining importance since BPA causes severe toxicities in important tissues such as testes, lungs, brain, liver and kidney. The current study was planned to study ameliorative effect of 18 beta-glycyrrhetinic acid (18 beta-GA) on BPA induced neurotoxicity. Fourty Wistar albino rats were divided into five equal groups as follows: I-Control group, II-18 beta-GA group (100 mg/kg), III- BPA group (250 mg/kg), IV-250 mg/kg BPA +50 mg/kg 18 beta-GA group, V-250 mg/kg BPA +100 mg/kg 18 beta-GA group. BPA intoxication was associated with increased MDA level while reduced GSH concentration, activities of glutathione peroxidase, superoxide dismutase, and catalase. BPA supplementation caused apoptosis in the brain by up-regulating caspase-3 and Bax levels and down-regulating Bcl-2. BPA also caused endoplasmic reticulum (ER) stress by increasing mRNA transcript levels of PERK, IRE1, ATF-6 and GRP78. Additionally, it was observed that BPA administration activated JAK1/STAT1 signaling pathway and levels of TNF-alpha, NF-kappa B, p38 MAPK and INK in the brain. However, co-treatment with 18 beta-GA at a dose of 50 and 100 mg/kg considerably ameliorated oxidative stress, inflammation, apoptosis, ER stress and JAK1/STAT1 signaling pathway in brain tissue. Overall, the data of this study indicate that brain damage associated with BPA toxicity could be ameliorated by 18 beta-GA administration

<i>In vitro</i> effects of some antibiotics on glucose-6-phosphate dehydrogenase from rat (<i>Rattus norvegicus</i>) erythrocyte

<p>Glucose-6-phosphate dehydrogenase (G6PD) plays a key function in various biochemical processes as they produce reducing power of the cell. Thus, metabolic reprogramming of nicotinamide adenine dinucleotide homeostasis is reported to be an important step in cancer progression as well as in combinational therapeutic approaches. In this study, the effects of the antibiotics, furosemide, cefazolin, cefuroxime, gentamicin and clindamycin on rat erythrocyte G6PD enzyme was studied in <i>in vitro</i> conditions. The enzyme was purified by 2', 5'-adenosine diphosphate Sepharose 4B affinity chromatography in a single purification step with 1825 fold and 83.7% yield. The specific activity of the enzyme was 29.2 EU/mg proteins. The inhibition studies of these antibiotics were carried out on the enzyme revealing that gentamicin, clindamycin and furosemide inhibited the activity of the G6PD with an IC₅₀ of 1.75, 34.65 and 0.526 mM, respectively with K_i of 0.7, 39.8 and 0.860 mM, respectively. All inhibition types were analyzed by Lineweaver-Burk diagram showing noncompetitive inhibition for furosemide and gentamicin while clindamycin inhibited the activity competitively. On the other hand, cefazolin and cefuroxime increased the activity of the enzyme.</p

Hesperidin attenuates oxidative stress, inflammation, apoptosis, and cardiac dysfunction in sodium fluoride‐Induced cardiotoxicity in rats

Excessive fluoride intake has been reported to cause toxicities to brain, thyroid, kidney, liver and testis tissues. Hesperidin (HSP) is an antioxidant that possesses anti-allergenic, anti-carcinogenic, anti-oxidant and anti-inflammatory activities. Presently, the studies focusing on the toxic effects of sodium fluoride (NaF) on heart tissue at biochemical and molecular level are limited. This study was designed to evaluate the ameliorative effects of HSP on toxicity of NaF on the heart of rats in vivo by observing the alterations in oxidative injury markers (MDA, SOD, CAT, GPX and GSH), pro-inflammatory markers (NF-κB, IL-1β, TNF-α), expressions of apoptotic genes (caspase-3, -6, -9, Bax, Bcl-2, p53, cytochrome c), levels of autophagic markers (Beclin 1, LC3A, LC3B), expression levels of PI3K/Akt/mTOR and cardiac markers. HSP treatment attenuated the NaF-induced heart tissue injury by increasing activities of SOD, CAT and GPx and levels of GSH, and suppressing lipid peroxidation. In addition, HSP reversed the changes in expression of apoptotic (caspase-3, -6, -9, Bax, Bcl-2, p53, cytochrome c), levels of autophagic and inflammatory parameters (Beclin 1, LC3A, LC3B, NF-κB, IL-1β, TNF-α), in the NaF-induced cardiotoxicity. HSP also modulated the gene expression levels of PI3K/Akt/mTOR signaling pathway and levels of cardiac markers (LDH, CK-MB). Overall, these findings reveal that HSP treatment can be used for the treatment of NaF-induced cardiotoxicity

Morin ameliorates methotrexate-induced hepatotoxicity via targeting Nrf2/HO-1 and Bax/Bcl2/Caspase-3 signaling pathways

Organ toxicity limits the therapeutic efficacy of methotrexate (MTX), an anti-metabolite therapeutic that is frequently used as an anti-cancer and immunosuppressive medicine. Hepatocellular toxicity is among the most severe side effects of long-term MTX use. The present study unveils new confirmations as regards the remedial effects of morin on MTX-induced hepatocellular injury through regulation of oxidative stress, apoptosis and MAPK signaling