Regulation of Keap-1/Nrf2/AKT and iNOS/NF-κB/TLR4 signals by apocynin abrogated methotrexate-induced testicular toxicity: Mechanistic insights and computational pharmacological analysis

AIM

Male reproductive toxicity is becoming of growing significance due to clinical chemotherapy usage. Methotrexate (MTX) is an anti-folate used on a large scale for different tumors and autoimmune conditions. Despite its wide clinical use, MTX is associated with severe testicular intoxication. The exact underlying mechanism is unclear.

METHODS

Our study was conducted to explore the pathogenesis mechanism of MTX-induced testicular damage and the potential testicular protective effects of apocynin (APO) on testicular injury induced by single i.p. MTX (20 mg/kg). APO was administered orally (100 mg/kg) for ten days.

RESULTS

As compared to rats given MTX alone, co-administration of MTX with APO demonstrated multiple beneficial effects evidenced by a marked increase in testosterone, FSH, and LH and significantly restored testes histopathological alterations. Mechanistically, APO restored antioxidant status through up-regulation of Nrf2, cytoglobin, PPAR-γ, SIRT1, AKT, and p-AKT, while effectively lowering Keap-1. Moreover, APO significantly attenuated inflammation by down-regulating NF-κB-p65, iNOS, and TLR4 expressions confirmed by in-silico evidence. Additionally, network pharmacology analysis, a bioinformatics approach, was used to decipher various cellular processes' molecular mechanisms.

SIGNIFICANCE

The current investigation proves the beneficial effects of APO in MTX-associated testicular damage through activation of cytoglobin, Keap-1/Nrf2/AKT, PPAR-γ, SIRT1, and suppressing of TLR4/NF-κB-p65 signal. Our data collectively encourage extending the investigation to the clinical setting to explore APO effects in MTX-treated patients.

R, Sharma S. Neuroprotective Ability of Apocynin Loaded Nanoparticles (APO-NPs) as NADPH Oxidase (NOX)-Mediated ROS Modulator for Hydrogen Peroxide-Induced Oxidative Neuronal Injuries

Apocynin (APO) is a known multi-enzymatic complexed compound, employed as a viable NADPH oxidase (NOX) inhibitor, extensively used in both traditional and modern-day therapeutic strategies to combat neuronal disorders. However, its therapeutic efficacy is limited by lower solubility and lesser bioavailability; thus, a suitable nanocarrier system to overcome such limitations is needed. The present study is designed to fabricate APO-loaded polymeric nanoparticles (APO-NPs) to enhance its therapeutic efficacy and sustainability in the biological system. The optimized APO NPs in the study exhibited 103.6 ± 6.8 nm and -13.7 ± 0.43 mV of particle size and zeta potential, respectively, along with further confirmation by TEM. In addition, the antioxidant (AO) abilities quantified by DPPH and nitric oxide scavenging assays exhibited comparatively higher AO potential of APO-NPs than APO alone. An in-vitro release profile displayed a linear diffusion pattern of zero order kinetics for APO from the NPs, followed by its cytotoxicity evaluation on the PC12 cell line, which revealed minimal toxicity with higher cell viability, even after treatment with a stress inducer (H2O2). The stability of APO-NPs after six months showed minimal AO decline in comparison to APO only, indicating that the designed nano-formulation enhanced therapeutic efficacy for modulating NOX-mediated ROS generation.

Biological Activities of Paeonol in Cardiovascular Diseases: A Review

Paeonol is a naturally existing bioactive compound found in the root bark of Paeonia suffruticosa and it is traditionally used in Chinese medicine for the prevention and management of cardiovascular diseases. To date, a great deal of studies has been reported on the pharmacological effects of paeonol and its mechanisms of action in various diseases and conditions. In this review, the underlying mechanism of action of paeonol in cardiovascular disease has been elucidated. Recent studies have revealed that paeonol treatment improved endothelium injury, demoted inflammation, ameliorated oxidative stress, suppressed vascular smooth muscle cell proliferation, and repressed platelet activation. Paeonol has been reported to effectively protect the cardiovascular system either employed alone or in combination with other traditional medicines, thus, signifying it could be a hypothetically alternative or complementary atherosclerosis treatment. This review summarizes the biological and pharmacological activities of paeonol in the treatment of cardiovascular diseases and its associated underlying mechanisms for a better insight for future clinical practices.

Computational Structural Revision of a 4-Hydroxy-3-(1'-angeloyloxy-2',3'-epoxy-3'-methyl)butylacetophenone Compound from Ageratina grandifolia

The structure of the reported compound 4-hydroxy-3-((S)-1'-angeloyloxy-(R)-2',3'-epoxy-3'-methyl)butylacetophenone (1), isolated from Ageratina grandifolia, has been revised through the use of DFT computational predictions. Re-examination of the reported experimental and DFT computed chemical shifts has led to the proposal of a chromane skeleton rather than the original epoxide derivative. Empirical predictions of the ¹³C and ¹H NMR shifts showed a much better fit for the chromane structure than for the epoxide. The relative configuration of the molecule was established using CASE-3D methodology on the basis of new DFT chemical shielding and J-coupling predictions, allowing the proposal of a new rel-2,2-dimethyl-3R-hydroxy-4S-(1-angeloyloxy)chromane structure (2) for the isolated compound. However, DFT prediction of the optical rotation for the CASE-3D selected configuration/conformations did not provide a conclusive answer for the absolute configuration.

Synthesis and Antinociceptive Effect of Some Thiazole-Piperazine Derivatives: Involvement of Opioidergic System in the Activity

In this study, we aimed to design and synthesize novel molecules carrying both the thiazole and piperazine rings in their structures and to investigate their antinociceptive activity. Targeted compounds were obtained by reacting thiosemicarbazide derivative and appropriate 2-bromoacetophenone in ethanol. The structures of the obtained compounds were determined using data from various spectroscopic methods (IR, ¹H-NMR, ¹³C-NMR, and LCMSMS). Experimental data from in vivo tests showed that test compounds 3a–3c, 3f, and 3g (50 mg/kg) significantly prolonged reaction times of animals in tail-clip and hot-plate tests compared to the controls, indicating that these compounds possess centrally mediated antinociceptive activities. Furthermore, these compounds reduced the number of writhing behaviors in the acetic acid-induced writhing tests, showing that the compounds also possess peripheral antinociceptive activity. In the mechanistic studies, naloxone pre-treatments abolished the antinociceptive activities of compounds 3a–3c, 3f, and 3g, indicating that opioidergic mechanisms were involved in their antinociceptive effects. Molecular docking studies demonstrating significant interactions between the active compounds and µ- and δ-opioid receptor proteins supported the pharmacological findings. This study is the first showing that molecules designed to bear thiazole and piperazine moieties together on their structure exert centrally and peripherally mediated antinociceptive effects by activating the opioid system.

Validated green chromatographic methods for determination of amlodipine and celecoxib in presence of methylacetophenone

Aim: Green, accurate and rapid methods, namely LC-MS/MS and thin layer chromatography-densitometric methods, were developed for determination of amlodipine besylate and celecoxib in presence of its process-related impurities, 4-methylacetophenone in pure and formulated tablets. Results: LC-MS/MS was achieved on ZORBAX Eclipse Plus C18 column using methanol:aqueous solution of 5 mM formic acid (95:5 v/v). High sensitivity with low limit of detection values 0.00028, 0.00027 and 0.0003 for amlodipine, celecoxib and 4-methylacetophenone, respectively were obtained. While, thin layer chromatography-densitometric was established using methanol:water:ammonia (70:25:1.5, by volume). Good linearity was obtained in the range of 0.1-10 μg/band, 1-150 μg/band and 0.01-2 μg/band for amlodipine, celecoxib and 4-methylacetophenone, respectively. Conclusion: The proposed method validation was achieved according to ICH guidelines. Those methods possess advantages of being ecofriendly methods which permit their application in quality control laboratories.

Chromoselective Photocatalysis Enables Stereocomplementary Biocatalytic Pathways*

Controlling the selectivity of a chemical reaction with external stimuli is common in thermal processes, but rare in visible-light photocatalysis. Here we show that the redox potential of a carbon nitride photocatalyst (CN-OA-m) can be tuned by changing the irradiation wavelength to generate electron holes with different oxidation potentials. This tuning was the key to realizing photo-chemo-enzymatic cascades that give either the (S)- or the (R)-enantiomer of phenylethanol. In combination with an unspecific peroxygenase from Agrocybe aegerita, green light irradiation of CN-OA-m led to the enantioselective hydroxylation of ethylbenzene to (R)-1-phenylethanol (99 % ee). In contrast, blue light irradiation triggered the photocatalytic oxidation of ethylbenzene to acetophenone, which in turn was enantioselectively reduced with an alcohol dehydrogenase from Rhodococcus ruber to form (S)-1-phenylethanol (93 % ee).

New Acetophenones and Chromenes from the Leaves of Melicope barbigera A. Gray

The dichloromethane extract from leaves of Melicope barbigera (Rutaceae), endemic to the Hawaiian island of Kaua'i, yielded four new and three previously known acetophenones and 2H-chromenes, all found for the first time in M. barbigera. The structures of the new compounds obtained from the dichloromethane extract after purification by chromatographic methods were unambiguously elucidated by spectroscopic analyses including 1D/2D NMR spectroscopy and HRESIMS. The absolute configuration was determined by modified Mosher's method. Compounds 2, 4 and the mixture of 6 and 7 exhibited moderate cytotoxic activities against the human ovarian cancer cell line A2780 with IC₅₀ values of 30.0 and 75.7 µM for 2 and 4, respectively, in a nuclear shrinkage cytotoxicity assay.

Lithium Hydroxide Hydrolysis Combined with MALDI TOF Mass Spectrometry for Rapid Sphingolipid Detection

Sphingolipids have diverse structural and bioactive functions that play important roles in many key biological processes. Factors such as low relative abundance, varied structures, and a dynamic concentration range provide a difficult analytical challenge for sphingolipid detection. To further improve mass-spectrometry-based sphingolipid analysis, lithium adduct consolidation was implemented to decrease spectral complexity and combine signal intensities, leading to increased specificity and sensitivity. We report the use of lithium hydroxide as a base in a routine hydrolysis procedure in order to effectively remove common ionization suppressants (such as glycolipids and glycerophospholipids) and introduce a source of lithium into the sample. In conjunction, an optimized MALDI matrix system, featuring 2',4',6'-trihydroxyacetophenone (THAP) is used to facilitate lithium adduct consolidation during the MALDI process. The result is a robust and high-throughput sphingolipid detection scheme, particularly of low-abundance ceramides. Application of our developed workflow includes the detection of differentially expressed liver sphingolipid profiles from a high-fat-induced obesity mouse model. We also demonstrate the method's effectiveness in detecting various sphingolipids in brain and plasma matrices. These results were corroborated with data from UHPLC HR MS/MS and MALDI FT-ICR, verifying the efficacy of the method application. Overall, we demonstrate a high-throughput workflow for sphingolipid analysis in various biological matrices by the use of MALDI TOF and lithium adduct consolidation.

An in vitro mechanistic approach towards understanding the distinct pathways regulating insulin resistance and adipogenesis by apocynin

Adipogenesis is a cascade of processes that entail the differentiation of fibroblasts into mature adipocytes, which results in the accumulation of triglycerides in the adipose cells due to high dietary supplements. This physiological condition increases the risk of type 2 diabetes. Apocynin (4-hydroxy-3-methoxyacetophenone), an organic compound from the root extracts of the medicinal herb Picrorhiza kurroa, has been used in various experimental studies. The current study focuses on deciphering the cellular and molecular mechanisms interlinking obesity and diabetes by validating the various key targets involved in insulin signaling and adipogenesis. Apocynin exhibited enhanced glucose uptake and decreased lipid accumulation in the adipocytes. Furthermore, the expression of molecular markers involved in the insulin signaling pathway, such as IRTK, IRS-1, PI3K, GLUT-4, and the adipogenic pathway, such as PPAR α, adiponectin, C/EBP-α and SREBP1C, by qPCR supported our hypothesis largely. Apocynin mimicked insulin in the insulin-signaling pathway by showing equivalent gene expression. It ameliorated adipogenesis by downregulating the key markers in the adipogenic pathway. Corroborating the hypothesis that Apocynin is antihyperlipidemic in nature, it reduced the expression of PPARα and adiponectin. These results substantiate that Apocynin exerts anti-diabetic and anti-adipogenic effects by regulating resistin and antioxidant enzyme levels in vitro.

Non-invasive intranasal administration route directly to the brain using dendrimer nanoplatforms: An opportunity to develop new CNS drugs

There are several routes of administration to the brain, including intraparenchymal, intraventricular, and subarachnoid injections. The blood-brain barrier (BBB) impedes the permeation and access of most drugs to the central nervous system (CNS), and consequently, many neurological diseases remain undertreated. For past decades, to circumvent this effect, several nanocarriers have been developed to deliver drugs to the brain. Importantly, intranasal (IN) administration can allow direct delivery of drugs into the brain through the anatomical connection between the nasal cavity and brain without crossing the BBB. In this regard, dendrimers may possess great potential to deliver drugs to the brain by IN administration, bypassing the BBB and reducing systemic exposure and side effects, to treat diseases of the CNS. In this original concise review, we highlighted the few examples advocated regarding the use of dendrimers to deliver CNS drugs directly via IN. This review highlighed the few examples of the association of dendrimer encapsulating drugs (e.g., small compounds: haloperidol and paeonol; macromolecular compounds: dextran, insulin and calcitonin; and siRNA) using IN administration. Good efficiencies were observed. In addition, we will present the in vivo effects of PAMAM dendrimers after IN administration, globally, showing no general toxicity.

Rotational Spectroscopy Meets Quantum Chemistry for Analyzing Substituent Effects on Non-Covalent Interactions: The Case of the Trifluoroacetophenone-Water Complex

The most stable isomer of the 1:1 complex formed by 2,2,2-trifluoroacetophenone and water has been characterized by combining rotational spectroscopy in supersonic expansion and state-of-the-art quantum-chemical computations. In the observed isomer, water plays the double role of proton donor and acceptor, thus forming a seven-membered ring with 2,2,2-trifluoroacetophenone. Accurate intermolecular parameters featuring one classical O-H···O hydrogen bond and one weak C-H···O hydrogen bond have been determined by means of a semi-experimental approach for equilibrium structure. Furthermore, insights on the nature of the established non-covalent interactions have been unveiled by means of different bond analyses. The comparison with the analogous complex formed by acetophenone with water points out the remarkable role played by fluorine atoms in tuning non-covalent interactions.

Enzyme-Inspired Assembly: Incorporating Multivariate Interactions to Optimize the Host-Guest Configuration for High-Speed Enantioselective Catalysis

To achieve a rapid asymmetry conversion, the substrate objects suffer from accelerated kinetic velocity and random rotation at the cost of selectivity. Inspired by natural enzymes, optimizing the host-guest configuration will realize the high-performance enantioselective conversion of chemical reactions. Herein, multivariate binding interactions were introduced into the 1D channel of a chiral catalyst to simulate the enzymatic action. An imidazolium group was used to electrophilically activate the C═O unit of a ketone substrate, and the counterion binds the hydrogen donor isopropanol. This binding effect around the catalytic center produces strong stereo-induction, resulting in high conversion (99.5% yield) and enantioselectivity (99.5% ee) for the asymmetric hydrogenation of biomass-derived acetophenone. In addition, the turnover frequency of the resulting catalyst (5160 h^-1 TOF) is more than 58 times that of a homogeneous Ru-TsDPEN catalyst (88 h^-1 TOF) under the same condition, which corresponds to the best performance reported till date among all existing catalysts for the considered reaction.

An improved and highly selective fluorescence assay for measuring phosphatidylserine decarboxylase activity

Phosphatidylserine decarboxylases (PSDs) catalyze the conversion of phosphatidylserine (PS) to phosphatidylethanolamine (PE), a critical step in membrane biogenesis and a potential target for development of antimicrobial and anti-cancer drugs. PSD activity has typically been quantified using radioactive substrates and products. Recently, we described a fluorescence-based assay that measures the PSD reaction using distyrylbenzene-bis-aldehyde (DSB-3), whose reaction with PE produces a fluorescence signal. However, DSB-3 is not widely available and also reacts with PSD's substrate, PS, producing an adduct with lower fluorescence yield than that of PE. Here, we report a new fluorescence-based assay that is specific for PSD and in which the presence of PS causes only negligible background. This new assay uses 1,2-diacetyl benzene/β-mercaptoethanol, which forms a fluorescent iso-indole-mercaptide conjugate with PE. PE detection with this method is very sensitive and comparable with detection by radiochemical methods. Model reactions examining adduct formation with ethanolamine produced stable products of exact masses (m/z) of 342.119 and 264.105. The assay is robust, with a signal/background ratio of 24, and can readily detect formation of 100 pmol of PE produced from Escherichia coli membranes, Candida albicans mitochondria, or HeLa cell mitochondria. PSD activity can easily be quantified by sequential reagent additions in 96- or 384-well plates, making it readily adaptable to high-throughput screening for PSD inhibitors. This new assay now enables straightforward large-scale screening for PSD inhibitors against pathogenic fungi, antibiotic-resistant bacteria, and neoplastic mammalian cells.

Tyrosinase-Targeting Gallacetophenone Inhibits Melanogenesis in Melanocytes and Human Skin-Equivalents

Demands for safe depigmentation compounds are constantly increasing in the pharmaceutical and cosmetic industry, since the numerous relevant compounds reported to date have shown undesirable side effects or low anti-melanogenic effects. In this study, we reported three novel inhibitors of tyrosinase, which is the key enzyme in melanogenesis, identified using docking-based high throughput virtual screening of an in-house natural compound library followed by mushroom tyrosinase inhibition assay. Of the three compounds, gallacetophenone showed high anti-melanogenic effect in both human epidermal melanocytes and a 3D human skin model, MelanoDerm. The inhibitory effect of gallacetophenone on tyrosinase was elucidated by computational molecular modeling at the atomic level. Binding of gallacetophenone to the active site of tyrosinase was found to be stabilized by hydrophobic interactions with His367, Ile368, and Val377; hydrogen bonding with Ser380 and a water molecule bridging the copper ions. Thus, our results strongly suggested gallacetophenone as an anti-melanogenic ingredient that inhibits tyrosinase.

Uncovering matrix effects on lipid analyses in MALDI imaging mass spectrometry experiments

The specific matrix used in matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) can have an effect on the molecules ionized from a tissue sample. The sensitivity for distinct classes of biomolecules can vary when employing different MALDI matrices. Here, we compare the intensities of various lipid subclasses measured by Fourier transform ion cyclotron resonance (FT-ICR) IMS of murine liver tissue when using 9-aminoacridine (9AA), 5-chloro-2-mercaptobenzothiazole (CMBT), 1,5-diaminonaphthalene (DAN), 2,5-Dihydroxyacetophenone (DHA), and 2,5-dihydroxybenzoic acid (DHB). Principal component analysis and receiver operating characteristic curve analysis revealed significant matrix effects on the relative signal intensities observed for different lipid subclasses and adducts. Comparison of spectral profiles and quantitative assessment of the number and intensity of species from each lipid subclass showed that each matrix produces unique lipid signals. In positive ion mode, matrix application methods played a role in the MALDI analysis for different cationic species. Comparisons of different methods for the application of DHA showed a significant increase in the intensity of sodiated and potassiated analytes when using an aerosol sprayer. In negative ion mode, lipid profiles generated using DAN were significantly different than all other matrices tested. This difference was found to be driven by modification of phosphatidylcholines during ionization that enables them to be detected in negative ion mode. These modified phosphatidylcholines are isomeric with common phosphatidylethanolamines confounding MALDI IMS analysis when using DAN. These results show an experimental basis of MALDI analyses when analyzing lipids from tissue and allow for more informed selection of MALDI matrices when performing lipid IMS experiments.

Paeonol alleviates primary dysmenorrhea in mice via activating CB2R in the uterus

BACKGROUND AND PURPOSE

Primary dysmenorrhea is the most common gynaecologic problem in menstruating women and is characterized by spasmodic uterine contraction and pain symptoms associated with inflammatory disturbances. Paeonol is an active phytochemical component that has shown anti-inflammatory and analgesic effects in several animal models. The aim of this study was to explore whether paeonol is effective against dysmenorrhea and to investigate the potential mechanism of cannabinoid receptor signalling.

EXPERIMENTAL APPROACH

Dysmenorrhea was established by injecting oestradiol benzoate into female mice. The effects of paeonol on writhing time and latency, uterine pathology and inflammatory mediators were explored. Isolated uterine smooth muscle was used to evaluate the direct effect of paeonol on uterine contraction.

KEY RESULTS

The oral administration of paeonol reduced dysmenorrhea pain and PGE2 and TNF-α expression in the uterine tissues of mice, and paeonol was found to be distributed in lesions of the uterus. Paeonol almost completely inhibited oxytocin-, high potassium- and Ca²⁺-induced contractions in isolated uteri. Antagonists of CB2R (AM630) and the MAPK pathway (U0126), but not of CB1R (AM251), reversed the inhibitory effect of paeonol on uterine contraction. Paeonol significantly blocked L-type Ca²⁺ channels and calcium influx in uterine smooth muscle cells via CB2R. Molecular docking results showed that paeonol fits well with the binding site of CB2R.

CONCLUSIONS AND IMPLICATIONS

Paeonol partially acts through CB2R to restrain calcium influx and uterine contraction to alleviate dysmenorrhea in mice. These results suggest that paeonol has therapeutic potential for the treatment of dysmenorrhea.

Asymmetric Transfer Hydrogenation of Arylketones Catalyzed by Enantiopure Ruthenium(II)/Pybox Complexes Containing Achiral Phosphonite and Phosphinite Ligands

A family of complexes of the formula trans-[RuCl₂(L)(R-pybox)] (R-pybox = (S,S)-ⁱPr-pybox, (R,R)-Ph-pybox, L = monodentate phosphonite, PPh(OR)₂, and phosphinite, L = PPh₂(OR), ligands) were screened in the catalytic asymmetric transfer hydrogenation of acetophenone, observing a strong influence of the nature of both the R-pybox substituents and the L ligand in the process. The best results were obtained with complex trans-[RuCl₂{PPh₂(OEt)}{(R,R)-Ph-pybox}] (2c), which provided high conversion and enantioselectivity (up to 96% enantiomeric excess, e.e.) for the reduction of a variety of aromatic ketones, affording the (S)-benzylalcohols.

Ferraria A, M. Botelho do Rego A, Correia LMM, Saraiva MS, Pombeiro AJL. Ultrasound and Radiation-Induced Catalytic Oxidation of 1-Phenylethanol to Acetophenone with Iron-Containing Particulate Catalysts

Iron-containing particulate catalysts of 0.1–1 µm size were prepared by wet and ball-milling procedures from common salts and characterized by FTIR, TGA, UV-Vis, PXRD, FEG-SEM, and XPS analyses. It was found that when the wet method was used, semi-spherical magnetic nanoparticles were formed, whereas the mechanochemical method resulted in the formation of nonmagnetic microscale needles and rectangles. Catalytic activity of the prepared materials in the oxidation of 1-phenylethanol to acetophenone was assessed under conventional heating, microwave (MW) irradiation, ultrasound (US), and oscillating magnetic field of high frequency (induction heating). In general, the catalysts obtained by wet methods exhibit lower activities, whereas the materials prepared by ball milling afford better acetophenone yields (up to 83%). A significant increase in yield (up to 4 times) was observed under the induction heating if compared to conventional heating. The study demonstrated that MW, US irradiations, and induction heating may have great potential as alternative ways to activate the catalytic system for alcohol oxidation. The possibility of the synthesized material to be magnetically recoverable has been also verified.

Targeting cellular microtubule by phytochemical apocynin exhibits autophagy-mediated apoptosis to inhibit lung carcinoma progression and tumorigenesis

BACKGROUND

Lung cancer is the leading cause of cancer-related deaths worldwide. Several targets have been identified for lung cancer therapy, amongst which 'Microtubule' and its dynamics are the most widely studied and used in therapy. Tubulin-microtubule polymer dynamics are highly sought after targets in the field of anti-cancer drug designing. Natural compounds are important sources for developing anticancer therapeutics owing to their efficacy and lower cytotoxicity. Evidence suggested that therapeutic targeting of microtubule by natural compounds is amongst the most widely used interventions in numerous cancer therapies including lung cancer.

PURPOSE

To determine the efficacy of apocynin (a natural compound) in suppressing the progression of lung carcinoma both in vitro and in vivo, along with the identification of targets and the underlying mechanism for developing a novel therapeutic approach.

METHODS

We have demonstrated themicrotubule depolymerizing role of apocynin by established protocols in cellular and cell-free system. The efficacy of apocynin to inhibit lung carcinoma progression was studied on A549 cells.The tumoricidal ability of apocynin was studied in BALB/c mice model as well.Mice were classified into 4 groups namely-group II mice as tumor control; group III-IV mice asalso tumor-induced but treated with differential apocynin doses whereas group I mice were kept as normal.

RESULTS

Apocynin, showed selective cytotoxicity towards lung cancer cells rather than normal lung fibroblast cells. Apocynin inhibited oncogenic properties including growth, proliferation (p < 0.05), colony formation (p < 0.05), invasion (p < 0.05) and spheroid formation (p < 0.05) in lung cancer cells. Apart from other established properties, apocynin was found to be a novel and potent component to bind with tubulin and depolymerize cellular microtubule network. Apocynin mediated cellular microtubule depolymerization was the driving mechanism to trigger autophagy-mediated apoptotic cell death (p < 0.05) which in turn retarded lung cancer progression. Furthermore, apocynin showed tumoricidal characteristics to inhibit lung tumorigenesis in mice as well.

CONCLUSION

Targeting tubulin-microtubule equilibrium with apocynin could be the key regulator to catastrophe cellular catabolic processes to mitigate lung carcinoma. Thus, apocynin could be a potential therapeutic agent for lung cancer treatment.

Electrochemical characteristics of the decolorization of three dyes by laccase mediator system (LMS) with synthetic and natural mediators

Laccase mediator system (LMS), a very attractive candidate for refractory organics biodegradation, harbors tremendous potential on industry application. However, the performance of LMS usually varies with the discrepancy of mediators and substrates in their chemical structures. Here, we adopt electrochemical analysis that is able to assess the degradation performance of various LMS on three different dyes by quantitative analysis of reaction outcome. Two mechanisms were suggested to explain the grafting of three mediators (1-Hydroxybenzotriazole, Violuric Acid and Acetosyringone), involving the transformation of proton or electron to produce active moieties, which subsequently react with target substrates. A thorough electrochemical insight into the redox features of mediators and its change in the presence of laccase and substrates were carried out using electrochemical analysis. The effectiveness of each kind of LMS on substrates was preliminarily evaluated by analyzing the change of the peak current and potential of mediators. The actual conversion rate of dyes was used to verify the analysis results, which confirms the important role of the stability of the oxidized form as well as their redox potential of the mediators in determining the mechanism of substrate oxidation. The application of electrochemical analysis in efficiency evaluation of LMS shed new light on effective selection of suitable mediators for degradation of refractory organics. It was therefore possible to prejudge the efficacy of LMS by analyzing the electrochemical parameters of target substances and mediators, which undoubtedly has broad further application prospects of LMS.

Prenylated Acetophloroglucinol Dimers from Acronychia trifoliolata: Structure Elucidation and Total Synthesis

The isolation of 12 secondary metabolites, including seven new acetophenone monomers, from the 50% CH3OH/CH2Cl2 extract (N089419-L/6) of Acronychia trifoliolata was reported previously. In the present work, three new prenylated acetophenone dimers (1-3) and five known dimers (4-8) were isolated, and their structures were elucidated by using various NMR spectroscopic techniques and HRMS. Among the new dimers, an unprecedented 4-isobutyl-3-isopropyltetrahydro-2H-pyran ring was observed in the structure of 1. This study is the first to report the formation of a 2H-pyran ring between two prenylated acetophloroglucinols. Only four related dimers have been reported before, and they were formylated phloroglucinol dimers from the family Eucalypteae. Compounds 2 and 3 are acrovestone-like dimers, and the structure of 3 was confirmed by total synthesis. The evaluation of the antiproliferative activity of isolated and synthesized acrovestone-like dimers indicated that a double bond in the prenyl-like moiety as found in the more active compounds might be important for mediating activity, while the pendant isobutyl group seems to be less important.

Transient UV-vis absorption spectroscopic characterisation of 2'-methoxyacetophenone as a DNA photosensitiser

2'-Methoxyacetophenone (2M) presents improved UVA absorption as compared with other acetophenone derivatives. On the basis of transient infrared spectroscopy it has been previously claimed that 2M is an interesting photosensitiser for cyclobutane pyrimidine dimers (CPDs) formation. In the present paper, a complete UV-Vis transient absorption spectroscopic characterisation of this compound is provided, including triplet-triplet spectra, triplet lifetimes and rate constants for quenching of 2M by a dimeric thymine derivative. Furthermore, generation of singlet oxygen has been proven by time-resolved near IR phosphorescence measurements. Overall, the obtained results confirm the potential of 2M as a DNA photosensitiser, not only for CPDs formation, but also for oxidative damage.

Synthesis of 6,12-Disubstituted Methanodibenzo[b,f][1,5]dioxocins: Pyrrolidine Catalyzed Self-Condensation of 2′-Hydroxyacetophenones

The preparation of unprecedented 6,12-disubstituted methanodibenzo[b,f][1,5]dioxocins from pyrrolidine catalyzed self-condensation of 2′-hydroxyacetophenones is herein described. This method provides easy access to this highly bridged complex core, resulting in construction of two C–O and two C–C bonds, a methylene bridge and two quaternary centers in a single step. The intricate methanodibenzo[b,f][1,5]dioxocin compounds were obtained in up to moderate yields after optimization of the reaction conditions concerning solvent, reaction times and the use of additives. Several halide substituted methanodibenzo[b,f][1,5]dioxocins could be prepared from correspondent 2′-hydroxyacetophenones.

Isolation, Chiral-Phase Resolution, and Determination of the Absolute Configurations of a Complete Series of Stereoisomers of a Rearranged Acetophenone with Three Stereocenters

A synthesis-inspired chemical investigation of the leaves of Melicope ptelefolia led to the isolation of evodialones A-D (1-4), four rearranged acetophenone stereoisomers possessing a prenylated acylcyclopentenone skeleton with three stereogenic carbons. Evodialones C and D (3 and 4) are new minor constituents. The chiral-phase HPLC resolution gave (+)-1-4 and (-)-1-4, eight enantiomers forming a complete stereoisomer library. Their absolute configurations were elucidated via extensive spectroscopic data and a modified Mosher's method. The relationship between the chiral structures and their NMR and ECD data is discussed. Compounds (±)-1, -2, and -4 have significant protective effects on high-glucose-induced oxidative stress in human vein endothelial cells.