Characterization of drugs as antioxidant prophylactics

Antioxidant and antihyperlipidemic activities of catechol derivatives and biflavonoid isolated from Semecarpus anacardium seeds

Semecarpus anacardium Linn. (Family: Anacardiaceae), commonly known marking nuts has been used in various traditional system of medicines for various ailments (such as antiatherogenic, antiinflammatory, antimicrobial, hypoglycemic, anticarcinogenic etc) since ancient times.Based on the wide pharmacological activities of this plant, the present study was aimed to explore the antioxidant and antihyperlipidemic potential in high fat diet fed rats using catechol derivatives I-IV and biflavonoid isolated from seeds of Semecarpus anacardium. Oral administration of catechol derivatives I-IV and biflavonoid at a concentration of 50 mg/kg b.wt to high fat diet fed rats for a period of 30 days significantly decreased the lipid profiles, body weight gain and organ weight when compared to untreated hypercholesterolemic rats. However, biflavonoid treated hypercholesterolemic rats showed more pronounced effects in all the parameters tested when compared to all catechol derivatives (I-IV) treated hypercholesterolemic rats. The effect produced by biflavonoid on various parameters was comparable to that of simvastastin- a standard drug. In vitro antioxidant activities were also conducted using these five compounds in which biflavonoid showed more significant antioxidant potential at a concentration of 1000 µg/ml when compared to catechol derivatives (I-IV). The pronounced antioxidant potential of biflavonoid might have contributed to the hypolipidemic action in hypercholesterolemic rats and improved oil red O staining of thoracic aorta has also supported the parameters investigated. Further, the molecular mechanism of cholesterol lowering potential of this drug is needed.

Interrelation of inflammation and oxidative stress in liver cirrhosis

Recently, the trend of research has been focused on the role of hematological indicators in assessing the activities of various diseases. The aim of the present study was to determine the usefulness of such hematological indicators for assessment of the relationship between inflammation and oxidative stress in order to provide new predictive tools for a non-invasive investigation of disease outcome for liver cirrhosis patients. A total of 35 subjects with compensated or decompensated liver cirrhosis and 10 age-matched healthy volunteers were included in this study. The patients were divided into two groups: Group 1, patients with toxic metabolic cirrhosis due to ethanol consumption; group 2, patients with liver cirrhosis following hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Using hematological data obtained after the complete counting of peripheral blood cells, the monocyte/lymphocyte (MLR), neutrophil/lymphocyte (NLR) and platelet/lymphocyte (PLR) ratios as well as systemic immune inflammation biomarkers were determined. The erythrocyte sedimentation ratio (ESR), C-reactive protein (CRP), fibrinogen and biochemical parameters related to liver function were also registered. Thiobarbituric acid reactive substances (TBARS), protein carbonyl content (PCARB), and total antioxidant capacity (TAC) were also investigated in the peripheral blood samples of healthy subjects and liver cirrhosis patients. The results revealed that NLR, MLR and PLR were significantly increased in group 2. PLR was significantly increased in group 1 compared with that noted in the control group. TBARS and PCARB were increased in patients from group 1 compared to patients from group 2 and the control group. However, no difference in TAC was found between the liver cirrhosis groups and the control. We showed that the pro-inflammatory status of liver cirrhosis patients can be easily appreciated by NLR, MLR but not PLR. However, the increase in these ratios was not significantly associated with a decrease in the antioxidant capacity and an augmentation of oxidative stress markers for the patients diagnosed with cirrhosis included in the two groups of study.

Preparation of a functional yogurt with Ligustrum robustum (Rxob.) Blume and its action mechanism

A functional yogurt was prepared with Ligustrum robustum (Rxob.) Blume extract (LRE), while its antioxidant and hypoglycemic activities were evaluated and its action mechanism was further explored. With the cofermentation of LRE, the yogurt showed the fine quality characteristics, including pH, titratable acidity, texture, syneresis susceptibility, color, microbiological content, and chemical composition. Meanwhile, the yogurt exhibited the remarkable antioxidant capability to enhance the activities of antioxidant enzymes and reduce the malondialdehyde level in animal serums. In addition, the yogurt showed the obvious hypoglycemic activity to inhibit the decrease of glucose tolerance and the increase of postprandial hyperglycemia of diabetes mice. Furthermore, using the analysis of molecular docking, the main compounds of LRE could combine tightly with α-amylase and α-glucosidase by hydrogen bond and hydrophobic interaction, so as to change their spatial structure and inhibit their biocatalytic activity in glucose metabolism. All present results suggested that LRE showed the potential value to be used as supplement to enhance the quality and functions of yogurt in food industry. PRACTICAL APPLICATION: The hypoglycemic and antioxidant activities of a functional yogurt cofermented with LRE were found and its relative action mechanism was also explored. This work provide the experimental and theoretical basis for the application of this yogurt as nutraceuticals to protect human health in food industry.

A novel exopolysaccharide produced by Lactobacillus coryniformis NA-3 exhibits antioxidant and biofilm-inhibiting properties in vitro

Background

Exopolysaccharides (EPSs) secreted from lactic acid bacteria are carbohydrate polymers with reported biological activities. In this study, we extracted and characterized the composition as well as antioxidant and biofilm-inhibitory properties of EPS from Lactobacillus coryniformis NA-3 isolated from northeast Chinese sauerkraut (Suan Cai).

Methods

Lactobacillus coryniformis NA-3 was identified with 16S rDNA amplification and Neighbor Joining (NJ) phylogenetic analysis. EPS derived from Lactobacillus coryniformis NA-3 (EPS-NA3) was analyzed, including compositions by high-performance liquid chromatography (HPLC), functional groups by Fourier-transform infrared spectroscopy (FT-IR) and glycosidic bond configuration by Hydrogen-1 Nuclear Magnetic Resonance (¹H NMR). Antioxidant activity of EPS was evaluated with hydroxyl and superoxide radical-scavenging. Anti-biofilm activities of EPS-NA3 were checked through inhibition and dispersion.

Results

The monosaccharide composition of EPS included α-rhamnose, α-mannose, α-galactose, and α-glucose in a ratio of 2.6:1.0:5.0:3.3. The free radical-scavenging abilities of EPS-NA3 were 37.77% ± 1.56% and 78.87% ± 3.07% on hydroxyl and superoxide reactive oxygen species respectively. Moreover, EPS-NA3 attenuated the formation of Bacillus cereus and Salmonella typhimurium biofilms by inhibition ratios of approximately 80% and 40% respectively. Additionally, treatment with EPS-NA3 dispersed established biofilms of B. cereus and S. typhimurium by approximately 90% and 20% respectively.

Conclusion

These results suggest that EPS-NA3 may be developed as antioxidant and anti-biofilm agents for industrial and clinical applications due to its capacity of scavenging free radicals, inhibition of bacterial biofilm formation, and dispersion of established biofilms.

A new dendrimer series: synthesis, free radical scavenging and protein binding studies

Tri-o-tolyl benzene-1,3,5-tricarboxylate (TOBT (T0)), tri-4-hydroxyphenyl benzene-1,3,5-tricarboxylate (THBT (T1)), and tri-3,5-dihydroxyphenyl benzene-1,3,5-tricarboxylate (TDBT (T2)), a series of 1^st tier dendrimers with a common 1,3,5-benzenetricarbonyl trichloride/trimesoyl chloride (TMC) core, are reported. T0 does not have any replaceable H⁺ on its terminal phenyl group, acting as a branch. T1 has one phenolic –OH at the para position and T2 has two phenolic –OH groups at the 3 and 5 positions of each terminal phenyl group. During synthesis, these –OH groups at the terminal phenyl groups were protected through tert-butyldimethylsilyl chloride (TBDMSCl) assisted with t-BuOK in DCM, THF, indazole, 4-dimethylaminopyridine (DMAP), and tertiary-n-butyl ammonium fluoride (TBAF). MTBDMSP (mono-tertiary butyl dimethylsilane phloroglucinol), DTBDMSP (di-tertiary butyl dimethylsilane phloroglucinol), and TTBDMSP (tri-tertiary butyl dimethylsilane phloroglucinol) were obtained with >90% yield, and TTBDMSP phenolic derivatives (PDs) were developed to synthesize T0, T1, and T2 dendrimers by deprotecting with TBAF. T0 showed superhydrophobic properties as it did not dissolve in methanol, contrary to T1 and T2, but dissolved in acetone. Their structures were determined using ¹H and ¹³C NMR spectroscopies, and mass spectrometry. Their scavenging activities were studied using UV-Vis spectrophotometry compared with ascorbic acid and protein binding was studied with bovine serum albumin (BSA) and lysozyme (lyso). T0 exhibited exceptional optical activity contrary to T1 and T2, which acted as antioxidants to scavenge free radicals.

Superhydrophobic dendrimers with excellent antioxidant properties, and the ability to bind proteins and enzymes in their functional void spaces.

A neutral Cu-based MOF for effective quercetin extraction and conversion from natural onion juice

A new neutral metal–organic framework can efficiently extract natural product quercetin (QT) from fresh QT-rich onion juice and rapidly convert it into Cu–QT with a relatively high conversion rate.

Phytochemical Investigation and In Vitro Antioxidant Activities of Tetracarpidium conophorum (African Walnut) Seeds

Background: Tetracarpidium conophorum (African walnut) is an African plant with ethnobotanical uses. Objectives: The purpose of this study was to evaluate the phytochemical screening and in vitro antioxidant activities of methanol extract and fractions (F) [n-hexane (HEX-F), dichloromethane (DCM-F) and, ethyl acetate (EA-F)] of T. conophorum seeds. Methods: Phytochemical screening and in vitro antioxidant activity study were carried out using DPPH, ABTs radical scavenging assays, nitric oxide inhibitory and reducing potential assays. Results: Methanol extract and its fractions contain phenols, flavonoids, saponins, tannins, terpenoids, and alkaloids. The concentrations of total phenols and flavonoids content were significantly higher in EA-F and crude methanol extract compared to other fractions. Crude methanol and EA-F contain higher concentrations of tannin while hexane fraction had the lowest tannin content but relatively higher proanthocyanidin content compared to other fractions. The antioxidant activity study showed that both methanol crude extract and fractions of T. conophorum seeds have significant activities for DPPH radical scavenging, reducing power, ferric reducing antioxidant potential, nitric oxide inhibitory activities, ABTS and hydroxyl radical scavenging for. DPPH radical scavenging activities of EA-F showed the lowest IC50 of 33.11 µg/mL, followed by Hex-F, DCM-F and crude methanol extract with IC50 of 33.43, 42.09 and 45.44 µg/mL, respectively, when compared to ascorbic acid with IC50 of 17.08 µg/mL. Conclusion: The study showed that T. conophorum seed is a rich source of secondary metabolites, which may be responsible for its antioxidant activities.

Short-term exposure to titanium, aluminum and niobium (Ti-6Al-4Nb) alloy powder can disturb the serum low-density lipoprotein concentrations and antioxidant profile in vital organs but not the behavior of male albino mice

A group of seven-week-old albino mice of both genders were orally administered with a suspension of 25 mg Ti-6Al-4Nb/ml of saline/kg body weight and evaluated in comparison with a control group of animals treated with saline. Evaluation of both the groups was conducted through behavioral tests (Rota rod, open field, novel object and light dark box test), blood biochemical tests [complete blood count and selected serum parameters ([cholesterol, high-density lipoproteins, low-density lipoproteins, creatinine and triglycerides)] and on the basis of measured concentration of antioxidant metabolites (superoxide dismutase, catalase and lipid peroxidation) in vital organs (brain, heart, liver, kidney and lungs). Based upon the results of these tests, it has been found that the applied dose of Ti-6Al-4Nb alloy powder has not effect on physical and neurological outcome of these animals. However, it can increase low-density lipoprotein concentrations as well as disturb the H₂O₂ and lipid peroxidation associated metabolic pathways, especially in male albino mice. Whereas all other hematological indices and antioxidative stress parameters were unaffected.

ROS and NO Dynamics in Endothelial Cells Exposed to Exercise-Induced Wall Shear Stress

Introduction

Intracellular reactive oxygen species (ROS) and nitric oxide (NO) levels are associated with vascular homeostasis and diseases. Exercise can modulate ROS and NO production through increasing frequency and magnitude of wall shear stress (WSS). However, the details of ROS and NO production in endothelial cells and their interplay under WSS induced by exercise at different intensities remain unclear.

Methods

In this study, we developed an in vitro multicomponent nonrectangular flow chamber system to simulate pulsatile WSS waveforms induced by moderate and high intensity exercise. Furthermore, the dynamic responses of ROS and NO in endothelial cells and the relationship between ROS and NO were investigated under the WSS induced by different intensity exercise.

Results

After exposing to WSS induced by moderate intensity exercise, endothelial cells produced more NO than those under high intensity exercise-induced WSS. In this process, ROS was found to play a dual role in the generation of intracellular NO. Under WSS induced by moderate intensity exercise, modest elevated ROS promoted NO production, whereas excessive ROS in endothelial cells exposed to WSS induced by high intensity exercise attenuated NO bioavailability. Interestingly, antioxidant N-acetylcysteine (NAC) could increase NO production under WSS induced by high intensity exercise.

Conclusions

Our results provide some cues for selecting appropriate exercise intensities and elevating benefits of exercise on endothelial function. Additionally, owing to the consistency of our results and some in vivo phenomena, this flow chamber system may serve as an in vitro exercise model of arterial vessel for future studies.

Short term exposure to titanium, aluminum and vanadium (Ti 6Al 4V) alloy powder drastically affects behavior and antioxidant metabolites in vital organs of male albino mice

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Body weight, complete blood count and studied serum parameters remained unaffected upon Ti 6 A l 4 V alloy powder exposure.

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Short tern exposure to Ti 6Al 4V powder drastically affected neuromuscular coordination in male mice during rota rod test.

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Reduced novel object recognition ability in female mice exposed to Ti 6Al 4V alloy powder.

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Disturbed antioxidant metabolites in vital organs of mice treated with Ti 6Al 4V alloy powder.

Titanium, Aluminum and Vanadium (Ti 6Al 4V) alloy are frequently used as surgical implant but regarding their compatibility in living systems is limited. Ti 6Al 4V was prepared from high purity constituents and Ti 6Al 4V alloy powder (25 mg/ml solvent/Kg body weight) was gavaged to albino mice for 8 days. A saline treated control group was maintained in parallel. A series of behavioral (rota rod, light and dark box, open field and novel object) test performance, complete blood count, selected serum (HDL cholesterol, LDL cholesterol, creatinine, cholesterol and triglycerides) parameters, antioxidant metabolites from vital organs (superoxide dismutase, catalase and lipid peroxidation) from vital organs and body weight were determined in both treatments. It was observed that rota rod test performance in male (P = 0.05) and novel object recognition capability in female mice (P = 0.04) were significantly reduced as compared to their respective control groups. Body weight, complete blood count and studied serum parameters remained unaffected when compared between two treatments of both genders. Concentration of superoxide dismutase in liver (P = 0.008), heart (P = 0.01) and lungs (P = 0.05) was significantly elevated while catalase concentration in liver (P = 0.001) was significantly decreased in female albino mice that were exposed to 25 mg/ml solvent/kg body weight of Ti 6 A l 4 V alloy powder. In case of male albino mice, superoxide dismutase concentration in lungs was reduced (P = 0.05) in mice exposed to Ti 6 A l 4 V alloy powder.

In conclusion, our results indicated that short term exposure to 25 mg/ml solvent/Kg body weight of Ti-6Al-4V alloy powder supplementation had adversely affected selected aspects of behavior of albino mice in a gender specific manner. Analysis of antioxidant parameters in vital organs has demonstrated that the applied dose of Ti-6Al-4V alloy powder can disturb the H₂O₂ associated metabolic pathways in albino mice, especially in female mice. As this alloy is part of surgical implants, so we recommend that their effects in living systems must be extensively explored under variable dose and exposure time conditions to know more about their biocompatibility.

In vivo and In vitro Anti-Inflammatory Activity of Indazole and Its Derivatives

INTRODUCTION

The inflammatory response is closely intertwined with the process of repair. However in some diseases the inflammatory response may be exaggerated and sustained without apparent benefit and even with severe adverse complications. For decades, we have been primarily relying upon Nonsteroidal (NSAID) and Steroidal Anti-Inflammatory agents for management of various inflammatory conditions. However, adverse effects of these drugs are severe which often leads to patient's non-compliance with inadequate relief. Therefore, there has been a constant pursuit to develop newer anti - inflammatory treatment with fewer side effects.

AIM

The study was designed to investigate the possible anti- inflammatory activity of indazole, its derivatives and to further investigate the possible cellular mechanisms underlying the anti-inflammatory effect.

MATERIALS AND METHODS

Carrageenan induced hind paw oedema in rats was employed to study the acute anti-inflammatory activity of indazole and its derivatives. Further, the role of cyclooxygenase - 2, pro-inflammatory cytokines like Tumour Necrosis Factor - α, Interleukin - 1β and free radical scavenging activity (LPO, DPPH and NO) in the action of indazole and its derivatives was investigated using in vitro assays.

RESULTS

SPSS version 16.0 software was used for analyse the anti-inflamatory data. The IC50 values of indazole and its derivatives obtained in in vitro experiments were calculated by linear regression analysis. Indazole and its derivatives significantly, dose dependently and time dependently inhibited carrageenan induced hind paw oedema. In addition, the test compounds inhibited cyclooxygenase-2, pro-inflammatory cytokines and free radicals in a concentration dependent manner.

CONCLUSION

The results of the present study revealed the potential anti-inflammatory action of investigated indazoles. The inhibition of cyclooxygenase -2, cytokines and free radicals may contribute to the anti-inflammatory effect of the test compounds.

Investigation of biochemical and histopathological effects of Mentha piperitaLabiatae and Mentha spicata Labiatae on liver tissue in rats

The plant Mentha piperita, or peppermint, is commonly used in the treatment of loss of appetite, common cold, bronchitis, sinusitis, fever, nausea and vomiting, and indigestion as a herbal agent. In this study, we aimed to investigate biochemical and histological effects of M. piperita Labiatae, growing in the Yenisar Bademli town of Isparta city, and Mentha spicata Labiatae, growing in the Anamas high plateau of the Yenisar Bademli town, on the rat liver tissue. Forty-eight male Wistar albino rats weighing 200-250 g were used for this study. Rats were divided into four groups of 12 animals: Group I received no herbal tea (control group); Group II received 20 g/L M. piperita tea; Group III received 20 g/L M. spicata tea; and Group IV received 40 g/L M. spicata tea. Herbal teas were prepared daily and provided at all times to the rats during 30 days as drinking water. Liver function tests, including aspartate aminotransferase (AST/GOT) and alanine aminotransferase (ALT/GPT) activities were measured. To evaluate liver antioxidant defences, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), cata lase (CAT) and thiobarbituric acid reactive substance (TBARS) activities were determined in the homogenates of liver tissue. In addition, liver tissues were submitted for histopathologic examination. AST and ALT activities were increased in Group II, Group III and Group IV gradually when compared with the control group. The difference between Group II and the control group was not statistically significant (P > 0.016). Increases in AST and ALT activities of Group III and Group IV were statistically significant when compared with the control group. SOD, GSH-Px and CAT activities were increased in Group II when compared with the control group but the difference was not statistically significant (P > 0.016). However, SOD, GSH-Px activities and the TBARS level were significantly increased, and CAT activity was significantly decreased in Group III when compared with the control group. In Group IV, while SOD, GSH-Px and CAT activities were decreased, the TBARS level was increased as compared with the control group (P < 0.0016). Histopathological evaluation of experimental groups revealed a mild to severe degree of hepatic damage when compared to the control group. In Group II, there was only minimal hepatocytes degeneration. In Groups III and IV, there were granular or ballooning hepatocyte degeneration and necrosis, sinusoidal and central vein dilatation. It was concluded that lipid peroxidation and hepatic damage occurs after M. piperita and M. spicata administration in rat liver and the damage seems to be dose dependent.

Polymer complexes. LX. Supramolecular coordination and structures of N(4-(acrylamido)-2-hydroxybenzoic acid) polymer complexes

A number of novel polymer complexes of various anions of copper(II), cobalt(II), nickel(II) and uranyl(II) with N(4-(acrylamido)-2-hydroxy benzoic acid) (ABH) have been synthesized and characterized by elemental analysis, IR, 1H NMR, magnetic susceptibility measurements, electronic spin resonance, vibrational spectra and thermal analysis. The molecular structures of the ligand are optimized theoretically and the quantum chemical parameters are calculated. Tentative structures for the polymeric metal complexes due to their potential application are also suggested. The IR data exhibit the coordination of ONO2/OAc/SO4 with the metal ions in the polymeric metal complex. Vibrational spectra indicate coordination of carboxylate oxygen and phenolic OH of the ligand giving a MO4 square planar chromophore. Ligand field ESR spectra support square planar geometry around Cu(II). The thermal decomposition of the polymer complexes were discussed in relation to structure, and the thermodynamic parameters of the decomposition stages were evaluated applying Coast-Redfern and Horowitz-Metzger methods.

Oxidant/antioxidant status in lambs and sheep with liver and lung cystic echinococcosis diagnosed by ultrasonography and necropsy

The aim of this study was to evaluate total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) in sheep and lambs with cyctic eccinocoocosis (CE) diagnosed by ultrasonography and necropsy findings. A total of 9 sheep and 17 lambs with CE were used in this study and the findings were compared to those of 6 healthy control sheep. Ultrasonography were used for the diagnosis of CE in sheep and lambs, and necropsy was performed to check the presence of cysts in liver and lungs. Serum TOS and TAC were measured by a novel colorimetric method. The TOS-to-TAC ratios were also calculated as OSI values. Serum biochemical profiles were determined by conventional measurement methods as well. The mean values for TOS, TAC and OSI were significantly (p<0.001) lower in sheep and lambs with CE when compared with those of the control sheep, and they were also significantly lower in lambs with CE in comparison to the mean values obtained in sheep with CE. The levels of serum albumin, total cholesterol, creatinine, and triglycerides in lambs with CE were found out to decrease significantly (p<0.001) when compared with those of both sheep with EC and the control group. There were no significant differences between the groups in terms of other serum parameters. In addition, when clinically and some biochemical values were evaluated, CE was found to be more severe in lambs than in sheep. It was concluded that although common diagnostic cyst detection is performed by postmortem examination, ultrasonography could successfully be used in conjunction with serum biochemical profile detection and serum TOS, TAC and OSI measurements for diagnosis of cysts in liver and lungs of severely infected living sheep and lambs. Serum albumin, total cholesterol, creatinine, total protein and triglycerides might be used as indicators in sheep and particularly in lambs for the diagnosis of CE.

New antioxidant drugs for neonatal brain injury

The brain injury concept covers a lot of heterogeneity in terms of aetiology involving multiple factors, genetic, hemodynamic, metabolic, nutritional, endocrinological, toxic, and infectious mechanisms, acting in antenatal or postnatal period. Increased vulnerability of the immature brain to oxidative stress is documented because of the limited capacity of antioxidant enzymes and the high free radicals (FRs) generation in rapidly growing tissue. FRs impair transmembrane enzyme Na⁺/K⁺-ATPase activity resulting in persistent membrane depolarization and excessive release of FR and excitatory aminoacid glutamate. Besides being neurotoxic, glutamate is also toxic to oligodendroglia, via FR effects. Neuronal cells die of oxidative stress. Excess of free iron and deficient iron/binding metabolising capacity are additional features favouring oxidative stress in newborn. Each step in the oxidative injury cascade has become a potential target for neuroprotective intervention. The administration of antioxidants for suspected or proven brain injury is still not accepted for clinical use due to uncertain beneficial effects when treatments are started after resuscitation of an asphyxiated newborn. The challenge for the future is the early identification of high-risk babies to target a safe and not toxic antioxidant therapy in combination with standard therapies to prevent brain injury and long-term neurodevelopmental impairment.

Free radicals, natural antioxidants, and their reaction mechanisms

The normal biochemical reactions in our body, increased exposure to the environment, and higher levels of dietary xenobiotic's result in the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS).

Polarity of extracts and fractions of four Combretum (Combretaceae) species used to treat infections and gastrointestinal disorders in southern African traditional medicine has a major effect on different relevant in vitro activities

ETHNOPHARMACOLOGICAL IMPORTANCE

Gastrointestinal disorders and infections are the major pathoaetiologies of diarrhoea causing many problems in human health and animal production. Many Combretum species are used in traditional medicine to treat infectious diseases including diarrhoea and many other ailments by rural people in Africa and Asia. Much of the work done to date on this genus was on the non-polar or intermediate polarity components. Some parameters that may cause diarrhoea and the evaluation of more polar extracts have apparently not been investigated.

AIMS

The polar components were extracted and fractionated by solvent-solvent fractionation to yield fractions with different polarities. The activity of these fractions on different parameters that could be involved in factors associated with diarrhoea was investigated. The cytotoxic activities of the extracts were also determined to evaluate the potential of these extracts to combat diarrhoea in production animals.

MATERIALS AND METHODS

Phenolic-enriched leaf extracts of Combretum bracteosum (COB), Combretum padoides (COP), Combretum vendae (COV) and Combretum woodii (COW) were obtained by extracting with a mixture of 70% acetone acidified with 1% HCl and n-hexane. Acetone was removed from a portion of the 70% acetone extract and it was sequentially treated by solvent-solvent fractionation with dichloromethane, ethyl acetate, and butanol to yield fractions with a large variation in polarity. The phenolic constituents of the extracts and fractions were determined using standard procedures The antioxidant activities were determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH); 2,2'-azino-bis (3-ethylbenzothiazoline)-6-sulphonic acid (ABTS(+)) radical scavenging, ferric reducing antioxidant power (FRAP) methods and lipid peroxidation inhibitory capacity standard methods. The ferric reducing antioxidant activities of the fractions were also determined. The minimum inhibitory concentrations (MICs) of the crude extracts and fractions against four bacterial and three fungal strains were assessed with a microplate serial dilution method. Cyclooxygenase (COX) and lipoxygenase (LOX) enzyme inhibitory assays and cytotoxicity studies against Vero cells were also carried out.

RESULT

Some of the fractions had much higher antioxidant activity than the positive controls. The average EC50 values of the extracts for the DPPH and ABTS antioxidant assays were 0.21-12µg/ml (COP), 0.25-16µg/ml (COV), 0.33-9.41µg/ml (COW) and 4.97-85µg/ml (COB) respectively while the mean EC50 values for the positive controls ascorbic acid and trolox were 1.28-1.51 and 1.02-1.19µg/ml respectively. All the crude extracts inhibited lipid peroxidation of linoleic acid by more than 80% at a concentration of 64 µg/ml. COP had the highest antibacterial activity with MICs ranging between 19-2500µg/ml, followed by COV with MICs ranging between 39-625µg/ml; COW and COB had similar MICs ranging between 39-2500µg/ml. COP also had the highest antifungal activity with MICs between 19-625µg/ml. The MIC for COW and COV ranged from 19 to 1250 µg/ml. COB had the lowest antifungal activity (MIC values were between 39 and 625 µg/ml). In general non-polar fractions had a high antimicrobial activity and polar fractions had a high antioxidant activity. The extracts had no activity against COX 1 and 2 enzymes in the anti-inflammatory assay but had good lipoxygenase inhibition. The crude extracts had high concentration of hydrolysable tannin (gallotannin). A good correlation (R(2)= 0.99) was found between the antioxidant activity and total tannin content indicating that, gallotannins may be responsible for the antioxidant activity.

CONCLUSION

The results obtained in this study with more polar extracts indicate that the use of extracts of these plant species as antidiarrhoeal agents may have a scientific basis. The extractant used here extracted a much higher percentage of the phytochemicals than acetone. It was better for isolating antioxidant compounds (polar) but not good for isolating antimicrobial compounds (non-polar) from the same species compared to acetone, ethyl acetate, dichloromethane, and hexane.

Multifunctional properties of polysaccharides from Dalbergia sissoo, Tectona grandis and Mimosa diplotricha

Three water-soluble polysaccharides were isolated and purified from the leaves of Dalbergia sissoo Roxb. (DSLP), bark of Tectona grandis L. f (TGBP) and seeds of Mimosa diplotricha var. diplotricha Sauvalle (MDSP). Antioxidant and moisture preserving activities of these three polysaccharides were investigated using in vitro methods. The antioxidant activities studied include superoxide (O2(*-)), 1,1-diphenyl-2-picrylhydrazyl (DPPH*), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS(*+)), hydroxyl (OH(-)), nitric oxide (NO*), N,N-dimethyl-p-phenylenediamine (DMPD(+)) radical scavenging activities, ferric ion (Fe(3+)) reducing ability, ferrous ion (Fe(2+)) chelating and lipid peroxidation activities. The study revealed higher activity of TGBP in all antioxidant assays than DSLP and MDSP. Further, the three polysaccharides showed effective moisture retention properties in comparison with hyaluronic acid and glycerol.

The impact of cold acclimation and hibernation on antioxidant defenses in the ground squirrel (Spermophilus citellus): an update

Any alteration in oxidative metabolism is coupled with a corresponding response by an antioxidant defense (AD) in appropriate subcellular compartments. Seasonal hibernators pass through circannual metabolic adaptations that allow them to either maintain euthermy (cold acclimation) or enter winter torpor with body temperature falling to low values. The present study aimed to investigate the corresponding pattern of AD enzyme protein expressions associated with these strategies in the main tissues involved in whole animal energy homeostasis: brown and white adipose tissues (BAT and WAT, respectively), liver, and skeletal muscle. European ground squirrels (Spermophilus citellus) were exposed to low temperature (4 ± 1 °C) and then divided into two groups: (1) animals fell into torpor (hibernating group) and (2) animals stayed active and euthermic for 1, 3, 7, 12, or 21 days (cold-exposed group). We examined the effects of cold acclimation and hibernation on the tissue-dependent protein expression of four enzymes which catalyze the two-step detoxification of superoxide to water: superoxide dismutase 1 and 2 (SOD 1 and 2), catalase (CAT), and glutathione peroxidase (GSH-Px). The results showed that hibernation induced an increase of AD enzyme protein expressions in BAT and skeletal muscle. However, AD enzyme contents in liver were largely unaffected during torpor. Under these conditions, different WAT depots responded by elevating the amounts of specific enzymes, as follows: SOD 1 in retroperitoneal WAT, GSH-Px in gonadal WAT, and CAT in subcutaneous WAT. Similar perturbations of AD enzymes contents were seen in all tissues during cold acclimation, often in a time-dependent manner. It can be concluded that BAT and muscle AD capacity undergo the most dramatic changes during both cold acclimation and hibernation, while liver is relatively unaffected by either condition. Additionally, this study provides a basis for further metabolic study that will illuminate the causes of these tissue-specific AD responses, particularly the novel finding of distinct responses by different WAT depots in hibernators.

Extraction and quantitation of coumarin from cinnamon and its effect on enzymatic browning in fresh apple juice: a bioinformatics approach to illuminate its antibrowning activity

Enzymatic browning by polyphenoloxidase (PPO) affects food quality and taste in fruits and vegetables. Thus, the study was designed to reduce browning in apple juice by coumarin. The ethanolic extract of cinnamon was prepared and its coumarin content was quantitated by HPLC, using authentic coumarin (AC) as standard. The effect of cinnamon extract (CE) and AC on enzymatic browning, its time dependent effects, and the specific activity of PPO and peroxidase (POD) were studied in apple juice. The docking of coumarin with PPO and POD was also performed to elucidate its antibrowning mechanism. The CE (73%) and AC (82%) showed better reduction in browning, maintained its antibrowning effect at all time points, and significantly (p < 0.05) reduced the specific activity of PPO and POD when compared with controls. Coumarin showed strong interaction with binding pockets of PPO and POD, suggesting its potential use as inhibitor to enzyme mediated browning in apple juice.

Effects of shear stresses and antioxidant concentrations on the production of reactive oxygen species in lung cancer cells

Reactive oxygen species (ROS) are known to be a key factor in the development of cancer, and many exogenous sources are supposed to be related to the formation of ROS. In this paper, a microfluidic chip was developed for studying the production of ROS in lung cancer cells under different chemical and physical stimuli. This chip has two unique features: (1) five relative concentrations of 0, 1/8, 1/2, 7/8, and 1 are achieved in the culture regions; (2) a shear stress gradient is produced inside each of the five culture areas. Lung cancer cells were seeded inside this biocompatible chip for investigating their response to different concentrations of H2O2, a chemical stimulus known to increase the production of ROS. Then the effect of shear stress, a physical stimulus, on lung cancer cells was examined, showing that the production of ROS was increased in response to a larger shear stress. Finally, two antioxidants, α-tocopherol and ferulic acid, were used to study their effects on reducing ROS. It was found that high-dose α-tocopherol was not able to effectively eliminate the ROS produced inside cells. This counter effect was not observed in cells cultured in a traditional chamber slide, where no shear stress was present. This result suggests that the current microfluidic chip provides an in vitro platform best mimicking the physiological condition where cells are under circulating conditions.

Intra- and inter-molecular interactions in salicylic acid — Theoretical calculations of 17O and 1H chemical shielding tensors and QTAIM analysis

A density functional theory (DFT) study was performed to examine intra- and inter-molecular hydrogen bond (HB) properties in crystalline salicylic acid (SA). BLYP, B3LYP, and M06 functionals with 6–311++G** basis set were employed to calculate NMR chemical shielding isotropy (σiso) and anisotropy (Δσ) at the sites of the 17O and 1H nuclei of SA. From this study, it appears that the intra- and inter-molecular O–H···O as well as C–H···O HBs around the SA molecule in the crystal lattice have a major influence on the chemical shielding tensors and more specifically on the carbonyl 17O isotropy value. The quantum theory of atoms in molecules (QTAIM) analysis was also employed to elucidate the interaction characteristics in SA H-bonded network. Based on QTAIM results, a partial covalent character is attributed to the intra- and inter-molecular O–H···O HBs in SA.

Evaluation of oxidative status in patients with Fasciola hepatica infection

BACKGROUND

F. hepatica infection is rare and mostly subclinical. Migration of juvenile forms of F. hepatica into the host's liver is accompanied by an inflammatory reaction followed by fibrosis and cirrhosis.

OBJECTIVE

The aim of this study was to evaluate oxidative status by using a novel automated method in patients with Fasciola hepatica.

METHODS

Twenty two patients with a diagnosis of F. hepatica and 26 healthy volunteers were enrolled in the study. Their Total antioxidant capacity status (TAC), total oxidant status (TOS) and catalase were measured in them and oxidative stress index (OSI) was calculated. These measurements were also taken for the control group and the values were compared.

RESULTS

Plasma levels of total TOS and OSI were significantly increased in patients as compared with healthy controls (P<0.001, P<0.001, P=0.001, P=0.008) respectively. In contrast, TAC level was significantly lower in patients as compared with controls (p<0.05). There was no significant difference between the catalase results of the two groups (p>0.05).

CONCLUSION

Total oxidative status and OSI were increased and total antioxidative status capacity was decreased in patients with F. hepatica infection. A high oxidative stress occurs during F. hepatica infection, which may cause severe damage in both the liver.

Production of reactive oxygen species in endothelial cells under different pulsatile shear stresses and glucose concentrations

A hemodynamic Lab-on-a-chip system was developed in this study. This system has two unique features: (1) it consists of a microfluidic network with an array of endothelial cell seeding sites for testing them under multiple conditions, and (2) the flow rate and the frequency of the culture medium in the microchannel are controlled by a pulsation free pump to mimic the flow profile of the blood in the blood vessel under different physiological conditions. The investigated physiological conditions were: (1) the resting condition in a normal shear stress of 15 dyne cm(-2) with a normal heart rate of 70 bpm, (2) an exhaustive exercise condition with a high shear stress of 30 dyne cm(-2) and a fast heart rate of 140 bpm, and (3) a constant high shear stress of 30 dyne cm(-2). Two chemical conditions were investigated (10 mM and 20 mM glucose) to mimic hyperglycemic conditions in diabetes patients. The effects of various shear stresses either alone or in combination with different glucose concentrations on endothelial cells were examined using the developed hemodynamic Lab-on-a-chip system by assessing two parameters. One is the intracellular level of reactive oxygen species (ROS) determined by a fluorescent probe, H(2)DCFDA. Another is the mitochondrial morphology revealed with a fluorescent dye, MitoTracker Green FM. The results showed that ROS level was elevated nearly 4-fold after 60 min of exhaustive exercise. We found that the pulsatile nature of the fluid was the determination factor for causing ROS generation in the cells as almost no increase of ROS was detected in the constant shear stress condition. Similarly, much higher level of ROS was detected when 10 mM glucose was applied to the cells under normal or high pulsatile shear stresses compared with under a static condition. These results suggest that it is necessary to use pulsatile shear stress to represent the physiological conditions of the blood flow, and demonstrate the advantage of utilizing this newly developed hemodynamic Lab-on-a-chip system over the conventional non-pulsatile system in the future shear stress related studies.

Protective effect of a polysaccharide isolated from a cultivated Cordyceps mycelia on hydrogen peroxide-induced oxidative damage in PC12 cells

Cordyceps sinensis as a well-known traditional Chinese tonic has many therapeutic functions. In the present study, an acid polysaccharide (APS) was isolated from cultivated Cordyceps mycelia by ion-exchange and sizing chromatography. The protective capacity of APS against H(2)O(2)-induced oxidative damage in rat pheochromocytoma PC12 cells was investigated by measuring cell viability, lactate dehydrogenase (LDH) release, antioxidant enzyme activity, malondialdehyde (MDA) levels and intracellular accumulation of reactive oxygen species (ROS) and Ca(2+). The results demonstrated that pretreatment of PC12 cells with APS, prior to H(2)O(2) exposure, significantly increased the survival of cells and the activities of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD), and reduced the levels of LDH and MDA. Intracellular accumulation of reactive oxygen species (ROS) and Ca(2+) were also inhibited by APS treatment. In conclusion, APS was found to increase the cellular antioxidant defence capacity, thereby protecting PC12 cells against oxidative stress.

Effects of aspirin and nimesulide on tissue damage in diabetic rats

This study was designed to compare the effect of Aspirin (AS) and Nimesulide (NM) on renal failure and vascular disorder in streptozotocin (STZ)-induced diabetic rats. Rats were divided into four groups; control, diabetic rats, diabetic rats plus AS and diabetic rats plus NM, which are COX inhibitors. The renal and aorta tissues morphology were investigated by light microscopy. Trunk blood was also obtained to determine plasma lipid peroxidation product malondialdehyde (MDA) and plasma activity of antioxidant enzymes. MDA levels were increased in the diabetic rats when compared to the control group. AS and NM administration caused a significant decrease in MDA production. Morphological damage in diabetic rats was severe in the kidney and in the aorta tissue. Treatment of AS reduced these damages, but NM did not exert positive effect on these damages in diabetic rats. As a result, although both AS and NM corrected lipid peroxidation parameters such as MDA via their antioxidant properties, only AS ameliorated pathological alteration in tissues. These findings indicate that there may be another mechanism in beneficial effect of AS in diabetic rats.

The antioxidant drink “effective microorganism-X (EM-X)” pre-treatment attenuates the loss of nigrostriatal dopaminergic neurons in 6-hydroxydopamine-lesion rat model of Parkinson’s disease

There is continued interest in the assessment and potential use of antioxidants as neuroprotective agents in diseases associated with increased oxidative stress, such as Parkinson's disease. The neuroprotective effect of a natural antioxidant drink, EM-X (a ferment derivative of unpolished rice, papaya and seaweeds with effective microorganisms), was investigated using the 6-hydroxydopamine (6-OHDA)-lesion rat model of Parkinson's disease. The nigrostriatal dopaminergic neurons were unilaterally lesioned with 6-OHDA (8 μg) in rats that were treated with a 10-times diluted EM-X drink (dilEM-X), standard EM-X drink (stdEM-X) or tap water for 4 days. Seven days post lesion, the integrity (no. of tyrosine hydroxylase positive cells (TH+ cells) in the substantia nigra pars compacta (SNpc)) and functionality (dopamine and its metabolites DOPAC and HVA content in the striata) of nigrostriatal dopaminergic neurons were assessed. In the vehicle-treated rats, infusion of 8 μg of 6-OHDA significantly reduced the number of TH+ cells in the SNpc as well as the levels of dopamine, DOPAC and HVA in the striata on the lesion side. The loss of TH+ cells, dopamine and HVA, but not the DOPAC levels, was significantly attenuated by stdEM-X pretreatment, but not by the dilEM-X pretreatment. There were no significant changes in the TH+ cells, or in the monoamine levels with the EM-X pretreatment per se, except for a small but significant fall in the levels of dopamine with the stdEM-X. The evidence presented supports the potential neuroprotective effects of stdEM-X drink, although its effect on dopamine levels needs further investigation.

Ultrastructural evaluation of the radioprotective effect of sodium selenite on submandibular glands in rats

The aim of this study was to evaluate the radioprotector effect of sodium selenite on the ultrastructure of submandibular glands in rats. Fifty-seven male albino Wistar rats were randomized to 4 groups: control, irradiated, sodium selenite and irradiated/sodium selenite. The animals in the sodium selenite and irradiated/sodium selenite groups received intraperitoneal injections of sodium selenite (0.5 mg/kg body weight) 24 h before irradiation. The animals belonging to the irradiated and irradiated/sodium selenite groups were submitted to 15 Gy of gamma radiation in the head and neck region. The submandibular glands were removed at 4, 8, 12, 24, 48 and 72 h after irradiation. The ionizing radiation induced damage to the secretory cells, especially the serous cells, right from the first period. Vacuolization, lysis of cytoplasmic inclusions and nuclear alterations occurred. The sodium selenite group also presented cellular alterations in the study periods, but with less damage compared to that caused by radiation. There was greater similarity between the irradiated/sodium selenite group and the control group than with the other groups treated in all study periods. Despite the alterations observed in the sodium selenite group, sodium selenite presented a radioprotective action on the secretory cells of submandibular glands.

Scavenging of superoxide anion radical and hydroxyl radical by novel thiazolyl-thiazolidine-2,4-dione compounds

The antioxidant behavior of a series of new synthesized substituted thiazolyl-thiazolidine-2,4-dione compounds (TZDs) was examined using chemiluminescence and electron paramagnetic resonance spin trapping techniques. 5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) was used as the spin trap. The reactivity of TZDs with superoxide anion radical (O2(*-)) and hydroxyl radical (HO(*)) was evaluated using potassium superoxide/18-crown-6 ether dissolved in dimethylsulfoxide, and the Fenton-like reaction (Fe(2+) + H2O2), respectively. The results showed that TZDs efficiently inhibited light emission from the O2(*-) generating system at a concentration of 0.05-1 mmol L(-1) (5-94% reductions were found at 1 mmol L(-1) concentration). The TZD compounds showed inhibition of HO(*)-dependent DMPO-OH spin adduct formation from DMPO (the amplitude decrease ranged from 8 to 82% at 1 mmol L(-1) concentration). The findings showed that examined TZDs had effective activities as radical scavengers.

Hydroxyl and superoxide radical scavenging abilities of chromonyl-thiazolidine-2,4-dione compounds

The oxygen free radical scavenging activities of 15 chromonyl-thiazolidine-2,4-dione compounds (CTDs) were examined in chemical systems producing superoxide anion radicals, O2(-*) (potassium superoxide-18-crown-6 ether-DMSO), and hydroxyl radicals, HO(*) (a Fenton reaction: Fe(II)-H2O2-sodium trifluoroacetate, pH 6.15). Chemiluminescence and electron spin resonance (ESR) spectroscopy using 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) as spin trap were applied to evaluate antioxidant behaviour of CTDs towards the oxygen radicals. The results indicated that 11 of the 15 tested compounds showed a significant inhibitory effect on the chemiluminescence generated from the O2(-*)-generating system, ranging from 41 to 86%, and 13 CTDs quenched the ESR signal of the DMPO-OH spin adduct by 33-86%, at a concentration of 1 mmol L(-1). Our findings demonstrate that CTDs could be good free radical scavengers.

Hydroxyl radical scavenging activities of isoquinoline alkaloids isolated from Coptis chinensis

The hydroxyl radical (*OH) scavenging and ferrous ion chelating activities of four isoquinoline alkaloids isolated from Coptis chinensis Franch were studied for the identification of their structural characteristics to scavenge *OH. The *OH was generated via Fe(II)-catalazed Fenton reaction in this study and the reliable measurement of *OH scavenging activities of isoquinoline alkaloids were achieved using electron spin resonance (ESR) spectrometry method. At the 1 mM concentration, berberrubine (85%) showed the strongest *OH scavenging activity and the next were in the decreasing order of coptisine (79%), berberine (23%), and palmatine (22%). The ferrous ion chelating effects of the alkaloids showed similar pattern with their *OH scavenging effects. These results suggest that *OH scavenging effects of the alkaloids were closely related to their ferrous ion chelating activities. In addition, metal chelating functional groups such as hydroxy group at C-9 and methylenedioxy group at C-9 and C-10 were thought to contribute to the *OH scavenging activities of the isoquinoline alkaloids.

Antioxidative defence alterations in skeletal muscle during prolonged acclimation to cold: role of L-arginine/NO-producing pathway

Early in cold acclimation (1-7 days), heat is produced by shivering, while late in cold acclimation (12-45 days), skeletal muscle contributes to thermogenesis by tissue metabolism other than contractions. Given that both thermogenic phases augment skeletal muscle aerobic power and reactive species production, we aimed in this study to examine possible changes in skeletal muscle antioxidative defence (AD) during early and late cold acclimation with special emphasis on the influence of the L-arginine/nitric oxide (NO)-producing pathway on the modulation of AD in this tissue. Adult Mill Hill hybrid hooded rat males were divided into two main groups: a control group, which was kept at room temperature (22+/-1 degrees C), and a group maintained at 4+/-1 degrees C for 45 days. The cold-acclimated group was divided into three subgroups: untreated, L-arginine treated and N(omega)-nitro-L-arginine methyl ester (L-NAME) treated. The AD parameters were determined in the gastrocnemius muscle on day 1, 3, 7, 12, 21 and 45 of cold acclimation. The results showed an improvement of skeletal muscle AD in both early and late cold acclimation. Clear phase-dependent changes were seen only in copper, zinc superoxide dismutase activity, which was increased in early cold acclimation but returned to the control level in late acclimation. In contrast, there were no phase-dependent changes in manganese superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase, the activities of which were increased during the whole cold exposure, indicating their engagement in both thermogenic phases. L-Arginine in early cold acclimation accelerated the cold-induced AD response, while in the late phase it sustained increases achieved in the early period. L-NAME affected both early and late acclimation through attenuation and a decrease in the AD response. These data strongly suggest the involvement of the L-arginine/NO pathway in the modulation of skeletal muscle AD.