Significant Antagonistic Effect Research Articles

Pharmacological characterization of a β-adrenergic-like octopamine receptor in Plutella xylostella.

The β-adrenergic-like octopamine receptor (OA2B2) belongs to the class of G-protein coupled receptors. It regulates important physiological functions in insects, thus is potentially a good target for insecticides. In this study, the putative open reading frame sequence of the Pxoa2b2 gene in Plutella xylostella was cloned. Orthologous sequence alignment, phylogenetic tree analysis, and protein sequence analysis all showed that the cloned receptor belongs to the OA2B2 protein family. PxOA2B2 was transiently expressed in HEK-293 cells. It was found that PxOA2B2 could be activated by both octopamine and tyramine, resulting in increased intracellular cyclic AMP (cAMP) levels, whereas dopamine and serotonin were not effective in eliciting cAMP production. Further studies with series of PxOA2B2 agonists and antagonists showed that all four tested agonists (e.g., naphazoline, clonidine, 2-phenylethylamine, and amitraz) could activate the PxOA2B2 receptor, and two of tested antagonists (e.g., phentolamine and mianserin) had significant antagonistic effects. However, antagonist of yohimbine had no effects. Quantitative real-time polymerase chain reaction analysis showed that Pxoa2b2 gene was expressed in all developmental stages of P. xylostella and that the highest expression occurred in male adults. Further analysis with fourth-instar P. xylostella larvae showed that the Pxoa2b2 gene was mainly expressed in Malpighian tubule, epidermal, and head tissues. This study provides both a pharmacological characterization and the gene expression patterns of the OA2B2 in P. xylostella, facilitating further research for insecticides using PxOA2B2 as a target.

Combined acute ecotoxicity of malathion and deltamethrin to Daphnia magna (Crustacea, Cladocera): comparison of different data analysis approaches.

We studied the combined acute effect (i.e., after 48h) of deltamethrin (a pyrethroid insecticide) and malathion (an organophosphate insecticide) on Daphnia magna. Two approaches were used to examine the potential interaction effects of eight mixtures of deltamethrin and malathion: (i) calculation of mixture toxicity index (MTI) and safety factor index (SFI) and (ii) response surface methodology coupled with isobole-based statistical model (using generalized linear model). According to the calculation of MTI and SFI, one tested mixture was found additive while the two other tested mixtures were found no additive (MTI) or antagonistic (SFI), but these differences between index responses are only due to differences in terminology related to these two indexes. Through the surface response approach and isobologram analysis, we concluded that there was a significant antagonistic effect of the binary mixtures of deltamethrin and malathion that occurs on D. magna immobilization, after 48h of exposure. Index approaches and surface response approach with isobologram analysis are complementary. Calculation of mixture toxicity index and safety factor index allows identifying punctually the type of interaction for several tested mixtures, while the surface response approach with isobologram analysis integrates all the data providing a global outcome about the type of interactive effect. Only the surface response approach and isobologram analysis allowed the statistical assessment of the ecotoxicological interaction. Nevertheless, we recommend the use of both approaches (i) to identify the combined effects of contaminants and (ii) to improve risk assessment and environmental management.

Structural characterization of polysaccharides from Saposhnikovia divaricata and their antagonistic effects against the immunosuppression by the culture supernatants of melanoma cells on RAW264.7 macrophages

Two purified native polysaccharides, namely, SDNP-1 and SDNP-2 with apparent molecular weight of 67.9×103 and 5.2×103, separately, were isolated from the water extract of Saposhnikovia divaricata by combined ion-exchange and gel permeation chromatography. The structures of these polysaccharides were characterized by high-performance gel permeation chromatography, chemical derivative analysis, GC–MS, FT-IR spectroscopy, and NMR spectroscopy. Results showed that SDNP-1 and SDNP-2 were composed of arabinose and galactose with molar ratio of approximately 1:1. The polysaccharides were deduced to be AGII-type arabinogalactans with distinct molecular weights and backbone chains. The backbone chain of SDNP-2 mainly consisted of (1→3)-linked and (1→6)-linked Galp residues with an approximate molar ratio of 1:3. Approximately half of the (1→6)-linked Galp residues were substituted at O-3, and small amounts of (1→6)-linked Galp were substituted at O-3 and O-4 by branches that mainly consisted of terminal and (1→5)-linked Araf residues. Bioactivity tests showed that SDNP-2 exhibited significant antagonistic effect against immunosuppression as shown by the cell viability of the culture supernatants of melanoma cells on RAW264.7 macrophages. However, SDNP-1 showed no effect. Thus, molecular weight and backbone chain may be the key factors for the antagonistic effects against immunosuppression.

Sliding Wear Characteristics of Friction Stir Processed CAST ZK60 Magnesium Alloy Under Different Applied Loads

Wear resistance and poor friction are the two main draw backs of magnesium alloys that restricts structural applications. Therefore it is essential to enhance the tribological properties of magnesium alloys with the help of surface engineering without causing significant antagonistic effects on the properties of the base metal. Friction stir processing (FSP) is one of the promising thermo-mechanical processing techniques that alters the micro-structural and tribological properties of the material with low production at less period of time. Hence, this investigation enable us to study an effect of friction stir processing on wear characteristics of cast ZK60 magnesium alloy. A pin-on-disc wear testing machine was used to evaluate the wear resistance of surface modified ZK60 magnesium alloy. The result shows that the surface modification by FSP resulted in 26% increase in hardness compared to parent metal. The formation of finer grains and subsequent increase in hardness are the main reasons to improve wear resistance of FSPed ZK60 magnesium alloy.

Inactivation kinetics, structural, and morphological modification of mango soluble acid invertase by high pressure processing combined with mild temperatures

The activity, structure and morphology of mango soluble acid invertase (SAI) were investigated after high pressure processing (HPP) combined with mild temperature at 50–600MPa and 40–50°C. The activity of mango SAI was efficiently reduced by HPP at 50MPa/45 and 50°C, or 600MPa/40, 45 and 50°C, while it was increased by 10–30% after HPP at 50–200MPa/40°C. Significant antagonistic effect of pressure and temperature on the activity of SAI was observed at 50–400MPa/50°C. The secondary structure of SAI was not influenced by HPP. However, its tertiary structure was modified by HPP, and severer modification occurred with higher pressure, higher temperature, and longer treatment time. Results of atomic force microscope suggested that HPP at 400MPa/50°C for 2.5min induced dissociation of SAI, and HPP at 600MPa/50°C for 30min resulted aggregation of SAI.

Ameliorative Effects of Selenium on Cadmium-Induced Injury in the Chicken Ovary: Mechanisms of Oxidative Stress and Endoplasmic Reticulum Stress in Cadmium-Induced Apoptosis.

Despite the well-established toxicity of cadmium (Cd) to animals and the ameliorative effects of selenium (Se), some specific mechanisms in the chicken ovary are not yet clarified. To explore the mechanism by which the toxicity effect of Cd is induced and explore the effect of supranutritional Se on Cd toxicity in female bird reproduction, forty-eight 50-day-old Isa Brown female chickens were divided randomly into four groups. Group I (control group) was fed the basic diet containing 0.2mg/kg Se. Group II (Se-treated group) was fed the basic diet supplemented with sodium selenite (Na2SeO3), and the total Se content was 2mg/kg. Group III (Se + Cd-treated group) was fed the basic diet supplemented with Na2SeO3; the total Se content was 2mg/kg, and it was supplemented with 150mg/kg cadmium chloride (CdCl2). Group IV (Cd-treated group) was with the basic diet supplemented with 150mg/kg CdCl2. The Cd, estradiol (E2), and progestogen (P4) contents changed after subchronic Cd exposure in chicken ovarian tissue; subsequently, oxidative stress occurred and activated the endoplasmic reticulum (ER) pathway to induce apoptosis. Further, Se decreased the accumulation of Cd in ovarian tissue, increased the E2 and P4 contents, alleviated oxidative stress, and reduced apoptosis via the ER stress pathway. The present results demonstrated that Cd could induce apoptosis via the ER stress pathway in chicken ovarian tissue and that Se had a significant antagonistic effect. These results are potentially valuable for finding a strategy to prevent Cd poisoning.

TOXICITY OF THE PHOTOACTIVE COMPOUNDS PHLOXINE B AND MENADIONE ON BACTROCERA ZONATA (DIPTERA: TEPHRITIDAE)

the photoactive compounds phloxine B and menadione are relatively safe food additives and possess efficient insecticidal properties against certain insect species. The two compounds were tested for toxicity to the peach fruit fly, Bactrocera Zonata (Saunders) under both dark and sunlight conditions. Both compounds had no significant toxic effect in dark and concentration-dependent toxicity when insect exposed to sunlight for 2 hrs. Phloxine B was approximately 1000 time more toxic to B. zonata than menadione with LC25 in the water of 0.0007 g% and 0.854 g% (w/v), respectively. Adding menadione to phloxine resulted in significant antagonistic effects on insect mortality, which could be due to menadione alteration of the pH of the feeding media and/or menadione induction of the ROS-detoxifying enzymes, particularly peroxidase. It is concluded that phloxine B and menadione are incompatible and their mixture is not likely to pose any significant addition to their control potential against B. zonata.

Walleye Autochthonous Bacteria as Promising Probiotic Candidates against Flavobacterium columnare.

Walleye (Sander vitreus) is the second most fished freshwater species in Canada. While much sought by anglers, walleye also supports substantial commercial fisheries. To cope with the recent decline of wild walleye populations, fish farmers produce juveniles for lake stocking. However, walleye breeding is particularly tedious, mostly due to high disease susceptibility at larval and juvenile developmental stages. The main threat is the columnaris disease, which is caused by Flavobacterium columnare, an opportunistic bacteria. As F. columnare strains exhibit increasing antibiotic resistance, there is a strong need to develop efficient and sustainable alternative strategies to control columnaris disease. Bacterial probiotics have been shown to mitigate infections either by enhancing host immune response or by inhibiting pathogen growth. Being successfully assessed in many fish/pathogen combinations, we developed a tailored probiotic strategy for walleye to prevent and treat columnaris disease. Thirty-seven endogenous bacterial strains were isolated from healthy walleye’s skin and gut, were tested in vitro against F. columnare. Significant antagonistic effect against F. columnare was measured for 2 out of 37 endogenous strains. These two probiotic strains were identified as Pseudomonas fluorescens. The antagonistic effect of these two successful probiotics was further validated in vivo during a 2-month stress trial: groups receiving probiotic treatments showed on average 53.74% survival improvement.

Removal of 2,4-dichlorophenoxyacetic acid in aqueous solution by pulsed corona discharge treatment: Effect of different water constituents, degradation pathway and toxicity assay

A multiple pin-plane corona discharge reactor was used to generate plasma for the degradation of 2,4 dichlorophenoxyacetic acid (2,4-D) from the aqueous solution. The 2,4-D of concentration 1 mg/L was completely removed within 6 min of plasma treatment. Almost complete mineralization was achieved after the treatment time of 14 min for a 2,4-D concentration of 10 mg/L. Effects of different water constituents such as carbonates, nitrate, sulphate, chloride ions, natural organic matter (humic acids) and pH on 2,4-D degradation was studied. A significant antagonistic effect of carbonate and humic acid was observed, whereas, the effects of other ions were insignificant. A higher first order rate constant of 1.73 min−1 was observed, which was significantly decreased in the presence of carbonate ions and humic acids. Also, a higher degradation of 2,4-D was observed in acidic pH conditions. Different 2,4-D intermediates were detected and the degradation pathway of 2,4-D in plasma treatment process was suggested. The toxicity of 10 mg/L 2,4-D was completely eradicated after 10 min of plasma treatment.

Joint effect of co-exposure of Cu and chlorpyrifos on the toxicity of earthworm.

In order to reveal the toxicity effect and risk of co-exposure of Cu and chlorpyrifos in the current soil environment of China, using the earthworm Eisenia fetida as model organism, the effect of single, and co-exposure of Cu and chlorpyrifos on the growth and antioxidant response of earthworm were analyzed by using the methods of filter paper test and artificial soil test. The results showed that the growth rate of earthworm tended to decrease with the increase of single exposure concentrations of Cu and chlorpyrifos in artificial soil test. The mass of earthworm had a relatively flat changing rate with the co-exposure of Cu and chlorpyrifos. Using the addition of probability, the q values of different concentration groups of Cu and chlorpyrifos on the earthworm mass were less than 0.55, which indicated significant antagonistic effect. The joint effect of Cu and chlorpyrifos on the activities of CAT and SOD indicated antagonistic effect in filter paper test, while the effects of co-exposure of Cu and chlorpyrifos on the contents of GSH and MDA showed a synergy effect of low concentrations and antagonism effect of high concentrations.

Graphene oxide alleviates the ecotoxicity of copper on the freshwater microalga Scenedesmus obliquus

The extensive industrial application of graphene oxide (GO), has increased its exposure risk to various aquatic organisms and its potential to affect the toxicity of other environmental pollutants. In this study, we investigated the combined toxicity of GO and copper on the freshwater microalga Scenedesmus obliquus, using the MIXTOX model. The effects of low concentration (1mg/L) exposure to GO were investigated with environmentally relevant concentrations of copper by using a 12-d subacute toxicity test, with pre- and post-GO treatment. Results showed that there were significant antagonistic effects between GO and copper on S. obliquus, and GO was found to reduce ecotoxicity of copper even at low and environmentally relevant concentrations (1mg/L).

Adsorption of emulsified oil from metalworking fluid on activated bleaching earth-chitosan-SDS composites: Optimization, kinetics, isotherms

The adsorption of emulsified oil from metalworking fluid (MWF) on activated bleaching earth (BE)-chitosan-sodium dodecyl sulfate (SDS) composites (BE/MCS) was investigated under a statistical design of experiments at a 95% confidence interval to identify the critical factors and to optimize the adsorption capacity. The BE/MCS adsorbents were characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller adsorption/desorption isotherms, contact angle analysis (sessile drop technique) and their zeta potential. From the results of a full 25 factorial design with three center points, the adsorbent weight and initial pH of the MWF had a significant antagonistic effect on the adsorption capacity while the initial MWF concentration and BE:chitosan:SDS weight ratio had a synergistic influence. Temperature factor has no discernible effect on the capacity. From the FCCC-RSM design, the optimal capacity range of 2840–2922.5 mg g−1 was achieved at sorbent weight of 1.6–1.9 g, pH of 5.5–6.5, initial MWF concentration of 52–55 g l−1 and BE:chitosan:SDS (w/w/w) ratio of 4.7:1:1–6.2:1:1. To test the validation and sensitivity of RSM model, the results showed that the estimated adsorption capacity was close to the experimental capacity within an error range of ±3%, suggesting that the RSM model was acceptable and satisfied. From three kinetics models (pseudo-first-order, pseudo-second-order model and Avrami's equation) and two adsorption isotherms (Langmuir model and Freundlich model), assessed using an error function (Err) and the coefficient of determination (R2), Avrami's equation and Freundlich isotherm model provided a good fitting for the data, suggesting the presence of more than one reaction pathway in the MWF adsorption process and the heterogeneous surface adsorption of the BC/ABE-5.5 composite.

Cold/hot pad differentiating assay of property differences of Mahuang and Maxingshigan decoctions

Context: Chinese medicines with different cold/hot properties have various pharmacological actions on multiple organisms.Objective: The objective of this study was to explore the cold/hot property differences of traditional Chinese medicine formulas of Mahuang and Maxingshigan decoctions.Materials and methods: A novel cold/hot pad differentiating assay method based on the Intelligent Animal Temperature Tropism Behavior monitoring system at 20 °C (cold pad) and 30 °C (hot pad) was introduced to investigate the variability of temperature tropism among the mice treated by 0.4 mL/20 g (drug volume/body weight) of Mahuang decoction and Maxingshigan decoction, respectively. Meanwhile, the oxygen consumption and activities of adenosine triphosphatase (ATPase) were measured to explore the energy metabolism mechanism.Results: Results showed that the differences between cold/hot properties of Mahuang decoction and Maxingshigan decoction were significant (p < 0.05). Mahuang decoction produced significant synergic effect (a combination index of 1.60), while Maxingshigan decoction expressed significant antagonistic effect (a combination index of 0.35). The changes of energy metabolism including ATPase activity and oxygen consumption might be the possible factors to result in the differences. Those influences tended to be coherent with the definition of cold/hot properties of Chinese medicines based on traditional Chinese medicinal theory.Conclusions: The results indicated that the method based on cold/hot pad differentiating array could objectively and quantitatively represent the cold/hot properties of different compatibilities of traditional Chinese medicines in an ethological way according to the changes of animal’s temperature tropism. These findings would provide some experimental basis and data references as well as a novel evaluation method for the study of the regularity of recipe composition.

Anti-inflammatory effects of noradrenaline on LPS-treated microglial cells: Suppression of NFκB nuclear translocation and subsequent STAT1 phosphorylation

Noradrenaline (NA) has marked anti-inflammatory effects on activated microglial cells. The present study was conducted to elucidate the mechanisms underlying the NA effects using rat primary cultured microglial cells. NA, an α1 agonist, phenylephrine (Phe) and a β2 agonist, terbutaline (Ter) suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO) release by microglia and prevented neuronal degeneration in LPS-treated neuron-microglia coculture. The agents suppressed expression of mRNA encoding proinflammatory mediators. Both an α1-selective blocker terazocine and a β2-selective blocker butoxamine overcame the suppressive effects of NA. cAMP-dependent kinase (PKA) inhibitors did not abolish the suppressive NA effects. LPS decreased IκB leading to NFκB translocation into nuclei, then induced phosphorylation of signal transducer and activator of transcription 1 (STAT1) and expression of interferon regulatory factor 1 (IRF1). NA inhibited LPS-induced these changes. When NFκB expression was knocked down with siRNA, LPS-induced STAT1 phosphorylation and IRF1 expression was abolished. NA did not suppress IL-6 induced STAT1 phosphorylation and IRF1 expression. These results suggest that one of the critical mechanisms underlying the anti-inflammatory effects of NA is the inhibition of NFκB translocation. Although inhibitory effects of NA on STAT1 phosphorylation and IRF1 expression may contribute to the overall suppressive effects of NA, these may be the downstream events of inhibitory effects on NFκB. Since NA, Phe and Ter exerted almost the same effects and PKA inhibitors did not show significant antagonistic effects, the suppression by NA might not be dependent on specific adrenergic receptors and cAMP-dependent signaling pathway.

Acute toxicity and synergistic and antagonistic effects of the aromatic compounds of some essential oils against Culex quinquefasciatus Say larvae.

The efficacy of 30 aromatic compounds and their mutual binary combinations was assessed for acute toxicity against the larvae Culex quinquefasciatus. Based on comparison of the lethal doses, thymol and p-cymene were selected as the most effective (LD50 = 18 and 21 mg L(-1), respectively, and LD90 = 25 and 30 mg L(-1), respectively). Although the LD50 for terpinolene and trans-anethole was also estimated at 21 mg L(-1), their LD90 was significantly higher compared to the substances above (245 and 34 mg L(-1), respectively). In total, 435 binary combinations were tested, of which 249 combinations showed a significant synergistic effect, while 74 combinations showed a significant antagonistic effect on mortality. Only nine substances were identified as being able to create a synergistic effect with more than 20 substances: limonene, trans-anethole, 4-allylanisole, carvacrol, isoeugenol, menthone, carvone, borneol, and camphor. The highest synergistic effect on larval mortality was achieved for the combinations: eugenol and isoeugenol, carvone and carvacrol, carvone and 4-allylanisole, carvone and α-terpineol, carvone and menthone, limonene and trans-anethole, limonene and menthone, α-pinene and menthone, β-citronellol and menthone, carvacrol and 4-allylanisole, carvacrol and terpineol, α-terpinene and trans-anethole, camphor and menthone, camphene and menthone, and 4-allylanisole and menthone. Significant differences between achieved mortality and the mutual mixing ratio were found for the five selected binary mixtures that had shown the most significant synergistic effect in the previous tests. The mixture of limonene and trans-anethole showed the highest mortality, with the mixing ratio 1:1; the mixture of eugenol and isoeugenol caused 90.2% mortality, with the mixing ratio 1:3. One hundred percent mortality was achieved if carvacrol was contained in a mixture with carvone in a ratio >2. After a comparison of all our results, based on our experiments, we can choose two pairs that caused mortality higher than 90% in concentrations lower than 20 mg L(-1): limonene and trans-anethole (with the mixing ratio 1:1), and carvone and carvacrol (with the mixing ratio 1:2-3). The information gained can thus be used in the development of new botanical insecticides based on essential oils (EOs) and particularly in the creation of formulations.

Short-Term Effects of Fine Particulate Matter and Temperature on Lung Function among Healthy College Students in Wuhan, China

Ambient fine particulate matter (PM) has been associated with impaired lung function, but the effect of temperature on lung function and the potential interaction effect between PM and temperature remain uncertain. To estimate the short-term effects of PM2.5 combined with temperature on lung function, we measured the daily peak expiratory flow (PEF) in a panel of 37 healthy college students in four different seasons. Meanwhile, we also monitored daily concentrations of indoor and outdoor PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm), ambient temperature and relative humidity of the study area, where the study participants lived and attended school. Associations of air pollutants and temperature with lung function were assessed by generalized estimating equations (GEEs). A 10 μg/m3 increase of indoor PM2.5 was associated with a change of −2.09 L/min in evening PEF (95%CI: −3.73 L/min–−0.51 L/min) after adjusting for season, height, gender, temperature and relative humidity. The changes of −2.17 L/min (95%CI: −3.81 L/min– −0.52 L/min) and −2.18 L/min (95%CI: −3.96 L/min–−0.41 L/min) in evening PEF were also observed after adjusting for outdoor SO2 and NO2 measured by Environmental Monitoring Center 3 kilometers away, respectively. An increase in ambient temperature was found to be associated with a decrease in lung function and our results revealed a small but significant antagonistic interactive effect between PM2.5 and temperature. Our findings suggest that ambient PM2.5 has an acute adverse effect on lung function in young healthy adults, and that temperature also plays an important role.

Effects of Bio-organic Fertilizers Produced by Four Bacillus amyloliquefaciens Strains on Banana Fusarium Wilt Disease

ABSTRACTContinuous planting of banana disrupts the micro-ecological balance, resulting in severe fusarium wilt disease caused by Fusarium oxysporum f. sp. cubense (FOC). In this study, fifty-eight antagonistic bacterial strains were isolated from the rhizosphere soils in fields with different soil types and cropping histories, four bacterial strains among which identified as Bacillus amyloliquefaciens, based on 16S rRNA analysis combining with morphological, physiological, and biochemical properties and possessing best survival and antibiotic abilities were further selected. Greenhouse experiments showed that these four bacterial strains were found to observably decrease the fusarium wilt incidence and promote the growth of banana plants when combined with organic fertilizers, demonstrating an effective management strategy. An in vitro assessment using cell-free extracts of liquid culture validated that the four Bacillus antagonists possessed the ability to produce antifungal compounds, including iturin, surfactin, fengycin, and bacillomycin families, all of which were identified by liquid chromatograph-mass spectrometer (LC-MS) analysis during the growth of the antagonists. In addition to lipopeptides, these bacterial strains could also produce volatile antifungal compounds with significant antagonistic effect against FOC. Thus, the work described herein highlights the possibility for using the novel bio-organic fertilizers to control fusarium wilt of banana in the field in the future.

Utilization of nanotechnology to enhance percutaneous absorption of acyclovir in the treatment of herpes simplex viral infections.

This study aimed to formulate an optimized acyclovir (ACV) nanoemulsion hydrogel in order to provide a solution for the slow, variable, and incomplete oral drug absorption in patient suffering from herpes simplex viral infection. Solubility of ACV in different oils, surfactants, and cosurfactants was explored utilizing a cubic model mixture design to obtain a nanoemulsion with minimum globule size. Preparation of an optimized ACV nanoemulsion hydrogel using a three-factor, three-level Box–Behnken statistical design was conducted. The molecular weight of chitosan (X1), percentage of chitosan (X2), and percentage of Eugenol as a skin permeation enhancer (X3) were selected to study their effects on hydrogel spreadability (Y1) and percent ACV permeated through rat skin after 2.5 hours (Y2). A pharmacokinetic study of the optimized ACV nanoemulsion hydrogel was conducted in rats. Mixtures of clove oil and castor oil (3:1 ratio), Tween 80 and Span 80 (3:1 ratio), and propylene glycol and Myo-6V (3:1 ratio) were selected as the oil, surfactant, and cosurfactant phases, respectively. Statistical analysis indicated that the molecular weight of chitosan has a significant antagonistic effect on spreadability, but has no significant effect on the percent ACV permeated. The percentage of chitosan also has a significant antagonistic effect on the spreadability and percent ACV permeated. On the other hand, the percentage of Eugenol has a significant synergistic effect on percent ACV permeated, with no effect on spreadability. The ex vivo study demonstrated that the optimized ACV nanoemulsion hydrogel showed a twofold and 1.5-fold higher permeation percentage than the control gel and marketed cream, respectively. The relative bioavailability of the optimized ACV nanoemulsion hydrogel improved to 535.2% and 244.6% with respect to the raw ACV hydrogel and marketed cream, respectively, confirming improvement of the relative bioavailability of ACV in the formulated nanoemulsion hydrogel.

Phenolic composition and anticholinesterase, antioxidant, antifungal and antibiotic modulatory activities of Prockia crucis (Salicaceae) extracts collected in the Caatinga biome of Ceará State, Brazil

IntroductionA phytochemical and biological activity investigation was performed in extracts of Prockia crucis P. Browne ex. L., Salicaceae, occurring in the Caatinga biome. MethodsEthanol extracts of leaves and bark were analysed by high performance liquid chromatography (HPLC) and evaluated for anti-Candida activity, as well as testing for fluconazole-modifying activity. In addition, antioxidant activity was assayed by the DPPH free radical scavenging method and acetylcholinesterase (AChE) inhibitory activity was determined. ResultsSignificant growth of acetylcholinesterase inhibition zones was observed with both extracts, which was comparable to the standard physostigmine, indicating potential activity against Alzheimer's disease. Good antioxidant action was found with EC50 values of 47.731μg/mL for bark extract and 137.64μg/mL for leaf extract. HPLC analysis of the extracts showed the presence of gallic acid and luteolin mainly in the bark and the more kaempferol and coumarin in the leaves. Using the microdilution method, fungal strains of Candida albicans, C. krusei and C. tropicalis showed a minimum inhibitory concentration ≥1024μg/mL. In the test of fluconazole modulation against multiresistant Candida clinical isolates, there was a clear synergism of both extracts on the C. tropicalis strain when combined with fluconazole. A significant antagonistic effect of the bark extract on C. albicans was observed for P. crucis, showing no potentiation of the antifungal effect when fluconazole was used in combination with the natural product. ConclusionsThe extracts of P. crucis demonstrated an interesting antioxidant, anti-AChE and antibiotic modulatory activities, and due probably to the active phenolic compounds.

A systems-level perspective of the biomechanics of the trunk flexion-extension movement: Part II – Fatigued low back conditions

Our companion paper demonstrated the importance of a systems-level perspective on spine biomechanics by showing the effects of lower extremity constraints during simple, trunk flexion-extension motions. This paper explores the impact of trunk muscle fatigue and stress-relaxation of lumbar passive tissues on this systems-level response. Twelve participants performed experimental protocols to achieve lumbar passive tissue stress-relaxation fatigue and lumbar muscle fatigue. Participants performed full range of sagittal-plane trunk flexion-extension under unconstrained stoop movement and pelvic/lower extremity constrained stoop movement. They performed these motions both before and after the fatigue protocols and trunk kinematics and muscle activities in trunk and lower extremity muscles were monitored. Under the condition of passive tissue fatigue, low back muscles and lower extremity muscles revealed significantly increased activation level (21% and 22%, respectively) in the free stoop condition but under the restricted stoop condition, there was no significant effect of the protocol. Under the lumbar muscle fatigue condition, a significant antagonistic and lower extremity activation effect (34% increase in abdominal muscles, 16% increase in lower extremity muscles) was observed in the free stooping condition while these variables were not affected by the protocol under the restricted stooping condition. Relevance to industryFatigue of the lumbar musculature and passive tissues is prevalent in jobs requiring full trunk flexion postures. Developing accurate biomechanical models of spinal stress in these full stooping postures can help in the development of appropriate interventions to reduce the prevalence of back injuries in these jobs.