Scavenging Research Articles

Divided Exhaust Period Assessment for Fuel-Enrichment Reduction in Turbocharged Spark-Ignition Engines

<div>Turbocharged spark-ignition (SI) engines, owing to frequent engine knocking events, utilize retarded spark timing that causes combustion inefficiency, and high turbine inlet temperature (Trb-In T) levels. Fuel enrichment is implemented at high power levels to prevent excessive Trb-In T levels, resulting in an additional fueling penalty and higher CO emissions. In current times, fuel-enrichment reductions are of high strategic importance for engine manufacturers to meet the imminent emissions regulations. To that end, the authors investigated the divided exhaust period (DEP) concept in a 2.2 L turbocharged SI engine with a geometric compression ratio of 14 by decoupling blowdown (BD) and scavenge (SC) events during the exhaust process. Using a validated 1D engine model, the authors first analyzed the DEP concept in terms of pumping mean effective pressure (PMEP) and engine knocking (KI) reduction. Subsequently, the authors examined the effectiveness of the DEP concept using a “low-restriction exhaust flowpath” and varying late intake valve closing (LIVC) duration.</div> <div>First, using DEP, significant PMEP and KI reductions benefits were observed at high power engine conditions along with a large increase in Trb-In T from the early blowdown event. Subsequently, use of a low restriction exhaust flowpath and a shortened LIVC duration further elevated the DEP benefits, including Trb-In T reduction that facilitated enrichment reduction. At 4,000 RPM/20 bar BMEP, ~70% lower PMEP and a 2.2 point increase in ITEg were noted relative to the base engine. However, the 2,000 RPM peak torque engine condition was compromised using DEP, due to knock limitation and deteriorated stock turbocharger performance. Finally, DEP design integrated with an off-the-shelf (new) turbocharger system remedied the low-end torque challenges and demonstrated a notable enrichment reduction and thermal efficiency benefits at the full load engine curve including the 200 kW rated condition.</div>

Первый опыт применения нового поглотителя свободных радикалов Ксаврона при ишемическом инсульте

Актуальность. При остром ишемическом инсульте (ОИИ) исследовано более 1000 веществ с возможным нейропротекторным действием, однако их эффективность считают недостаточно убедительной. В 2018 году в Украине начался выпуск нового поглотителя свободных радикалов Ксаврона (действующее вещество — эдаравон), который с 2001 года успешно назначается в Японии для лечения ОИИ и входит в японский национальный протокол лечения ОИИ. Цель: исследовать эффективность применения нового нейропротективного препарата Ксаврон (эдаравон) в комплексе терапии у больных ОИИ. Материалы и методы. Было проведено проспективное комплексное клинико-неврологическое и лабораторное обследование 28 больных (13 женщин и 15 мужчин), перенесших ОИИ. Больных разделили на две группы, которые не различались по основным характеристикам и проводимому лечению. Однако больным первой группы (n = 18) назначали Ксаврон (30 мг эдаравона) дважды в сутки. В группе контроля (n = 10 больных) препараты с нейропротективным действием не использовали. Результаты. Анализ оценок по шкале комы Глазго показал наличие положительной динамики у большинства пациентов обеих групп без существенной статистической разницы (p > 0,05). Однако анализ оценок по шкале FOUR показал, что в группе Ксаврона начиная с 5-го дня уровень сознания восстанавливался быстрее, чем в группе контроля. Согласно анализу по шкале FOUR, до 9–10-го дня лечения разница между первой группой и контролем стала достоверной (p < 0,05). На третий день лечения у больных контрольной группы уровень нейронспецифической енолазы (NSE) вырос в 10 раз (с 9,2 до 96,4 нг/мл). В дальнейшем наблюдалось быстрое снижение уровня NSE, который в основной группе больных до 10-го дня лечения нормализовался, а в контрольной группе до 10-го дня лечения не достиг референтных значений (p < 0,05). Выводы. Введение Ксаврона (эдаравон) у больных с ОИИ оказалось достоверно эффективным по показателям неврологического статуса (уровень сознания по шкале FOUR) и динамики уровней неврологических маркеров (NSE). Требуются дальнейшие исследования для выяснения роли Ксаврона (эдаравон) в комплексе интенсивной терапии ОИИ.

Ultraviolet absorbance of Sphagnum magellanicum, S. fallax and S. fuscum extracts with seasonal and species-specific variation

Bryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species.

Determinación de la composición fenólica en granos ancestrales de uso alimentario. Comparación de métodos analíticos y de actividad antioxidante

El objetivo de este estudio fue cuantificar los compuestos fenólicos totales de diferentes granos ancestrales: dos variedades de tef (Eragrostis tef), trigo sarraceno (Fagopyrum esculentum) y trigo espelta (Triticum spelta) por diferentes métodos espectrofotométricos (Folin-Ciocalteu y Fast Blue BB) y comparar con los resultados obtenidos de estudiar la composición fenólica individualizada mediante cromatografía líquida de alta resolución acoplada a un sistema de detección de fotodiodos y espectrometría de masas (HPLC-DAD-MS). También se determinó la actividad antioxidante in vitro de los extractos de los granos ancestrales estudiados por el método TEAC (capacidad antioxidante equivalente de Trolox) y FRAP (poder antioxidante reductor del hierro). El uso de HPLC-DAD-MS permitió identificar un gran número de compuestos fenólicos: compuestos hidroxibenzoicos, hidroxicinámicos, flavonoles, flavonas y flavanoles. Las flavonas fueron la familia de compuestos fenólicos más abundante detectada en las muestras de espelta, teff, blanco y marrón. Sin embargo, en el trigo sarraceno son los flavanoles (64 %). La cuantificación de los compuestos fenólicos por HPLC-DAD-MS parece más oportuna que por los métodos espectrofotométricos. Con respecto a la actividad antioxidante, el trigo sarraceno mostró los valores más altos frente a su capacidad de captar radicales libres y poder reductor en relación a las otras muestras estudiadas, pudiéndose relacionar con su alto contenido en compuestos fenólicos.

Assessment of the antioxidant and antimicrobial activities of Caralluma deflersiana growing in the South of Saudi Arabia

Reactive oxygen species and oxidative stress are related to a large number of human degenerative diseases. Consequently, plants have been investigated across the world to exploit their potential antioxidant and antimicrobial activities. In the current study, Caralluma deflersiana is native to Saudi Arabia and was screened to assess its antioxidant and antimicrobial potential activities as well as the phenolic content/phytochemicals. Subsequently, the collected aerial parts were extracted by maceration with different solvents. The antioxidant activity was investigated using the total antioxidant capacity, diphenylpicryl hydrazine (DPPH)- radical scavenging assay, ABTS radical scavenging assay, and Ferric reducing antioxidant power assay (FRAP). Regarding the antimicrobial activity, the Minimum Inhibitory Concentration (MIC) assays were used. The total phenolic content of C. deflersiana extracts was quantified using standard methods. As a result, the water extract of C. deflersiana displayed a strong antioxidant activity in all tested methods compared to other plant extracts. Moreover, it was also noted that water and methanolic extracts exhibited approximately similar bacterial and fungal growth inhibition. Additionally, the water extract of C. deflersiana also demonstrated the highest phenol content among other plant extracts, consistent with the higher antioxidant activity found in C. deflersiana. In conclusion, Caralluma species could be a promising source of antioxidant and antimicrobial agents. Key words: Caralluma deflersiana, antioxidant, antimicrobial.

Hepatoprotective and free radical scavenging activities of methanol extract fractions of Capparis decidua Edgew (Forssk.) (Capparidaceae)

The main objective of the study is to evaluate the hepatoprotective and antioxidant activities of different extracts and fractions of a Sudanese traditionally used plant, Capparis decidua Edgwe (Forssk.) (Capparidaceae). Carbon tetrachloride (CCl4) induced hepatotoxicity in rats, and DPPH radical scavenging activity (RSA) were the methods used to evaluate the hepatoprotective and antioxidant activities of this plant respectively. The rats were injected i.p. with dichloromethane and methanol 80% extracts at 250 and 500 mg/Kg body weight by the C. decidua stem. It was found that the methanol extract showed significant hepatoprotective activity when compared with control group (CCl4 group); also its liver function parameters were as effective as the positive control (Silymarin group). Fractionation of the methanol extract of C. decidua stem was applied by using dichloromethane (DCM), ethyl acetate, n-butanol and aqueous solvents. The fractions were tested on CCl4- induced hepatotoxicity rats at dose 500 mg/kg body weight where ethyl acetate, DCM and n-butanol fractions showed significant hepatoprotective activity when compared with control group (CCl4 group); their liver function parameters were within the normal ranges as well as the standard drug group (silymarin group). DPPH radical scavenging activities (RSA) of DCM, ethyl acetate and n-butanol fractions were 86, 92 and 53% respectively. These findings prove the high linkage between hepatoprotective and antioxidant activities. The aqueous fraction showed very weak hepatoprotective property, and antioxidant activity (14% RSA). Key words: Capparis decidua Edgwe (Forssk.), methanol extract fractions, hepatoprotective activity, CCl4, DPPH.

Quality Characteristics of Jelly Made from Fermented Red Ginseng Concentrate with Increased Ginsenoside Content by Enzyme Treatment

The purpose of this study is to investigate the physicochemical properties of jelly made from fermented red ginseng concentrate (FRGC) that can be easily absorbed and digested for the health promotion of the elderly. The pH of the jellies tended to decrease with increasing concentration of FRGC. Soluble solid content has significantly higher value when added more than 2%, and the water content of the sample was significantly lower when the FRGC was added 4%. As the amount of FRGC was increased, the total color difference increased, and the hardness of samples decreased significantly. On the other hand, the total ginsenoside contents of the FRGC was 45.50 mg/g. As the concentration of FRGC increased, the content of polyphenol and flavonoids increased. The increasing pattern of polyphenols and flavonoids showed a similar trend. As the content of FRGC increased, ABTS free radical scavenging activity significantly increased (p<0.05), and in the control, the minimum value (62.6 AEAC) and the 4% sample were highest (116.2 AEAC). DPPH radical scavenging activity was like that of ABTS radical scavenging activity. However, there was no significant difference in DPPH radical scavenging activity of 3% and 4% red ginseng jelly.

Pengaruh Perbedaan Pre-Treatment terhadap Stabilitas Karotenoid dan Fenol pada Ekstrak Sargassum duplicatum selama Penyimpanan

Karotenoid, fukosantin dan fenol merupakan senyawa yang terkandung pada rumput laut Sargassum duplicatum. Senyawa-senyawa ini berperan dalam menghambat radikal bebas. Namun, kemampuan penghambatan radikal bebas senyawa ini mempunyai kestabilan yang rendah, terutama terhadap perlakuan suhu. Tujuan penelitian ini adalah untuk menentukan pengaruh pre-treatment suhu tinggi (blanching) dan suhu rendah (pembekuan) serta perlakuan terbaik yang dapat mempertahankan stabilitas senyawa aktif pada ekstrak metanol rumput laut selama penyimpanan. Metode penelitian yang digunakan adalah experimental laboratories menggunakan rancangan acak lengkap (RAL) faktorial 2x5 yaitu pola terbagi menjadi faktor suhu pengolahan (suhu tinggi dan suhu rendah) dan lama penyimpanan (0, 2, 4, 6, dan 8 hari). Blanching dilakukan pada suhu 95 oC sedangkan pembekuan pada suhu -27 oC. Hasil penelitian menunjukkan karotenoid, fukosantin, dan senyawa fenol dengan perlakuan blanching lebih stabil dibandingkan perlakuan pembekuan. Berdasarkan hasil penelitian menunjukkan bahwa adanya interaksi antara pre-treatments dan lama penyimpanan yang berpengaruh nyata terhadap nilai total karotenoid, kandungan fukosantin, total kandungan fenol, dan nilai perubahan warna (ΔE).

Ceria Nanoparticles Mitigate the Iron Oxidative Toxicity of Human Retinal Pigment Epithelium.

Oxidative injury is implicated in retinal damage observed in age-related macular degeneration (AMD), as well as other degenerative conditions. Abnormally elevated levels of iron accumulation within the retinal pigment epithelium have been detected in eyes with AMD, and it is suspected to play a role in the pathogenesis through the production of reactive oxygen species (ROS). Ceria nanoparticles (CNP) have the ability to scavenge ROS. This study sought to evaluate the ability of CNP to mitigate iron-induced oxidative stress and assess cell viability in the human ARPE-19 cell line in vitro. Cell viability was measured by an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and compared between experimental groups undergoing 48-hr exposure to a ferrous iron solution with and without 24-hr CNP pre-treatment. The CNP effect on ROS formation was evaluated additionally by H2DCFDA (2,7-dichlorodihydrofluorescein diacetate) fluorescent probe assay and superoxide dismutase assay. CNP demonstrated a three-fold increase in cell viability and a reduction in ROS generation. The results show a promising treatment modality for diseases causing oxidative damage in the eye.

Prospects for the use of regulators of oxidative stress in the comprehensive treatment of the novel Coronavirus Disease 2019 (COVID-19) and its complications.

Some surface proteins of the newly identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can bind to the hemoglobin molecule of an erythrocyte, which leads to the destruction of the structure of the heme and the release of harmful iron ions to the bloodstream. The degradation of hemoglobin results in the impairment of oxygen-carrying capacity of the blood, and the accumulation of free iron enhances the production of reactive oxygen species. Both events can lead to the development of oxidative stress. In this case, oxidative damage to the lungs leads then to the injuries of all other tissues and organs. The use of uridine, which preserves the structure of pulmonary alveoli and the air-blood barrier of the lungs in the course of experimental severe hypoxia, and dihydroquercetin, an effective free radical scavenger, is promising for the treatment of COVID-19. These drugs can also be used for the recovery of the body after the severe disease.

Geographical variation in total phenolics, flavonoids and antioxidant activities of Eucalyptus camaldulensis leaves in Burkina Faso

This study aimed to elucidate the effect of sampling location of Eucalyptus camaldulensis leaves on antioxidant activity, total phenolic content (TPC) and total flavonoid content (TFC). Leaves of E. camaldulensis collected at three different locations in Burkina Faso (north, central, south-west) were subjected to hydrodistillation to obtain a water extract and subsequent ethanol extraction of the solid residue. The extracts were analysed for antioxidant activity using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, TPC, TFC and high-performance thin layer chromatography (HPTLC) fingerprint. TPC were higher in water extracts and presented considerable variation from 129±9 to 266±4 milligram Gallic Acid Equivalent per gram of extract (mg GAE/g) with the highest value 266±4 mg GAE/g at the south-west site. This aqueous extract also showed high antioxidant activity with EC50 8.3 µg/mL. Furthermore, HPTLC fingerprint of the extracts showed both band intensity and size differences. For TFC, we found a slight differences within both water and ethanolic extracts with the highest value of 38.3 ±4.2 mg QE/g for the south-west ethanolic extract. The noticeable impact of climate on chemical variability of E. camaldulensis leaves needs to be taken into consideration for any further applications based on TPC biological activity of the extracts. Key words: Eucalyptus camaldulensis, total phenolic content, total flavonoid content, antioxidant activity, sample location, chemical variation.

Effect of Roasting on Bioactive and Antinutritional Components of Flaxseed (Linum Usitatissimum)

Flaxseed (Linum usitatissimum) collected from Morang district, Nepal was studied to explore the effect of roasting at 180oC for 5, 10, 15 and 20 min and soaking (12 h followed by sun drying followed by roasting at 180oC for 15 minutes) on its bioactive compounds (flavonoids, polyphenol and anti-oxidant activity), nutritional and anti-nutritional compounds (hydrocyanic acid and oxalate). The crude extracts of samples were prepared using 80% methanol by maceration technique for analysis of total flavonoid content, polyphenol content and free radical scavenging activity. Roasting of flaxseed had significant impact on its bioactive, nutritional and anti-nutritional components. Flavonoid content increased significantly (p<0.001) from 45.33 ± 5.03 mg QE/100 g to 238.16 ± 8.8 mg QE/100 g on roasting whereas there was no significant increment of flavonoid on soaking. Polyphenols content decreased significantly (p<0.001) on roasting and soaking followed by roasting. The highest amount of antioxidant activity was found to be in raw and 15 min roasting i.e 1.57 mg AAE/mg DM. And antioxidant activity was further increased on soaking followed by roasting. Hydrocyanic acid on raw sample was 649.3 ± 1.41 mg/kg decreased significantly (p<0.001) to 115.2 ± 10.41 mg/kg at 15 min roasting. Similarly, oxalate content decreased significantly (p<0.001) on roasting. Soaking followed by roasting further decreased HCN and oxalate content significantly (p<0.001). Protein, fat and fiber content were decreased significantly whereas calcium content increased significantly on 15min roasting. Similarly, on soaking followed by roasting, protein, fat and calcium content were decreased and crude fiber increased significantly.

Development of a novel in vitro assay to evaluate environmental water using an IL-8 reporter cell line.

The IL-8 luciferase reporter cell line, THP-G8 cells, used in the in vitro sensitization test, OECD442E, can respond to a variety of stimuli other than haptens, such as lipopolysaccharide (LPS), other bacterial toxins, and detergents. Considering these characteristics, we examined the ability of the IL-8 luciferase assay using THP-G8 cells to evaluate water pollution. We first stimulated THP-G8 cell with various Toll-like receptor (TLR) agonists and nucleotide-binding oligomerization domain-like receptor (NLR) agonists, and found that TLR1, 2, 4, 5, 6 agonists and NOD 1, 2 agonists significantly augmented IL-8 luciferase activity (IL8LA). Then, we examined the detection threshold of LPS by THP-G8 cells, and found it 0.4 EU/ml. Next, we examined whether THP-G8 cells can differently respond to a variety of sources of environmental water around Sendai, Japan and Manila, Philippine and whether there is a correlation between the IL8LA of different sources of water and their level of endotoxin assessed by the LAL assay. There was a clear trend that the IL8LA was lower in the upper stream and higher in the downstream in both Japan and Philippine. Moreover, there was a strong correlation between the IL8LA of the environmental water and its endotoxin level. Finally, using N-acetyl-L-cysteine, an antioxidant/radical scavenger, and polymyxin B that neutralizes endotoxin, we demonstrated that there was a difference in the suppressive effects by them between the water from Japan and that from Philippine. These data suggest the potential of the IL-8 luciferase assay for evaluating environmental water pollution both quantitatively and qualitatively.

Antioxidant Activity and Isoflavonoid Components in Different Sections of Pueraria lobata Root

The isoflavonoids content and antioxidant activity in different sections of Pueraria lobata roots, including the root outer bark, kudzu root and whole root were investigated in this study. Isoflavonoid concentrations in p. lobata roots were determined by high performance liquid chromatography. The antioxidant activity of P. lobata roots was assessed by total phenol content. DPPH free radical scavenging assay, ABTS free radical scavenging assay and reducing power. The root outer bark of P. lobata root possessed higher isoflavonoids content than whole root or kudzu root (p ＜ 0.05). The levels of antioxidant potential of the root outer bark assayed by total phenolic content, DPPH, ABTS and reducing power were significantly higher than those of the whole root or the kudzu root (p ＜ 0,05) , The main isoflavonoids in all sections of P. lobata roots were puerarin, daidzin, daidzein, genistin and genistein. The major isoflavonoid puerarin in root outer bark exhibited the greatest antioxidant activity in P. lobata roots.

Analgesic and Anti-Inflammatory Activities of Aqueous Extracts of Fructus Ligustri Lucidi

Fructus Ligustri Lucidi has been used for its anti-inflammatory effects in traditional Chinese medicine. This study investigated the analgesic and anti-inflammatory effects of aqueous extracts of Fructus Ligustri Lucidi (AFLL) in mice. AFLL significantly inhibited the production of radicals and lipid oxidation in various models. The reference compounds present in AFLL, including quercetin, myricetin, caffeic acid, gallic acid and ellagic acid, exhibited the pharmacological activities by scavenging radicals and decreasing LPS-induced nitric oxide (NO) production in macrophages. Administration of AFLL showed a concentration dependent inhibition on the number of acetic acid-induced writhing responses and formalin-induced pain in the late phase, and paw edema development after Carr treatment in mice. The anti-inflammatory activities of AFLL could be via NO and tumor necrosis factor α(TNF-α) suppression and associated with the increase in the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Western blotting revealed that AFLL decreased Carr-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions. These results suggest that anti-inflammatory mechanisms of AFLL might be correlated to the decrease in the level of malondialdehyde (MDA), iNOS and COX-2 in the edema paw via increasing the activities of CAT, SOD and GPx in the liver. Overall, the results showed that AFLL could serve as a natural source of antioxidant, analgesic and anti-inflammation.

Studies on the Antimutagenicity and Antioxidant Activity of the Hot Water Extract of Glechoma hederacea

Several studies have demonstrated that herbal plants contain various potential antioxidants and these antioxidant components may be potential antimutagens or anticarcinogens. Glechoma hederacea belongs to the Labiatae family. According to ancient Chinese prescriptions, G. hederacea was used for treating diuresis and stimulating blood circulation. However, there are few reports on its biophysical functions to date. The objective of this study was to evaluate the antioxidant, mutagenic and antimutagenic activities of the hot water extract of G. hederacea (HWG). G. hederacea was extracted with distilled water at 100℃ for 3h. The antioxidant activities tested included α,α-diphenyl-s-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) and superoxide anion radical-scavenging effects, Fe^2+ -che1ating ability, reducing power and lipid peroxidation inhibition. The in vitro mutagenic and antimutagenic properties of the extracts were investigated using the Ames test. The results showed that HWG possessed antioxidant characteristics. Moreover, the antioxidant activities of HWG were significantly higher than those of Vitamin C and Trolox in terms of superoxide anion radical scavenging activity and Fe^2+ -chelating ability (p ＜ 0.05). The results of Ames test indicated that HWG had no mutagenicity toward all tester strains including Salmonella typhimurium TA97, TA98, TA100, TA102 and TA1535 with/without the metabolic activator (S9 mix). The extracts had marked inhibition effects against the mutagenicities of the diagnostic mutagens with the S9 mix System. The HWG showed antioxidant and anti-mutagenic potential. However, the active compounds of HWG need be further investigated.

Phytochemical Screening and Antioxidant Activity of Algerian Aristolochia longa Flavonoids

Introduction: Aristolochia longa, is widely used as a medicinal plant, in Algerian folk medicine since ancient times and passed through the generations. This study focused on the qualitative examination of different phytochemical constituents to determine their antioxidant activities.Materials and Methods: Leaves and roots were extracted by liquid-liquid extraction technique using the methanol as solvent. The total phenolic and flavonoids content was determined by Folin–Ciocalteu and AlCl3 methods, respectively. The antioxidant activity was evaluated with two distinct methods: DPPH radical scavenging assay and ferric reducing antioxidant power test (FRAP). Then, the high-performance liquid chromatography (HPLC) method was performed to analyze leaves and roots n-butanol fractions. Results: Leaves gave a significant value of polyphenols (8.580 ± 0.04 mg GAE/g DW). Whereas, n-butanol fraction flavonoids extracted from leaves was observed much highest (4.54 ± 1.94 mg CE/g DW). N-butanol fraction leaves showed a powerful scavenging activity and reducing activity with an IC50 = 0.044 ± 0.001 mg/ml and EC50 = 0.126 ± 0.041 mg/ml, respectively. The HPLC analysis of leaves and roots n-butanol fraction revealed different bioactive compounds in which they belong to the flavonoids category.Conclusions: The results obtained from this study suggest that Aristolochia longa leaves were considered as an important resource of flavonoids, which have an interesting antioxidant power.

Study of the Procedure for Bath Ultrasound-Assisted Extraction of Total Flavonoid from Lotus Seeds and Testing Some Biological Activities

In this study, we investigated impact of single factor: solvent concentration ethanol, solvent pH, ultrasound time, solvent ratio: raw material and ultrasound temperature on the total flavonoid extraction from lotus seeds. Based on survey on factors affecting extraction conditions by the ultrasound bath method, all five surveyed factors were found to have strong influences on total flavonoid extraction process. From factorial design of experimental planning using surface response methodology (RSM), optimal conditions for extraction of total flavonoid from lotus seeds were found in extraction time (98.005 min); solvent concentration ethanol (86.160 %), pH solvent ethanol (4.546), bath ultrasound temperature (22.210°C) and solvent/material ratio (8.376 (v/w)). Under above optimum conditions, total extracted flavonoids was 0.812 (mg Catechin/g extract). Experimental results showed a high compatibility with estimated RSM model. Total flavonoid content obtained in the original liquid extract was 0.797 ± 0.011 (mg Catechin/g extract). The highest antioxidant activity was found to be from ethanol extract with IC50 value (0.058 ± 0.004 (µg/mL), in comparison with IC50 of ascorbic acid, 0.002 ± 0.001 (µg/mL). Moreover, 50 % of DPPH scavenging ability of liquid and condensed extract differed from each other.

Effect of lentivirus-mediated shRNA targeting down-regulation of PPARα on perfluorododecanoic acid induced oxidative damage in rat hepatocytes BRL 3A

To investigate the role of peroxisome proliferator-activated receptor alpha(PPARα) in perfluorododecanoic acid(PFDoA)-induced liver oxidative damage in rats by observing lentivirus-mediated shRNA targeting and down-regulating PPARα expression in rat hepatocytes BRL 3 A. A PPARα lentivirus-compatible shRNA interference vector Lenti-iPα and a negative control vector Lenti-NC were constructed, and co-transfected with lentivirus packaging helper plasmids into 293 FT cells for lentivirus packaging. The lentivirus stock solution was collected, concentrated and the virus titer was determined. The experimental grouping was as follows, NC-group(infected with negative control lentivirus, without PFDoA exposure), NC+ group(infected with negative control lentivirus, 75 μmol/L PFDoA exposure), iPα-group(infected with interference lentivirus, without PFDoA exposure), iPα+ group(infected with interference lentivirus, 75 μmol/L PFDoA exposure). Rat hepatocytes BRL 3 A cells were treated with lentivirus for 96 h, and then exposed with 75 μmol/L PFDoA in the NC+ group and iPα+ group in the last 24 h. The interference of PPARα in BRL 3 A cells and the role of PPARα in reactive oxygen species(ROS) changes caused by PFDoA were observed. Lentivirus-mediated shRNA successfully achieved targeted downregulation of PPARα expression in BRL 3 A cells. Compared with the NC-group, the mean fluorescence intensity of ROS in rat hepatocytes BRL 3 A in the iPα-group was 12043. 42±808. 58, significantly increased(P&lt;0. 05); The transcription levels of acyl-CoA thioesterases(Acot) 1 gene and its protein expression levels were 0. 43±0. 04 and 0. 34±0. 08, respectively, both significantly decreased(P&lt;0. 05). After PFDoA treatment, compared with NC+ group, the mean fluorescence intensity of ROS in iPα+ group was 12386. 25±356. 36, which also increased significantly(P&lt;0. 05). The transcription levels of Acot1 gene and its protein expression levels were 0. 85±0. 10 and 0. 33±0. 04, respectively, which also decreased significantly(P&lt;0. 05). PPARα and its downstream target protein Acot1 may play a role in scavenging ROS in rat hepatocytes BRL 3 A, keeping hepatocytes from oxidative damage caused by foreign substances to the liver.

Investigation of radical scavenging and anti-inflammatory activity of the extract and fractions of Termitomyces albuminosus

Investigation of radical scavenging and anti-inflammatory activity of the extract and fractions of Termitomyces albuminosus