Relationship between Antioxidant Properties and Chemical Composition of Abutilon Indicum Linn

Aim of this paper is to find out the relationship between antioxidant activity of Abutilon indicum Linn and their phytochemical composition especially phenols and flavonols. Successive extractions were carried out for the Abutilon indicum plant with petroleum ether, chloroform, ethyl acetate, n-butanol, ethanol and water. All these extracts were evaluated for their antioxidant activities. Their antioxidant activities were correlated with their total phenol and flavonol content present in the plant. Ethyl acetate showed maximum free radical scavenging activity. IC₅₀ value for various antioxidant methods for all extract showed no significance with total antioxidant capacity except IC₅₀ value of LPO (r² = 0.7273). Correlation between total antioxidant capacity and total phenolic content was not significant with r² = 0.2554, P<0.3065. Total antioxidant capacity and total flavonol content showed similar correlation with r² = 0.2554, P<0.0962.     

Antioxidant,free radical scavenging activities of Salvia brachyantha and its protective effect against oxidative cardiac cell injury

In this study, antioxidant and free radical scavenging activities of an endemic Salvia species (Salvia brachyantha (Bordz) probed. was assessed in vitro using 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, β-carotene linoleic acid, superoxide anion radical, hydroxyl radical, and reducing power assays. Regarding our data, the plant extract exhibited antioxidant and radical scavenging activities at different magnitudes of potency. In addition, this study was undertaken to assess whether methanol extract of S. brachyantha could increase the endogenous antioxidant enzymes in cells, and where such increased cellular defences could provide protection against oxidative cell injury. Pre treatment of rat heart cell lines with 100 μg/ml of plant extract for 24 h significantly prevented cell damage and enhanced activity of antioxidant enzymes induced by a treatment with xanthine/xanthine oxidase. Increased reactive oxygen species and cell apoptosis induced by xanthine/xanthine oxidase was dose-dependently prevented when cells were pre treated for 24 h with plant extract. These results indicated that S. brachyantha could protect against cell injury via induction of the antioxidant enzyme defences. The extract of this plant might be valuable antioxidant natural sources and seemed to be applicable in both healthy medicine and food industry.     

Toxic effects of diazinon and its photodegradation products

The toxic effects of diazinon and its irradiated solutions were investigated using cultivated human blood cells (lymphocytes and erythrocytes) and skin fibroblasts. Ultra Performance Liquid Chromatography (UPLC)–UV/VIS system was used to monitor the disappearance of starting diazinon during 115-min photodegradation and formation of its by-products (diazoxon and 2-isopropyl-6-methyl-4-pyrimidinol (IMP)) as a function of time. Dose-dependent AChE and Na⁺/K⁺-ATPase inhibition by diazinon was obtained for all investigated cells. Calculated IC₅₀ (72 h) values, in M, were: 7.5 × 10⁻⁶/3.4 × 10⁻⁵, 8.7 × 10⁻⁵/6.6 × 10⁻⁵, and 3.0 × 10⁻⁵/4.6 × 10⁻⁵ for fibroblast, erythrocyte and lymphocyte AChE/Na⁺/K⁺-ATPase, respectively. Results obtained for reference commercially purified target enzymes indicate similar sensitivity of AChE towards diazinon (IC₅₀ (20 min)-7.8 × 10⁻⁵M), while diazinon concentrations below 10 mM did not noticeably affect Na⁺/K⁺-ATPase activity. Besides, diazinon and IMP induced increasing incidence of micronuclei (via clastogenic mode of action) in a dose-dependent manner up to 2 × 10⁻⁶ M and significant inhibition of cell proliferation and increased level of malondialdehyde at all investigated concentrations. Although after 15-min diazinon irradiation formed products do not affect purified commercial enzymes activities, inhibitory effect of irradiated solutions on cell enzymes increased as a function of time exposure to UV light and resulted in significant reduction of AChE (up to 28–45%) and Na⁺/K⁺-ATPase (up to 35–40%) at the end of irradiation period. Moreover, photodegradation treatment strengthened prooxidative properties of diazinon as well as its potency to induce cytogenetic damage.     

Antioxidant and Antiinflammatory Activity of Vitex negundo

Reactive oxygen species are implicated in various inflammatory disorders. Vitex negundo is mentioned in Ayurveda as useful in treating arthritic disorders. The present work was undertaken to evaluate the antioxidant potential and anti-inflammatory activity of the plant. The total methanol extract of the plant was standardized in terms of total polyphenols. The standardized extract in a dose of 100 mg/kg caused a comparable reduction in edema with that of diclofenac sodium (25 mg/kg) when evaluated for antiinflammatory activity by carrageenan-induced rat paw edema method. The extract also exhibited a strong free radical scavenging activity by 1,1-diphenyl-2-picrylhydrazyl method and caused a significant reduction in the formation of thiobarbituric acid reacting substances when evaluated for its lipid peroxidation inhibitory activity. The results strongly suggest that radical quenching may be one of the mechanisms responsible for its antiinflammatory activity.     

Antioxidant and antilisterial effect of seed essential oil and organic extracts from Zizyphus jujuba

Hydrodistilled volatile oil from the seeds of Zizyphus jujuba was analyzed by GC–MS. Twenty three compounds representing 91.59% of the total oil was identified. The oil and organic extracts revealed a great potential of antilisterial effect against all five strains of Listeria monocytogenes ATCC 19111, 19116, 19118, 19166 and 15313. Also the oil had strong detrimental effect on the viable count of the tested bacteria. The samples were also subjected to screening for the antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals scavenging activities assay. In the first case, the IC₅₀ value of the Z. jujuba essential oil was determined to be 5.21 ± 0.01 μg/ml. Among the extracts, the strongest activity was exhibited by the methanol extract with an IC₅₀ value of 20.44 ± 0.18 μg/ml. In the superoxide radicals scavenging activities assay, methanol extract was superior to all other extracts (IC₅₀ = 18.60 ± 0.3 μg/ml). Furthermore, the amount of total phenolic compounds was determined. The results indicate that the essential oil and extracts of Z. jujuba could serve as natural antimicrobial and antioxidant agents for the food industry.     

Free radical scavenging and tyrosinase inhibition activity of oils and sericin extracted from Thai native silkworms (Bombyx mori)

Oils and sericin were extracted from pupae and silk cocoons, respectively, of the five Thai native silkworms (Bombyx mori, Linnaeus (Bombycidae)), namely, Keawsakol, Nangnoi, Somrong, Nangleung, and Noneruesee, which are variations of the same species. The oils were extracted by a hot process using Soxhlet apparatus and a cold process using petroleum ether, while sericin was extracted by basic hydrolysis and autoclaving. Sericin from the five Thai native silkworms showed free radical scavenging activity lower than the standard antioxidants (vitamin C, vitamin E, and BHT) by about 20–100-fold, but all oils gave higher activity than that of the standard linoleic acid by 11–22-fold. Oil extracted from Noneruesee by the cold process gave the highest DPPH scavenging activity, compared with other oil samples. All sericin samples showed tyrosinase inhibition activity with IC₅₀ values in the range of 1.2–18.76?mg/mL, but only oils from Noneruesee extracted by the hot process, and Nangleung, Somrong, and Noneruesee extracted by the cold process, showed this activity. Oil extracted by the hot process and sericin by basic hydrolysis from Noneruesee gave the highest tyrosinase inhibition activity, but lower than that of the standards vitamin C and kojic acid by 20–49 and 3–8 times, respectively. This study has suggested that sericin and oil from Noneruesee extracted by basic hydrolysis and the cold process, which gave the highest tyrosinase inhibition and free radical scavenging activity, respectively, can be applied in antiaging and whitening cosmetic products.     

Differential electrophysiologic and inotropic effects of phenylephrine in atrial and ventricular heart muscle preparations from rats

Summary Stimulation of ₁-adrenoceptors evokes a different pattern of inotropic responses in atrial and ventricular heart muscle preparations from rats. The inotropic effects are accompanied by different changes in membrane potential. In an attempt to clarify the question whether or to which extent these events are causally related, the effects of phenylephrine on force of contraction, transmembrane potential, Ca²⁺ current (I_Ca) and K⁺ currents were comparatively studied in either tissue.In atrial preparations, phenylephrine 10 mol/l caused an increase in force of contraction, a marked prolongation of the action potential duration and a depolarization of the membrane at rest. In the ventricle, however, the addition of phenylephrine 10 mol/l produced first a decline in force of contraction associated with a hyperpolarization of the membrane and a reduction in the action potential duration. These changes were followed by an increase in force,of contraction and a slight prolongation of the action potential, whereas the resting membrane potential remained increased. The hyperpolarization was eliminated in the presence of ouabain 100 mol/l.In enzymatically isolated atrial and ventricular myocytes, the whole-cell voltage clamp technique was used to study membrane currents on exposure to phenylephrine. Phenylephrine 30 mol/l did not affect the magnitude of I_Ca in either cell type. Transient and steady state K⁺ outward currents, however, were significantly diminished to a similar extent in atrial and in ventricular myocytes.It is concluded that the positive inotropic effect of ₁-adrenoceptor stimulation in the rat atrium is related to an increase in action potential duration and a decrease in resting membrane potential due to a decrease in K⁺ currents. In the ventricle, phenylephrine additionally activates the Na⁺/K⁺ pump thereby hyperpolarizing the membrane. The rapid onset of pump stimulation seems to overwhelm, in the beginning, the phenylephrine-induced decrease in K⁺ conductance and therefore to evoke a transient negative inotropic effect.It is assumed that phenylephrine can alter the intracellular Ca²⁺ concentration due to changes in the action potential duration. The way how Ca 2+ enters the cell remains speculative, since direct changes of Ica were not detected. The more complicated changes in membrane potential in the ventricle suggest that also other mechanisms for the positive inotropic response to phenylephrine must be considered. Send offprint requests to H. Nawrath at the above address     

Correlation between inhibition of (Na+, K+)-membrane-ATPase and positive inotropic activity of cardenolides in isolated papillary muscles of guinea pig

Summary Concentrations of 17 cardenolides, cardenolide glucuronides and sulfates producing halfmaximal inhibition of (Na⁺, K⁺)-membrane-ATPase from different organs and animal species were determined in vitro. In addition the concentrations that increased the contractility of guinea pig isolated papillary muscles to a particular level were investigated. Comparisons between ATPase-inhibiting and positive inotropic cardiac activities showed extensive parallelism: the correlation coefficients after log/log transformation were between 0.92 and 0.97. The same close correlations are found if dissociation constants of cardenolide receptor complexes and concentrations causing ⁸⁶Rb-uptake inhibition in human erythrocytes are examined.The concentrations necessary for inhibition of (Na⁺, K⁺)-membrane-ATPase of the guinea pig heart and the concentrations required to achieve a defined positive inotropic effect in guinea pig papillary muscle showed a log/log correlation coefficient of 0.97 (P<0.001). In both tests the potencies covered more than three orders of magnitude. The results support Repke's hypothesis on the digitalis receptor.     

Neurotoxicological effects of cinnabar (a Chinese mineral medicine, HgS) in mice

Cinnabar, a naturally occurring mercuric sulfide (HgS), has long been used in combination with traditional Chinese medicine as a sedative for more than 2000 years. Up to date, its pharmacological and toxicological effects are still unclear, especially in clinical low-dose and long-term use. In this study, we attempted to elucidate the effects of cinnabar on the time course of changes in locomotor activities, pentobarbital-induced sleeping time, motor equilibrium performance and neurobiochemical activities in mice during 3- to 11-week administration at a clinical dose of 10 mg/kg/day. The results showed that cinnabar was significantly absorbed by gastrointestinal (G-I) tract and transported to brain tissues. The spontaneous locomotor activities of male mice but not female mice were preferentially suppressed. Moreover, frequencies of jump and stereotype-1 episodes were progressively decreased after 3-week oral administration in male and female mice. Pentobarbital-induced sleeping time was prolonged and the retention time on a rotating rod (60 rpm) was reduced after treatment with cinnabar for 6 weeks and then progressively to a greater extent until the 11-week experiment. In addition, the biochemical changes in blood and brain tissues were studied; the inhibition of Na(+)/K(+)-ATPase activities, increased production of lipid peroxidation (LPO) and nitric oxide (NO) were found with a greater extent in male mice than those in female mice, which were apparently correlated with their differences in the neurological responses observed. In conclusion, these findings, for the first time, provide evidence of the pharmacological and toxicological basis for understanding the sedative and neurotoxic effects of cinnabar used as a Chinese mineral medicine for more than 2000 years.     

Free radical scavenging and antiatherogenic activities of Sesamum indicum seed extracts in chemical and biological model systems

An emerging consensus underscores the importance of oxidative events in vascular disease including excess production of reactive oxygen/nitrogen species (ROS/RNS), in addition to lipoprotein oxidation. Sesamum indicum has long been used extensively as a traditional food. The aim of present study was to evaluate antioxidant action of aqueous and ethanolic seed extracts from S. indicum using various in vitro ROS/RNS generated chemical and biological models. Results demonstrated that the graded-dose (25–1000 μg/ml) of aqueous and ethanolic extracts markedly scavenged the nitric oxide, superoxide, hydroxyl, 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radicals and, showed metal chelating ability as well as reducing capacity in Fe³⁺/ferricyanide complex and ferric reducing antioxidant power assays. In biological models, both extracts were found to inhibit metal-induced lipid peroxidation in mitochondrial fractions, human serum and LDL oxidation models. In lipoprotein kinetics study, both extracts significantly (P < 0.05) increased lag phase time along with reduced oxidation rate and conjugated dienes production. Ethanolic extract of S. indicum showed higher amounts of total polyphenol and flavonoid content as compared to their counterpart. The IC₅₀ values of both extracts were compared with respective antioxidant standards. Overall, ethanolic extract of S. indicum possess strong antioxidant capacity and offering effective protection against LDL oxidation susceptibility.     

Norlignan derivatives from <Emphasis Type="Italic">Curculigo crassifolia</Emphasis> and their DPPH radical scavenging activity

A novel norlignan derivative, crassifogenin C (1), and a known compound, curcapital (2), were isolated from the ethanolic extract of the rhizomes of Curculigo crassifolia. Their structures were elucidated on the basis of spectroscopic evidence and comparisons with literature data. Curcapital (2) was isolated from this plant for the first time. The free radical scavenging activity of the isolated compounds along with crassifoside E (3) and crassifoside F (4), which were reported previously, was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. All compounds showed strong radical scavenging activity. The primary structure-activity relationship is also discussed.     

Differential inhibitory effects of honokiol and magnolol on excitatory amino acid-evoked cation signals and NMDA-induced seizures

The effects of honokiol and magnolol, two major bioactive constituents of the bark of Magnolia officinalis, on Ca(2+) and Na(+) influx induced by various stimulants were investigated in cultured rat cerebellar granule cells by single-cell fura-2 or SBFI microfluorimetry. Honokiol and magnolol blocked the glutamate- and KCl-evoked Ca(2+) influx with similar potency and efficacy, but did not affect KCl-evoked Na(+) influx. However, honokiol was more specific for blocking NMDA-induced Ca(2+) influx, whereas magnolol influenced with both NMDA- and non-NMDA activated Ca(2+) and Na(+) influx. Moreover, the anti-convulsant effects of these two compounds on NMDA-induced seizures were also evaluated. After honokiol or magnolol (1 and 5 mg/kg, i.p.) pretreatment, the seizure thresholds of NMRI mice were determined by tail-vein infusion of NMDA (10 mg/ml). Data showed that both honokiol and magnolol significantly increased the NMDA-induced seizure thresholds, and honokiol was more potent than magnolol. These results demonstrated that magnolol and honokiol have differential effects on NMDA and non-NMDA receptors, suggesting that the distinct therapeutic applications of these two compounds for neuroprotection should be considered.     

Antioxidant and antigenotoxic activities in Acacia salicina extracts and its protective role against DNA strand scission induced by hydroxyl radical

The antioxidant potency of Acacia salicina extracts was investigated. Total antioxidant capacity was determined using an ABTS⁺ assay. Superoxide radical scavenging was measured using riboflavin-light-nitro blue tetrazolium (NBT) assay. In addition, the content of phenols, total flavonoids and sterols were measured in the tested extracts. The petroleum ether exhibited a potent scavenging activity toward ABTS radical cations. Whereas, chloroform extract showed the highest activity against superoxides radicals and was also able to protect pKS plasmid DNA against hydroxyl radicals induced DNA damages. The antimutagenicity of these extracts was assayed using the Ames assay against Salmonella typhimurium TA98 and S. typhimurium TA 1535 tester strains at different concentrations. These extracts decreased significantly the mutagenecity induced by sodium azide (SA) and 4-nitro-o-phenylenediamine (NOP). The antioxidant and antimutagenecity activities exhibited by A. salicina depended on the chemical composition of the tested extracts.     

2种藏紫草体外抗氧化及抗菌活性比较

目的 比较长花滇紫草和团花滇紫草75％乙醇提取物的体外抗氧化及抗菌活性.方法 采用ABTS法、FRAP法、邻苯三酚自氧化法测定体外抗氧化能力,并采用肉汤连续稀释法初步考察了 2种藏紫草体提取物体外对15种不同菌株的抗菌作用.结果 不同浓度藏紫草的75％乙醇提取物对ABTS自由基和超氧阴离子都有较强的清除能力,与BHT阳...     

Effects of various structurally related beta-adrenoceptor blocking agents on maximum upstroke velocity of action potential in guinea-pig papillary muscles

Summary The effects of indenolol (7.0–100 mol/l), befunolol (15.3–250 mol/l), metoprolol (58.4–1000 mol/l), Kö707 (7.3–100 mol/l), D-25 (3.7–100 mol/l) and Kö1313 (73.9–1000 mol/l) on action potentials were investigated in isolated guinea-pig papillary muscles. All these aryloxyisopropylaminopropanol derivatives produced a concentration-dependent reduction of _max at a basic rate of 1 Hz. The reduction was less prominent when interstimulus intervals were prolonged. The time course of recovery of _max during diastole was studied by assessing _max in premature responses at 0.25, 0.1 and 0.027 Hz and in responses after interrupting driving stimuli of 1 Hz. The recovery process was approximated by a single exponential function. The results, together with those reported previously (Sada and Ban 1980, 1981), revealed: (1) a significant correlation between potencies of these derivatives for depression of _max at 0.027, 0.25, 1 and 5 Hz and their log n-octanol/water partition coefficients (log P); (2) The time constants of recovery were relatively concentration independent and correlated significantly with the molecular weights. The results suggest that the potency of these drugs for the depression of _max was mainly determined by log P, being modified secondarily by the time constants of recovery which are intimately associated with the molecular weights.     

Biological potentials and cytotoxicity of various extracts from endemic Origanum minutiflorum O. Schwarz & P.H. Davis

The aim of the present study was to investigate antioxidative, antimicrobial and cytotoxic effects of endemic Origanum minutiflorum (O. Schwarz & P.H. Davis). Antioxidant activities of the extracts from O. minutiflorum were evaluated by using DPPH radical scavenging, β-carotene bleaching and metal chelating activity assays. In addition, the amounts of total phenol components in the plant extracts were determined. In the β-carotene bleaching test, the extracts exhibited in the range of 58.1 ± 0.2% – 98.2 ± 0.3% inhibition against linoleic acid oxidation. The antimicrobial efficiency of the plant was evaluated according to agar well diffusion and microdilution broth methods. The n-hexane extract of O. minutiflorum having an inhibition zone of 20.2 ± 0.2 mm, had the maximum antibacterial efficiency against Shigella sonnei RSKK 878. Cytotoxic effects of the extracts were determined by MTT assay. O. minutiflorum extracts (at concentration of 10–100 μg/ml) did not show any cytotoxic effect on baby hamster kidney fibroblast cell line. The results showed that O. minutiflorum could be used as a natural source in food industry.     

叶底珠内生真菌提取物的抗炎镇痛和抗氧化活性研究

目的 研究黄河三角洲贝壳堤岛叶底珠内生真菌代谢产物醋酸乙酯粗提物的体外抗炎镇痛和抗氧化活性,筛选鉴定具有活性的内生真菌。方法 以黄河三角洲贝壳堤岛叶底珠为实验材料分离内生真菌,通过1,1-二苯基-2-三硝基苯肼（DPPH）法、二甲苯致小鼠耳廓肿胀法以及醋酸扭体法测定其代谢产物醋酸乙酯粗提物的抗氧化活性、抗炎作用以及镇痛作用。通过雷氏盐剩余比色法、Folin-Ciocalteu法、亚硝酸钠-硝酸铝比色法检测活性菌株的总生物碱、总酚、总黄酮的含量,SPSS 16.0软件分析3种生物活性与3种成分含有量的相关性。基于核糖体RNA基因（即rDNA）内转录间隔区（Internal Transcribed Spacer,ITS）的多态性的序列分析,通过分子生物学方法对筛选出的活性菌株进行鉴定。结果 共分离得到内生真菌59株,其中8株表现出不同的抗氧化活性,10株对小鼠耳肿胀有不同程度的抑制作用,8株对醋酸诱导的疼痛有不同程度的抑制作用;总酚含量和抗氧化作用、总生物碱含量和抗炎活性间具有显著相关性;初步鉴定生物活性较高的8株内生真菌菌株为Chaetomium globosum、Chaetomium sp.、Fusarium sp.、Fusarium solani、Cladosporium ramotenellum、Leptosphaeria sp.、Phoma multirostrata和Phoma sp.。结论 黄河三角洲贝壳堤岛叶底珠内生真菌具有良好的体外抗炎镇痛和抗氧化活性,总酚和生物碱含量是影响生物活性的主要因素。     

Antioxidant and antidermatophytic activities of essential oil and extracts of Magnolia liliflora Desr.

This study was carried out to assess the antioxidant and antidermatophytic activities of the essential oil and extracts of Magnolia liliflora Desr. Antioxidant activity was evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The free radical scavenging activities of the oil and ethyl acetate extract were found to be superior (IC₅₀ values = 10.11 and 16.17 μg/ml, respectively) as compared to butylatedhydreoxyanisole (BHA), (IC₅₀ value = 18.27 μg/ml). Also the ethyl acetate extract revealed the highest phenolic contents (96.13 mg/g of dry wt) as compared to the other extracts. Further, the oil (1000 μg/disc) and extracts (1500 μg/disc) revealed 42.36–63.12% and 19.07–54.14% antidermatophytic effect, respectively along with their respective MIC values ranging from 62.5 to 500 and 250 to 2000 μg/ml against the members of Trichophyton and Microsporum spp. Also the oil had strong detrimental effect on spore germination of tested fungal pathogens as well as concentration and time dependent kinetic inhibition of Microsporum canis KCTC 6348. The results of this study justify a potential role of M. liliflora to serve as a natural antioxidant and antidermatophytic agent.