Phenolic and flavonoid contents and anti-oxidative potential of epicarp and mesocarp of Lagenaria siceraria fruit: a comparative study

ObjectiveTo conduct a comparative analysis of the phenolic and flavonoid contents and anti-oxidative potential of epicarp and mesocarp of Lagenaria siceraria fruit.MethodsThe dried methanolic extracts of mesocarp and epicarp of the fruit and their hexane, chloroform, ethyl acetate, n-butanolic and aqueous fractions were subjected to antioxidant assays including ferric reducing antioxidant potential, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid, reducing power capacity, 2,2-diphenyl-1-picrylhydrazyl, lipid peroxidation inhibitory and phosphomolybdate assays. Total phenolic and flavonoid contents were also determined.ResultsEthyl acetate fractions of epicarp and mesocarp had considerable amounts of phenolics (243.50 and 109.50 μg/mL of gallic acid equivalents, respectively). 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of ethyl acetate fractions of both the plant parts showed higher activity than vitamin C with IC₅₀ (0.75 and 3.91 mg, respectively). In phosphormolybdate assay, the hexane fractions of both the parts showed highest activity [1.16 and 2.99 μg/mL of ascorbic acid equivalents (AAE) for epicarp and mesocarp, respectively], mesocarp being much potent than epicarp. The n-butanolic fraction of mesocarp also showed much higher activity (1.13 μg/mL AAE) than that of epicarp (0.74 μg/mL AAE), while the chloroform and ethyl acetate fractions of epicarp were also considerably potent. In ferric reducing antioxidant potential assay, the chloroform fractions of both the fruit parts were most active. The hexane fractions of both the parts showed highest activity in reducing power assay, epicarp being more potent than mesocarp. In 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay, the antioxidant activities of ethyl acetate and chloroform fractions of both the parts were comparable to gallic acid and vitamin C. In lipid peroxidation inhibitory assay, all the samples were moderate to good activity sustainable over the period of 72 h, indicating the presence of both slow and fast releasing antioxidants.ConclusionsThe findings of the study suggest that epicarp is a better source of antioxidants than the mesocarp, and the ethyl acetate fractions of both the parts contain higher contents of antioxidants.     

Lipase inhibitory activity of Lagenaria siceraria fruit as a strategy to treat obesity

Objective:To explore pancreatic lipase inhibitory activity under different extraction conditions in order to track the most potent extract.Methods:The methanolic extract and its fractions in solvents of increasing polarity,ether,chloroform,ethyl acetate,n-butanol and water,were made through cold maceration.Extracts in ethanol,ethyl acetate,acetone and chloroform were similarly prepared.Aqueous extract was prepared through hot decoction method.A reported method was used to determine lipase inhibitory activity of extracts and fractions over wide ranges of concentrations.Results:The extracts and fractions exhibited concentration dependent activity.The IC50(μg/mL)values of methanolic,ethanolic,chloroform,ethyl acetate,acetone,ethyl acetate(after washing with water)and aqueous decoction were 293.40,266.47,157.59,182.12,352.34,257.00,and 190.00,respectively.The activity of chloroform,ethyl acetate and aqueous extracts were close to that of the drug orlistat(IC50 146μg/mL).Out of the fractions of the methanolic extract,the chloroform fraction was most active(IC50 189.6μg/mL).The order of inhibitory activity of the fractions was as follows:chloroformethern-butanolicaqueousethyl acetate.The GC/MS analysis of the most active chloroform faction showed the presence of hexadecanoic acid,methyl hexadecanoate,isopropyl palmitate,methyl 9,12-octadecadienate,and methyl 9,12,15-octadecatrienoate.Conclusions:The study suggests that Lagenaria siceraria has potential to inhibit pancreatic lipase activity,suppressing lipid digestion and thereby diminishing entry of lipids into the body.Regular intake of aqueous decoction of the fruit may therefore be recommended for control of obesity.Fatty acids and their esters may play role as inhibitors of lipase.     

Free radical scavenging and reducing power of Lawsonia inermis L. seeds

ObjectiveTo determine the antioxidant activity, total phenolic and flavonoid content of Petroleum ether extract (PE), Dichloromethane extract (DCM), Ethanol extract (ET) and aqueous extract (AQ) of henna seeds.MethodsTotal antioxidant assay (phosphomolybenum method), DPPH radical scavenging assay, reducing power assay and lipid peroxidation inhibition assay were used to ascertain the potential of seeds as an antioxidant.ResultsIn all the assays carried out ET showed a greater potential to scavenge DPPH radical, reduce MO (VI) to MO (V) complex and Fe (III) to Fe (II) and to inhibit lipid peroxidation. The IC₅₀ of ET was far greater than that of the standard, ascorbic acid (AS) in the lipid peroxidation assay. The activity of AQ was lesser when compared with that of ET but greater than PE and DCM. The amount of phenolics and flavonoids were present in higher amounts in ET followed by AQ. Trace amounts of phenolics were detected in PE and DCM, but the amount of flavonoids were below the detection level. The study showed that the antioxidant activity and the concentrations of phenolics and flavonoids are proportionate to each other.ConclusionsEthanolic extract of henna seeds are efficient antioxidants, which can be utilized for further isolation of active compounds and pharmaceutical applications.     

In vitro evaluation of free radical scavenging activity of Codariocalyx motorius root extract

ObjectiveTo determine the phenolic content in Codariocalyx motorius root extract and to evaluate its antioxidant properties using various in vitro assay systems.MethodsThe antioxidant activity was evaluated based on scavenging of 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radicals, superoxide anions, nitric oxide, hydrogen peroxide, peroxynitrite, reducing power and by inhibition of lipid peroxidation which was estimated in terms of thiobarbituric acid reactive substances.ResultsThe root extract of the Codariocalyx motorius (C. motorius) exhibited potent total antioxidant activity that increased with increasing amount of extract concentration, which was compared with standard drug such as quercetin, butylated hydroxytoluene, tocopherol at different concentrations. The different concentrations of the extracts showed inhibition on lipid peroxidation. In addition, the extracts had effective reducing power, free radical scavenging, super oxide anion scavenging, nitric oxide scavenging, lipid peroxidation, and total phenolic content depending on concentration. High correlation between total phenolic contents and scavenging potential of different reactive oxygen species (r²=0.831–0.978) indicated the polyphenols as the main antioxidants.ConclusionsCodariocalyx motorius (C. motorius) root possess the highly active antioxidant substance which can be used for the treatment of oxidative stress-related diseases.     

Free radical scavenging systems and the effect of peroxide damage in aged human skin fibroblasts

One prominent theory of aging postulates an accumulation of cell damage resulting from nonenzymatic chemical reactions between important cellular components and free radicals. Fibroblast lines derived from skin biopsies of psychiatric patients ranging in age from 22 to 70 were evaluated soon after adaptation to culture. No significant correlation was found between donor age and the detoxification enzyme activities of superoxide dismutase (SOD) or aryl hydrocarbon hydroxylase (AHH) or susceptibility to damage by oxygen metabolites as measured by cell viability or lactate dehydrogenase (LDH) leakage.     

Free radical scavenging and antioxidant activity of D-pinitol against 7, 12 dimethylbenz (a) anthracene induced breast cancer in sprague dawley rats

ObjectiveTo investigate whether D-pinitol efficiently scavenge free radicals using various in vitro models [1, 1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide, superoxide anion and total antioxidant activity] and in vivo models.MethodsFemale Sprague-Dawley rats (150-160 g) were divided into four groups and each group consisting of six animals. Group I and group IV were vector and drug control. The group II and group III animals were treated with 7, 12-dimethylbenz(a)anthracene (DMBA) 20 mg/kg body weight to induce mammary carcinoma. Rats received cancer bearing Group III animals were treated with D-pinitol at the concentration of 200 mg/kg bodyweight for 45 d orally. Five different concentrations of D-pinitol (100 to 500 μg/mL) were used in in vitro studies.ResutlsThe results revealed that D-pinitol efficiently scavenges DPPH radicals and the IC₅₀ was found to be 290 μg/mL and it also exhibited a dose dependent antioxidant activity at different concentrations. In addition, the superoxide and nitricoxide radicals were also significantly inhibited by D-pinitol at the concentrations of 360 and 390 μg/mL respectively. On the other hand, D-pinitol has significantly increased antioxidant enzymes during DMBA induced mammary carcinoma.ConclusionsIt can be concluded from the investigation that D-pinitol has an excellent antioxidant activity which could be due to the scavenging capacities on the stable DPPH radicals, superoxide, nitric oxide and DMBA induced free radicals thereby it exhibits remarkable total antioxidant activity.     

Phytopharmacological approach of free radical scavenging and anti-oxidative potential of eugenol and Ocimum gratissimum Linn.

ObjectiveTo evaluate phytopharmacologically eugenol and two extract products of Ocimum gratissimum Linn. (O. gratissimum) (Labiaceae) on free radical scavenging and antioxidant activity.MethodsAqueous and methanol extract of fresh aerial part of O. gratissimum were prepared and eugenol (1-allyl-4-hydroxy-3-methoxybenzene) was isolated from fresh leaves and characterized by high performance liquid chromatography, fourier transform infrared spectroscopy, 1 h nuclear magnetic resonance. To establish the antioxidant potentiality of aqueous extract, methanol extract and eugenol, 1, 1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, nitric oxide scavenging activity, antioxidant activity by ferric thiocyanate and reducing power were measured in chemical system in vitro.ResultsSignificant (P<0.05) concentration-dependent free radical scavenging activity, antioxidant activity, and reducing power was observed by O. gratissimum products. Moreover, eugenol is more potent than the two extract products of O. gratissimum, but lower than potent antioxidant ascorbic acid.ConclusionsHence, O. gratissimum presents a potentially valuable source of natural antioxidant and bioactive material.     

Free radical scavenging property and antiproliferative activity of Rhodiola imbricata Edgew extracts in HT-29 human colon cancer cells

ObjectiveTo investigate the in vitro antioxidant and antiproliferative activity of rhizome extracts of Rhodiola imbricata (R. imbricata) in HT-29 human colon cancer cell line.MethodsThe successively extracted rhizome of R. imbricata using various solvents was analyzed for their total phenolics, tannins and flavonoid contents. In vitro antioxidant activity was evaluated by employing different assays, including DPPH, ABTS radical scavenging assays, FRAP, phosphomolybdenum reduction assay, superoxide anion, hydroxyl radical scavenging activities and metal chelating ability.ResultsAcetone and methanol extracts recorded higher phenolic content and showed comparable antioxidant activity with standard reference. Additionally, they also inhibited the proliferation of HT-29 cells upon treatment at higher concentration (200 μg/mL) (acetone and methanol, 84% and 84%, respectively). On examination acetone extract exhibited antiproliferative activity in a concentration dependent manner whereas, methanol extract showed both dose dependent and time dependent inhibitory activity.ConclusionsThe results obtained justify the traditional usage of R. imbricata from their promising antioxidant activity.     

Effects of young barley leaf extract and antioxidative vitamins on LDL oxidation and free radical scavenging activities in type 2 diabetes

BACKGROUND: The effects of supplementation of young barley leaf extract (BL) and/or antioxidative vitamins C and E on different low-density lipoprotein (LDL) subfractions susceptibility to oxidation and free radical scavenging activities in patients with type 2 diabetes were evaluated. METHODS: Thirty-six type 2 diabetic patients were enrolled in this study. The subjects received one of the following supplements daily for 4 weeks: 15 g BL, 200 mg vitamin C and 200 mg vitamin E (CE), or BL plus CE (BL + CE). RESULTS: The lucigenin-chemiluminescence (CL) and luminol-CL levels in blood were significantly reduced in all groups. Vitamin E content of LDL subfractions increased significantly following supplements, especially for BL + CE group. The percent increase of lag times in the BL + CE was significantly higher than those in the BL or CE group. The antioxidative effect of BL + CE was the greatest for small, dense LDL (Sd-LDL) with further increases in percentage of lag times 4 folds compared to BL alone. CONCLUSION: Our results indicate that supplementation with BL may help to scavenge oxygen free radicals, save the LDL-vitamin E content, and inhibit LDL oxidation. Furthermore, the addition of vitamins C and E to BL can inhibit the Sd-LDL oxidation more effectively, which may protect against vascular diseases in type 2 diabetic patients.     

Free use of fruits and vegetables in phenylketonuria

This study aimed to evaluate systematically the effect of the free use of fruits and vegetables containing an intermediate amount of phenylalanine (51–100 mg/100 g) on the biochemical control in children with phenylketonuria (PKU). Fifteen subjects with PKU, with a median age of 6 years (range 1–24 years) were studied. In a three-part prospective 15-week study, subjects sequentially ate fruits and vegetables containing phenylalanine 0–50 mg/100 g for weeks 1 to 3; 51–75 mg/100 g for weeks 4 to 8; and 76–100 mg/100 g for weeks 9 to 15. Plasma phenylalanine concentrations were measured twice daily for three consecutive days in weeks 1, 3, 6, 8, 11, 13 and 15. A standard menu was followed on the blood sampling days. Daily dietary records of fruits and vegetables under study were kept throughout the trial. Control of phenylalanine concentrations was not adversely affected by the free use of fruits and vegetables containing 51–100 mg/100 g. Pre-breakfast median plasma concentrations were: weeks 1 to 3, 260 μmol/L (range 90–890); weeks 4 to 8, 255 μmol/L (range 130–920); and weeks 9 to 15, 278 μmol/L (range 30–880). Pre-evening meal median plasma phenylalanine concentrations were: weeks 1 to 3, 240 μmol/L (range 30–820); weeks 4 to 8, 210 μmol/L (40–880); and weeks 9 to 15, 238 μmol/L (range 20–880). These data suggest that free use of fruits and vegetables containing 51–75 mg/100 g poses no problem for children with PKU. This revised version was published online in August 2006 with corrections to the Cover Date.     

Radical scavenging and antibacterial activity of Arnebia benthamii methanol extract

ObjectiveTo evaluate in vitro antioxidant and antibacterial activity of methanolic extract of Arnebia benthamii (A. benthamii) whole plant.MethodsPlasmid damage was analyzed by agarose gell electrophoresis. Calf thymus DNA was monitored by TBARS formation. DPPH, reducing power and lipid peroxidation was evaluated by using standard procedures. Antibacterial assay was monitored by disc diffusion method.ResultsDPPH radical scavenging and hydroxyl radical scavenging potential of the plant revealed that the extract to be active radical scavenger. Reducing (Fe³⁺-Fe²⁺) power and lipid peroxidation inhibition efficiency (TBARS assay) of the extract was also evaluated and the extract showed promising activity in preventing lipid peroxidation and might prevent oxidative damages to biomolecules. The extract offered a significant protection against plasmid and calf thymus DNA damage induced by hydroxyl radicals. The extract was also evaluated on different bacterial strains and the maximum antibacterial activity was exhibited against Escherichia coli (E. coli) when compared with standard drug.ConclusionsThese findings demonstrate that the methanol extract of A. benthamii has excellent anti-oxidant activities and could be considered as a potential source of lead molecules for pharmaceutical industries.     

Free radical scavenger activity of rutosides

BACKGROUND: The O-(beta-hydroxyethyl)-rutosides (HRs) are a standard mixture of flavonoid-derivatives that have a clinico-pharmacological activity on peripheral circulation, particularly on the endothelial cells of veins and lymphatics. Flavonoids are believed to prevent the oxidative damage derived from radical oxidative species (ROS), like hydroxyl radicals (HO.) and hypochlorite (-OCl). The aim of the study was to investigate the stability and capability of HRs in toto and of their single components (7-mo-nohydroxy ethyl rutoside; 7,4'-dihydroxyethyl rutoside; 7,3',4'-trihydroxyethyl rutoside and the 7,5,3',4'-tetrahydroxyethyl rutoside) of scavenging ROS and other radicals generated by different oxidative systems, and also their anti-lipoperoxidative activity at mM concentrations (1.0-10.0 mM). METHODS: The following oxidative systems have been employed: Fenton reaction for the hydro-xylation of l-tyrosine to l-DOPA and the peroxidation of arachidonic acid; photo-Fenton type reaction for the oxidation of toluene in the aqueous UV irradiated TiO2 system; the azocompound 2.2'-azobis(2, 4-dimethylvaleronitrile (AMVN) to produce peroxy radicals and the daily autoxidation of arachidonic acid. Analyses were performed by HPLC, HPLC-MS, GC-MS, and spectrophotometry. RESULTS: At 5.0 mM concentration, HRs produced the following inhibitions: 63+/-5% of the overall formation of cresols, benzaldehyde, benzyl alcohol, and biphenyl induced by photo-Fenton reaction; 91.6+/-5% and 59+/-8% of the synthesis of l-DOPA induced by HO. generated by Fenton reaction; 45+/-7% and 52+/-6% of the oxidation of arachidonic acid induced by Fenton reaction and AMVN; 60+/-4% of the autoxidation of arachidonic acid. These effects were strictly concentration dependent. CONCLUSIONS: At mM concentrations, HRs display a significant antilipoperoxidative activity due to their notable scanvenging activity against HO.; moreover these actions are concentration-dependent.     

心脑肾康对自由基清除作用的实验研究

目的研究心脑肾康对自由基的清除作用。方法连续给大鼠灌胃心脑肾康7d后，以线栓法建立大脑中动脉梗死（MCAO）缺血再灌注模型，缺血1．5h再灌注24h后断头取脑，检测大脑皮层丙二醛（MDA）、超氧化物歧化酶（SOD）、一氧化氮（NO）、活性氧（ROS）、谷胱甘肽（GSH）含量。结果与模型组相比，商、中、低3个剂量心脑肾康用药后均能显著降低缺血后脑组织匀浆中MDA、NO、ROS含量，增加SOD、GSH活性（P〈0．05）并呈剂量依赖性。其中，高剂量效果最好，优于阳性对照药（P〈0．05）。结论心脑肾康具有良好的自由基清除作用。     

The antiplasmodial and radical scavenging activities of flavonoids of Erythrina burttii

The acetone extract of the root bark of Erythrina burttii showed in vitro antiplasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC(50) values of 0.97 ± 0.2 and 1.73 ± 0.5 μg/ml respectively. The extract also had radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical with an EC(50) value of 12.0 μg/ml. The isoflav-3-enes burttinol-A and burttinol-C, and the 2-arylbenzofuran derivative burttinol-D were identified as the most active antiplasmodial (IC(50)<10 μM) and free radical scavenging (EC(50)ca. 10 μM) principles. The acetone extract of E. burttii at 800 mg/kg/day, in a 4-day Plasmodium berghei ANKA suppressive test, showed in vivo antimalarial activity with 52% chemosuppression. In the same in vivo test, marginal activities were also observed for the extracts of the root and stem bark of Erythrina abyssinica and the root bark of Erythrina sacleuxii.     

Isolation of leptospires from a one week dead coypu (Myocastor coypus Molina)

The isolation of L. Interrogans from a one week dead coypu is reported. The isolate was identified as a pathogenic strain of leptospira belonging to the Icterohaemorrhagiae serogroup.     

Receptor-independent intracellular radical scavenging activity of an angiotensin II receptor blocker

OBJECTIVES: Angiotensin II plays a crucial role in the induction of oxidative stress and the pathogenesis of cardiovascular and renal diseases, and the beneficial mechanisms of angiotensin II receptor 1 blockers (ARBs) are multifactorial. We investigated the receptor-independent protective role of an ARB using primary-cultured mesangial cells from angiotensin II receptor 1 knockout or wild-type mice and a highly lipophilic ARB, telmisartan. METHODS AND RESULTS: Intracellular reactive oxygen species were estimated using a fluorogenic probe, CM-H2DCFDA. Non-angiotensin II-induced reactive oxygen species production was generated by exposing cells to hydrogen peroxide alone or after treatment with telmisartan. Flow cytometry analysis showed that angiotensin II induced an increase in oxidant production in a dose-dependent manner in wild-type cells, but not in knockout cells. In contrast, hydrogen peroxide induced oxidative stress in both wild-type and knockout cells. Interestingly, telmisartan attenuated the oxidative stress induced by hydrogen peroxide in both cells, suggesting that it acted via a receptor-independent antioxidant effect. Intracellular concentrations of telmisartan were confirmed by high-performance liquid chromatography analysis. Expression of plasminogen activator inhibitor 1, which is stimulated by oxidative stress, was also attenuated by telmisartan in a receptor-independent as well as receptor-dependent manner. Telmisartan did not change expression levels of antioxidative enzymes such as catalase or glutathione peroxidase. Furthermore, the amelioration of oxidative stress by telmisartan did not involve the peroxisome proliferator-activated receptor-gamma pathway. CONCLUSIONS: Telmisartan inhibits intracellular oxidative stress, at least in part, in a receptor-independent manner, possibly owing to its lipophilic and antioxidant structure.     

Free radical generation by neutrophils: a potential mechanism of cellular injury in acute alcoholic hepatitis.

Liver membrane vesicles were prepared from operative liver biopsies from six patient volunteers undergoing abdominal surgery for non-hepatic disease. Neutrophils were extracted from their blood. The liver membrane vesicles were exposed to 1 mmol/l acetaldehyde with or without reduction of the resultant adducts formed. The production of superoxide anion by the neutrophils upon exposure to the liver membrane vesicles prepared from the same patient was assessed by measuring the rate of cytochrome c reduction before and after the addition of superoxide dismutase. Preincubation with acetaldehyde significantly increased superoxide production in response to both the reduced (from 35.5 +/- 7.1 nmol O2-/10(8) cells/min to 128 +/- 25, mean +/- SEM, p less than 0.01) and the non-reduced liver cell membranes (from 17.2 +/- 4.3 to 81 +/- 17, p less than 0.01); 1 mmol/l acetaldehyde alone caused no superoxide production. Neutrophil free radical production in response to acetaldehyde altered hepatocyte membranes could be an important mechanism of cellular injury in acute alcoholic hepatitis.