Free radical scavenging and antioxidant activities of Glinus oppositifolius (carpet weed) using different in vitro assay systems

Glinus oppositifolius (L.) Aug. DC. (Aizoceae), commonly called slender carpet weed, is a prostrate or diffuse herb which acts as stomachic, uterine stimulant, aperient and lochia. It is used traditionally in the treatment of earache, itch and skin diseases. Glinus oppositifolius was extracted with ethanol (70%) and used for the evaluation of various in vitro antioxidant assays which includes H-donor activity, nitric oxide scavenging, superoxide anion scavenging, reducing ability, hydroxyl radical, hydrogen peroxide scavenging, total phenolic content, total flavonoid content, total antioxidant activity by thiocyanate and phosphomolybdenum method, metal chelating, β-carotene bleaching, total peroxy radical assays. The pro-oxidant activity was measured using bleomycin-dependent DNA damage. Ex vivo models such as lipid peroxidation were used to study the antioxidant property of the extract. The various antioxidant activities were compared with suitable standard antioxidants such as ascorbic acid, butylated hydroxyl toluene (BHT), α-tocopherol, curcumin, quercetin and Trolox. The generation of free radicals, viz., O₂^·?, OH^·, H₂O₂, NO^· and peroxyl radicals, were effectively scavenged by the ethanol extract of Glinus oppositifolius. The antioxidant activity depends on concentration and increases with increasing amounts of the extract. The total phenolic content, flavonoid content and total antioxidant activity in Glinus oppositifolius were determined as microgram (μg) pyrocatechol, quercetin and α-tocopherol equivalent/mg, respectively. The extract did not exhibit any pro-oxidant activity when compared with ascorbic acid. The results obtained in this study indicate that Glinus oppositifolius scavenges free radicals and reduces lipid peroxidation, ameliorating the damage imposed by oxidative stress in different disease conditions and serve as a potential source of natural antioxidant.     

Profiling of rutin‐mediated alleviation of cadmium‐induced oxidative stress in Zygophyllum fabago

Zygophyllum fabago grows in arid, saline soil, or disturbed sites, such as former industrial or mining areas. This species is able to grow in coarse mineral substrates contaminated with heavy metals. To investigate the effects of the flavonoid rutin (Rtn) on certain heavy metal stress responses such as antioxidant defense systems and water status, seedlings were subjected to 100 and 200 μM CdCl₂ treatment without or with 0.25 and 1 mM Rtn for 7 and 14 d (days). Cd stress decreased growth (RGR), water content (RWC), leaf osmotic potential (Ψ_Π), and chlorophyll fluorescence, all of which could be partly alleviated by addition of Rtn. Activities of superoxide dismutase, peroxidase (POX), ascorbate peroxidase, and glutathione reductase increased within the first 7 d after exposure to Cd. However, failure of antioxidant defense in the scavenging of reactive oxygen species (ROS) was evidenced by an abnormal rise in superoxide anion radical ( ${\mathrm{O}}_2^{??}$) and hydrogen peroxide contents and a decline in hydroxyl radical (OH^?) scavenging activity, resulting in enhancement of lipid peroxidation (TBARS) as a marker of Cd‐induced oxidative stress. However, exogenously applied Rtn considerably improved the stress tolerance of plants via a reduction in Cd accumulation, modulation of POX activity, increase of proline (Pro) content, decrease in TBARS and ROS content and consequent lowering of oxidative damage of membrane. Overall, 0.25 and 1 mM Rtn could protect Z. fabago from the harmful effects of 100 μM Cd‐induced oxidative stress throughout the experiment. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 816–835, 2015.     

Antioxidant potential of lichen species and their secondary metabolites. A systematic review

Context: Pharmacological interest of lichens lies in their capacity to produce bioactive secondary metabolites, being most of them phenolic compounds with reactive hydroxyl groups that confer antioxidant potential through various mechanisms. Increasing incidence and impact of oxidative stress-related diseases (i.e., neurodegenerative disorders) has encouraged the search of new pharmacological strategies to face them. Lichens appear to be a promising source of phenolic compounds in the discovery of natural products exerting antioxidant activity.

Objective: The present review thoroughly discusses the available knowledge on antioxidant properties of lichens, including both in vitro and in vivo studies and the parameters assessed so far on lichen constituents.

Methods: Literature survey was performed by using as main databases PubMed, Google Scholar, Scopus, Science Direct, and Recent Literature on Lichens. We reviewed 98 highlighted research articles without date restriction.

Results: Current report collects data related to antioxidant activities of more than 75 lichen species (from 18 botanical families) and 65 isolated metabolites. Much information comes from in vitro investigations, such as chemical assays evaluating radical scavenging properties, lipid peroxidation inhibition, and reducing power of lichen species and compounds; similarly, research on cellular substrates and animal models generally measures antioxidant enzymes levels and other antioxidant markers, such as glutathione levels or tissue peroxidation.

Conclusion: Since consistent evidence demonstrated the contribution of oxidative stress on the development and progression of several human diseases, reviewed data suggest that some lichen compounds are worthy of further investigation and better understanding of their antioxidant and neuroprotective potentials.     

Protective effect of partially purified 35 kDa protein from silk worm (Bombyx mori) fecal matter against carbon tetrachloride induced hepatotoxicity and in vitro anti-viral properties

Context: It has been found that many proteins from silkworm (Bombyx mori L.) fecal matter have been active against human immunodeficiency virus, Sendai virus, herpes simplex virus type-1, and nuclear polyhedrosis virus.

Objective: A partially purified 35?kDa protein from silkworm was screened for its hepatoprotective activity, and in vitro antioxidant, and antiviral properties against camelpox and goatpox viruses.

Materials and methods: The study investigated the efficiency of the partially purified 35kDa protein from silk worm fecal matter against CCl₄-induced liver damage measured in terms of enzyme levels such as aspartate aminotransferase (AST), alanine amino transferase(ALT), alkaline phosphatase (ALP) and total bilirubin, which maintain liver integrity. In vitro antioxidant potential of this protein was determined based on its ability to scavenge 2, 2-diphenylpicrylhydrazyl (DPPH) and superoxide anions scavenging activity. Further, in vitro cytotoxic effect on Vero cells and antiviral activity against goatpox and camelpox viruses were also studied.

Results: The protein had significant hepatoprotection against CCl₄-induced liver damage and scavenging of DPPH radical and superoxide anion activity. However, the protein did not inhibit the multiplication of either virus tested at its maximum non-toxic concentration (MNTC) in vitro.

Discussion and conclusion: The partially purified 35?kDa protein from silk worm Bombyx mori L fecal matter possessed protective effect against CCl₄-induced oxidative stress in rat model. The protein was found to be ineffective against camelpox and goatpox viruses at its MNTC in vitro.     

Purification of chicken breast protein hydrolysate and analysis of its antioxidant activity

Chicken breast protein was hydrolyzed by papain under optimal conditions. The antioxidant activity of the chicken breast protein hydrolysate was then evaluated in vitro and in vivo using different measurements, including reducing power and DPPH radical scavenging assays. The reducing power of the hydrolysate was 0.5 at 2.37 mg/mL. The DPPH radical scavenging assay showed that the EC₅₀ value of the hydrolysate was 1.28 mg/mL. In antioxidant assays in vivo, d-galactose-induced aging mice administrated the fraction peptides of chicken breast protein hydrolysate showed significantly increased antioxidant enzyme activities, while malondialdehyde levels decreased both in serums and livers. Under a transmission electron microscope (TEM), the ultramicrostructure of hepatic tissue was observed and we found that the hydrolysate may play a part in inhibiting oxidative stress in hepatocytes in vivo. Therefore, we concluded that chicken breast protein hydrolysate exhibits significant antioxidant activity.     

Evaluation of the antioxidant activity of Betula pendula leaves extract and its effects on model foods

Context: Betula pendula Roth (Betulaceae) exhibits many pharmacological activities in humans including anticancer, antibacterial, and antiviral effects. However, the antioxidant activity of BP towards lipid degradation has not been fully determined.

Objective: The BP ethanol and methanol extracts were evaluated to determine antioxidant activity by an in vitro method and lyophilized extract of BP was added to beef patties to study oxidative stability.

Materials and methods: Antioxidant activities of extracts of BP were determined by measuring scavenging radical activity against methoxy radical generated by Fenton reaction 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (TEAC) radical cation, the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) assays. The lipid deterioration in beef patties containing 0.1% and 0.3% (w/w) of lyophilized extract of BP stored in 80:20 (v/v) O₂:CO₂ modified atmosphere (MAP) at 4?°C for 10 days was determined using thiobarbituric acid reacting substances (TBARS), % metmyoglobin and colour value.

Results: The BP methanol extract revealed the presence of catechin, myricetin, quercetin, naringenin, and p-coumaric acid. The BP ethanol (50% w/w) extract showed scavenging activity in TEAC, ORAC and FRAP assays with values of 1.45, 2.81, 1.52?mmol Trolox equivalents (TE)/g DW, respectively. Reductions in lipid oxidation were found in samples treated with lyophilized BP extract (0.1% and 0.3% w/w) as manifested by the changes of colour and metmyoglobin concentration. A preliminary study film with BP showed retard degradation of lipid in muscle food.

Conclusion: The present results indicated that the BP extracts can be used as natural food antioxidants.     

Ligularia fischeri extract attenuates liver damage induced by chronic alcohol intake

Context Ligularia fischeri (Ledebour) Turcz. (Compositae) has been used as a leafy vegetable and in traditional medicine to treat hepatic disorder in East Asia.

Objective The present study explores the antioxidant activity of LF aqueous extract on EtOH-induced oxidative stress accompanied by hepatotoxicity both in vitro and in vivo.

Materials and methods In vitro study using the mouse liver NCTC-1469 cell line was conducted to estimate the cytotoxicity as well as the inhibitory effect of LF extract against alcohol-treated cell damage. In vivo study used an alcohol-fed Wister rat model orally administered EtOH (3.95?g/kg of body weight/d) with or without LF extract (100 or 200?mg/kg body weight) for 6 weeks. Serum and liver tissue were collected to evaluate hepatic injury and antioxidant-related enzyme activity.

Results The EC₅₀ value for the DPPH radical scavenging capacity of LF extract was 451.5?μg/mL, whereas the IC₅₀ value of LF extract in terms of EtOH-induced reactive oxygen species (ROS) generation was 98.3?μg/mL without cell cytotoxicity. LF extract (200?mg/kg body weight) significantly reduced the triglyceride content of serum (33%) as well as hepatic lipid peroxidation (36%), whereas SOD activity was elevated three-fold. LF extract suppressed expression of CYP2E1 and TNF-α, and attenuated alcohol-induced abnormal morphological changes.

Discussion and conclusion LF extract attenuated liver damage induced by alcoholic oxidative stress through inhibition of ROS generation, down-regulation of CYP2E1, and activation of hepatic antioxidative enzymes. Homeostasis of the antioxidative defence system in the liver by LF extract mitigated hepatic disorder following chronic alcohol intake.     

Antioxidant and anti-inflammatory activities of Aerva pseudotomentosa leaves

Context: Aerva pseudotomentosa Blatt. &; Hallb. (Amaranthaceae), commonly called ‘Bui’, is a medicinal plant of the arid region. It is used for the treatment of inflammatory disorders, such as rheumatic pain, and healing of wounds, which are associated with oxidative stress.

Objective: The present study evaluated the antioxidant potential of Aerva pseudotomentosa leaves by in vitro models and its anti-inflammatory effect in rats.

Material and methods: The aqueous extract (APAE) was analyzed by HPTLC and HPLC. The antioxidant effect of APAE was evaluated by various in vitro methods [DPPH (1, 1-diphenyl-2-picryl-hydrazil) and hydrogen peroxide free radical scavenging, reducing power, and anti-lipid peroxidation assays]. Anti-inflammatory effect was studied in carrageenan and formalin-induced paw oedema models in rats. APAE (200 and 400?mg/kg) and standard drug, indomethacin (10?mg/kg), were administered orally 1?h before carrageenan/formalin administration and inflammation was noted up to 5?h.

Results: HPLC analysis of APAE revealed the presence of rutin. APAE showed significant scavenging effect on DPPH (IC₅₀ 49.37?μg/mL) and peroxide (IC₅₀ 288.2?μg/mL) radicals. The extract exhibited reducing potential and inhibition of lipid peroxidation. APAE treatment significantly attenuated mean increase in paw volume and exhibited inhibition of paw oedema in both in vivo models with inhibition of 45.11% and 49.42%, respectively at 5?h.

Discussion and conclusion: APAE exhibited in vitro antioxidant and anti-inflammatory activities. Anti-inflammatory effect of APAE may be attributed to its antioxidant potential, due to the presence of rutin and other phenolics. This study substantiates folk use of leaves in inflammatory disorders.     

Potential in vitro antioxidant and protective effects of Gymnema montanum H. on alloxan-induced oxidative damage in pancreatic β-cells, HIT-T15

The present study describes the antioxidant activities of ethanol extract from Gymnema montanum (GLEt) which is an endemic plant of India. Antioxidant activity of the GLEt was studied in vitro based on scavenging of hydroxyl radicals, superoxide anions, nitric oxide, hydrogen peroxide, peroxynitrite, reducing power and inhibition of lipid peroxidation estimated in terms of thiobarbituric acid reactive substances (TBARS). Further, we examined its protective effect against alloxan-induced oxidative stress in pancreatic β-cells, HIT-T15 by measuring the free radical generation, malonaldehyde formation and antioxidant levels such as CAT, GPx and GSH. Results showed that G. montanum leaves exhibited significant antioxidant activities measured by various in vitro model systems. The HIT-T15 cell line studies showed the tendency of GLEt to increase antioxidant levels meanwhile decrease the free radical formation and inhibit the lipid peroxidation. The antioxidant activity was found to be well correlated with the phenolic phytochemicals present in the extract. GC–MS analyses revealed the presence of few phenolic compounds in the extract. As this plant has already been demonstrated for a variety of medicinal properties from our laboratory, results of this study suggest that G. montanum is an interesting source for antioxidant compounds and useful for various therapeutic applications.     

Aqueous extract of Boerhaavia diffusa root ameliorates ethylene glycol-induced hyperoxaluric oxidative stress and renal injury in rat kidney

Introduction: Boerhaavia diffusa Linn. (Nyctaginaceae) is widely used in traditional Indian medicines against renal afflictions including calcium oxalate (CaOx) urolithiasis and is known for antioxidant activity.

Objective: The present study was designed to investigate the ameliorating effect of aqueous extract of B. diffusa roots (BDE) in hyperoxaluric oxidative stress and renal cell injury.

Material and methods: In vitro antioxidant activity of BDE was estimated in terms of total phenolic content and 1,1-diphenyl-2-picryl hydrazyl free radical scavenging activity. Wistar albino rats were given 0.75% v/v ethylene glycol in drinking water to induce chronic hyperoxaluria and simultaneously BDE was given to nephrolithiasic treated rats at the dose of 100 and 200?mg/kg b.w. orally for 28 days. Urinary volume, oxalate, serum creatinine, blood urea nitrogen (BUN), malondialdehyde (MDA) and antioxidant enzyme (SOD, CAT, GST, GPx) were evaluated.

Results and discussion: BDE extract was found to posses a high total phenolic content and exhibited significant free radicals scavenging activity. Oxalate excretion significantly increased in hyperoxaluric animals as compared to control which was protected in BDE-treated animals. BDE treatment significantly reduced level of MDA and improved the activity of antioxidant enzymes followed by reduction in BUN and serum creatinine. In addition, BDE reduced the number of CaOx monohydrate crystals in the urine. Histological analysis depicted that BDE treatment inhibited deposition of CaOx crystal and renal cell damage.

Conclusion: The present study reveals that antioxidant activity of BDE significantly protects against hyperoxaluric oxidative stress and renal cell injury in urolithiasis.     

Antioxidant activity and protective effect of Turnera ulmifolia Linn. var. elegans against carbon tetrachloride-induced oxidative damage in rats

The present study aimed to determine whether the leaves of Turnera ulmifolia Linn. var. elegans extract exert significant antioxidant activity. The antioxidant activity of its hydroethanolic extract (HEETU) was evaluated by assessing (a) its radical scavenging ability in vitro, and (b) its in vivo effect on lipid peroxidation and antioxidant enzyme activities. The in vitro antioxidant assay (DPPH) clearly supported HEETU free radical scavenging potential. Moreover, glutathione content and antioxidant enzyme activities (glutathione peroxidase, superoxide dismutase and catalase) were significantly enhanced in CCl₄-treated rats due to oral HEETU-treatment (500 mg/kg b.w.) over 7 and 21 days. In addition, an improvement was observed in lipid peroxidation and serum biochemical parameters (aspartate aminotransferase and alanine aminotransferase), indicating a protective effect against CCl₄-induced liver injuries, confirmed by histopathological studies. The HEETU effect was comparable to the standard drug Legalon® (50 mg/kg b.w.) under the same experimental condition. Quantitative analysis of the HPLC extract revealed the presence of flavonoids, wich mediate the effects of antioxidant and oxidative stress. In conclusion, extract components exhibit antioxidant and hepatoprotective activities in vitro and in vivo.     

Phytochemical investigation and radical scavenging activities of Melia azedarach and its DNA protective effect in cultured lymphocytes

Abstract

Context: Melia azedarach Linn (Meliaceae) is an Ayurvedic medicinal plant which is native to India. It is traditionally used for the treatment of leprosy, inflammation, scrofula, anthelmintic, antilithic, diuretic, deobstruent and cardiac disorders.

Objective: To evaluate the phytochemical constituents and antioxidant activities of the ethanol leaf extract of Melia azedarach (MA) and its protective effect against H₂O₂-induced cellular damage in cultured lymphocytes.

Materials and methods: The dose-dependent study of MA (20, 40, 60, 80, 100?µg/ml) was used to study in vitro radical scavenging assays. The effective dose of MA (60?µg/ml) was further used to study the H₂O₂-induced DNA damage (comet assay and DNA fragmentation assay) in cultured lymphocytes.

Results: The ethanol extract of MA (20, 40, 60, 80, 100?µg/ml) exhibited a significant dose-dependent inhibition of in vitro radical scavenging assays and their corresponding IC₅₀ values as follows: hydroxyl radical (26.50?±?0.26?µg/ml), superoxide anion (30.00?±?0.32?µg/ml), nitric oxide radical (48.00?±?0.48?µg/ml), DPPH radical (30.55?±?0.32?µg/ml) and reducing power (22.00?±?0.22?µg/ml). The increase in the severity of DNA damage and TBARS was increased significantly (p?<?0.05) at 500?µM H₂O₂-treated cultured lymphocytes and RBC cellular membranes. The phytochemical screening studies identified 13 chemical constituents present in the leaf extract of MA.

Discussion and conclusion: The results of this study demonstrate that MA offers protection against H₂O₂-induced cellular damage and it can be developed as an effective antioxidant during oxidative stress.     

Direct contact with particulate matter increases oxidative stress in different brain structures

Abstract

Introduction: Several experimental and epidemiological studies have demonstrated the neurological adverse effects caused by exposure to air pollution, specifically in relation to pollutant particulate matter (PM). The objective of this study was to investigate the direct effect of PM in increased concentrations in different brain regions, as well as the mechanisms involving its neurotoxicity, by evaluating oxidative stress parameters in vitro.

Methods: Olfactory bulb, cerebral cortex, striatum, hippocampus and cerebellum of rats were homogenized and incubated with PM?<?2.5?μm of diameter (PM_2.5) at concentrations of 3, 5 and 10?µg/mg of tissue. The oxidative damage caused by lipid peroxidation of these structures was determined by testing the thiobarbituric acid reactive species (TBA-RS). In addition, we measured the activity of antioxidant enzyme catalase (CAT) and superoxide dismutase (SOD).

Results: All PM concentrations were able to damage the cerebellum and hippocampus, strongly enhancing the lipid peroxidation in both structures. PM incubation also decreased the CAT activity of the hippocampus, cerebellum, striatum and olfactory bulb, though it did not generate higher levels of lipid peroxidation in either of the last two structures. PM incubation did not alter any measurement of the cerebral cortex.

Conclusion: The cerebellum and hippocampus seem to be more susceptible than other brain structures to in vitro direct PM exposure assay and the oxidative stress pathway catalyzes the neurotoxic effect of PM exposure, as evidenced by high consumption of CAT and high levels of TBA-RS. Thus, PM direct exposure seems to activate toxic neurological effects.     

Antioxidant and neuroprotector effect of Lepidium meyenii (maca) methanol leaf extract against 6-hydroxy dopamine (6-OHDA)-induced toxicity in PC12 cells

Reactive oxygen species (ROS) are normally produced during cell metabolism, there is strong evidence to suggest that ROS produced in excess impair the cell and may be etiologically related to various neurodegenerative diseases. This study was undertaken to examine the effects of Lepidium meyenii (MACA) methanol leaf extract on neurotoxicity in PC12 cell exposed to 6-hydroxydopamine (6-OHDA). Fresh samples of “maca” leaves were processed in order to obtain foliar extracts and to evaluate the neurobiological activity on PC12 cells, subjected to the cytotoxic effect of 6-OHDA through the determination of the capacity antioxidant, cell viability and cytotoxicity assays on PC12 cells. The results of the tests of antioxidant activity, showed maximum values of 2262.37 and 1305.36 expressed in Trolox equivalents (TEAC), for the methanolic and aqueous fractions respectively. Cell viability assays at a dose of 10?μg extract showed an increase of 31% and 60% at 6 and 12?h of pretreatment, respectively. Cytotoxicity assays at the same dose and exposure time showed a 31.4% and 47.8% reduction in lactate dehydrogenase (LDH) activity and an increase in superoxide dismutase (SOD) activity. The results allow us to affirm that the methanolic foliar extract of “maca” presents in vitro neurobiological activity of antioxidant protection, increase in cell viability and reduction of cytotoxicity against oxidative stress generated by 6-OHDA. In conclusion, the present study shows a protective role for Lepidium meyenii leaf extract on 6-OHDA-induced toxicity by an antioxidant effect.     

Effect of fibrin glue on antioxidant defense mechanism,oxidative DNA damage and chromosomal aberrations

Abstract

Oxidative stress is involved in diverse biological phenomenon, and is caused by the imbalance between reactive oxygen species (ROS) and antioxidant defense system. 8-Hydroxy-2′-deoxyguanosine (8-OHdG) is the most critical biomarker in the estimation of ROS-induced DNA damage. This investigation focuses on the effect of fibrin glue on lipid peroxidation (LPO), antioxidant enzymes and oxidative DNA damage (both in vitro and in vivo). The blood biochemical parameters of the implanted animals and in vitro chromosomal aberrations were also studied. Fibrin glue was applied on the calvarial defect made on the anesthetized rats for an observation period of 4, 12, 26 and 52 weeks. At the end of the observation period, animals were anesthetized; blood was collected for serum analysis and was sacrificed. Brain was collected for the detection of 8-OHdG using competitive ELISA and liver was collected for analyzing the antioxidant enzymes and LPO. The results of this study suggest that the effect of fibrin glue on rat brain (in vivo and in vitro) and mice liver (in vitro) did not make any significant influence on LPO and antioxidant defense system. Similarly, there was no change observed in the expression of 8-OHdG. Serum constituents of implanted rats were observed to be within the normal range. The normal karyotype obtained indicates that the physiological saline extract of fibrin glue does not induce any chromosomal anomalies. Hence, it was concluded that the fibrin glue material does not have any potential to produce oxidative stress, alterations in the C-8 position of guanine and chromosomal anomalies.     

Hepatoprotective effects and HSV-1 activity of the hydroethanolic extract of Cecropia glaziovii (embaúba-vermelha) against acyclovir-resistant strain

Context: Cecropia glaziovii Snethl. (Cecropiaceae), commonly known as “embaúba-vermelha”, is widely distributed throughout Latin America and has been reported in Brazilian folk medicine to treat cough, asthma, high blood pressure and inflammation.

Objective: Investigate the hepatoprotective properties of crude hydroethanolic extract of C. glaziovii as well as its in vitro antioxidant and antiviral (HSV-1 acyclovir resistant strain) activities.

Materials and methods: The hepatoprotective effect, the antioxidant properties and antiviral activity of crude hydroethanol extract (RCE40) from C. glaziovii leaves were evaluated by carbon-tetrachloride (CCl₄)-induced hepatotoxicity, by TBARS (thiobarbituric acid reactive species) and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assays, respectively.

Results: The RCE40 extract (20?mg/kg) inhibited lipid peroxidation on liver in post injury treatment and decreased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In addition, in this protocol the RCE40 (20?mg/kg) enhanced the activity of hepatic enzymes (SOD/CAT) which are involved in combating reactive oxygen species (ROS), suggesting that it possesses the capacity to attenuate the CCl₄-induced liver damage. Moreover the RCE40 (20?mg/kg) inhibited TBARS formation induced by several different inductors of oxidative stress showing significant antioxidant activity, including physiologically relevant concentration, as low as 2 µg/mL. Concerning antiviral activity, the RCE40 was effective against herpes simplex virus type 1 replication (29R acyclovir resistant strain) with EC₅₀?=?40 µg/mL and selective index (SI)?=?50.

Discussion and conclusion: These results indicate that C. glaziovii could be a good source of antioxidant and anti-HSV-1 lead compounds.     

Redox properties and cytoprotective actions of atranorin, a lichen secondary metabolite

Atranorin (ATR) is a lichenic secondary metabolite with potential uses in pharmacology. Antinociceptive and antiinflammatory actions have been reported, and the use of atranorin-enriched lichen extracts in folk medicine is widespread. Nonetheless, very few data on ATR biological actions are available. Here, we evaluated free radical scavenging activities and antioxidant potential of ATR using various in vitro assays for scavenging activity against hydroxyl radicals, hydrogen peroxide, superoxide radicals, and nitric oxide. The total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) indexes and in vitro lipoperoxidation were also evaluated. Besides, we determined the cytoprotective effect of ATR on H₂O₂-challenged SH-SY5Y cells by the MTT assay. ATR exerts differential effects towards reactive species production, enhancing hydrogen peroxide and nitric oxide production and acting as a superoxide scavenger; no activity toward hydroxyl radical production/scavenging was observed. Besides, TRAP/TAR analysis indicated that atranorin acts as a general antioxidant, although it demonstrated to enhance peroxyl radical-induced lipoperoxidation in vitro. ATR was not cytotoxic, and also protected SH-SY5Y cells against H₂O₂-induced cell viability impairment. Our results suggest that ATR has a relevant redox-active action, acting as a pro-oxidant or antioxidant agent depending on the radical. Also, it will exert cytoprotective effects on cells under oxidative stress induced by H₂O₂.     

Antioxidant,antihemolytic, and inhibitory activities of endemic Primula heterochroma against Fe2+-induced lipid peroxidation and oxidative stress in rat brain in vitro

Context: The genus Primula (Primulaceae) has been used in traditional medicine to treat convulsion and microbial or viral infections.

Objective: In the present study, we evaluate antioxidant, antihemolytic, and protective effects of flavonoid-rich fractions of endemic Primula heterochroma Stapf. (Primulaceae) against Fe²⁺-induced lipid peroxidation and oxidative stress in rat brain in vitro.

Materials and methods: Aerial parts of plant were defatted and extracted with 60% acetone. Then, 60% acetone extract was fractionated sequentially with n-hexane, ethyl acetate, and water. Antioxidant activity of fractions was evaluated by employing six different assays, i.e., 1,1-diphenyl-2-picryl hydrazyl (DPPH) and hydrogen peroxide scavenging, metal chelating and reducing power activities and hemoglobin-induced linoleic acid system and Fe²⁺-induced lipid peroxidation and oxidative stress in rat brain. Also, its antihemolytic activity was determined using 2,2′-azobis(2-amidinopropane) dihydrochloride-induced hemolysis in rat erythrocyts.

Results: Among the flavonoid-rich fractions of Primula heterochroma, aqueous fraction demonstrated the most protective effect through decreasing brain thiobarbituric acid reactive substances (TBARS) levels at a dose 200?μg mL^?1 (40%, p < 0.001 versus iron group). Also, the aqueous fraction showed better activity in Fe²⁺ chelating (89 ± 3.8 μg mL^?1) and DPPH radical scavenging (394.4 ± 18.4 μg mL^?1) models than other fractions. The probable protective mechanism of flavonoid-rich fractions may be attributed to their Fe²⁺ chelating, DPPH radical scavenging and reducing power activities. Also, the n-hexane fraction demonstrated a higher protective effect in the hemoglobin-induced linoleic acid system and 2,2′-azobis(2-amidinopropane) dihydrochloride-induced hemolysis (67 ± 2.6 μg mL^?1).

Discussion and conclusion: Results of this study demonstrate Primula heterochroma is a rich source of natural antioxidant compounds.     

Antioxidant and radical scavenging properties of <Emphasis Type="Italic">Iris germanica</Emphasis>

The antioxidant activity of aqueous and ethanol extracts of iris (Iris germanica L., family Iridaceae) has been evaluated in vitro using various antioxidant assays, including reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. Both aqueous and ethanol extracts exhibit strong total antioxidant activity, showing 95.9, 88.4, 79.9% and 90.5, 78.0, 65.3% inhibition on peroxidation of linoleic acid emulsion in concentrations of 10, 30, and 50 μg-ml, respectively. Both extracts also possess effective reducing power and exhibit free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities in concentrations of 20, 40, and 60 μg-ml. The antioxidant properties were compared to those of reference antioxidants (BHA, BHT, and α-tocopherol). In addition, the total content of phenolic compounds in both aqueous and ethanol iris extracts has been determined as gallic acid equivalent. The results indicate that iris has in vitro antioxidant properties, which can be the major factor responsible for the inhibition of lipid peroxidation. Published in Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 8, pp. 13–18, August, 2007.     

Antioxidant and Free Radical Scavenging Effects of Lippia nodiflora

This study evaluated the in vitro antioxidant potential of methanol extract of Lippia nodiflora Mich. (Verbenaceae) (MELN). The different antioxidants assays, including total antioxidant activity, reducing power, free radical, superoxide anion radical, hydroxyl radical, hydrogen peroxide, nitric oxide scavenging, and total phenolic content, were studied. MELN exhibited potent total antioxidant activity that increased with increasing amount of extract concentration (50, 100, 200, and 400 μg/mL), which were compared with standard drug α -tocopherol (400 μg/mL). The different concentrations of MELN and α -tocopherol showed inhibition of 49.07%, 58.96%, 63.07%, 68.29%, and 74.59%, respectively, on peroxidation in linoleic acid emulsion. In addition, MELN had effective reducing power, free radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, hydrogen peroxide radical scavenging, and nitric oxide scavenging activity, and total phenolic content depending on concentration. These various antioxidant activities were compared with standard antioxidants such as BHA, BHT, catechin, and α -tocopherol.