Thiobarbituric Acid Test Research Articles

Bioactive Compounds, Antioxidant, Xanthine Oxidase Inhibitory, Tyrosinase Inhibitory and Anti-Inflammatory Activities of Selected Agro-Industrial By-products

Evaluation of abundantly available agro-industrial by-products for their bioactive compounds and biological activities is beneficial in particular for the food and pharmaceutical industries. In this study, rapeseed meal, cottonseed meal and soybean meal were investigated for the presence of bioactive compounds and antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities. Methanolic extracts of rapeseed meal showed significantly (P < 0.01) higher phenolics and flavonoids contents; and significantly (P < 0.01) higher DPPH and nitric oxide free radical scavenging activities when compared to that of cottonseed meal and soybean meal extracts. Ferric thiocyanate and thiobarbituric acid tests results showed rapeseed meal with the highest antioxidant activity (P < 0.01) followed by BHT, cotton seed meal and soybean meal. Rapeseed meal extract in xanthine oxidase and tyrosinase inhibitory assays showed the lowest IC50 values followed by cottonseed and soybean meals. Anti-inflammatory assay using IFN-γ/LPS stimulated RAW 264.7 cells indicated rapeseed meal is a potent source of anti-inflammatory agent. Correlation analysis showed that phenolics and flavonoids were highly correlated to both antioxidant and anti-inflammatory activities. Rapeseed meal was found to be promising as a natural source of bioactive compounds with high antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities in contrast to cotton and soybean meals.

Wound healing and anti-inflammatory activities of the Michauxia L’Hérit (Campanulaceae) species native to Turkey

Ethnopharmacological relevanceThe leaves of Michauxia species are used for the treatment of wounds in Turkish traditional medicine. In the present study, wound healing, anti-inflammatory and antioxidant activities of the extracts obtained from the root and herb of 5 species of Michauxia collected in different parts of Turkey were evaluated. Material and methodsIn vivo incision and excision wound models were used in order to assess the wound healing effects of the methanolic extracts of the plants. Skin samples were also evaluated histopathologically. In vivo inhibitory effect of the extracts on acetic acid-induced increase in capillary permeability was studied for the assessment of anti-inflammatory activity. TBA (thiobarbituric acid) test, qualitative and quantitative DPPH (2,2-diphenyl-1-picrylhydrazyl) tests were used to evaluate the antioxidant activity. ResultsNoteworthy wound healing activity was observed for the ointment formulation prepared with 1% Michauxia nuda (root) and Michauxia tchihatchewii (herb) extracts. The results of histopathological evaluation supported the outcome of incision and excision wound models. Moreover, the Michauxia nuda (root) exerted remarkable anti-inflammatory effect. The highest antioxidant activity was observed with the ethyl acetate extract of Michauxia tchihatchewii herb. ConclusionThe experimental study revealed that Michauxia displays remarkable wound healing and anti-inflammatory and antioxidant activities.

Antioxidant, Anti-inflammatory and Cytotoxicity of Phaleria macrocarpa (Boerl.) Scheff Fruit

BackgroundPhaleria macrocarpa (Scheff.) Boerl (Thymelaceae) originates from Papua Island, Indonesia and grows in tropical areas. The different parts of the fruit of P. macrocarpa were evaluated for antioxidant, anti-inflammatory, and cytotoxic activities.MethodsPhaleria macrocarpa fruit were divided into pericarp, mesocarp and seed. All parts of the fruit were reflux extracted with methanol. The antioxidant activity of the extracts were characterized in various in vitro model systems such as FTC, TBA, DPPH radical, reducing power and NO radical. Anti-inflammatory assays were done by using NO production by macrophage RAW 264.7 cell lines induced by LPS/IFN-γ and cytotoxic activities were determined by using several cancer cell lines and one normal cell lineResultsThe results showed that different parts (pericarp, mesocarp, and seed) of Phaleria macrocarpa fruit contain various amount of total phenolic (59.2 ± 0.04, 60.5 ± 0.17, 47.7 ± 1.04 mg gallic acid equivalent/g DW) and flavonoid compounds (161.3 ± 1.58, 131.7 ± 1.66, 35.9 ± 2.47 mg rutin equivalent/g DW). Pericarp and mesocarp showed high antioxidant activities by using DPPH (71.97%, 62.41%), ferric reducing antioxidant power (92.35%, 78.78%) and NO scavenging activity (65.68%, 53.45%). Ferric thiocyanate and thiobarbituric acid tests showed appreciable antioxidant activity in the percentage hydroperoxides inhibitory activity from pericarp and mesocarp in the last day of the assay. Similarly, the pericarp and mesocarp inhibited inducible nitric oxide synthesis with values of 63.4 ± 1.4% and 69.5 ± 1.4% in macrophage RAW 264.7 cell lines induced by LPS/IFN-γ indicating their notable anti-inflammatory potential. Cytotoxic activities against HT-29, MCF-7, HeLa and Chang cell lines were observed in all parts.ConclusionsThese results indicated the possible application of P. macrocarpa fruit as a source of bioactive compounds, potent as an antioxidant, anti inflammatory and cytotoxic agents.

Storage studies on mustard oil blends.

Mustard oil blends were investigated for fatty acid composition and oxidative stability during storage for 3months at room temperature (15°C to 35°C). The blends were prepared using raw mustard oil with selected refined vegetable oils namely; palm, safflower, soybean, rice bran, sunflower and sesame oil (raw). The fatty acid compositions of all these blends were studied using GLC. The developed blends were found to obey the ideal fatty acid ratio as laid down by health agencies i.e. 1:2:1:: SFA:MUFA:PUFA. The oxidative stability of blends was studied by measuring peroxide value (PV), Kries and Thiobarbituric acid (TBA) test. Blends MPSu (mustard oil, palm oil and sunflower oil), MPT (mustard oil, palm oil and sesame oil) and MPGr (mustard oil, palm oil and groundnut oil) were more stable than other blends during storage. The presence of mustard oil in all blends might make them a healthier option for many consumers as it is a rich source of ω-3 fatty acids and has anti-carcinogenic properties.

Effects of Mango (Mangifera indica L.) and Guava (Psidium guajava L.) Extract on Frozen Chicken Meat Balls’ Storage Quality

A study was carried out to determine the effect of mango and guava extract on frozen Chicken Meat Balls (CMB) storage quality. CMB were added with four different formulations; mango extract (400 ppm); guava extract (800 ppm); synthetic antioxidant (BHA) (200 ppm) and a control group. Antioxidant activities, Total Phenolic Compound (TPC), Ferum (III)Reducing Power (FRAP) and Ferric Thiocyanate (FTC) were also analyzed. Determination of Thiobarbituric Acid (TBA) test and Peroxide Value (PV) were done on CBM samples which had been stored in -18oC for 0, 1, 2 and 3 months and sensory evaluation for 0 and 2 months. TPC showed that mango had higher value at 548.77 μg/100 g fresh weight compared to guava at 222.09 μg/100 g fresh weight. FRAP value significantly (p<0.05) indicated that mango extract able to reduce ferric ions more effectively compared to guava extract. FTC test significantly (p<0.05) showed that both mango and guava extracts efficient slowed down the oxidation process compared to control group after seven days of incubation. PV control group was significantly high (p<0.05); 3.38 meq/kg as compared to other formulation groups. TBA analysis showed that mango and guava extract able to inhibit the oxidation process which similar to BHA. In conclusion, additional mango and guava extract did not affect on frozen CBM storage quality and consumers’ acceptance.

Effects of roasting on phenolics composition and antioxidant activity of peanut (Arachis hypogaea L.) kernel flour

The effects of roasting on the phenolics composition and antioxidant activity of peanut (Arachis hypogaea L.) kernel flour were appraised. Peanut kernel flour, with and without skin, were roasted at 160 °C for 10, 20, 30, 40 and 50 min. The resultant changes in the antioxidant activity of roasted peanut kernel flour were assessed by the determinations of total phenolics, 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging capacity, percent inhibition of linoleic acid oxidation and thiobarbituric acid test and compared with those of unroasted kernel flour. It was observed that roasting significantly (p < 0.05) increased the antioxidant activity of the peanut kernel flour. HPLC analysis revealed the detection of three phenolic acids (p-hydroxybenzoic, chlorogenic, p-coumaric), two flavonols (quercetin, kaempferol), and a stilbene (resveratrol) both in the roasted and unroasted samples. In peanut kernel flour without skin, the contents of the phenolics increased in the initial roasting phase, however, decreased gradually in the later phase (>20 min of roasting time). In contrast, over the course of heating, the amounts of phenolics were noted to be slightly increased in the peanut kernel flour with skin; the most significant (p < 0.05) increase occurred in the concentration of p-coumaric acid and quercetin at 30, 40, and 50 min of roasting. The results of this study reveal that optimum roasting time should be sought to enhancing the antioxidant capacity and phenolics concentration in peanut kernel flour.

Total phenolic contents and antioxidant activities of Michauxia L'Hérit (Campanulaceae) species growing in Turkey

The genus Michauxia L'Hérit (Campanulaceae) is represented by five species in Turkey, namely Michauxia campanuloides L'Hérit ex Aiton, M. laevigata Vent., M. tchihatchewii Fisch. et Mey. (E); M. thyrsoidea Boiss. & Heldr. (E), and M. nuda A.DC. The fresh stem and roots of M. campanuloides and M. tchihatchewii have been used as a vegetable.In the present study, the phenolic contents and antioxidant activities of the water, methanol (MeOH), dichlormethane (DCM), Ethyl acetate (EtOAc) and butanol (BuOH) extracts obtained from the root and herb of 5 species of Michauxia collected in different parts of Turkey were compared. The phenolic contents of the samples were determined using Folin-Ciocalteu's phenol reagent. Antioxidant activities of the extracts were studied by qualitative and quantitative DPPH· (1,1-diphenyl-2-picrylhydrazyl radical) assay to detect the free radical scavenging activity and by thiobarbituric acid (TBA) assay to detect their liposome lipid peroxidation. The total phenolic contents of extracts in the five different polarity were found the EtOAc extracts ranged from 108.1 to 439.1mg/g in dry weight expressed as gallic acid equivalents (GAE). All extracts showed a moderately antioxidant activity with the qualitative DPPH· test. In the quantitative DPPH· method the highest activity were determinated in EtOAc extracts of five plants. High activity was observed in the herb EtOAc extracts of M. tchihatchewii (IC50=4.94±6,46) and the MeOH extracts of M. campanuloides herb (IC50=97.58±6,03) when compared to the other extracts in the TBA test. Propyl gallate (IC50=0.09±0,18) is used as a positive control.

Antioxidant and antimicrobial activities of branches extracts of five Juniperus species from Turkey

Context: Several Juniperus species (Cupressaceae) are utilized in folk medicine in the treatment of infections and skin diseases.Objective: This work was designed to evaluate the antioxidant and antimicrobial potential of methanol and water branches extracts of Juniperus species from Turkey: Juniperus communis L. var. communis (Jcc), Juniperus communis L. var. saxatilis Pall. (Jcs), Juniperus drupacea Labill. (Jd), Juniperus oxycedrus L. subsp. oxycedrus (Joo), Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. (Jom).Materials and methods: Total phenolics, total flavonoids and condensed tannins were spectrophotometrically determined. The antioxidant properties were examined using different in vitro systems. The toxicity was assayed by Artemia salina lethality test. The antimicrobial potential against bacteria and yeasts was evaluated using minimum inhibitory concentration and minimum bactericidal concentration (MIC/MBC) measurements. The effect on bacteria biofilms was tested by microtiter plate assay.Results: Both in the DPPH (1,1-diphenyl-2-picrylhydrazyl) and TBA (thiobarbituric acid) test Jom resulted the most active (IC50 = 0.034 ± 0.002 mg/mL and 0.287 ± 0.166 µg/mL). Joo exhibited the highest reducing power (1.78 ± 0.04 ASE/mL) and Fe2+ chelating activity (IC50 = 0.537 ± 0.006 mg/mL). A positive correlation between primary antioxidant activity and phenolic content was found. The extracts were potentially non-toxic against Artemia salina. They showed the best antimicrobial (MIC = 4.88-30.10 µg/mL) and anti-biofilm activity (60–84%) against S. aureus.Discussion and conclusion: The results give a scientific basis to the traditional utilization of these Juniperus species, also demonstrating their potential as sources of natural antioxidant and antimicrobial compounds.

ROSMARINIC ACID AMELIORATES DIABETIC NEPHROPATHY IN UNINEPHRECTOMIZED DIABETIC RATS

Objective(s) Oxidative stress plays an important role in diabetic nephropathy pathogenesis. Rosmarinic acid, a plant phenolic compound, was first used as an antioxidant agent for inhibition of diabetic nephropathy. Material and Methods Forty male rats were uninephrectomized from the left flank.The rats were divided in four groups randomly; group one as control, group two diabetic untreatment, groups three and four treatment with rosmarinic acid by 100 or 200 mg/kg/d orally respectively. Diabetes was induced in the second, third and fourth groups by alloxan injection subcutaneously. After 8 weeks treatment, serum malondialdehyde was measured by thiobarbituric acid (TBA) test. Serum creatinine and serum urea were measured by kits. Kidney paraffin sections were prepared and stained by periodic acid Schiff method.Glomerular volume and glomerular number were estimated by stereological rules and glomerular sclerosis was studied semi-quantitatively. Data were analyzed by non-parametric Man Whitney test ( using SPSS 13 software) and P< 0.05 was considered significant. Results Rosmarinic acid (100 or 200 mg/kg) significantly inhibited glomerular hypertrophy, glomerular number loss, glomerulosclerosis, lipid peroxidation, serum urea and creatinine compared with the diabetic untreated group. The level of glomerular number and serum malondialdehyde in the treated groups (100 mg/kg or 200 mg/kg of rosmarinic acid) was maintained at the same level as compared to the control group. Conclusion Rosmarinic acid could significantly reduce glomerular hypertrophy, loss of glomerular number, glomerulosclerosis and attenuated serum urea and serum creatinine in diabetic rats.

Effects of Continuous Intravenous Infusion of MCI-186 on Functional Recovery after Spinal Cord Injury in Rats

We investigated the effects of a free radical scavenger, MCI-186 (edaravone), on neuroprotection in the rat post-traumatic spinal cord using various doses and routes of administration. The injury was produced with a weight-drop device. Lipid peroxide formation in the spinal cord was measured using the thiobarbituric acid test for malonyldialdehyde (MDA). In the first experiment, MDA production in the untreated post-traumatic spinal cord reached peak values at 1 h post-trauma, and gradually decreased to control levels in 7 days. In the second experiment, rats received twice-daily injections (0, 1, 3, 5, 10, or 20 mg/kg) for 3 days. We found that 3 mg/kg was most effective functionally and histologically. In the third experiment, rats received a 3 mg/kg bolus + continuous infusion (0, 1.5, 2.4, or 3.0 mg/kg/h) for 1, 2, 4, and 8 h. We found that a 3 mg/kg bolus + infusion of 3.0 mg/kg/h was most effective for the inhibition of MDA production. In the fourth experiment, a 3 mg/kg bolus given once immediately after injury and twice daily for 3 days, a 3 mg/kg bolus + 3.0 mg/kg/h for 1 day, or a 3 mg/kg bolus + 3.0 mg/kg/h for 3 days were administered. The continuous infusion for 1 day showed significant improvement functionally and histologically, but continuous infusion at the same rate for another 2 days did not show any further improvement. To effectively reduce secondary neuronal damage, strong inhibition of free radical chain reactions at the early stage, particularly within the first 24 h post-trauma, is important.

Total phenolic contents and antioxidant activities of Prangos Lindl. (Umbelliferae) species growing in Konya province (Turkey)

Prangos species are widely used as medicinal plants in Turkey, and 14 species of this genus grow naturally in Anatolia. In the present study, the phenolic contents and antioxidant activities of the water and methanol (MeOH) extracts obtained from the root, herb, and fruits of 4 species of Prangos (Prangos ferulacea, P. heyniae, P. meliocarpoides var. meliocarpoides, and P. uechtritzii) collected in Konya province were compared. The phenolic contents of the samples were determined using Folin-Ciocalteu's phenol reagent. Antioxidant activities of the extracts were studied by qualitative DPPH^. (1,1-diphenyl-2-picrylhydrazyl radical) assay to detect the free radical scavenging activity and by thiobarbituric acid (TBA) assay to detect their liposome lipid peroxidation. Total phenolic contents of the MeOH extracts were found to range from 77.99 to 140.29 mg/g and the water extracts ranged from 37.53 to 97.29 mg/g in dry weight expressed as gallic acid equivalents (GAE). All extracts showed a slightly antioxidant activity with the DPPH^. test. High activity was observed in the MeOH extracts when compared to the water extracts in the TBA test.

Salvia leriifolia Benth (Lamiaceae) extract demonstrates in vitro antioxidant properties and cholinesterase inhibitory activity

The object of the present study was to investigate the in vitro antioxidant properties and cholinesterase inhibitory activity of Salvia leriifolia Benth extracts and fractions. The functional role of herbs and spices and their constituents is a hot topic in food-related plant research. Salvia species have been used since ancient times in folk medicine for cognitive brain function and have been subjected to extensive research. Thus, we hypothesize that S leriifolia, because of its functional properties, would be a good candidate to use as a nutraceutical product for improving memory in the elderly or patients affected by Alzheimer disease (ad). To test this hypothesis, we examined the cholinesterase inhibitory activity using the modified colorimetric Ellman's method against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The n-hexane exhibited the highest activity, with inhibitory concentration 50% (IC(50)) values of 0.59 and 0.21 mg/mL, for AChE and BChE, respectively. This extract was fractionated, and 9 of these fractions (A-I) were obtained and tested. Fraction G, characterized by the presence of sesquiterpenes as major components, was the most active against AChE (IC(50) = 0.05 mg/mL). Because oxidative stress is a critical event in the pathogenesis of AD, we decided to screen the antioxidant activity (AA) using 2,2-diphenyl-1-picrylhydrazyl test, β-carotene bleaching test, and bovine brain peroxidation (thiobarbituric acid) assay. The ethyl acetate extract showed the highest activity, with IC(50) values of 2 and 33 μg/mL on β-carotene bleaching test and thiobarbituric acid test, respectively. These results suggest potential health benefits of S leriifolia extracts. However, this finding requires additional investigation in vivo.

Suitability of the TBA method for assessing lipid oxidation in a meat system with added phenolic-rich materials

Numerous protocols and modifications of the thiobarbituric acid (TBA) test are available in the literature. The present paper compares the effectiveness of different TBA tests in minimizing the interferences caused by the addition of phenolic-rich materials (wild fruits) as antioxidants in cooked burger patties. The aqueous acid extraction procedure (EM) and a modified distilation TBA method (DM) were tested with different conditions of incubation – boiling (B) vs. room temperature (RT) – for monitoring lipid oxidation in cooked burger patties during refrigerated storage. DM-B and DM-RT were more suitable than EM procedures for assessing TBA-reactive substances (TBA-RS) in meat samples containing compounds such as anthocyanins, with similar spectral properties than that of the TBA–malondialdehyde (MDA) adduct. Additionally, interferences caused by browning development during incubation were avoided by DM procedures or by performing RT incubations. Correlations between TBA-RS numbers and hexanal contents in cooked pork burger patties were calculated in order to corroborate the suitability of the tested TBA procedures. The DM-RT procedure showed the highest correlation with hexanal content (R2=0.90; p<0.001).

Pollen-mediated gene flow in flax (Linum usitatissimum L.): can genetically engineered and organic flax coexist?

Coexistence allows growers and consumers the choice of producing or purchasing conventional or organic crops with known standards for adventitious presence of genetically engineered (GE) seed. Flax (Linum usitatissimum L.) is multipurpose oilseed crop in which product diversity and utility could be enhanced for industrial, nutraceutical and pharmaceutical markets through genetic engineering. If GE flax were released commercially, pollen-mediated gene flow will determine in part whether GE flax could coexist without compromising other markets. As a part of pre-commercialization risk assessment, we quantified pollen-mediated gene flow between two cultivars of flax. Field experiments were conducted at four locations during 2006 and 2007 in western Canada using a concentric donor (20 × 20 m) receptor (120 × 120 m) design. Gene flow was detected through the xenia effect of dominant alleles of high α-linolenic acid (ALA; 18:3(cisΔ9,12,15)) to the low ALA trait. Seeds were harvested from the pollen recipient plots up to a distance of 50 m in eight directions from the pollen donor. High ALA seeds were identified using a thiobarbituric acid test and served as a marker for gene flow. Binomial distribution and power analysis were used to predict the minimum number of seeds statistically required to detect the frequency of gene flow at specific α (confidence interval) and power (1-β) values. As a result of the low frequency of gene flow, approximately 4 million seeds were screened to derive accurate quantification. Frequency of gene flow was highest near the source: averaging 0.0185 at 0.1 m but declined rapidly with distance, 0.0013 and 0.00003 at 3 and 35 m, respectively. Gene flow was reduced to 50% (O₅₀) and 90% (O₉₀) between 0.85 to 2.64 m, and 5.68 to 17.56 m, respectively. No gene flow was detected at any site or year > 35 m distance from the pollen source, suggesting that frequency of gene flow was ≤ 0.00003 (P = 0.95). Although it is not possible to eliminate all adventitious presence caused by pollen-mediated gene flow, through harvest blending and the use of buffer zones between GE and conventional flax fields, it could be minimized. Managing other sources of adventitious presence including seed mixing and volunteer populations may be more problematic.

Antioxidative Activities of Palm Sugar-Like Flavouring~!2009-09-17~!2010-01-25~!2010-04-01~!

Maillard reaction products have been considered to have antioxidant capacities due to the reductones com- pound formations which contribute to antioxidant activity. Besides caramelisation, Maillard reaction takes place during the production of palm sugar. This paper reports the antioxidative activity of palm sugar-like flavourings and the commer- cial palm sugar (CPS) which was obtained from Pahang by using different types of methods. Formulation of palm sugar- like flavourings which had been optimised was obtained from the previous studies. Palm sugar-like flavourings (PSLFs) were prepared from sucrose and selected amino acids (Asparagine, Glutamine, Arginine and Lysine) at various ratios with buffer solutions (pH 7.86), heated at 143°C for 116 minutes. The results revealed that the PSLF (C) showed a significant difference (p<0.05) in reducing power, thiobarbituric acid (TBA) test, and radical scavenging activity (DPPH) compared to other formulations of PSLF and commercial palm sugar.

Scavenging properties of metronidazole on free oxygen radicals in a skin lipid model system

Reactive oxygen species (ROS) play a vital role in the pathophysiology of the skin disease rosacea, a chronic, genetically-determined and UV-triggered disease, leading to facial redness and blemishes and exhibiting a deep impact on a patient's self-esteem and quality of life. ROS can cause oxidative damage to nucleic acids, sugars, proteins and lipids, thereby contributing to adverse effects on the skin. Metronidazole has been the first-line topical agent therapy for many years; nevertheless the mechanism of action is still not well understood. The therapeutic efficacy of metronidazole has been attributed to its antioxidant effects, which can involve two pathways: decreased generation of ROS within tissues or scavenging and inactivation of existing ROS. Previous investigations have shown that metronidazole reduces ROS by decreasing ROS production in cellular in-vitro systems. The aim of the following study was to demonstrate that metronidazole additionally exhibits antioxidative properties in a cell-free system, by acting as an antioxidant scavenger. A simple skin lipid model (oxidative) system and a complex skin adapted lipid system in conjunction with thiobarbituric acid (TBA) test, a quantitative assay for the detection of malondialdehyde (MDA) and therefore lipid peroxidation, were used to determine the antioxidative properties of metronidazole after UV irradiation. Results clearly show that metronidazole has antioxidative properties in a cell-free environment, acting as a free radical scavenger. Simple skin lipid model: in the presence of 10, 100 and 500 microg mL(-1)metronidazole the MDA concentration was reduced by 25, 36 and 49%, respectively. Complex skin lipid system: in the presence of 100 and 500 microg mL(-1)metronidazole the MDA concentration was reduced by 19 and 34%, respectively. The results obtained in this study and from previous publications strongly suggest that metronidazole exhibits antioxidative effects via two mechanisms: decrease in ROS production through modulation of neutrophil activity and decrease in ROS concentration by exhibiting ROS scavenging properties. The remarkable clinical efficacy of metronidazole in the treatment of rosacea is probably due to its ability to decrease ROS via different mechanisms, thereby protecting skin components from induced damage.

Cytotoxic, apoptotic and antioxidant activity of the essential oil of Amomum tsao-ko

The antioxidant activity, cytotoxicity and mechanism of induction of HepG2 cell death of essential oil from Amomum tsao-ko were determined. The essential oil was cytotoxic to HepG2, Hela, Bel-7402, SGC-7901 and PC-3 cell lines. The lowest IC 50 of 31.80 ± 1.18 μg/ml was measured for HepG2 carcinoma cell lines. The IC 50 for normal human cell lines (HUVEC and HL-7702) was 163.91 ± 5.11–272.41 ± 0.97 μg/ml. Analyses by flow cytometry, Hoechst 33258 staining and agarose gel electrophoresis indicated that the essential oil induced apoptosis. The essential oil has weak antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay, thiobarbituric acid (TBA) test and ferric reducing antioxidant power (FRAP) assay. The data suggest that the essential oil of A. tsao-ko could be a potential medicinal resource.

Oxidative stress response in the adult rat retina and plasma after repeated administration of methamphetamine

Methamphetamine (MA) is a psychostimulant that target the sensory systems, with the neurosensory retina having been shown to be affected. In the brain, MA-related toxicity can be linked to oxidative stress; the same relationship has yet to be established for the retina. The aim of this study, therefore, was to evaluate the effects of repeated exposure to MA on oxidative stress parameters in the rat retina. Oxidative stress parameters in the blood plasma were also assessed. Male Wistar rats were given 5mg/kg MA every 2h for a period of 6h (i.e., 4 injections) daily between postnatal day (PND) 91 and 100. Evolution of body weight was registered. Rats were sacrificed at PND 110. Blood plasma was collected and immediately frozen for storage at -70 degrees C. The eyes were enucleated, and the retina and choroids rapidly dissected on ice under dim light also to be stored at -70 degrees C. Lipid peroxidation activity was measured by the thiobarbituric acid (TBA) test. Total antioxidant status, superoxide dismutase (SOD) activity, catalase (Cat) activity, and nitrogen oxides contents were also determined. Lipid peroxidation was significantly higher in the retina and blood plasma of the MA-treated rats. Total antioxidant levels were significantly lower in both retina and blood plasma of the MA-treated rats. The activity of SOD was significantly increased in the retina and blood plasma of MA-treated rats. Catalase activity did not differ between groups in either the retina or the blood plasma. Nitric oxide production was significantly higher in both the retina and blood plasma in the MA-treated animals. The overall findings show that the oxidative stress defence mechanisms in the retina are compromised by MA toxicity. The results are similar to those found in the brain, and, moreover, showed some correlation with the blood plasma.

Antioxidant activity of plants methanolic extracts containing phenolic compounds

The presence of natural antioxidant in plants is well known. This paper reports the antioxidative activities of some methanolic plant extracts namely ‘ulam raja’ (Cosmos caudatus), ‘kesum’ (Polygonum minus), ‘selom’ (Oenanthe javanica), ‘pegaga’ (Centella asiatica) and ‘curry leaf’ (Murraya koenigii). The analysis carried out was total phenolic content, ferric reducing power, ferric thiocyanate (FTC) and thiobarbituric acid (TBA) tests. From the analyses, M. koenigii had the highest yield extraction (1.65%), highest total phenolic content (38.60 mg TAE/ 100 g fresh weight) and antioxidant activity (70.60%) using FTC method. Increasing the concentration of the extracts resulted in increased ferric reducing antioxidant power for all methanolic extracts tested. TBA analysis showed that C. caudatus extract had the highest antioxidant effect. Total phenolic content had positive correlation with antioxidant capacity (r = 0.451). This shows that the plants, especially M. koeniigi, may be potent source of natural antioxidants.

Antioxidant activity of plants methanolic extracts containing phenolic compounds

The presence of natural antioxidant in plants is well known. This paper reports the antioxidative activities of some methanolic plant extracts namely ‘ulam raja’ (Cosmos caudatus), ‘kesum’ (Polygonum minus), ‘selom’ (Oenanthe javanica),‘pegaga’ (Centella asiatica) and ‘curry leaf’ (Murraya koenigii). The analysis carried out was total phenolic content, ferric reducing power, ferric thiocyanate (FTC) and thiobarbituric acid (TBA) tests. From the analyses, M. koenigii had the highest yield extraction (1.65%), highest total phenolic content (38.60 mg TAE/ 100 g fresh weight) and antioxidant activity (70.60%) using FTC method. Increasing the concentration of the extracts resulted in increased ferric reducing antioxidant power for all methanolic extracts tested. TBA analysis showed that C. caudatus extract had the highest antioxidant effect. Total phenolic content had positive correlation with antioxidant capacity (r = 0.451). This shows that the plants, especially M.koeniigi, may be potent source of natural antioxidants. Key words: Antioxidative activities, plants, total phenolic content, reducing power, thiobarbituric acid.