Superoxide Radical Scavenging Activity Research Articles

도정률 및 로스팅 조건에 따른 향미벼의 이화학적 품질특성

In this study, the physicochemical properties of aromatic rice prepared using different milling recoveries and roasting procedures were investigated. As a result, we found that the L value of different milling recoveries of aromatic rice (BA-1, BA-2, BA-4, and BA-6) increased as the aromatic rice (BA-0) decreased, while the a and b values decreased as the different milling recoveries increased. The major contributors to the different milling recoveries of aromatic rice were total polyphenol (28.11-33.84 mg/100 g), amylose (24.97-31.06 mg/100 g), total starch (68.27-73.04%) content. In addition, three different roasting methods were applied; the aromatic rice was roasted at 250℃ for 0 min (BAR-0M), 15 min (BAR-15M), or 30 min (BAR-30M). As a result, the color in terms of the L value decreased, whereas the a and b values increased. Also, the total phenolic and flavonoid contents in BAR-30M (41.65 mg/100 g and 22.30 mg/100 g, respectively) were higher than those in BAR-0M (33.00 mg/100 g and 20.78 mg/100 g, respectively). Similarly, the amylose and total starch contents in BAR-30M (26.10 g/100 g and 81.81%, respectively) were higher than those in BAR-0M (22.10 g/100 g and 74.26%, respectively). Furthermore, the DPPH, superoxide radical scavenging activity, and ferric reducing antioxidant potential of BAR-0M at 5,000 μg/mL were found to be 67.78%, 52.90%, and 0.79 mM, respectively. Based on these results, we can conclude that in order to provide the best physicochemical characteristics of aromatic rice, it should be manufactured in the following conditions: 20% milling recovery of the aromatic rice and roasting at 250℃ for 30 min.

Synthesis, structure, electrochemical properties and superoxide radical scavenging activities of two thiocyanate copper(II) complexes with different pyridyl-benzoxazole ligands

Reaction of 2-(2′-pyridyl)benzoxazole (2-PBO) or 2-(4′-pyridyl)benzoxazole (4-PBO) ligands with CuSCN afforded two thiocyanate copper (II) complexes, Cu(2-PBO) (SCN)2 (1) and Cu(4-PBO)2(SCN)2 (2), have been characterized by elemental analysis, UV–Vis, IR spectra and single-crystal X-ray diffraction. The structural analysis reveals that although the structures of complexes 1–2 are both four coordinated and show plane quadrilateral structure, the distorted of complex 1 is greater than 2. The cyclic voltammogram of complexes 1–2 represent quasi-reversible Cu2+/Cu+ pairs. The superoxide radical scavenging test in vitro showed that complex 1–2 had significant antioxidant activity on superoxide radicals, and the activity of complex 2 was higher than that of 1. This may be due to the structure of complex 2 being closer to the Cu, Zn-SOD.

Chemical Analysis and Antioxidant Activity of Essential Oils of Two Morphotypes of Lippia alba (Mill.) N.E. Br. ex Britton & P. Wilson (Verbenaceae)

Lippia alba (Mill.) N.E.Br.ex Britton & P.Wilson is an aromatic shrub of Verbenaceae family. L. alba exhibits variability among its different accessions, showing difference in morphology and in the composition of essential oil. The objective of this study was to chemically characterize and evaluate the antioxidant activity of essential oil of two L. alba morphotypes. The essential oils were isolated by hydrodistillation using a Clevenger apparatus and the identification was done through GC/GC-MS analysis. The antioxidant activity was evaluated using DPPH radical scavenging, Iron chelating activity, FRAP assay, Super oxide radical scavenging and Nitric oxide radical scavenging activity. More than eighty constituents were identified in both the oil's. Both the oils were characterized by a high amount of oxygenated monoterpenes (80.8%) and (82.0%). The major constituent in both the morphotypes was linalool. The other major constituents found in type-I were eucalyptol (4.2%), neral (1.1%), geranial (1.5%), E-caryophyllene (3.1%), germacrene-D (3.3%), germacrene-B (1.6%), 3E,5E-2,6-dimethyl-3,5,7-octatriene-2-ol (2.1%), 3E,5Z-2,6-dimethyl-3,5,7-octatriene-2-ol (3.8%) whereas in type-II were eucalyptol (4.7%), β-citronellol (1.3%), neral (2.3%), geranial (2.8%), β-caryophyllene (2.3%), germacrene-D (3.0%), germacrene-B (1.4%), carryophyllene oxide (1.1%), 3E,5E-2,6-dimethyl-3,5,7-octatriene-2-ol (1.6%), 3E,5Z-2,6-dimethyl-3,5,7-octatriene-2-ol (2.9%). Both the morphotypes exhibited good antioxidant activity but the activity, was found higher in type-II L. alba morphotype than type-I. The chemical composition and antioxidant activity suggest L. alba as a potential source of natural linalool and further its use in ethanopharmacological applications.

Extraction and recovery of phytochemical components and antioxidative properties in fruit parts of Dacryodes rostrata influenced by different solvents.

This study investigated the recovery of phytochemical antioxidants in Dacryodes rostrata fruit using different extraction solvents. The effects of solvent of varying polarities with sequential extraction method on the recovery of phenolics, flavonoids, carotenoids and anthocyanins from different parts of the fruit (seed, pulp and peel) were determined. Their antioxidant activities were further determined using DPPH radical, ferric reducing antioxidant power (FRAP), hydroxyl radical scavenging, superoxide anion radical scavenging and phosphomolybdenum method. Dacryodes Rostrata seed had the highest total phenolic content with 50% ethanol as the most efficient extraction solvent. The highest total flavonoid content was obtained in ethyl acetate extract of fruit pulp, whereas peel extracted with hexane and 50% ethanol was the highest in total carotenoid content and total anthocyanin content, respectively. The seed extracted with 50% ethanol exhibited the strongest DPPH radical scavenging activity. Iron chelating activity measured by FRAP assay was the best in seed extracts, particularly in those polar extracts derived from water and 50% ethanol. Antioxidant activities of 50% ethanol extract of D. rostrata seed was the highest when determined by FRAP and phosphomolydenum assays. However, the influence of extraction solvents is not distinctly shown by hydroxyl radical and superoxide anion radical scavenging activities. This is the first report on the effect of various extraction solvents on the recovery of phytochemicals in D. rostrata fruit parts and the seed of D. rostrata is a potential source of polar antioxidants.

Urtica dioica L. leaf extract modulates blood pressure and oxidative stress in spontaneously hypertensive rats

BackgroundUrtica dioica L. (Stinging nettle) has been used for centuries for the treatment of numerous health issues. PurposeThis study investigates the antioxidant capacity and the most abundant phenolic compounds of Urtica dioica L. leaf extract (UE), and its antihypertensive and antioxidative effects in vivo. Study designSpontaneously hypertensive rats were supplemented with 10, 50, and 200 mg/kg/day of UE and 10 mg/kg/day of losartan during 4-week period. MethodsIn this study, HPLC analysis of UE was performed, as well as the determination of antioxidant capacity, superoxide radical scavenging activity, and metal chelating ability. Hemodynamic parameters were measured directly in anesthetized rats. Also, antioxidant enzyme activity and concentration in erythrocytes were determined, as well as systemic oxidative stress and plasma antioxidant status. ResultsUE showed higher ferric reducing antioxidant power and Trolox equivalent antioxidant capacity than BHT, but lower than vitamin C. Furthermore, UE showed good metal chelating ability, but weak superoxide radical scavenging activity. All three tested UE doses managed to reduce systolic and diastolic blood pressure, as well as cardiac index, and to improve the antioxidative defense by increasing the activity of superoxide dismutase and catalase, without changing the concentration of the enzymes. Moreover, UE supplementation increased plasma antioxidant capacity and reduced systemic oxidative stress. ConclusionChronic UE dietary supplementation had beneficial effects in the experimental model of essential hypertension.

Phytochemicals and antidiabetic activity of Eusideroxylon zwageri stem bark collected from East Kalimantan, Indonesia

Eusideroxylon zwagery (Lauraceae), a tropical tree species known as ulin or borneo iron wood and traditionally used for the treatment of diabetes in the Ethnic of Kutai. Plant extract was prepared by maceration using ethanol. The plant extract was evaluated its DPPH and superoxide radicals scavenging activity, the inhibition on α-glucosidase and α-amylase activity as antidiabetic potential and the analysis of the total phenolic, total flavonoids and proanthocyanidin contents. The ethanolic extract of the stem bark was 8.62% on the dry weight basis. The IC50 values of antioxidant activity of the extract in DPPH and superoxide radical scavenging mechanisms were 44.90 µg/ml and 30.47 µg/ml. In antidiabetic assay, the E. zwageri stem bark extract showed IC50 value 58.45µg/ml in ɑ-glucosidase inhibition, and 9.04 µg/ml in ɑ-amylase inhibition. Quercetin, an antidiabetic activity-having flavonoid, displayed IC50 values 2.00 µg/ml and 4.04 µg/ml in ɑ-glucosidase and ɑ-amylase inhibitory assays. In phytochemical assay, the extract had 31.28 GAE/g extract (mg), 30.48 CE/g extract (mg) and 183.3 PE/g extract (mg) for the total phenolic, total flavonoid and total proanthocyanidin contents. The limited reports of E. zwageri indicated the needs to search the active compounds from plant as potential antidiabetic agents by considering plant conservation status.

Potential of antioxidant and toxicity of some medical plants used by sub-ethnic communities of Bahau in East Kalimantan

The purpose of this research is to assay the potential antioxidant and toxicity of several plants from Bahau, a sub-ethnic in East Kalimantan in regard to their utilization as traditional medicines. This research includes phytochemical analysis, DPPH radical and superoxide radical scavenging activity as well as toxicity assay using Artemiasalina shrimp larvae. The results of the extraction showed the highest yield was 2,91% obtained from avung tanaq (Ficus uncinata), while the lowest is 1.14% obtained from tevoqsalah (Saccharum sp.) species. The result of phytochemicals showed that all plants contain alkaloid and carbohydrate. While carotenoids, saponins, triterpenoids and steroids were absence in all plant extracts. The DPPH radical scavenging activity test showed that the lowest IC50 value of kayog kue (Dictamnus albus) by 23.96 μg/mL. The superoxide radical scavenging activity assay showed IC50 values of all extract samples were >100 μg/mL. The toxicity assay showed that LC50 values of all samples of extract tested were >1000 μg/mL. The present research suggested good potential activity of some plants from Bahau ethnic and further research oriented to wide uses of the plants as herbal products is needed.

ANTIMICROBIAL AND FREE RADICAL SCAVENGING ACTIVITY OF LEAF AND STEM EXTRACT OF LIMONIA ALATA WIGHT AND ARN.

Objective: In the present study, antioxidant activities leaves and stem of the petroleum, chloroform, acetone, and methanolic extracts from Limonia alata (L.). Leaf and stem were investigated by employing established in vitro studies. The leaves and bark are used for the fomentation of rheumatic pain; the dried fruit is useful in malignant and pestilent fevers and is used as an antidote for poisons, the folklore claim suggests that the leaf is showing wound healing property. L. alata is belonging to the family Rutaceae.Methods: The ability of the plant extract to act as hydrogen/electrons donor or scavenger of radicals was determined by in vitro antioxidant assays using 2,2-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, reducing power assay, superoxide radical (O2*−) scavenging activity, phosphomolybdenum assay, ferric reducing antioxidant power and metal chelating activity, was performed to know the antioxidant potency and antimicrobial studies of the plant extract of leaves and stem of L. alata.Result: Results are evaluated higher in leaves, stem and root of L. alata (L.) recorded total phenol (59.95±5.30). The present state of work was designed to evaluate the phytochemical, antioxidant as well as to screen the antimicrobial present in the plant extracts of L. alata. The plant L. alata petroleum ether extract of leaf showed greater IC50 for DPPH assay (154.8 μg/mL) and compare to another extract, higher reducing power activity stem in methanol (0.99EDTAE/100 g extract), better phosphomolybdenum reduction (0.512 mg/g extract) higher ferric reducing power (11542.3MmolFe(II)E/mg) extract and higher superoxide radical scavenging activity in leaf extract (332.13%). However, the better metal chelating ability was shown by the water extracts of the leaf (18.24 EDTAE/100 g) compared to other solvent extracts.Conclusion: The result indicates the antioxidant and antibacterial activity potential of L. alata.

Evaluation of antibacterial and antioxidant potential of the zinc oxide nanoparticles synthesized by aqueous and polyol method

In this paper, we have reported the synthesis, characterization, and evaluation of antimicrobial and antioxidant potential of monodispersed Zinc Oxide (ZnO) nanoparticles synthesized by the room temperature precipitation (aqueous phase) and polyol method (organic phase). ZnO nanoparticle synthesized by both the methods had shown excellent DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging, metal chelating (MC), ABTS (2,2′-azino-bis; 3-ethylbenzothiazoline-6-sulphonic acid), hydroxyl radical and superoxide radical scavenging activity (SAS). Scavenging activities were assayed within a concentration range of 25–75 ng ml−1. The antibacterial activities with MIC were investigated against two Gram-positive bacteria Streptococcus mutans (MTCC 497) and S. pyogens (MTCC 1926); three Gram negative bacteria Vibrio cholerae (MTCC 3906), Shigella flexneri (MTCC 1457) and Salmonella typhii (MTCC 1252). ZnO nanoparticles synthesized by the polyol method showed better MIC values against both Gram-positive and Gram-negative bacteria as compared to particles synthesized by aqueous precipitation method. Present study demonstrates the successful synthesis of ZnO nanoparticles with antioxidant property and significant broad spectrum antibacterial activity against several clinical bacterial pathogens.

Antioxidant capacity of hydroalcoholic extracts of Grewia serrulata DC and Grewia nervosa (Lour.) Panigrahi

The current investigation is intended to evaluate the content of phytochemical constituents and antioxidant potential of hydroalcoholic extracts of stem and root of Grewia serrulata DC (HAESGS & HAERGS) and leaf and bark of Grewia Nervosa (Lour.) panigrahi (HAELGN & HAEBGN). Initially, all the extracts at different concentrations were estimated for their total phenolic content and total flavonoid content. The study was further extended for their antioxidant potential evaluation using various in vitro methods such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical scavenging assays. The total phenolic content (mg gallic acid equivalent per gram of extract) was high in HAELGN (170.82±0.19) and HAERGS (123.00±0.48) than HAESGS (111.2±0.26) and HAEBGN (119.60±0.23). The total flavonoid content (mg quercetin equivalent per gram) is greater in HAERGS (71.24±0.50) and HAESGS (65.68±0.27) than HAELGN (55.82±0.35) and HAEBGN (62.38±0.45). The IC50 values (µg/ml) of different plant extracts inferred that DPPH radical scavenging activity is greater in HAELGN (42.91±0.88) and HAEBGN (53.87±0.35) than HAESGS (126.73±1.20) and HAERGS (88.87±1.25). However, hydroxyl and superoxide radical scavenging activity is more in HAERGS (135.41±1.19 & 88.00±1.42) and HAELGN (172.28±1.91 & 108.163±1.09) than HAESGS (237.3±1.65 & 110.074±0.87) and HAEBGN (204.7±1.04 & 125.54±1.07). The results of present comprehensive analysis demonstrated that both the plants Grewia serrulata DC and Grewia Nervosa (Lour.) panigrahi possess high phenolic, flavonoid contents and potential antioxidant activity, and could be used as a valid source of natural antioxidants and might be utilized for pharmacological screening of various therapeutic activities.
 Keywords: Grewia serrulata; Grewia Nervosa; Total Phenolic content; Total flavonoid content; Antioxidant potential

Functional Expression, Purification and Identification of Modified Antioxidant Peptides from Pinctada fucata Muscle

The aim of this study was to establish a system for the functional expression, purification and identification of new subtypes of modified antioxidant peptides from Pinctada fucata muscle (named MMP). After molecular modification, MMP had a primary coil spatial conformation that resembled an α-helix and improved the functional activity of MMP. The MMP DNA sequence was modified and codon optimized based on the amino acid sequence of the natural antioxidant peptide (named MP), which was isolated and purified from Pinctada fucata muscle by enzymatic hydrolysis. Antioxidant activity assay results showed that the IC50 values for DPPH-radical scavenging activity, superoxide-radical scavenging activity and hydroxyl-radical scavenging activity of MMP were 0.056, 0.310 and 0.126 mg/ml, respectively, which were higher than the antioxidant activities of enzymatically digested or chemically synthesized MMP (p < 0.05). In addition, this protocol exhibited great advantage in purity, speed, cost, and degree of automation for preparing MMP compared with enzymatic hydrolysis or chemical synthesis. Thus, the proposed method can be used to obtain MMP with high antioxidant activity and at a high yield. In addition, this method provided test data and a theoretical basis for high-value application of polypeptides from marine sources.

Synthesis and evaluation of antibacterial and anti-oxidant activity of small molecular chitosan–fucoidan conjugate nanoparticles

Low-molecular weight chitosan (LMWC) and low-molecular weight fucoidan (LMWF) have been reported to possess diverse biological activity. In this study, LMWC and LMWF of different molecular weights were prepared by a H2O2-involved oxidative depolymerization method. Covalently linked LMWC–LMWF conjugates were synthesized through the activation of carboxyl groups of LMWF and an amidation reaction between the activated LMWF and LMWC. Light transmittance assay and TEM analysis showed that the LMWC–LMWF conjugates gradually form colloidal nanoparticles during the amidation reaction. The LMWC–LMWF conjugates prepared from lower-molecular weight (depolymerized in a longer degradation time) LMWC and LMWF have larger particle sizes and lower zeta potentials. The LMWC–LMWF conjugates were investigated for their ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals. The DPPH and superoxide anion radical scavenging activities of the LMWC–LMWF conjugates were higher than that of LMWC alone and generally increased with a decrease in degradation time during the preparation of LMWF and LMWC. LMWC has superior hydroxyl radical scavenging activity, thus the hydroxyl radical scavenging activity of LMWC–LMWF conjugates were higher than that of LMWF alone. Bacterial inhibition assay of the conjugates against Escherichia coli and Staphylococcus aureus indicated that the conjugation of LMWC with LMWF improved the antibacterial activity of LMWF.

Physicochemical parameters, chemical composition, antioxidant capacity, microbial contamination and antimicrobial activity of Eucalyptus honey from the Andean region of Ecuador

This study aims to evaluate the pollen profile, physicochemical parameters, chemical composition, antioxidant capacity, microbial contamination and antimicrobial activity of Eucalyptus honey from the Andean region of Ecuador. Aerobic mesophiles, molds and yeasts, fecal coliforms and sulfite-reducing clostridia contamination were also assessed. All honey samples met the quality standards required by international legislation, except for hydroxymethylfurfural, for which three samples did not satisfy international standards. Apparent phenolic and flavonoid content, as well as free amino acid and protein content fell within the ranges previously reported for other types of honey of distinct floral and geographical origins. No microbial contamination was observed, while total antioxidant capacity showed evidence of the Eucalyptus honey’s ability to reduce Fe3+ to Fe2+ as well as to verify the superoxide radical scavenging activity and metal ion chelating capacity. Eucalyptus honey was able to inhibit the growth of Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Escherichia coli, but was not effective against Candida albicans.

A chelated calcium-procyanidine-attapulgite composite inhibitor for the suppression of coal oxidation

In this study, the impact of chelated calcium-procyanidine-attapulgite composite inhibitor on coal oxidation process is studied. The hydroxyl and superoxide anion radical scavenging activity for procyanidine-calcium chloride complexes was measured, and the result show that the complex with ligand-to-calcium ion ratio 1:5 has the highest radical clearing activity. Due to the water adsorption quality of CaCl2, the thermal analysis of samples with/without procyanidine-calcium chloride complexes indicated that the complex can slow down the coal oxidation well and the best ratio of procyanidine and CaCl2 should be determined at 1:7. Then the water retension capacity of procyanidine, CaCl2, ATP and composite inhibitors were compared, and the result indicated that ATP can improve the water retention of the composite inhibitor, so ATP as introduced into the composite inhibitor, and the optimal ratio of chelated inhibitor and ATP was determined as 1:5 by TG-DSC curves. Therefore, a chelated calcium-procyanidine-attapulgite composite inhibitor was chosen as an additive to suppress coal oxidation. The measurements of CPT, oxygen consumption during low temperature oxidation and CO emissions all demonstrated that the addition of the composite inhibitor to coal samples has an obvious suppression effect on the oxidation process. The in situ FTIR spectra of coal samples during the oxidation process show that the coal oxidation slows down due to the addition of chelated calcium-procyanidine-attapulgite composite inhibitor by eliminating free radicals and keeping the coal hydrated.

GC-MS Assisted Phytoactive Chemical Compounds Identification and Profiling with Mineral Constituents from Biologically Active Extracts of Aerva javanica (Burm. f) Juss. ex Schult.

Aerva javanica (Burm. f) Juss. ex Schult. (Family: Amaranthaceae) family is one of the traditional medicinal plant growing in the United Arab Emirates. Apart from studies related to some medicinal properties, phytochemical, GC MS compound characterization and biological activities still to be investigated. An experiment was conducted to determine the possible bioactive components with their chemical structures and elucidation of phytochemicals from the aerial parts of the plant. The macro and micro-mineral constituents and antioxidant activities were also evaluated. Aerial parts of A. javanica were extracted sequentially with hexane, chloroform, ethyl acetate, acetone, methanol by cold percolation method. Free radical scavenging and antioxidant properties of methanolic extract were evaluated by using in vitro antioxidant assays such as hydroxyl radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide radical scavenging activity and ABTS radical scavenging activity. Primary phytochemical and micro-macro element was tested using standard protocol. The chemical characterization was done with the help of Gas Chromatography-Mass Spectrometry (GC–MS), and the mass spectra of the total compounds in the extract were matched with the National Institute of Standard and Technology (NIST) library. Mineral constituents were identified and estimated by ICP-OES. Ninety-nine metabolites were obtained by GC-MS anslysis; indole was found to be major components followed by 2-Chlorallyl diethyldithiocarbamate (CDEC), Carbaril, Bis(2-ethylhexyl) phthalate, Quinoline, 4H-Cyclopenta[def]phenanthrene,2-[Bis(2-chloroethylamino)]-tetrahydro-2H-1,3,2-oxazaphosphorine-2-oxide, Phenobarbital, 1H-Indole, 2-methyl-, 2,3,7,8-Tetrachlorodibenzo-p-dioxin Disulfide, diphenyl. The presence of various bioactive compounds in the extract validates the traditional medicinal uses of this plant.

Green and solvent-free simultaneous ultrasonic-microwave assisted extraction of essential oil from white and black peppers

Essential oils were extracted from white and black peppers (Piper nigrum L.) by green and solvent-free ultrasonic-microwave assisted extraction (UMAE), microwave assisted extraction (MAE) and ultrasonic assisted extraction (UAE), and the efficiency and free radical scavenging activities of the essential oils by different extraction methods were compared in order to illuminate their advantages and disadvantages. The oil yield and superoxide radical scavenging activity of white pepper by UMAE were both significantly higher than those oil extracted by MAE and UAE, implying that UMAE was far more efficient extracting method than MAE and UAE. The same trends were also found for black pepper. Meanwhile, the bioactive compounds of the essential oils from white and black peppers were also characterized and compared by GC coupled with mass spectrometry (GC–MS) and electronic nose based on fast gas chromatography (GC). The essential oil from black pepper contained more monoterpenes than the oil from white pepper, while white pepper oil showed higher content of sesquiterpenes than black pepper. For the different extraction methods, generally, UMAE could obtain more monoterpenes and sesquiterpenes than MAE and UAE. UMAE should be an emerging effective green extraction technique for essential oil from P. nigrum because of the maximum extraction yields, shortest extraction time and solvent-free. The electronic nose has been proven as a useful tool for quick analysis and discrimination of the essential oils by different extraction methods.

Inhibition of Protein Glycation by Tiger Milk Mushroom [Lignosus rhinocerus (Cooke) Ryvarden] and Search for Potential Anti-diabetic Activity-Related Metabolic Pathways by Genomic and Transcriptomic Data Mining.

Naturally occurring anti-glycation compounds have drawn much interest in recent years as they show potential in reducing or preventing the risk of chronic complications for diabetic patients. In this study, annotation of the genome–transcriptome data from tiger milk mushroom (Lignosus rhinocerus, syn. Lignosus rhinocerotis) to PlantCyc enzymes database identified transcripts that are related to anti-diabetic properties, and these include genes that are involved in carotenoid and abscisic acid biosynthesis as well as genes that code for glyoxalase I, catalase-peroxidases, and superoxide dismutases. The existence of these genes suggests that L. rhinocerus may contain bioactive compound(s) with anti-glycation properties that can be exploited for management of diabetic complications. A medium-molecular-weight (MMW) fraction which was obtained from a combination of cold water extraction and Sephadex® G-50 (fine) gel filtration chromatography of L. rhinocerus sclerotia powder was demonstrated to exhibit potent anti-glycation activity. The fraction specifically inhibited the formation of N𝜀-(carboxymethyl)lysine, pentosidine, and other advanced glycation end-product (AGE) structures in a human serum albumin-glucose system, with an IC50 value of 0.001 mg/ml, almost 520 times lower than that of the positive control, aminoguanidine hydrochloride (IC50 = 0.52 mg/ml). Its ability to suppress protein glycation may be partly associated with its strong superoxide anion radical scavenging activity (10.16 ± 0.12 mmol TE/g). Our results suggest that the MMW fraction of L. rhinocerus shows potential to be developed into a potent glycation inhibitor for preventing AGE-mediated diabetic complications.

Optimization, chain conformation and characterization of exopolysaccharide isolated from Leuconostoc mesenteroides DRP105

Response surface methodology (RSM) was used to optimize the fermentation condition of exopolysaccharide (EPS) producing strain Leuconostoc mesenteroides DRP105. Result showed that the optimum condition was sucrose 86.83g/L, tryptone 15.47g/L, initial pH7.18 and maximum yield was 53.79±0.78g/L in 36h fermentation. Chain conformation was characterized by Congo red test, β-elimination and circular dichroism (CD), which indicated that the EPS was O-linkage and exhibited random coil structure in aqueous solution. CD results concluded hydrogen-bond interaction and chirality might be connected with concentration. Purified EPS has a higher degradation temperature of 279.42°C, suggesting high thermal stability of the EPS. The absolute value of zeta potential and particle size were enhanced with increasing concentration. Crude EPS and its purified fraction were found to have moderate DPPH, hydroxyl, superoxide anion radicals scavenging activities and reducing power. This study provided a high yield EPS with unique characteristics for industrial applications.

The Antioxidant and Xanthine Oxidase Inhibitory Activity of Plumeria rubra Flowers.

Plumeria rubra Linn of the family Apocynaceae is locally known in Malaysia as “Kemboja”. It has been used by local traditional medicine practitioners for the treatment of arthritis-related disease. The LCMS/MS analysis of the methanol extract of flowers (PR-ME) showed that it contains 3-O-caffeyolquinic acid, 5-caffeoquinic acid, 1,3-dicaffeoquinic acid, chlorogenic acid, citric acid, 3,3-di-O-methylellagic acid, kaempferol-3-O-glucoside, kaempferol-3-rutinoside, kaempferol, quercetin 3-O-α-l-arabinopyranoside, quercetin, quinic acid and rutin. The flower PR-ME contained high amounts of phenol and flavonoid at 184.632 mg GAE/g and 203.2.2 mg QE/g, respectively. It also exhibited the highest DPPH, FRAP, metal chelating, hydrogen peroxide, nitric oxide superoxide radical scavenging activity. Similarly, the XO inhibitory activity in vitro assay possesses the highest inhibition effects at an IC50 = 23.91 μg/mL. There was no mortality or signs of toxicity in rats at a dose of 4 g/kg body weight. The administration of the flower PR-ME at doses of 400 mg/kg to the rats significantly reduced serum uric acid 43.77%. Similarly, the XO activity in the liver was significantly inhibited by flower PR-ME at doses of 400 mg/kg. These results confirm that the flower PR-ME of P. rubra contains active phytochemical compounds as detected in LCMS/MS that contribute to the inhibition of XO activity in vitro and in vivo in reducing acid uric level in serum and simultaneously scavenging the free radical to reduce the oxidative stress.

Preliminary Phytochemical Screening and In vitro Antioxidant Activity of Nigella sativa and Allium cepa Oil

Many oxidative stress related diseases are as a consequence of accumulation of free radicals in the body. The various researches are going on globally directed towards finding natural antioxidants of plants origins. We planned to investigate the preliminary phytochemical screening and in vitro antioxidant activity of Nigella sativa and Allium cepa oil. The yield of oil of Nigella sativa and Allium cepa were 21.5% and 27.3%, respectively. Phytochemical screening was performed by using standard methods. The in vitro antioxidant study was done for Nigella sativa and Allium cepa oil by using hydrogen-donating activity, superoxide scavenging activity, hydrogen peroxide scavenging assay and reducing power assay. The result of phytochemical screening demonstrated the presence of flavonoids, steroids and fats in Nigella sativa and Allium cepa oil. The findings of DPPH, superoxide, reducing power and H2O2 radical scavenging activity exhibited that the oil of Nigella sativa and Allium cepa showed moderately to strongly free radical scavenging activity. Hence Nigella sativa and Allium cepa oil can play a major role in alleviating the number of oxidative stress by reducing the oxidative damage to cellular component caused by Reactive oxygen species (ROS).