Peroxide Scavenging Activity Research Articles

Evaluation of phytochemical constituents and antioxidant potential of hydro-alcoholic and aqueous extracts of Murraya koenigii L. and Ficus carica L.

Summary Introduction: Murraya koenigii L. and Ficus carica L. have been traditionally used in folk medicine for treating several diseases. Objective: The present study was proposed to investigate the phytochemical constituents and antioxidant potential of hydro-alcoholic and aqueous extracts of leaves of M. koenigii and dried fruits of F. carica. Methods: Phytochemical screening was performed using different methods and antioxidant activity was evaluated by measuring total phenolic content, total antioxidant capacity (TAOC), hydrogen peroxide (H2O2) scavenging activity, DPPH radical-scavenging activity, reducing power assay, nitric oxide radical scavenging activity, and superoxide radical-scavenging activity. Results: The results showed that the hydro-alcoholic and aqueous extracts of leaves of M. koenigii and dried fruits of F. carica possess a significant quantity of flavonoids, saponins, terpenoids (9.0%, 0.9%, 0.6% and 7.3%, 8.7%, 0.44%, respectively) and also possess a significant antioxidant activity as evaluated by employing different antioxidant assays. Conclusion: It may be concluded that the hydro-alcoholic and aqueous extracts of leaves of M. koenigii and dried fruits of F. carica exhibit significant antioxidant activity.

Recovery of major phenolic acids and antioxidant activity of highland barley brewer’s spent grains extracts

Highland barley brewer's spent grain (BSG) is a valuable by-product with a significant amount of antioxidant phenolic acids (APA). The aim of the present study was to assess the total phenolic contents and the radical scavenging activity of highland barley BSG. The in vitro methods, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ABTS radical scavenging activity assay, ferric reducing/antioxidant power assay, 2-deoxyribose assays, and hydrogen peroxide scavenging activity, were applied. The extracts produced with acetone from highland barley BSG exhibited antioxidant activities. However, at 40% v/v extract exhibited the highest antioxidant capacity and the highest content of total phenolic acids. HPLC-DAD analysis also demonstrated that the highland barley BSG extracts generated with 40% v/v exhibited the highest amount of major phenolic acids such as ferulic acid (5.07 mg/g) followed by p-coumaric acid (2.10 mg/g) and then caffeic acid (0.644 mg/g). The results indicated the highland barley BSG was a valuable source of antioxidant phenolic compounds. Whereas the solid–liquid extraction technique with 40% v/v acetone was as simple, low cost, and most effective method to recover APA from highland barley BSG. Practical applications Highland barley BSG is attracting increasing attention due to its significant potential as a natural antioxidant to reduce the risk of diseases and to promote health.

The Graft Copolymerization of N-(Hydroxymethyl) Acrylamide onto Xanthan Gum and Its Anti-Oxidative Property

The graft copolymers of N-(hydroxymethyl) acrylamide were synthesized by radical grafting of N‑(hydroxymethyl) acrylamide onto the xanthan gum as a substrate. On increasing the concentration of N‑(hydroxymethyl) acrylamide the grafting parameters decreased gradually, whereas the similar parameters for homopolymer increased. The antioxidant activity of the graft copolymer was 5% less than for xanthan gum and 17% less than for butylated hydroxytoluene. The hydrogen peroxide scavenging activity of graft copolymer was 31 and 15% higher than that of xanthan gum and butylated hydroxytoluene, respectively. The hydroxyl radical scavenging activity of graft copolymer was 15% less than gum and 16% more than butylated hydroxytoluene. The superoxide scavenging activity of graft copolymer was 11% less than that of xanthan gum and 24% more than that of butylated hydroxytoluene.

Effect of different processing conditions on antioxidant activity of Gracilaria edulis(Rhodophyseae) in Sri Lanka

Gracilaria edulis is red marine algae currently cultivated in Sri Lanka but relatively low than other country such as China and Japan. This species are used to produce drugs and healthy delicious low calorie foods because of they are primary source of secondary metabolite and to be used as natural antioxidants and antimicrobials. The Purpose of this research investigates effect of different processing conditions on antioxidant activity of G.edulis (Rhodophyseae) by hydrogen peroxide scavenging activity assay. Absorbance at 230 nm, hydrogen peroxide scavenging assays were done. Different processed G.edulis such as fresh, steamed, boiled, dried and microwaved were extracted with methanol. Their antioxidant properties were compared to the L-ascorbic acid which used as positive control. The methanolic extracts of this red algae was prepared keeping methanol as a standard. Methanol was used as control. In minitab-15 statistical software package, Paired T-Test was clearly shown the absorbance, inhibition or hydrogen peroxide scavenging activity depend on the processing conditions of the G.edulis methanol extract. This statistical test did tell about the difference between the different processing conditions of the methanol extract of the G.edulis (p<0.05) and antioxidant activity and these were not independent factors such are depend on each other. Hence antioxidant activity or H2O2 scavenging activity was highly in boiled G.edulis, followed by fresh, microwaved, dried and steamed respectively. L-ascorbic acid was used as Positive control and its antioxidant activity was higher than dried and steamed but relatively lowers than microwaved, fresh and boiled G.edulis. Finally Boiled G.edulis sample was recorded prominent antioxidant activity due to leaching of less antioxidant compounds. In future this study is used to functional product development incorporation of dried followed by boiled G. edulis into bakery Products.

Nicotine-induced oxidative stress, testis injury, AChE inhibition and brain damage alleviated by Mentha spicata.

Nicotine mediates some of the injurious effects caused by consuming tobacco products. The aim of this work is to investigate the protective effects of Mentha spicata extract (ME) supplementation on the testis and brain of nicotine-induced oxidative damage rats. ME extract showed interesting hydrogen peroxide-scavenging activity. HPLC-DAD analysis of ME revealed the presence of nine compounds among them gallic acid was the major one (165.44µg/g ME). Thirty-two rats were randomly divided into four groups: control, a nicotine-treated group (1mg/kg i.p.), a group receiving ME (100mg/kg), and a group receiving both ME (100mg/kg) and nicotine (1mg/kg). After 2months of treatment, the in vivo results showed that nicotine exhibited an increase in the body, brain, testis and accessory sex organ weights, sperm count and sperm motility. In addition, exposure to nicotine significantly (p < 0.01) increased acetylcholinesterase level (AChE) in brain, lipid peroxidation level in brain and testis as compared to control group. The antioxidant enzymes results showed that nicotine treatment induced a significant decrease (p < 0.01) in brain and testis antioxidant enzymes such as catalase, superoxide dismutase and glutathione peroxidase as compared to control group. Interestingly, pretreatment with ME significantly (p < 0.01) restored the majority of these biological parameters to normal levels, as well as ahistologicalimprovement. Obtained results suggest that ME contains promising substances that counteract the nicotine-intoxication and can be efficient in the prevention of brain and testis toxicity complications.

Inhibitory Effect of Dry Garlic Powder on the Nickel Chloride-induced Somatic and Germinal Cell Damages in Male Mice

Background: Nickel is commonly used in industry, utensils and also present in cigarette. Over-exposure of nickel is known to cause several health complications including somatic and germinal cell injuries. Garlic (Allium sativum) being a spice has several pharmacological properties. However, its role on the nickel chloride induced somatic and reproductive cells damages are poorly studied in the literature.&#x0D; Objective: To evaluate the effect of garlic powder on nickel chloride induced somatic and germinal cell damages in male mice.&#x0D; Methods: Dried garlic clove powder is used in this study in three doses via., 50. 100 and 150 mg/kg, per oral (p.o) for 4-weeks against the nickel chloride [(10 mg/kg, intraperitoneal (i.p)] induced somatic and germinal damages. Somatic cells damages were studied using peripheral micronucleus test and germinal cell damages by sperm count and sperm shape abnormalities in male mice. Further, the in-vitro hydrogen peroxide scavenging activity of the garlic was evaluated. Ascorbic acid was tested as a standard drug. The data of the results were analyzed by One-way Anova and Tukey as post hoc test.&#x0D; Results: The result indicated that nickel chloride enhanced significantly (p&lt;0.001) both somatic and germinal cell damages compared to control animals. The administration of garlic powder at 150 mg/kg significantly (p&lt;0.001) minimized the frequency of micronuclei in the erythrocytes and reduced the spermatozoa anomalies compared to the nickel chloride group. The garlic powder also exhibited significant hydrogen peroxide scavenging activity.&#x0D; Conclusion: The data indicated that garlic powder at 150 mg/kg reduced the cellular damaging effects of nickel chloride on somatic and germinal cells and the mechanism could be related to the free radical scavenging activity.

Biochemical, Phytochemical Profile and Angiotensin-1 Converting Enzyme Inhibitory Activity of the Hydro-methanolic Extracts of Tulbaghia acutiloba Harv.

Phytotherapeutic treatments have been on the ascendancy over the years as the quest for alternate and easily accessible health care is on the rise. Tulbaghia acutiloba has been used by both traditional healers and the South African population for the management of chronic conditions, but lacks scientific authentication. Hydro-methanolic extracts (roots, rhizomes, leaves and flowers) of the plant were evaluated for their antioxidant activities, biochemical and phytochemical profile. Additionally, the heavy metal content and antihypertensive effects including Angiotensin 1-Converting Enzyme Inhibitory (ACEI) activities were investigated. The antioxidant ability of the hydro-methanolic extracts were determined by 2, 2- diphenyl-1-picryl hydrazyl ( DPPH ), hydrogen peroxide and nitric oxide scavenging activities. Phytochemical profile was assessed using qualitative and quantitative methods whereas the heavy metal toxicity was determined by using Inductively- Coupled Plasma-Optical Emission Spectrometry (ICP-OES). In vitro ACEI activity was determined by the hydrolysis of the tripeptide, hippuryl –L-Histidyl-L-leucine (Hip-His-Leu ). All the extracts showed potent antioxidant activities which was concentration dependent. Phytochemical analysis showed the presence of phenols, amino acids and alkaloids in all the extracts. The leaves showed a relatively higher total phenolic content of 43.26±1.15 mgGAE/g. Gas Chromatography–Mass Spectrometry (GC-MS) analysis showed the presence of major compounds such as α-linolenic acid in the leaves as well as oleic acid and palmitic acid in other parts of the plants. Toxicity of heavy metal was undetected in all extracts of the plant. All the extracts of the plants showed a >50% ACE inhibition at different concentrations with the leaves showing a relatively higher inhibitory activity (76.66 ± 1.65, IC50 ; 154.23 μg/ml) compared with the other parts of the plants. It is therefore concluded in this study that the biological activities and phytochemical component of the hydro-methanolic extracts of T. acutiloba is indicative of its possible use for the treatment as well as prevention of hypertension and oxidative stressrelated diseases.

PHYTOCHEMICAL INVESTIGATION AND EVALUATION OF IN VITRO ANTIOXIDANT ACTIVITY OF THE PLANT CYPERUS TEGETUM ROXB

Objective: The objective of the present study is to isolate the lead molecules and the antioxidant activity is also evaluated.&#x0D; Method: Cyperus tegetum Roxb. (Cyperaceae) is found in the tribal area of West Midnapur district of West Bengal, India. It is commonly known as Madur Kathi. Different chromatographic techniques, namely, thin-layer chromatography, column chromatography, and high-performance liquid chromatography (HPLC) were used to isolate and identify the different secondary metabolites.&#x0D; Results: The different spectral studies (nuclear magnetic resonance [NMR], infrared [IR], and ultraviolet [UV]) confirmed the presence of stigmasterol as an isolated compound from the extract of C. tegetum (ECT). HPLC analysis revealed the presence of flavonoids, namely, rutin (retention time [Rt]: 3.00), myricetin (Rt: 3.9), and quercetin (Rt: 5.6) and phenolic acids, namely, gallic acid (Rt: 4.0), caffeic acid (Rt: 5.4), chlorogenic acid (Rt: 7.3), and ferulic acid (Rt: 8.8) in ECT. ECT showed strong reducing power, diphenyl-2-picrylhydrazyl hydrate radical, superoxide anion scavenging, and hydrogen peroxide scavenging activities when compared to standard compounds.&#x0D; Conclusion: From this study, several flavonoid and phenolic compounds were identified by RP-HPLC analysis. Flavonoids are rutin, quercetin, and myricetin and phenolic compounds are gallic acid, ferulic acid, chlorogenic acid, and caffeic acid, respectively. The different spectral studies (NMR, IR, and UV) confirmed the presence of stigmasterol as an isolated compound from ECT.

Isolation and structural characterization of sulfated polysaccharide from Spirulina platensis and its bioactive potential: In vitro antioxidant, antibacterial activity and Zebrafish growth and reproductive performance

In this study, the sulfated polysaccharide (SPs) was isolated from Spirulina platensis. The isolated SPs contains carbohydrate, sulfate, protein and uronic acid at 38.7 ± 0.30%, 21.3 ± 0.87%, 7.1 ± 0.15% and 7.9 ± 0.4% respectively. The elemental analysis confirmed the presence of carbon (18.01 ± 0.10%), hydrogen (1.83 ± 0.02%) and nitrogen (3.43 ± 0.01%). The monosaccharide composition and molecular weight of SPs were analyzed by high-performance liquid chromatography and size exclusion chromatography respectively. The monosaccharide composition analysis showed the existence of glucose, rhamnose, xylose, fucose, mannose, galactose and the molecular weight of SPs was 1016 kDa. Further, the characterization of SPs was done by UV–visible spectroscopy, X-ray diffraction, FT-IR, 1H NMR and 13C NMR analysis. The obtained SPs exhibited potent antioxidant activity in DPPH (76.45 ± 0.49%), reducing power (absorbance: 1.3 ± 0.02), hydrogen peroxide scavenging (66.3 ± 1.16%), hydroxyl scavenging (68.6 ± 3.2%), nitric oxide (81.36 ± 1.85%) and total antioxidant (absorbance:1.66 ± 0.02) activities at 5 mg/ml. In addition, SPs revealed the highest antibacterial efficacy against the pathogenic bacteria Vibrio vulnificus in disc diffusion, agar bioassay and protein leakage assays at 100 μg/ml. Furthermore, the supplementation of 2% SPs through a feed to the Danio rerio fish enhances the growth and reproductive performances. This finding confirmed that the isolated SPs from S. platensis possess pharmaceutical as well as nutritional properties.

Highly supportive hydrogen peroxide as a hole scavenger to improve the visible light water splitting activity of flake-like Co-doped ZnO thin films

In the present work, we explored the hole scavenging activity of hydrogen peroxide (H2O2) on flake-like Co-doped ZnO thin films to improve the visible light photoelectrochemical (PEC) water splitting activity. To address this phenomenon, we developed promising Co (0, 0.8, 1.7 and 2.2 at.%)-doped ZnO thin films by simultaneous RF and DC magnetron sputtering. First, precise control on Co doping level in the ZnO host lattice has been demonstrated to facilitate superior water splitting activity through the strategic surface transformation. Accordingly, Co doping concentration significantly modulated the structural properties of ZnO (0 0 2). From FESEM analysis, clear morphological changes were observed from granular (Co-0 at.%) to flake-like (Co-1.7 at.%). Also, AFM analysis provided insights into surface roughness (7.0 nm) and maximum height of roughness (35 nm) of Co (1.7 at.%)-ZnO thin films. Furthermore, TEM analysis highlighted the crystalline changes on Co (1.7 at.%)-ZnO thin films. Thus, Co (1.7 at.%)-ZnO exhibited a reduced band gap (3.07 eV). Notably, flake-like Co (1.7 at.%)-ZnO thin films validated with prominent hydrophilicity. As a result, the morphology of Co (1.7 at.%)-ZnO facilitated superior visible light PEC activity than others. Second, to accelerate the PEC activity, hole scavenging mechanism has been proposed by the addition of H2O2 into the KOH. Our results show how the HO2* radicals contributed to suppressing the hole accumulation, recombination and cathodic currents at the interface of Co-ZnO/electrolyte. Overall, we believe that the proposed hole scavenger strategy provides new insight into improved visible light PEC water splitting activity on flake-like Co-ZnO thin films.

Antioxidant (in vitro), Antidiabetic (in vitro) and Photocatalytic Activity of Costus speciosus Leaf Extract Assisted CS-Ag-TiO2 Composites

The researchers have currently targeted bio-synthesis nanoparticles (NPs) and their potential applications toward bio and photocatalytic field. The in vitro antidiabetic activity of noble metal modified TiO2 is really scare in literature. In the present work, green synthesis of CS-Ag nanoparticles was achieved through Costus speciosus (Crape ginger, an Indian ornamental plant, has long been medicinally used in traditional systems of medicine) leaf extract, and followed by solvothermal synthesis of CS-Ag-TiO2 composites. The prepared nanocomposites effectively utilized for in vitro antioxidant, in vitro antidiabetic study and azo dye AB 1 degradation under visible light. Costus speciosus leaf extract mediated bioreduction process has been successfully employed for the preparation of silver nanoparticles (CS-Ag) followed by the solvothermal synthesis of CS-Ag-TiO2 nanocomposites. The different characterization techniques were adopted for characterization of the prepared materials. in vitro antioxidant activities of the prepared materials were tested through 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (APTS) radical scavenging, iron reducing, superoxide anion radical scavenging, hydrogen peroxide scavenging and hydroxyl radical scavenging activities. Furthermore, in vitro anti-diabetic study such as α-amylase activity was studied. XRD measurements reveal that the presence of anatase phase of TiO2. XPS reveal that Ag is in the form of Ag0 in CS-Ag-TiO2 composites. HR-TEM images reveal that the CS-Ag-TiO2 exhibits sphere like particles and are formed by aggregation of individual fine nanosize particles. The photocatalytic activity of TiO2 was slightly influenced by CS-Ag. The results conclude that the Costus speciosus assisted CS-Ag-TiO2 nanoparticles can be potent natural antioxidants and can be essential for health preservation against oxidative stress related degenerative diseases. The results of in vitro antidiabetic study showing promising outcome which can be lead to develop Costus speciosus CS-Ag-TiO2 nanoparticles as potential antidiabetic materials.

Synthesis and Evaluation of Aldehyde Derivatives of Sulfonyl Chloride Quinoxaline

In pyrazine mesomeric interaction between the protonated &amp; neutral nitrogen atoms probably destabilizes the cation.N, N’-diprotonation is very easier for pyrazine Synthesis of 2, 3-diphenylquinoxaline by phenylene-diamine in 16 ml of rectified spirit was added &amp; combine solution was warm in water bath for 30 min. added water until slight colorless persist &amp; allow to cool recrystallize the product in ethanol. Synthesis of 2, 3-diphenylquinoxaline 7-sulfonylchloride (R) using chlorosulfonic acid under ice-cold condition, then Synthesis of 2-hydroxyphenyl-2,3-diphenylquinoxaline-7-sulphonate(R1) throughresorcinol with 3ml pyridine &amp; sulphonyl chloride derivative, Synthesis of 2-formylphenyl-2,3-diphenylquinoxaline-7-sulphonate(R7)obtained by reaction of salicylaldehyde with pyridine &amp; sulphonyl chloride derivative then Synthesis of 3-formylphenyl-2,3-diphenylquinoxaline-7-sulphonate(R9) obtained by heating on water bath mixture of3-hydroxybenzaldehyde with pyridine &amp; sulphonyl chloride, Synthesized quinoxaline derivatives were subjected to antimicrobial susceptibility testing by well diffusion method against gram positive (S.aureus, 2079) and gram negative bacteria (E. coli, 2685). The results of quinoxaline derivatives in terms of zone of inhibition recorded. MIC of quinoxaline derivative was determined by tube micro dilution technique against S. aureus and E. coli. The turbidity was measured by UV at about 420 nm. Hydrogen peroxide scavenging activity and 1, 1 diphenyl 2, picryl hydrazyl Method (DPPH) calculated and Most of the derivatives have shown comparable antioxidant activity in relation to standard Ascorbic acid and DPPH. Keywords: QSAR, Sulfonyl Chloride Quinoxaline, Ant-microbial, Antioxidant

Statistical optimization of process parameters for improvement of phycobiliproteins (PBPs) yield using ultrasound-assisted extraction and its kinetic study.

The present study is mainly concerned for the development of an optimal ultrasound-assisted extraction (UAE) condition for phycobiliproteins (PBPs) from Oscillatoria sp. (BTA 170) using Taguchi methodology. Four process parameters viz. solid to liquid ratio, duty cycle, electrical acoustic intensity, and pH, for UAE were optimized using Taguchi methodology for enhanced PBPs extraction. The ratio of signal to noise (S/N) was used to compute the optimized condition required to attain a higher yield of PBPs, the average performance of individual parameter and corresponding interactive effects. The statistically significant parameters with their contribution were assessed using Analysis of variance (ANOVA). Results showed that duty cycle contributed the maximum influence (30.81%) on phycocyanin (PC) extraction followed by a solid liquid ratio (28.62%), pH (22.46%) and electrical acoustic intensity (18.10%). The highest contribution on the extraction of phycoerythrin (PE) was found from pH (33.16%), followed by duty cycle (31.57%), solid to liquid ratio (22.83%) and electrical acoustic intensity (12.45%). For extraction of allophycocyanin (APC), the duty cycle, solid to liquid ratio, pH and electrical acoustic intensity contributed 29.47, 29.07, 29.03, and 12.43% respectively. Results obtained from Taguchi methodology indicated that enhanced PC (94.10%), PE (95.20%) and APC (90.54%) can be achieved with solid-liquid ratio (0.2 g/ml), electrical acoustic intensity (16.99 w/cm2), duty cycle (75%), and pH 7 than the yield of PBPs obtained under unoptimized condition. In the present study, higher yield of PC (38.99%), PE (20.84%), and APC (11.93%) were attained with UAE compared to yield obtained from homogenized Oscillatoria sp. BTA 170 using 0.05 M phosphate buffer. Batch extraction data of PBPs under UAE was fitted well with the second order model. The values of second-order rate constant (k) were computed as 6.66 × 10-4, 64.09 × 10-4 and 1.49 × 10-4 L/mg/min for extraction of PC, PE and APC respectively. The PBPs exhibited significant antioxidant property and hydrogen peroxide scavenging activity, which were increased with the enhancement of PBPs concentration.

In Vitro Screening of Immunomodulatory Activity of Methanolic Extract of Physalis minima Unripe Fruits

At the present plants play a key role in Medicine. Many phyto pharmaceuticals are used to treat different ailments. In the present study, methanolic extract of Physalis minima unripe fruits was screened for immunomodulatory activity using anti-oxidant activity by determining DPPH radical scavenging activity, Hydrogen peroxide scavenging activity, Ferric reducing antioxidant power assay, Immunomodulatory activity by Nitroblue tetrazolium test. The extract showed that the plant extracts have ability to act as free radical scavengers in DPPH radical scavenging activity, reducing ability in Ferric reducing antioxidant power assay, ability to prevent lipid peroxidation in Hydrogen peroxide scavenging activity, ability to stimulate the phagocytic activity in leucocytes in Nitroblue tetrazolium test. The literature survey revealed that these studies were not reported earlier. So, the present study was aimed to reveal the antioxidant and immunomodulatory activity of the plant extract. The study reports concluded that the extract possess immunomodulatory activity.

English

Ocimum americanum L. (Lamiaceae) and Pupalia lappacea (L) Juss. (Amaranthaceae) are two plants used in Benin to manage hypertension. Little scientific data is available on the antihypertensive properties of these plants. Therefore, we investigated the antihypertensive potential of ethanolic extracts of O. americanum and P. lappacea on L-NAME-induced hypertensive rats. The DPPH free radical scavenging potential, Fe3+ reducing capacity, superoxide anion radical and hydrogen peroxide scavenging were assessed. Extracts were also screened for their active compounds using ultimate high-performance liquid chromatography 3000. CODA™ non-invasive blood pressure system was used to record blood pression parameters. Both extracts induced significant decrease of systolic, diastolic blood pressure and mean arterial pression. O. americanum extract at 250 mg/kg body weight, decreased mean blood pressure (MBP) from 146 ± 4.80 to 98.4 ± 9.44 mmHg and P. lappacea extract from 154.4 ± 11.28 to 111.8 ± 9.44 mmHg. A significant decrease of MBP was also observed with Losartan and Captopril at 100 mg/kg body weight. P. lappacea showed the higest ferric reducing/antioxidant power 4905 ± 87.79 µmol AAE g-1. Superoxide anion and hydrogen peroxide scavenging activities showed higher activity, 68.42 ± 3.68 and 38.68 ± 4.18%, respectively for O. americanum. The chromatography analysis of extracts suggested the presence of ferulic acid, chlorogenic, tannic, ellargic, caffeic acids and chrysin, rutin and isorhamnetin. The obtained results justify the traditional use of O. americanum and P. lappacea in management of hypertension in southern Benin. Key words: Ocimum americanum, Pupalia lappacea, antihypertensive activity, antioxidant activity.

The antioxidative effects of bioactive products from Sargassum polycystum C. Agardh and Sargassum duplicatum J. Agardh against inflammation and other pathological issues

The present study was aimed to determine the phenol, total flavonoids and antioxidant potentials of Sargassum polycystum C. Agardh and Sargassum duplicatum J. Agardh from south east coast of Tamil Nadu and India using DPPH, phophomolybdenum and hydrogen peroxide scavenging activity. The total phenols, total flavonoids and antioxidant activities of S. polycystum and S. duplicatum were determined. Highest phenols (33.49 and 149.52 mg GAE/g) were observed in chloroform extracts of S. polycystum and methanolic extracts of S. duplicatum. The acetone extracts of S. polycystumand S. duplicatum demonstrated maximum amount of flavonoids compared to other studied extracts. Maximum amount of phosphomolybdenum reduction was observed in acetone extracts of S. polycystum and methanolic extracts of S. duplicatum. The DPPH radical scavenging activity of different extracts of S. polycystum and S. duplicatum were as follows acetone > chloroform > Petroleum ether > methanol and acetone > chloroform > methanol >Petroleum ether respectively. The H2O2 scavenging activity of S. polycystum extracts were as follows Petroleum ether extracts of S. polycystum (67.9%) > acetone (67.3%) > chloroform (58.6%) > methanol (51.78%). Acetone extracts of S. duplicatum showed maximum inhibition (90.39%) followed by petroleum ether, chloroform and methanolic extracts (75.11, 72.37 and 54.59%) respectively. The present study results confirmed the antioxidant properties of the two selected brown seaweeds viz., S. polycytum and S. duplicatum. The total phenols, flavonoids and alkaloids may be responsible for the antioxidant activities.

Deciphering the Antioxidant and Free Radical-Scavenging Capacity of Anthocleista vogelii

The empirical survey comparatively explores the antioxidant activity and the free radical-scavenging capacity of various fractions of Anthocleista vogelii leaves. The dried and pulverized leaves of A. vogelii were subjected to cold maceration for 4, 8 and 12 days using 70 % methanol and filtered. The filtrate was concentrated to a slurry crude extract by means of a rotary evaporator at 40ºC with a salvaged yield of 34.10 %. Exactly 0.23 kg of crude extract was defatted and fractionated using two chromatographic techniques in chloroform-methanol-hexane solvent system (3:21 v/v). The fractions were screened qualitatively for polyphenolic compounds. The fractions containing these bioactive compounds were quantified and further subjected to free radical-scavenging activity: DPPH assay, ferric reducing power (FRP) assay, hydrogen peroxide scavenging activity (HPA) and total antioxidant capacity (TAC) respectively. There was marked significant difference (p&lt;0.05) in the total phenolic and flavonoid contents (TPC and TFC) among the fractions with ample amount found in n-hexane fraction. There were marked significant differences (p&lt;0.05) in the IC 50 values among fractions for DPPH, FRP, HPA and TAC assays. Thus, the ample antioxidant activity of n-hexane fraction among other fractions was further validated by the extrapolated IC 50 values. The study inferred that A. vogelii leaves are possible sources of antioxidants with health benefits, especially for disease conditions characterized by oxidative stress. Keywords: Anthocleista vogelii , Antioxidant activity, Free radical-scavenging capacity, IC 50 value, Oxidative stress DOI : 10.7176/JNSR/9-12-09 Publication date :June 30 th 2019

Chemical ingredients and antioxidant activities of underutilized wild fruits

This study evaluated nutritional values, bioactive constituents and antioxidant activities of the five wild underutilized fruits in the mountains of southwest Saudi Arabia (Coccinia grandis (L.) Voigt, Diospyros mespiliformis Hochst. Ex A.Dc., Cissus rotundifolius (L.), Ephedra foeminea Forssk., and Grewia villosa Willd.). The moisture content, crude fibers, total protein, total lipids, total hydrolyzable carbohydrate, total soluble sugars, and total free amino acids were analyzed. The results showed varying amounts among fruits of the five study species. In addition, the mineral composition, amino acid content, phenolic compounds, vitamins, and antioxidant activity were assessed. The highest content of total phenolic and total tannins was measured in D. mespiliformis (20.69 mg/g and 3.84 mg/g) and the lowest in E. foeminea (10.83 mg/g and 1.44 mg/g), respectively. The methanol extract (1 mg/ml) of D. mespiliformis displayed higher percentage of DPPH radical scavenging activity (87.36%). The methanol extract (1 mg/ml) of C. grandis exhibited the highest effect of total antioxidant activity and hydrogen peroxide scavenging activity (71.53%). The sufficient nutritional and antioxidant value of these wild fruits provide healthy food source for the local residents, much the same as many cultivated fruits and vegetables.

In vitro Antioxidant Potentials of Ethanol Extract of Unripe and Ripe Dennetia tripetala Fruits

Dennettia tripetala fruit is a popular Nigerian fruit from the family of plant known as Annonaceae. The whole fruit (flesh and seed) is usually consumed as snacks and it is oftentimes consumed with local gin (ufofop in Ibibio or kaikai in Igbo) or added to dishes as spice due to its peculiar strong pepperish taste and sweet aroma. The present study is aimed at evaluating the antioxidant potentials of ethanol extract of ripe and unripe D. tripetala (DT) fruit in vitro. The antioxidant activity of the ethanol extract of DT was evaluated spectrophotometrically using various in vitro models like 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) and hydrogen peroxide scavenging activity; metal chelating activity and reducing power. Vitamin C was used as the standard antioxidant.Unripe and ripe DT fruits, as well as vitamin C showed a competitive inhibition of DPPH and H2O2 free radicals. As concentration of the extracts increased from 20 to100 µg/mL, the % scavenging activity for vitamin C increased from 87.86 ± 0.11 to 90.66 ± 0.07 and for ripe DT fruits from 15.15 ± 0.24 to 25.52 ± 0.23, while for unripe, fruits values increased from 12.09 ± 0.35 to 23.06 ± 0.12. The IC50 values was highest in unripe (549.23) followed by ripe (276.63) and lowest in vitamin C (12.92) indicating that vitamin C was the best scavenger of DPPH radical. Similar trend was obtained for H2O2 scavenging activity as well as reducing power. Unripe DT fruit extract was more potent at chelating metal ions (IC50 was 95.38), followed by the standard ascorbic acid with IC50 of 97.03 and was lowest in ripe DT fruit extract with IC50 value of 124.66. Unripe and ripe DT are potent antioxidants in nature and may be used to supplement our diets as rich sources of natural antioxidants for health protection.

A comprehensive review on the determination of enzymatic assay and nonenzymatic antioxidant activities.

This review article presents a comprehensive review pertaining to antioxidants and various assays that determined enzymatic and nonenzymatic antioxidants. Antioxidants have gained attention at the global scale on its prominent beneficial roles that can fight against many chronic infirmities, including cancer and cardiovascular diseases. Many studies have investigated different types of samples, such as medicinal plants, fruits, and vegetables, by using various antioxidant assays. Antioxidants can be grouped into enzymatic and nonenzymatic antioxidants. To date, most studies had looked into nonenzymatic antioxidants due to lack of references on enzymatic antioxidant assays. Therefore, this review article depicts on seven assays of enzymatic antioxidants (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, ascorbate oxidase, guaiacol peroxidase, and glutathione reductase) and fifteen activities of nonenzymatic antioxidants (total polyphenol, total phenolic acids, total flavonoids, total ascorbic acid, anthocyanin content, DPPH scavenging activity, FRAP assay, hydrogen peroxide scavenging activity, nitric oxide scavenging activity, superoxide radical scavenging activity, hydroxyl radical scavenging activity, phosphomolybdate assay, reducing power, metal ion chelating activity, and β‐carotene), which are described in detail to ease further investigations on antioxidants in future.