Peroxide Scavenging Research Articles

SEMI-ROLLED LEAF 10 stabilizes catalase isozyme B to regulate leaf morphology and thermotolerance in rice (Oryza sativa L.).

Plant architecture and stress tolerance play important roles in rice breeding. Specific leaf morphologies and ideal plant architecture can effectively improve both abiotic stress resistance and rice grain yield. However, the mechanism by which plants simultaneously regulate leaf morphogenesis and stress resistance remains elusive. Here, we report that SRL10, which encodes a double-stranded RNA-binding protein, regulates leaf morphology and thermotolerance in rice through alteration of microRNA biogenesis. The srl10 mutant had a semi-rolled leaf phenotype and elevated sensitivity to high temperature. SRL10 directly interacted with catalase isozyme B (CATB), and the two proteins mutually increased one other's stability to enhance hydrogen peroxide (H2 O2 ) scavenging, thereby contributing to thermotolerance. The natural Hap3 (AGC) type of SRL10 allele was found to be present in the majority of aus rice accessions, and was identified as a thermotolerant allele under high temperature stress in both the field and the growth chamber. Moreover, the seed-setting rate was 3.19 times higher and grain yield per plant was 1.68 times higher in near-isogenic line (NIL) carrying Hap3 allele compared to plants carrying Hap1 allele under heat stress. Collectively, these results reveal a new locus of interest and define a novel SRL10-CATB based regulatory mechanism for developing cultivars with high temperature tolerance and stable yield. Furthermore, our findings provide a theoretical basis for simultaneous breeding for plant architecture and stress resistance.

Probing cytoplasmic peroxide metabolism in Shewanella oneidensis.

The facultative anaerobe Shewanella oneidensis respires an extensive set of electron acceptors and, as a consequence, can leak electrons to produce reactive oxygen species such as hydrogen peroxide (H2O2). However, the effects of respiration on cytoplasmic redox homeostasis are poorly characterized in comparison. In the present study, the H2O2 sensor HyPer-3 was deployed to interrogate cytoplasmic peroxide levels of both wild-type and gene deletion mutants lacking peroxide scavenging enzymes following exposure to H2O2. HyPer-3 signals were validated in the S. oneidensis wild-type strain and exhibited a dynamic range of 0-250μM H2O2. As reported by the HyPer-3 sensor, the cytoplasm of H2O2-perturbed mutant strains lacking periplasmic glutathione peroxidase (PgpD) and double deletion mutants lacking catalase (KatB) and bifunctional catalase-peroxidases (KatG1 or KatG2) contained high H2O2 concentrations. The high cytoplasmic H2O2 concentrations correlated with impaired H2O2 removal rates displayed by the mutant strains. Results of the present study provide the first in vivo interrogation of the redox environment of the S. oneidensis cytoplasm with HyPer-3 sensors and indicate that proper redox conditions in minimal growth medium are maintained by the concerted action of both well-known (periplasmic PgpD, cytoplasmic KatB and KatG1) and previously overlooked (cytoplasmic KatG2) peroxidases and catalases.

Spermine-Salicylic Acid Interplay Restrains Salt Toxicity in Wheat (Triticum aestivum L.).

Spermine (SPM) and salicylic acid (SA) are plant growth regulators, eliciting specific responses against salt toxicity. In this study, the potential role of 30 mgL-1 SPM and/or 100 mgL-1 SA in preventing salt damage was investigated. Wheat plants were grown under non-saline or saline conditions (6.0 and 12.0 dS m-1) with and without SA and/or SPM foliar applications. Exogenously applied SA and/or SPM alleviated the inhibition of plant growth and productivity under saline conditions by increasing Calvin cycle enzyme activity. Foliage applications also improved ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase activities, which effectively scavenged hydrogen peroxide and superoxide radicals in stressed plants. Furthermore, foliar treatments increased antioxidants such as ascorbate and glutathione, which effectively detoxified reactive oxygen species (ROS). Exogenous applications also increased N, P, and K+ acquisition, roots' ATP content, and H+-pump activity, accompanied by significantly lower Na+ accumulation in stressed plants. Under saline environments, exogenous SA and/or SPM applications raised endogenous SA and SPM levels. Co-application of SA and SPM gave the best response. The newly discovered data suggest that the increased activities of Calvin cycle enzymes, root H+-pump, and antioxidant defense machinery in treated plants are a mechanism for salt tolerance. Therefore, combining the use of SA and SPM can be a superior method for reducing salt toxicity in sustainable agricultural systems.

Comparison of Conventional Extraction Techniques with Superheated Steam Distillation on Chemical Characterization and Biological Activities of Syzygium aromaticum L. Essential Oil

Syzygium aromaticum L. is an aromatic plant with a significant amount of essential oil (EO), which is used in food, medicine, for flavoring, and in the fragrance industry. The purpose of this study was to comparatively evaluate the chemical composition, yield, and antioxidant and antifungal activities of Syzygium aromaticum essential oils extracted by the conventional hydro-distillation, steam distillation, and the emerging superheated steam distillation methods. It was noticed that the extraction methods significantly influenced the yield, chemical composition, and antioxidant and antimicrobial activities of essential oils. The maximum yield was obtained using superheated steam distillation, followed by hydro-distillation and steam distillation. The antioxidant potential of EO extracts was evaluated following the scavenging of 2,2-dipenyl-1-picrylhydrazyl radicals, hydrogen peroxide scavenging activity and ferric reducing power assays. Results revealed that EO extracted superheated steam distillation exhibited the highest antioxidant activity. GC-MS analysis depicted eugenol (47.94–26.50%) and caryophyllene (20.24–9.25%) as the major compounds of Syzygium aromaticum EOs. The antimicrobial activity of EO extracts was evaluated, via the resazurin microtiter plate assay, microdilution broth assay, and disc diffusion methods, against normal and food pathogenic bacterial and fungal strains. After comparative evaluation, it was observed that superheated steam extracted EO exhibited the highest antimicrobial potential. Overall, methodical evaluation disclosed that superheated steam distillation is an effective method to extract EOs from plant sources, with greater yield and promising biological activities.

In situ hypoxia modulating nano-catalase for amplifying DNA damage in radiation resistive colon tumors.

Radiation therapy (RT) is a mainstream clinical approach in cancer treatment. However, the therapeutic efficacy of RT is greatly hindered by the presence of excessive hydrogen peroxide (H2O2) in the hypoxic region of the solid tumor, thus leading to tumor recurrence and metastasis. Herein, a thioketal-linked amphiphilic nano-assembly (MTS) loaded with hydrophobic manganese oxide (HMO) nanoparticles (MTS@HMO) is examined as a promising multi-purpose reactive oxygen species (ROS)-catalytic nanozyme for transforming an RT-resistant hypoxic tumor microenvironment (TME) into an RT-susceptible one by scavenging ROS in the hypoxic core of the solid tumor. After intravenous injection, the MTS@HMO nano-assembly was able to sense and be degraded by the abundant ROS in the hypoxic TME, thereby releasing HMO particles for subsequent scavenging of H2O2. The oxygen generated during peroxide scavenging then relieved the hypoxic TME, thereby resulting in an increased sensitivity of the hypoxic tumor tissue towards RT. Moreover, the in situ hypoxic status was monitored via the T1-enhanced magnetic resonance (MR) imaging of the Mn2+ ions generated by the ROS-mediated degradation of HMO. The in vitro results demonstrated a significant H2O2 elimination and enhanced oxygen generation after the treatment of the MTS@HMO nano-assembly with tumor cells under hypoxic conditions, compared to the control MTS group. In addition, the combination of RT and pre-treatment with MTS@HMO nano-assembly significantly amplified the permanent DNA strand breaks in tumor cells compared to the control RT group. More importantly, the in vivo results proved that the systemic injection of the MTS@HMO nano-assembly prior to RT irradiation enhanced the RT-mediated tumor suppression and down-regulated the hypoxic marker of HIF-1α in the solid tumor compared to the control RT group. Overall, the present work demonstrates the great potential of the versatile ROS-catalytic hypoxia modulating strategy using the MTS@HMO nano-assembly to enhance the RT-induced antitumor efficacy in hypoxic solid tumors.

Modulation of wheatgrass (Triticum aestivum Linn) toxicity against breast cancer cell lines by simulated microgravity

This study scrutinizes the effects of simulated microgravity on the antioxidant and cytotoxic potential, along with the phytochemical content of wheatgrass (Triticum aestivum Linn). To imitate microgravity, wheatgrass seeds were germinated in a 3D-clinostat at different rotations per minute (5, 10, 15, and 20 rpm), together with terrestrial gravity control, over 10 days. After germination, the methanolic extracts were analyzed using UPLC-Triple Quad LCMS for their phytochemical composition and tested for their hydrogen peroxide, nitric oxide, and DPPH scavenging activities. The cytotoxic effects of these extracts were evaluated against normal skin fibroblasts, normal breast cells (MCF-10), and breast cancer cells (MCF-7 and MDA-231). The findings showed an extended root growth in wheatgrass germinated under microgravity (WGM) compared to under gravity (WGG). Additionally, WGM extracts demonstrated increased H2O2–, NO–, and DPPH-scavenging activities and a higher content of polyphenols and flavonoids than WGG extracts. These effects were amplified with an increase in clinostat rotations. Moreover, WGM extracts were found to contain a unique set of bioactive compounds (compounds that were detected in the microgravity-germinated wheatgrass but were either absent or present in lower concentrations in wheatgrass germinated under standard gravity conditions.), including pyridoxine, apigenin, and tocopherol, among others, which were absent in WGG. The UPLC-Triple Quad LCMS analysis revealed these unique bioactive compounds in WGM. Notably, WGM extracts showed enhanced cytotoxic effects against normal skin fibroblasts, normal MCF-10, MCF-7, and breast cancer MDA-231 cell lines, with increased cytotoxicity correlating with the number of clinostat rotations. Particularly, WGM extract (at 20 rpm) demonstrated significantly stronger cytotoxicity against MCF-7 breast cancer cells. Further in-depth gene expression analysis of MCF-7 cells exposed to WGM revealed a significant downregulation of genes integral to breast cancer pathways, tyrosine kinase signaling, and DNA repair, complemented by upregulation of certain cell survival and cytotoxic genes. These alterations in genetic pathways associated with cell survival, hormone responses, and cancer progression may elucidate the enhanced cytotoxicity observed in WGM extracts. Our findings underscore the potential of microgravity as a tool to enhance the cytotoxic capabilities of wheatgrass against cancer cell lines, presenting a promising direction for future research in the field of space biology and its implications for terrestrial health.

A Role of Thyroid Hormones in Acute Myocardial Infarction: An Update.

The acute coronary syndrome is one of the commonest life-threatening illnesses. It encompasses the clinical spectrum of acute myocardial ischemia and includes unstable angina and acute myocardial infarction both with and without ST segment elevation. The acute coronary syndrome can be attributed to a significant hemodynamic insult that leads to atherosclerosis of the epicardial coronary arteries. The main causative risk factors, such as obesity, smoking, and alcohol intake, increase the burden of acute coronary syndrome. Owing to an increase in the utilization of antioxidants, the antioxidant capacity decreases concerning the scavenging of lipid peroxides. Moreover, the thyroid hormones are important regulators of the expression of cardiac genes, and many of the cardiac manifestations of thyroid dysfunction are associated with alterations in triiodothyronine- mediated gene expression. Cardiovascular signs and symptoms of thyroid disease are among the most acute clinically relevant findings that occur in combination with both hypothyroidism and hyperthyroidism. By understanding the cellular mechanism of the action of thyroid hormones on the heart and cardiovascular system, it is possible to explain rhythm disturbances and alterations in cardiac output, blood pressure, cardiac contractility, and vascular resistance that result from thyroid dysfunction. Oxidative stress is thereby induced, together with a decrease in antioxidant capacity for overcoming oxidative stress, which leads to endothelial dysfunction, subsequent atherosclerosis, and, ultimately, acute myocardial infarction. The implications for the identification of the effects of thyroid disease on acute myocardial infarction include the observation that restoration of normal thyroid function repeatedly reverses abnormalities in cardiovascular hemodynamics.

Biological Activities of Papaya (Carica papaya L.) Seed, Rind and Pulp Oil Extracts

Background: Carica Papaya L. is widely cultivated for food and traditional medicine throughout the World due to its rich source of bioactive compounds in its fruit, leaves, latex and stem. Objective: The aim of this work was to assess the physicochemical properties, and antioxidant and antimicrobial activities of oils extracted from papaya seeds, fruit pulp and rind using the solvent ex-traction method. Methods: Hexane mediated extraction of oil was made. Then, physicochemical properties of the oil extracts were based on the determination of oil yield, specific gravity, acid value, free fatty acid and peroxide value, while the antioxidant activities were conducted based on ascorbic acid content, DPPH and hydrogen peroxide free radical scavenging activities. The antimicrobial experiment was conducted based on disc diffusion and broth dilution methods. Results: The result of physicochemical properties of papaya seeds, pulp and rind oil extracts demon-strated significantly the highest oil yield (42.50%) and specific gravity (0.85) obtained for seed oil. Significantly the highest DPPH (19.35%), and hydrogen peroxide scavenging activities (32.45%) were recorded for seed oil extract. The strongest antibacterial activity with maximum zone of inhibition (18.50 mm), minimum inhibitory concentration MIC (0.03 μg/mL) and minimum bactericidal concen-tration MBC (0.05 μg/mL) were recorded for seed oil extract against S. pyogenes. However, the strong-est antifungal activity with maximum zone of inhibition (16.75 mm), MIC (0.05 μg/mL) and MFC (0.10 μg/mL) against C. albicans was recorded for rind oil extract against C. albicans. Conclusion: It can be concluded from the result of this study that seed oil was found to have antioxidant and antibacterial potential but fruit rind oil extract was the most effective antifungal in papaya.

Valorização do resíduo casca da fruta lichia para a produção sustentável de um ingrediente de valor agregado

Abstract Lychee (Litchi chinensis Sonn.) is an exotic fruit from Asia, recently introduced in Europe. With the increase in the world production of this fruit, many by-products are wasted during industrial processing, including their peels and seeds. Considering the utilization of fruit peels as edible material as a new functional ingredient, this work aimed to assess the nutritional and phytochemical characterization, as well as the antioxidant activity of two lychee peel extracts (alcoholic and hydroalcoholic). Also, it was evaluated the scavenging capacity against reactive species (O2•-, H2O2, NO•) of the two extracts. The peels, at a nutritional level, showed high levels of carbohydrates and total energy (76.8 ± 1.0 g/100 g and 331.4 kcal/100 g, respectively) and low protein and lipid content. Total phenolic and flavonoid contents were higher in alcoholic extraction (1578 mg GAE/g and 55.1 mg CE/g, respectively). The antioxidant activity evaluated in vitro by DPPH and FRAP assays was also higher in the ethanolic extract, verifying a positive correlation with the extractive yield of the bioactive compounds. In general, the ethanolic extracts of lychee peels showed higher antioxidant capacity and the maximum scavenging activity against reactive oxygen (O2-•) and nitrogen species (NO•). The hydrogen peroxide scavenging activity observed in ethanolic extract (64 µg/mL) was like the values obtained in the positive controls (quercetin and ascorbic acid, 62 µg/mL, and 46 µg/mL, respectively). These preliminary results suggest this undervalued ingredient is a promising source of bioactive compounds with high biological potential for the development of new products as functional ingredient, always focusing on sustainability.

Correlation between oxidative stress markers and cytokines in different stages of breast cancer.

This study aims to estimate the level of malondialdehyde (MDA) as oxidative stress marker and reduced glutathione (GSH) as antioxidant and correlate them to different inflammatory markers as interleukins (IL-6, IL-8, IL-10) and tumor necrosis factor alpha (TNF-α) in different stages of breast cancer (BC). For the purpose of comparisons, 35 healthy subjects matched for age, sex and ethnic background were selected who have no history or clinical evidence of BC or any chronic disease and obvious abnormalities as a control group and 35 patients of different stages of BC were participated in the study. The cancer patients were diagnosed by specialists. Even the exact cause of the disease has not been identified but according to this study, 5% of the patients were having family history of the disease and 62% of the patients were having a BMI over 25. Over 60% of the patients were postmenopausal and all females participated in this study were nonsmokers. MDA level showed a significant increase when BC patients were compared to healthy subjects, this oxidative stress marker showed a significant increase with the increase of the stage of the disease. In contrast the level of the lipid peroxide scavenger GSH reduced with increasing the stage of the disease. The level of some cytokines showed a significant change between different stages and the control group. Correlation between MDA and GSH with these cytokines showed a positive correlation between all cytokines and the MDA level and a negative correlation between GSH and the cytokines. The results of this study suggests that BC stimulates the oxidative stress response and for that, different inflammatory cytokines will be produced and there is a pronounced relationship between oxidative stress parameters and these cytokines and the level of these cytokines are associated with aggressive tumors.

Assessment of Antimicrobial and Antioxidant Activities of Four Ethnomedicinal Plants Used by Magars in Nawalpur District, Nepal

Ethnobotanical survey in the Magar villages in Nawalpur district, Gandaki province, Nepal revealed that root of Phanera vahlii (Wight & Arn.) Benth, bark of Rhododendron arboreum Sm. and flower of Woodfordia fruticosa (L.) Kurz, have been in use for diarrhea and dysentery. Root of Thalictrum foliolosum DC. has been used for the treatment of rheumatic pain. The study aimed to evaluate antimicrobial and antioxidant effects as well as total phenol content in Phanera vahlii, Rhododendron arboreum, Woodfordia fruticosa and Thalictrum foliolosum. Total phenol content (TPC) was estimated using Folin-Ciocalteu method. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) free radical and hydrogen peroxide scavenging assays were used to evaluate the antioxidant capacity. Antibacterial effect was established by the Agar well diffusion assay. The minimum TPC value of 65.78±3.44 mg GAE/g dry extract was estimated in 70% methanolic extract of Thalictrum foliolosum and maximum TPC value of 258.40±6.26 mg GAE/g dry extract was estimated in 70% methanolic extract of Woodfordia fruticosa. IC50 value range 21.59±0.26 µg/ml in Rhododendron arboreum to 1124.79±3.69 µg/ml in Thalictrum foliolosum was calculated in DPPH free radical scavenging assay. Scavenging of DPPH free radical range from 12.40% to 94% at 100 µg/mL concentration of 70% methanolic extracts were estimated and scavenging of hydrogen peroxide range from 36% to 73%. The maximum zone of inhibition (ZOI) against Escherichia coli at loading dose of 5 mg of the extract observed was 18±0.73 mm by 70% methanolic extract of Woodfordia fruticosa and its minimum inhibition concentration (MIC) was <1.56 µg /ml.The extracts efficiently inhibited the growth of Escherichia coli verifying the rural knowledge. At the same time, the extracts displayed efficient antioxidant activity.

Phytochemical Investigation and Therapeutical Potential of Cotinus coggygria Scop. in Alloxan-Induced Diabetic Mice.

Plants are a significant source for the development of new phytomedicines due to their great clinical benefits, efficiency, cost-effectiveness, fewer side effects, and more affordable therapies. Numerous plants used in traditional treatments, such as Cotinus coggygria Scop., have been effective in the treatment of diabetes mellitus (DM). Therefore, the study is aimed at assessing the phytochemical, antioxidant, and antidiabetic properties of C. coggygria. The hypoglycemic and hypolipidemic activity was evaluated in Swiss male Albino mice by administering an oral dose of 150-250 mg/kg of C. coggygria extracts in alloxan-induced diabetic mice for 15 days. The antioxidant activity and phytochemical composition of the extracts were assessed by using α, α diphenyl-β-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging assays and through standard chemical procedures. The effects of extracts on blood glucose, body weight, lipid profile, and biochemical parameters like total cholesterol (TC), triglyceride (TG), low-density lipids (LDL), high-density lipids (HDL), plasma insulin, liver glycogen, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, and creatinine were determined according to standard procedures. The activities of antioxidant enzymes such as superoxide-dismutase (SOD), peroxidase (POD), and catalase (CAT) were also analyzed spectrophotometrically. The hypoglycemic and hypolipidemic effects with chloroform extracts of 250 mg/kg were found significant in the treatment of diabetes in alloxanised mice compared to the diabetic group. The haematological parameters such as TC, TG, HDL, LDL, creatinine, urea, AST, ALT, and ALP were significantly improved (p < 0.01) by the chloroform extract of 250 mg/kg compared to the diabetic group. Treatment for 15 days showed significant elevation (p < 0.01) of antioxidant enzymes. Fourier-transform infrared spectroscopic (FTIR) and gas chromatography-mass spectrometry (GC-MS), column chromatography (CC), and nuclear magnetic resonance (NMR) analyses tentatively identified different phytoconstitutents and metabolites in C. coggygria leaves, which have been reported to possess antihyperglycemic properties. In conclusion, the chloroform extract of 250 mg/kg of C. coggygria possesses significant hypoglycemic and hypolipidemic potential which may prove the claimed use of the plant in amelioration of diabetes and associated complications in folkloric medicine. Additional studies are required for the purification, characterization, and structural elucidation of bioactive compounds.

A phytochemical screening, antioxidant and antibacterial activity analysis in the leaves, stems and roots of Portulacaria afra

Introduction: Portulacaria afra is a medicinal plant commonly used among African traditional healers to treat skin conditions and dehydration. The aim of this study was to scientifically validate the use of P. afra among traditional healers. Methods: Standard phytochemical colour tests were used to determine the presence of ten phytochemicals, using four solvents of varying polarities (hexane, ethyl acetate, methanol, and water). The antioxidant activity was determined using 1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging assays. An agar-well diffusion assay was used to determine the antibacterial activities of the leaves, stems, and roots of P. afra against Staphylococcus aureus and Escherichia coli. Results: P. afra exhibited a high phytochemical presence in the methanolic extracts, with seven out of the 10 phytochemical groups present. Flavonoids and phlobatannins were absent in all of the plant’s extracts. The methanolic root extract exhibited the highest DPPH scavenging activity (IC50=0.39) whilst the hexane leaf extract (IC50= 14.83) was the only extract to exceed the acceptable upper limit. The scavenging activity of the plant was stronger against hydrogen peroxide than it was against DPPH. The methanolic and hot water stem extracts displayed the largest zone of inhibition (of 20 mm) against E. coli. The cold-water and room-temperature water extracts, of all three plant parts, showed no zone of inhibition against either bacterial strain. Conclusion: P. afra has the capacity to be used as a nutritional supplement for its antioxidant properties, while the antibacterial properties may provide relief against E. coli infections.

Antioxidant and Hepatoprotective Activity of Leaf Extract of Smilax Anceps Wild

Introduction: Smilax anceps leaf is used for general healing of the body in traditional medicine. The aim of this study was to investigate the in-vitro antioxidant potential and in-vivo hepatoprotective activity of the ethanol leaf extract of Smilax anceps against carbon tetrachloride induced hepatotoxicity. Materials and Methods: Preliminary phytochemical screening and acute toxicity were determined. In-vitro antioxidant activity of the plant was evaluated using 2, 2-diphenyl-1-picryl-hydrazyl (DPPH), reducing power activity, nitric oxide scavenging, and lipid peroxidation scavenging activity assays. In- vivo hepatoprotective activity was determined using albino rats, divided into groups of six comprising of 5 animals each vis the control, CCl4, extract 250,500 and 1000mg/kg, and silymarin 100mg/kg. Treatments were done for seven days and carbon tetrachloride dissolved in olive oil was administered on the seventh day. Biochemical analysis was performed to assay the levels of aspartate aminotransferase (AST), alanine amino transaminase (ALT), alkaline phosphatase (ALP), albumin (ALB), total protein (TP) and Total bilirubin (TB) with histological examination of the liver. Phytochemical screening showed the presence of saponins, flavonoids, tannins, carbohydrates and steroids/ terpenoids. Results: The extract showed significant (P&lt;0.01) scavenging activity against DPPH, reducing power activity, nitric oxide scavenging, and lipid peroxidation. There was a statistically significant (P&lt;0.05) decrease in total bilirubin (TB), alanine amino transaminase (ALT) and alkaline phosphatase (ALP). Conclusion: The findings of this study showed that the ethanol leaf extract of S. anceps possesses significant antioxidant and hepatoprotective which might be due to the presence of flavonoids.

EFFECT OF VARIOUS ENVIRONMENTALLY FRIENDLY REDUCING AGENTS ON THE ANTIOXIDANT ACTIVITY OF GREEN SYNTHESIZED SILVER NANOPARTICLES

This study's objective was to assess the antioxidant properties of green produced silver nanoparticles (AgNPs) using ecologically friendly reducing agents such as extracts of parsley (Petroselinum crispum), rosemary (Rosmarinus officinalis), and cinnamon (Cinnamomum zeylanicum). The ultrasonic-assisted extract of plant material served as a reducing agent for silver ions. Spectrophotometric assessment with a resolution of 1 nm and a wavelength range of 300-600 nm confirmed the synthesis of silver nanoparticles. On the basis of the observed Surface Plasmon Resonance (SPR) peak, the size of the AgNPs was determined using correlation equations. The hydrogen peroxide scavenging activity was used to evaluate the antioxidant activity of the green nanoparticles that were synthesized. Cinnamon-derived silver nanoparticles displayed the highest scavenging activity. The results shown that environmentally friendly reducing agents can be employed to generate AgNPs, which can be utilized for antioxidant activity in several domains.

Antioxidant activity of essential oil of Artemisia vulgaris collected from sub-tropical region of Bagmati province, Nepal.

Artemisia vulgaris is one of the highly used plant species as traditional medicine because of its antioxidant activity, anti-allergic effect and other several health benefits. This study was carried out with the objectives to explore the phytochemical constituents and assess the antioxidant property of essential oils of A. vulgaris found in sub- tropical regions of Bagmati province. Hydro distillation method was used for the extraction of essential oil and gas chromatography–mass spectrometry (GC-MS) analysis was performed to identify various phytochemicals present in essential oil. Evaluation of antioxidant activity by in vitro method was carried out by observing hydrogen peroxide scavenging effects of essential oils at different concentrations. GC-MS analysis showed 41 different phytochemicals including mono- and sesquiterpenes. Among them, highly expressed phytochemicals were Cadinene&lt;gamma-&gt; (14.95%), Caryophyllene(E) (9.32%), Camphor (8.74%), Thujone&lt;alpha-&gt; (6.57%), Eucalyptol (6.25%). Essential oil also showed scavenging effect against hydrogen peroxide with EC50 value of 48.49. This preliminary study shows that essential oil of A. vulgaris can be used as a source of natural antioxidants, but in vivo and other clinical trials must be done for oral use.

Green Synthesis of Ceiba pentandra copper nanoparticles and their characterization

In the present study, Ceiba pentandra (CP) aqueous leaf extract was used for the synthesis of copper nanoparticles (CuNPs). Techniques like UV-visible spectrophotometer, SEM, EDX, XRD and in vitro antioxidants assay were used to characterize synthesized nanoparticles. UV-Visible spectrophotometer showed absorbance peak at 310 nm. SEM analysis demonstrated that the CuNPs are spindly shaped structures with average size of about 62.63nm. XRD analysis revealed the face centered cubic like structures of CuNPs. Ceiba pentandra copper nanoparticles (CP-CuNPs) exhibited good in vitro antioxidant activities i.e. 80 % inhibition of free radicals with DPPH assay, 70% inhibition of H2O2 with hydrogen peroxide scavenging assay and 75% inhibition in phosphomolybdenum assay compared to leaf extract. Hence the above protocol is a humble, fast, environmentally friendly, non-hazardous and an alternative for physical/chemical methods.

Biological activities of essential oil and methanolic extract of endemic &lt;em&gt;Dorytoechas hastata&lt;/em&gt; Boiss et Heldr. ex Bentham (Lamiaceae) from Turkey

Extracts and essential oils from plant sources have always been a subject of interest to scientists for their biological activities and application in food, pharmacy and cosmetic industries. Here, we have explored the essential oil compositions and antimicrobial and antioxidant activities of the essential oil as well as the methanolic extract of Chalba tea, Dorystoechas hastata Boiss et Heldr. ex Bentham (Lamiaceae). Essential oil was isolated from the aerial parts by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The main compounds were determined as eucalyptol (1,8-cineol) (25.47%) and borneol (20.06%). Phosphomolybdenum, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, hydrogen peroxide scavenging, β-carotene bleaching activity, ferric-ion reducing power (FRAP), reducing power and cupric ions (Cu2+) reducing antioxidant capacity (CUPRAC) assays were utilized to determine the antioxidant activity. D. hastata methanolic extract showed an effective total antioxidant, DPPH scavenging, cupric ions (Cu2+) and ferric ions (Fe3+) reducing activities. Essential oil and methanolic extract were evaluated for antimicrobial activity by the agar diffusion assay against 15 microorganisms. Methanol extract exerted antibacterial effect against all of the bacteria tested. Streptococcus pneumoniae was the most sensitive bacteria to extract while Aeromonas hydrophila was the most sensitive bacteria to essential oil. According to present results, D. hastata may be potential natural antioxidant and antimicrobial agent.

Pharmacognostic characteristics and antioxidant studies of Psydrax subcordata (DC.) Bridson

• Psydrax subcordata is a small flowering tree or shrub that grows in central and western Africa belonging to the family Rubiaceae. • Pharmacognostic (organoleptic, macroscopic, microscopic and physico-chemical) parameters of P. subcordata leaves can serve as simple means to identification and also for the quality control of the plant material. • Antioxidants are endogenous or exogenous substances that interact with and neutralize free radicals • Numerous stomata of paracytic type occurred on both the upper and lower surfaces but more abundantly on the lower surface of the plant P. subcordata . • P. subcordata leaf microscopic features include shiny, circular and irregularly shaped calcium oxalate crystals, fibres, unicellular trichomes and starch granules. Psydrax is a genus of flowering plants in the family Rubiaceae with over 80 accepted plant species. Psydrax subcordata is a small tree or shrub that grows in Central and Western Africa countries where its roots, leaves and stem are used locally by traditional healers for medicinal purposes. These local uses include the treatment of malaria fever, inflammation, haemorrhoids, enteritis, stomach ulcer, epilepsy and cardiovascular ailments. This study was carried out to examine parameters for identification of the plant and investigate potential antioxidant activity. The macroscopic, microscopic and physico-chemical characteristics of the leaf were determined using standard procedures. Antioxidant activity was also investigated using five different antioxidant models namely; DPPH Radical scavenging activity, FRAP assay, Total antioxidant capacity (Phosphomolybdenum) assay, Hydrogen peroxide scavenging assay and Reducing power assay. The leaves of the plant are simple, broad and entire. Ovate in shape, shortly acuminate apex and subcordate at the leaf base. The dark green upper surface is hairy or pubescent while greyish-green lower surface is sparely pubescent. The leaf showed microscopic mono-cyclic calcium oxalate crystals, unicellular trichomes, xylem vessels and other diagnostic features. The in-vitro antioxidant assays conducted, suggested that the extract contains antioxidant compounds. The characteristic macroscopic, microscopic and physico-chemical parameters evaluated for the plant sample can be used in rapid identification, authentication and for the quality control of the plant material before they are used for treatment and manufacturing of herbal medicines. The results of the antioxidant study showed that the extract exhibited potent antioxidant activity.

Cytotoxicity effect of nanoparticles of Euphorbia antiquorum on breast cancer cell line

Euphorbia antiquorum was known for its various therapeutic values like anti-inflammatory, anti-diabetic activity etc. Preliminary phytochemicals screening of plant extract disclosed the existence of various important bioactive constituents in hexane, ethanol and aqueous extract of the plant. Aqueous extract of Euphorbia antiquorum was used for silver and copper nanoparticle synthesis. Synthesized silver and copper nanoparticle showed the absorbance line at 422 and 367 nm respectively. Fourier-transform infrared spectroscopy analysis of synthesized nanoparticles reported the presence of phenol groups, amines and esters. Shape and morphology of the synthesized nanoparticles were characterized through Field Emission Scanning Electron Microscopy which showed the spherical shaped nanoparticles. Energy dispersive X-ray spectroscopy images showed the composition of analysed nanoparticles. The antioxidant activity of synthesized silver and copper nanoparticles of Euphorbia antiquorum by hydrogen peroxide scavenging activity method using ascorbic acid as the standard showed effective scavenging activity and indicated the potentiality of the plant as a source of natural antioxidant. Cytotoxicity study of silver nanoparticles showed 73.22% of inhibition at the concentration of 1000 µg/ml whereas copper nanoparticles at the same concentration showed 68.85% of inhibition against breast cancer cell line.