Peroxide Scavenging Activity Research Articles

Phytoconstituents profiling and antioxidant potential of Wrightia tinctoria R. Br.

In the Indian traditional system of medicine, Wrightia tinctoria R.Br. (Apocyanaceae) is recognized as a biologically effective therapeutic plant for the treatment of jaundice. It is a natural medicinal tree possessing antidiabetic, anti-inflammatory, hepatoprotective, antinociceptive, antifungal, antibacterial, antipsoriatic, antiviral, anthelmintic, anticancerous, analgesic, antipyretic, and aphrodisiac activities. Methanolic extract of W. tinctoria plant was investigated with Gas Chromatography–Mass Spectrometry (GC-MS), Fourier transform infrared spectroscopy (FTIR) and the antioxidant activity of W. tinctoria was analysed by most probable hydrogen peroxide scavenging (H2O2) activity, DPPH activity and Thiobarbutaric acid. The phytochemical in W. tinctoria leaf and bark have been assessed by GC-MS analysis. GC-MS analysis of W. tinctoria methanolic extract exposed the existence of the GC-MS chromatograms of 10 peaks in the leaf and 20 peaks in the bark. The FTIR spectroscopy analyses were identified by various functional compounds in the extracts with distinctive peak values. The FTIR analysis of methanolic leaf extracts of W. tinctoria confirmed the presence of alcohol, amine, alkane, carboxylic acid, sulfur compounds, halogen compounds and alkyne which showed major peaks. Also the methanolic bark extracts of W. tinctoria confirmed the presence of amines, phenol, alcohols, alkane, aldehydes, carboxylic acid, nitrogen compounds, sulfur compounds, and halogen compounds which also exhibited major peaks. Significant antioxidant activity is displayed by the plant part of leaf and bark sample. The results obtained in the determination of antioxidant activity of MEWT displayed considerable free radical scavenging capacity against DPPH which generated free radicals. This study includes the identification of phytochemicals and antioxidant potential of methanolic and aqueous extract of W. tinctoria which assist in therapeutic claims about this species in the traditional medicinal plant system.

English

Cyclooxygenase 2 (COX-2) is involved in the production of prostaglandins that sustain the inflammatory process. Inflammatory cells release a number of reactive species. Furthermore, reactive oxygen species can initiate intracellular signaling cascades and enhance the expression of pro-inflammatory genes. The objective was to study the cyclooxygenase and protein denaturation inhibition and antioxidant activity of ten extracts from five plants. Cyclooxygenases inhibitory activity of the extracts was measured using the Cayman Kit method and the protein denaturation inhibitory activity using the bovine serum albumin. Ferric reducing antioxidant power and hydrogen peroxide scavenging activity were used to evaluate the antioxidant capacity of aqueous and hydroethanolic extracts. COX-2 inhibition was more important with the hydroethanolic extract of X. americana (IC50 = 11.13 ± 1.24 µg/ml) and T. macroptera (IC50 = 12.79 ± 0.56 µg/ml). COX-1 was strongly inhibited with the hydroethanolic extract of S. senegalensis. The hydroethanolic extracts of C. tinctorium and X. americana showed the strongest inhibitory activities of protein denaturation with 86.61 ± 1.22% and 84.5 ± 0.56% respectively. The greatest effects on iron reduction were observed with the hydroethanolic extracts of X. americana (R2 = 0.996; IC50 = 29 µg/ml) and T. macropteria (R2 = 0.990; IC50 = 35.46 µg/ml). The hydrogen peroxide scavenging activity of the extracts varied from 39.31 ± 3.6 to 77.37 ± 2.16 µg/ml. The present study concluded to an important antioxidant activity, protein denaturation and COX-2 inhibitory activities of the hydroethanolic extracts of X. americana, T. macroptera and C. tinctorium. Further studies are needed to confirm the anti-inflammatory effect of these extracts in vivo. Key words: X. Americana, T. macroptera, cyclooxygenases, antioxidant, protein denaturation.

Attenuation of COX-2 enzyme by modulating H2O2-mediated NF-κB signaling pathway by monoamine oxidase inhibitor (MAOI): a further study on the reprofiling of MAOI in acute inflammation.

This study aims to investigate the anti-inflammatory mechanism of monoamine oxidase inhibitor (MAOI) in carrageenan (CARR) induced inflammation models to reprofile their use. We also aimed to explore the role of monoamine oxidase (MAO)-mediated H2O2-NF-κB-COX-2 pathway in acute inflammation. In vitro anti-inflammatory activity and hydrogen peroxide (H2O2) scavenging activity were performed according to the established procedure. Inflammation was induced using CARR in BALB/c mice at the foot paw and peritoneal cavity. Hourly measurement of paw swelling was performed. The level of nitric oxide (NO), myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) and nuclear factor κB (NF-κB) was determined using enzyme-linked immunosorbent assay (ELISA). Peritoneal fluid was collected to investigate total count, differential count of leukocytes, and capillary permeability. In vitro anti-inflammatory evaluations revealed the potential role of MAOI to inhibit heat-induced protein denaturation and human red cell membrane destabilization. H2O2 inhibition activity of MAOI also proved their powerful role as an H2O2 scavenger. Treatment with MAOI in CARR-induced mice significantly reduced paw edema, leukocyte extravasation, and total and differential leukocyte count. The result of ELISA showed MAOI effectively reduce the level of COX-2, PGE2 and NF-κB in inflamed tissue. In short, this study demonstrates that inhibition of H2O2 by MAOI alleviates CARR-induced paw edema possibly by inhibiting the H2O2-mediated NF-κB-COX-2 pathway. The present investigation identifies MAOI might reprofile for the treatment of acute inflammation also, the MAO enzyme may use as a novel therapeutic target to design and develop new class of anti-inflammatory agents.

Phytochemicals content and in-vitro antioxidant properties of Azadirachta indica seeds, leaves and twigs prepared from different extraction techniques

The current study was design to exploit the Azadirachta indica leaves, seeds and twigs for %yield, phytochemicals content and antioxidant activities using infusion, hydroalcoholic, decoction and microwave extraction techniques. The phytochemicals contents were determined by standard reported methods. While antioxidant activity was assessed by three (03) standards In-vitro antioxidant test systems as 1, 1’-diphynyl- 2-picrylhydrazyl (DPPH), Hydrogen peroxide (H2O2) scavenging activity and Nitric oxide (NO) scavenging activity method using ascorbic acid as standard. The highest extractive yield was observed in seed were 44.00±02% (infusion), 38.00±00% (Hydroalcoholic) and 20.00±03% (decoction). Followed by leaves and twigs parts of neem. The high amount (+++) phytochemicals contents were extracted from neem leaves infusion and hydroalcoholic extracts as compared to seeds and twigs neem parts with decoction and microwave extraction methods. The highest Azadirachta indica (neem) leaves infusion extract showed at 1000 mg/L remarkably inhibited DPPH inhibition activity (85±01), H2O2 scavenging activity (83±01%), and NO scavenging activity (78±01%). The antioxidants activities showed a dose dependant manner, the higher the concentration showed high antioxidant activities. The results pointed to the significant antioxidant activities of the leaves infusion and hydroalcoholic extraction techniques, the overall strength being in the order of infusion >hydroalcoholic >decoction >microwave in leaves, seeds and twigs extracts. In all cases, the extracts obtained from leaves showed higher antioxidant activity and higher phytochemicals contents than the other extraction technique obtained from seeds and twigs. The results indicate that Azadirachta indica leaves, seeds and twigs extracts have potent antioxidant activities that would have beneficial effects on human health and infusion extracts are superior with better antioxidant potential.

Gold nanoparticles capped with L-glycine, L-cystine, and L-tyrosine: toxicity profiling and antioxidant potential.

Biomolecules-based surface modifications of nanomaterials may yield effective and biocompatible nanoconjugates. This study was designed to evaluate gold nanoconjugates (AuNCs) for their altered antioxidant potential. Gold nanoparticles (AuNPs) and their conjugates gave SPR peaks in the ranges of 512-525nm, with red or blueshift for different conjugates. Cys-AuNCs demonstrated enhanced (p < 0.05) and Gly-AuNCs (p > 0.05) displayed reduced DPPH activity. Gly-AuNCs and Tyr-AuNCs displayed enhanced ferric-reducing power and hydrogen peroxide scavenging activity, respectively. Cadmium-intoxicated mice were exposed to gold nanomaterials, and the level of various endogenous parameters, i.e., CAT, GST, SOD, GSH, and MTs, was evaluated. GSH and MTs in liver tissues of the cadmium-exposed group (G2) were elevated (p < 0.05), while other groups showed nonsignificance deviations than the control group. It is concluded that these nanoconjugates might provide effective nanomaterials for biomedical applications. However, more detailed studies for their safety profiling are needed before their practical applications.

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.

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.

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.

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.

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.

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.

The Effect of Hydrolysis on the Antioxidant Activity of Olive Mill Waste

This study presents the effect of hydrolysis on the antioxidant activity of olive mill waste. The olive pomace samples were collected at different stages of maturity and were investigated for their phenolic content and antioxidant activity. Three different extraction procedures were employed, including methanolic maceration extraction and two hydrolysed procedures using 6 M HCL for acid hydrolysis and 10 M NaOH for alkaline hydrolysis. The total phenolic, flavonoid and ortho-diphenolic content, metal ion reducing activity, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-Diphenyl-1-picrylhydrazyl Radical Scavenging, hydrogen peroxide and superoxide scavenging activity assays were determined for the different extracts. In this study, cultivar and maturation of olives was one of the factors that affected the phenolic content in the olive pomace samples. Results show that alkaline hydrolysis had the highest antioxidant activity with respect to total phenolic content, 2,2-Diphenyl-1-picrylhydrazyl scavenging activity, metal ion reducing activity and superoxide scavenging activity, whereas acid hydrolysis had the highest 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity. The correlation analysis carried out on the different phenolic classes revealed that the total phenolic, flavonoid and ortho-diphenolic content were correlated with metal ion reducing activity and Radical Scavenging activity.

Antioxidant activity and blood alcohol concentration lowering effect of fermented Hovenia dulcis fruit vinegar.

In this study, Hovenia dulcis fruit fermented vinegar (HFV) was produced by the two-step fermentation of the H. dulcis fruit. The bioactivities before and after fermentation were compared. During the two-stage fermentation, the highest total acidity (4.99%) in the H. dulcis fruit extract juice was determined to be 16°Bx. During fermentation, the acetic acid content increased from 54.45 to 5404.30mg%, and the fructose level in the HFV decreased from 130.68 to 54.91mg%. The levels of DPPH and ABTS·+ free radicals scavenging activities, reducing power, hydrogen peroxide scavenging and β-carotene bleaching activities were found to be increased in HFV as compared to before fermentation. Furthermore, the serum alcohol and acetaldehyde levels were reduced significantly in HFV compared to before fermentation. This study shows that HFV enhances the antioxidant and alcohol degradation activities and can potentially be used as a functional drink to prevent hangovers.

Antioxidant properties, element contents and antimicrobial activities of bee pollen collected by Apis mellifera L. in Türkiye

Aim of study: Recently, pollen has become a preferred nutritional supplement because of its complex composition. We examined the botanical origin, total phenolic/flavonoid content (TPC/TFC), antioxidant/antimicrobial activity, and element content of pollen samples collected from honeybees. This study also examined whether the elements contained in pollen, when consumed as food, posed a risk to human health. Area of study: Ten mixed pollen samples were randomly collected from honeybees in the apiaries of four different Turkish regions, which fall among the three phytogeographic regions of Türkiye. Material and methods: We evaluated total flavonoid (TFC) and phenolic (TPC) contents; antioxidant activities (radical scavenging activity, hydrogen peroxide scavenging activity - HPSA, ferric reducing antioxidant power - FRAP, and ferrous ion chelating activity - FICA), element concentrations and antimicrobial activity. Main results: According to the melissopalynological analysis, one sample was determined to be unifloral and nine samples were found to be multifloral. The values found ranged 271.42-601.85 mg GAE/100 g TPC, 23.53-34.50 mg CAE/100 g TFC, 22.19-23.78 μg/mL DPPH, 6.50-78.40 µg/mL ABTS, 20.43-150.94 μg/mL HPSA, 97.26-99.83% FRAP and 74.84-91.79% FICA. Rosmanic acid, p-coumaric acid, quercetin, apigenin, and naringin were identified in all samples, while catechin was detected only in S6 and S7. Element contents were found Mg &gt; Fe &gt; Mn &gt; Zn &gt; Cu &gt; Se &gt; Cr &gt; Ni &gt; Cd &gt; Co. All the samples had high antibacterial activity against Bacillus cereus (MIC= 4.17-8.33 g/mL), and against Staphylococcus aureus (MIC= 8.33 g/mL), except S3 and S4. Research highlights: Different levels and combinations of these components are efficient in the antioxidant and antibacterial activity of pollen.

Anti-oxidant property of ailanthus excelsa Roxb used by local tribes of Pocharam wildlife sanctuary, Medak and Nizamabad districts, Telangana

The present study deals with the anti oxidant activity of Ailanthus excelsa Roxb used by Yerukula and Lambadi ethnic tribal living in Pocharam Wildlife Sanctuary of erstwhile Medak and Nizamabad Telangana, India. These people live in harmony with Nature and they employ plant and their derivatives for the basic health needs. Phytochemical analysis revealed the presence of numerous secondary metabolites of potential medical use. DPPH, Nitric Oxide, Superoxide, Hydrogen peroxide scavenging activity of methanol leaf extracts at different concentrations were studied (ascorbic acid used as standard). The present study revealed the anti oxidant activity of the leaf extracts of selected plants at all concentrations tested.

Phytochemical screening and anti-oxidant property of Diospyros melanoxylon used by Gothi Koya and Konda Reddi Tribes of Kinnerasani Wildlife Sanctury, Paloncha, Bhadradri Kothagudem district, Telangana

The Present study emphasizes that the preliminary phytochemical screening and the anti-oxidant activity of an important medicinal plant which was often used by primitive tribal groups of Gothi Koya and Konda Reddi located at Kinnerasani wildlife Sanctuary, Paloncha, Bhadradri Kothagudem district, Telangana state, India. Based on the uses of whole plant, phytochemical constituents, anti-oxidant property Diospyros melanoxylon Roxb was considering an important medicinal plant. Diospyros melanoxylon Roxb leaf extracts were screened for phytochemical components and for anti-oxidant activity. DPPH, Nitric Oxide, Superoxide, Hydrogen peroxide scavenging activity of methanol leaf extracts at different concentrations were studied (ascorbic acid used as standard). The present study revealed the presence of phytochemical compounds and anti-oxidant activity of the extracts of Diospyros melanoxylon Roxb at all concentrations tested.

Evaluation of Hydrogen peroxide Scavenging and Antibacterial activity of successive extracts of Luisia tenuifolia Blume against skin and wound infections

Skin and wound infections might trigger severe secondary complications when left untreated. A proper balance between reactive oxygen species generation and antioxidant formation is necessary to achieve redox haemostasis. Luisia tenuifolia Blume (Orchidaceae) has been traditionally applied on cuts, boils and wounds in regions of Western Ghats. The present study was aimed to validate the antioxidant and antibacterial effect of the whole plants of Luisia tenuifolia against five pathogenic bacteria often responsible for skin and wound infections The whole plants of L.tenuifolia, after drying under shade, was pulverised, successively extracted with solvents of different polarity and evaporated to dryness. The hydrogen peroxide scavenging potential of all the four extracts was determined by H2O2 assay. The agar-well diffusion technique was employed for the preliminary screening of antibacterial activity. Further, the minimum inhibitory concentration was determined by broth-dilution assay. Among the four extracts, the ethanol extract of L. tenuifolia exhibited a strong antioxidant activity with an IC50 value of 42.61μg/mL compared to the standard Ascorbic acid (IC50 value of 21.56μg/mL). Moreover, the n-hexane extract was found to be more effective against Staphylococcus aureus whereas the ethanol extract exhibited highest antibacterial effect on Streptococcus oralis, Pseudomonas aeruginosa, Aeromonas hydrophila and Escherichia coli. Furthermore, the ethanol extract was found to be a promising antibacterial candidate with an MIC value of 0.312μg/mL against S.oralis and A.hydrophila. Thus the current study validate the antioxidant and antibacterial potential of L. tenuifolia whole plant extracts and further studies were aimed at identification of active components responsible for the activity.

Structural and physicochemical characterization of an aminosugar-rich exopolysaccharide isolated from a Chlorella sp.

In the present work an aminosugar-rich exopolysaccharide (EPS) of a novel Chlorella sp. strain was isolated and characterized. Isolation of the EPS matrix was a fast and financially viable procedure based upon consecutive centrifugation and resuspension steps without the use of hazardous chemicals. After acidic hydrolysis, the EPS matrix was examined by Nuclear Magnetic Resonance (NMR) Spectroscopy as well as Electrospray Ionization Tandem Mass Spectrometry (ESI-MS/MS), and it was shown that it is a heteropolysaccharide. Aminosugar moieties, mainly glucosamine and galactosamine, constituted >40 % of the structure's relative molar ratio, followed by rhamnose, arabinose, galactose, xylose and mannose. Differential scanning calorimetry (DSC) analysis showed that the EPS matrix exhibited specific thermal transitions in the range of 59–88 °C corresponding to crystallization steps, while thermogravimetric analysis showed that the polysaccharide presented exceptional thermal stability at temperatures up to 600 °C. Powder X-ray diffraction analysis showed that the polymer exhibited high crystallinity after one DSC cycle. The isolated EPS exhibited a maximum total antioxidant capacity of 11.5 mg ascorbic acid equivalents·g−1 and a reducing power of 11.2 mg ascorbic acid equivalents·g−1, while the ferric reducing antioxidant power of the EPS reached 37.2 μM Fe2+·g−1. In all cases the antioxidant and reducing power of the EPS was dose-dependent. The EPS exhibited a moderate hydrogen peroxide and hydroxyl radical scavenging activity reaching a maximum of approximately 40 % at 2 mg mL−1 concentration. All these structural and physicochemical characteristics, along with the strong antioxidant profile, make this macromolecule a strong candidate for further exploitation in commercial applications in the pharmaceutical, nutraceutical and bioplastic industries.

Screening of Phytochemical Profile and Biological Activities in the Leaves, Stems and Roots of South African Portulacaria Afra using Four Extraction Solvents

Portulacaria afra, is indigenous to South Africa and has been identified to have several medicinal properties according to traditional knowledge and few studies. The drive around this research is to evaluate the medicinal properties of the leaves, stems and for the first time the roots extracts of Portulacaria afra, using four solvents with different polarities. The aqueous (60°C), methanol, n-hexane and ethyl acetate whole plant extracts of P. afra were investigated for their phytochemical properties, antimicrobial and antioxidant activity. The phytochemical screening revealed that the methanolic and aqueous extracts of the leaves displayed high presence of secondary metabolites compared to n-hexane and ethyl acetate extracts. The methanolic leaves extracts showed strong presence of quinones, phenols, steroid and coumarins while the aqueous leaves extracts contained a moderate presence of saponins, terpenoids, quinones and coumarins. Ethyl acetate leaves extracts revealed a strong presence of tannins, moderate presence of phytosteroids and a low presence of volatile oil. Meanwhile, the leaves extracts with n-hexane showed a considerable amount of saponins with a moderate presence, and a low presence of tannins, volatile oils and terpenoids. The methanolic stems extracts displayed the most significant presence of secondary metabolites, showing a high presence of terpenoids, steroids, phenols and coumarins. The aqueous stems extracts showed a strong presence of glycosides with a moderate presence of saponins. However, ethyl acetate and n-hexane stems extracts displayed a few secondary metabolites with their concentration ranging from medium to low. The ethyl acetate roots extracts displayed a significant elevated amount of quinones with a strong presence. n-hexane roots extracts showed a moderate presence of volatile oil and a low presence of tannins and steroids. Methanolic roots extracts showed a moderate presence of coumarins and glycosides while aqueous roots extracts showed a low presence of glycosides. The overall highest total phenolics contents (TPCs) and total flavonoids contents (TFCs) in all the plant parts, were found to be in the methanol stems extracts and aqueous roots extracts respectively. Next to the methanol leaves and aqueous leaves extracts respectively. However, in the root’s extracts, the aqueous extracts showed the highest total phenolics content while the water extracts had the highest total flavonoids contents. The antimicrobial activities of P. afra whole plant extracts with the various four solvents were tested against three microorganisms Escherichia coli, Staphylococcus aureus and Streptomyces griseus using agar-well diffusion method. The Antimicrobial activity of the n-hexane extracts of the leaves, stems and roots of P. afra presented a wide range of inhibition against all the test microorganisms, ethyl acetate leaves extract showed a considerable effect against Staphylococcus aureus while the methanolic extracts were not active. Aqueous roots extracts demonstrated a strong antimicrobial activity against Staphylococcus aureus while the other extracts were not active. The zones of inhibition ranged from 13 to 24 mm for the plant extracts. The antioxidant activity potential of the aqueous, methanol, n-hexane and ethyl acetate extracts of P. afra leaves, stems and roots extracts were observed through a 2, 2 diphenylpicryhydrazyl (DPPH) free radical assay, hydrogen peroxide scavenging (H₂O₂) and metal chelating activity assay. Ethyl acetate roots extracts exhibited the strongest hydrogen peroxide scavenging activity compared to the other extracts. Meanwhile, aqueous stems extracts showed the highest antioxidant activity against DPPH radical. Aqueous and n-hexane roots extracts displayed the strongest metal chelating ability. These findings reveal the efficacy of the use of several solvents with different polarities for effective and more accurate extraction of various compounds and indicate that the antimicrobial and antioxidant activity of P. afra parts are dependent on the solvent extracts.

Evaluation of Bioactive Secondary Metabolites from Ponyfish Associated Bacteria (&lt;i&gt;Photobacterium leiognathi&lt;/i&gt;)

The marine environment continues to surprise us by producing novel bioactive substances with a wide range of benefits for humans. Materials and Methods: Marine bioluminescent bacteria Photobacterium leiognathi was isolated from pony fish, Secutorruconius which was confirmed with microscopic and molecular characterization. The secondary metabolite of the isolated bacteria was extracted with dichloromethane. The chemical fingerprinting of the isolated metabolite was analyzed through TLC, FT-IR, and HPLC. The nature of the compound present in the metabolite was identified in the gas chromatography-mass spectrometry analysis (GC - MS). The isolated extract was investigated for its antibacterial property against 10 human pathogenic bacteria and also its antioxidant activity using different assays such as 1, 1-Diphenyl-2-picrylhydrazyl, Phosphomolybdenum, Metal chelating, Hydroxyl radical scavenging and hydrogen peroxide scavenging activity. Results: The Presence of functional groups including phenols, sugars, and amino acids in the extracts were identified by TLC. Totally, nine peaks were obtained for the crude extract through the FTIR spectrum range of 400 to 4000 cm-1 for the active sample. The DCM extract showed a broad spectrum of antibacterial activity against the six human bacterial pathogens. Secondary metabolites from the bioluminescent bacteria, P. leiognathi, have strong antioxidant properties. These results will be instrumental in developing novel products with biosensors and bio-imaging applications using P. leiognathi.