Superoxide Radical Scavenging Assays Research Articles

Analysis of Antioxidant, Acetylcholinesterase Inhibitory Properties and Chemical Composition of Some Indian Himalayan Species of Berberis: A Comparative Study

Background: Methanolic extracts of the stems of six species of Berberis e.g., Berberis umbellata, B. vulgaris (Syn: B. nepalensis), B. insignis, B. asiatica, and B. aristata were studied for their antioxidant properties and acetylcholinesterase inhibitory properties. Materials and Methods : Antioxidant property was studied in different systems of assay e.g., DPPH radical scavenging assay, superoxide radical scavenging assay, nitric oxide scavenging assay, assay to chelate metal. Acetylcholinesterase (AChE) inhibitory property was measured using AChE from electric eel. Results: It was observed that all the extracts scavenged DPPH, superoxide and nitric oxide radical and chelated metal ion in a dose dependent manner. The antioxidant properties were correlated with total phenol content, total flavonoid content, berberine and palmatine content. The AChE inhibitory activities of the extracts were also correlated well with berberine, palmatine, total phenol and total flavonoid content. A few phenolic compounds were detected by GC-MS. Highest activity in all respect was observed in B. aristata. Conclusion: Methanolic extracts of the stems of B. aristata exhibited the highest antioxidant activity.

Genomic and physiological traits provide insights into ecological niche adaptations of mangrove endophytic Streptomyces parvulus VCCM 22513

PurposeEndophytic Streptomyces parvulus VCCM 22513 isolated from Bruguiera gymnorrhiza in Quang Ninh mangrove forest, northern Vietnam showed abiotic stress tolerance consisting of antioxidant, salt-tolerant, and aromatic-compound degrading activities. The goal of this study was to shed light on genomic bases rendering mangrove endophytic S. parvulus more resilient to environmental stressors.MethodsPhenotypic analysis including antioxidant activities, hydrogen peroxide and sodium chloride resistance, and aromatic compound utilization were evaluated. The genome of strain VCCM 22513 was sequenced using Illumina Miseq sequencing platform and assembled using SPAdes.ResultsOut of 15 endophytic actinomycetes associated with B. gymnorrhiza in Quang Ninh mangrove, northern Vietnam, VCCM 22513 extract showed remarkable antioxidant activities through (1,1-diphenyl-2-picrylhydrazyl) DPPH and superoxide radical scavenging assays of 72.1 ± 0.04% and 38.3 ± 0.16% at 1.6 mg/ml, respectively. The genome consists of a 7,688,855 bp linear chromosome, 6782 protein-coding sequences, and 68 tRNAs. Genomic analysis identified strain VCCM 22513 as Streptomyces parvulus and confirmed a highly conserved core genome and stability of S. parvulus under natural selection. Genome mining revealed the presence of genetic determinants involved in mycothiol and ergothioneine biosynthesis (26 genes), oxidative stress resistance (43 genes), osmoadaptation (87 genes), heat and cold stress (34 genes), aromatic compound degradation (55 genes). Further genome-wide comparison between S. parvulus VCCM 22513 and 11 Streptomyces genomes showed that VCCM 22513 possesses significantly higher copies of genes involved in mycothiol and ergothioneine biosynthesis. In support of this finding, the strain exhibited much resistance to 0.6–1.0 M H2O2 and 6% (w/v) NaCl as compared to Streptomyces cavourensis YBQ59 isolated from Cinnamomum cassia Prels. In addition, the complete pathways for degradation of aromatic compounds including protocatechuate, gentisate, 4-hydroxyphenylpyruvate, cinnamate, 3-phenylpropionate, and styrene were only identified in the genome of VCCM 22513.ConclusionsThe present study revealed for the first time adaptive responses of mangrove endophytic S. parvulus VCCM 22513 to survive in hostile environment. The information shown here provided better understanding of underlying mechanisms related to adaptation and partially plant-microbe interaction of Streptomyces associated with mangrove plants.

In vitro Screening for Antioxidant and Antimicrobial Properties of 3,5-Bis(E-thienylmethylene) piperidin-4-one, a Curcumin Analogue

Pharmacognosy Research,2022,14,3,276-283.DOI:10.5530/pres.14.3.40Published:July 2022Type:Original ArticleAuthors:Jayaseelan Nivedha, Kaliyamoorthi Kanimozhi, Subashchandrabose Olikkavi, T. Vidhyasagar, Natesan Vijayakumar, Chinnaiyan Uma, K. Rajeswari, and Lakshmanan Vennila Author(s) affiliations:Jayaseelan Nivedha1, Kaliyamoorthi Kanimozhi1, Subashchandrabose Olikkavi1, T. Vidhyasagar2, Natesan Vijayakumar1, Chinnaiyan Uma4, K. Rajeswari2,3, Lakshmanan Vennila1,* 1Department of Biochemistry and Biotechnology, Annamalai University, Chidambaram, Tamil Nadu, INDIA. 2Department of Chemistry, Annamalai University, Chidambaram, Tamil Nadu, INDIA. 3Department of Chemistry, GAC-CDM, Chidambaram, Tamil Nadu, INDIA. 4Department of Microbiology, Annamalai University, Chidambaram, Tamil Nadu, INDIA. Abstract:Background: Curcumin is a naturally occurring bis-chalcone derivative in the commonly used Indian spice turmeric and is well-known for its potent chemopreventive, anti-angiogenic, anti-cancer properties. 3,5-bis[(E)-thienylmethylene] piperidin-4-one (BTMP) is the newly synthesised synthetic analogue of curcumin that is tested for its antioxidant and antimicrobial properties in vitro. Objectives: This study was to determine the antioxidant activity and antibacterial potentials of newly synthesised analogues of curcumin viz., 3,5-bis[(E)- thienylmethylene] piperidin-4-one (BTMP), was examined in vitro. Materials and Methods: BTMP was evaluated for its antioxidant and antimicrobial using 1,1-diphenyl-2-picryl hydroxyl (DPPH•) radical scavenging assay, 2,2’-azinobis3-ethyl benzothiazoline-6-sulfonic acid (ABTS•+), ferric reducing antioxidant power (FRAP), nitric oxide scavenging assay, superoxide anion radical scavenging assay (O2•−), hydrogen peroxide scavenging, reducing ability assay, metal ion chelating and phosphomolybdenum assays. Results: 40μg/ml of BTMP showed higher antioxidant activity than the other three doses due to its highest free radical scavenging ability at this particular dose. All doses of BTMP showed antimicrobial activity against E. coli and S. aureus. 40μg/ml of BTMP showed the highest zone of inhibition against both tested pathogens. Conclusion: The introduction of basic functionality and the presence of exocyclic double bonds of BTMP has significantly contributed to the antioxidant activity and antimicrobial activity against both gram-positive and gram-negative bacteria. Keywords:Antibacterial, Antioxidant, Curcumin, DPPH, Reducing abilityView:PDF (361.28 KB)

A Folk Medicine: <i>Passiflora incarnata</i> L. Phytochemical Profile with Antioxidant Potency

Passiflora incarnata L., commonly called folk medicine declaredly used for an enormous range of therapeutic purposes, one such is antioxidant potency. The study prioritized to determine the phytochemical analysis of total phenolics, flavonoids, alkaloids, and tannins contents as well as the antioxidant properties through 1,1-diphenyl-2-picrylhydrazyl (DPPH) quenching assay, 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation decolorization test, superoxide, and hydrogen peroxide radical scavenging assays of ethanol extract of P. incarnata leaves.The organoleptic characteristics such as color, odor, appearance, taste, and other characters such as drying range and fiber contents were analyzed as preliminary data. Analytical parameters like total phenolic content, total tannins, total alkaloid content, and total flavonoid with multiple antiradical scavenging activity (DPPH, ABTS, superoxide and H2O2 scavenging assays) with IC50 (μg/mL) in terms of inhibition percentage with various concentrations of the ethanolic extract studied.P. incarnata possessed a high radical scavenging activity with a phenolic content of 2.48 mg gallic acid equivalent/g of extract in leaves, whereas the total flavonoid content was 2.1, respectively.High antioxidant activity was noticed in P. incarnata extract, in which might be of higher levels of flavonoids and phenols. Findings in the studies revealed that P. incarnata is a veritable source for antioxidant drug bioprospecting in scientific research and pharmaceutical industries.

Bioactive Components from Ampelopsis japonica with Antioxidant, Anti-α-Glucosidase, and Antiacetylcholinesterase Activities

The dried root of Ampelopsis japonica (Thunb.) Makino (A. japonica.) is a traditional medicine used to treat fever, pain, and wound healing. It exhibits anti-inflammatory, antitumor, antityrosinase, and antimelanogenic activities. In this paper, we used different solvent extracts from the root of A. japonica to determine their antioxidant activity. Acetone extract showed relatively strong antioxidant properties by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), superoxide radical scavenging activity, and ferric reducing antioxidant power (FRAP) assays. In addition, these extracts also showed significant α-glucosidase and acetylcholinesterase (AChE) inhibitory activities. Acetone extract significantly inhibited α-glucosidase with an IC50 value of 8.30 ± 0.78 μg/mL, and ethanol extract remarkably inhibited AChE with an IC50 value of 37.08 ± 7.67 μg/mL. Using HPLC analysis and comparison with the chemical composition of various solvent extracts, we isolated seven active compounds and assessed their antioxidant, anti-α-glucosidase, and anti-AChE activities. Catechin (1), gallic acid (2), kaempferol (3), quercetin (4), resveratrol (6), and epicatechin (7) were the main antioxidant components in the root of A. japonica. According to the results of DPPH, ABTS, and superoxide radical scavenging assays, these isolates showed stronger antioxidant capacity than butylated hydroxytoluene (BHT). Moreover, 1, 3, 4, euscaphic acid (5), 6, and 7 also expressed stronger anti-α-glucosidase activity than the positive control acarbose, and all the isolated compounds had a good inhibitory effect on AChE. Molecular docking models and hydrophilic interactive modes for AChE assays suggest that 1 and 5 exhibit unique anti-AChE potency. This study indicates that A. japonica and its active extracts and components may be a promising source of natural antioxidants, α-glucosidase, and AChE inhibitors.

In-vitro antioxidant activity of hydroalcoholic extract of crinum latifolium using different method

The purpose of this research is to look for phytochemicals and determine the antioxidant potential of C. latifolium aerial parts. The qualitative analysis of several phytochemical components was determined using a well-known test methodology. The 1,1-diphenyl-2-picryl hydrazyl (DPPH) assay, hydrogen peroxide, and nitric oxide radical scavenging method were used to investigate the antioxidant activity of a hydro ethanol extract of Crinum latifolium bark in vitro. Phytochemical studies discovered the existence of phenols and flavonoids. The extract demonstrated dose-dependent free radical scavenging capabilities in the models studied. For the DPPH method, aerial portions of Crinum latifolium extract had an IC50 value of 46.35µg/ml, which was close to that of ascorbic acid (IC50=20.03g/ml). The IC50 value for the Superoxide radical scavenging assay was determined to be 60.94µg/ml, which is comparable to ascorbic acid (IC50= 20.91g/ml). The IC50 value was determined to be 50.30µg/ml in reducing power determination, which was close to that of ascorbic acid (IC50=20.84g/ml). The phytochemical profile and antioxidant activity of Crinum latifolium, which will be exploited for medicinal purposes, are described in this paper.

Targeting Akt/NF-κB/p53 Pathway and Apoptosis Inducing Potential of 1,2-Benzenedicarboxylic Acid, Bis (2-Methyl Propyl) Ester Isolated from Onosma bracteata Wall. against Human Osteosarcoma (MG-63) Cells.

Onosma bracteata Wall. is an important medicinal and immunity-enhancing herbs. This plant is commonly used in the preparation of traditional Ayurvedic drugs to treat numerous diseases. Inspired by the medicinal properties of this plant, the present study aimed to investigate the antiproliferative potential and the primary molecular mechanisms of the apoptotic induction against human osteosarcoma (MG-63) cells. Among all the fractions isolated from O. bracteata, ethyl acetate fraction (Obea) showed good antioxidant activity in superoxide radical scavenging assay and lipid peroxidation assay with an EC50 value of 95.12 and 80.67 µg/mL, respectively. Silica gel column chromatography of ethyl acetate (Obea) fraction of O. bracteata yielded a pure compound, which was characterized by NMR, FTIR, and HR-MS analysis and was identified as 1,2-benzene dicarboxylic acid, bis (2-methyl propyl) ester (BDCe fraction). BDCe fraction was evaluated for the antiproliferative potential against human osteosarcoma MG-63, human neuroblastoma IMR-32, and human lung carcinoma A549 cell lines by MTT assay and exhibited GI50 values of 37.53 μM, 56.05 μM, and 47.12 μM, respectively. In MG-63 cells, the BDCe fraction increased the level of ROS and simultaneously decreased the mitochondria membrane potential (MMP) potential by arresting cells at the G0/G1 phase, suggesting the initiation of apoptosis. Western blotting analysis revealed the upregulation of p53, caspase3, and caspase9 while the expressions of p-NF-κB, p-Akt and Bcl-xl were decreased. RT-qPCR studies also showed upregulation in the expression of p53 and caspase3 and downregulation in the expression of CDK2, Bcl-2 and Cyclin E genes. Molecular docking analysis displayed the interaction between BDCe fraction with p53 (−151.13 kcal/mol) and CDK1 (−133.96 kcal/mol). The results of the present work suggest that the BDCe fraction has chemopreventive properties against osteosarcoma (MG-63) cells through the induction of cell cycle arrest and apoptosis via Akt/NF-κB/p53 pathways. This study contributes to the understanding of the utilization of BDCe fraction in osteosarcoma treatment.

Biogenic synthesis of zinc oxide nanoparticles using mushroom fungus Cordyceps militaris: Characterization and mechanistic insights of therapeutic investigation

The present research demonstrates the Cordyceps militaris (a medicinal mushroom) mediated fabrication of zinc oxide nanoparticles (Cor-ZnONPs) and its therapeutic investigation. The biosynthesized Cor-ZnONPs were characterized by UV–Visible spectroscopy, FT-IR, XRD, SEM with EDX, HRTEM, particle size, and zeta potential analysis and evaluated for their antidiabetic, antioxidant, and antibacterial potential by in-vitro methods. The nanoparticles showed SPR peak at 354 nm. FT-IR analysis exhibited a sharp peak at 432.05 cm−1, demonstrating the distinctive Zn–O bond. Cor-ZnONPs had an average particle size of 1.83 nm with a polydispersity index of 0.29 and were crystalline as obtained from XRD analysis. Zeta potential of −6.42 mV indicates the moderate stability of nanoparticles. EDX analysis confirmed the presence of Zinc and Oxygen. Cor-ZnONPs expressed a 70–90% survival rate in brine shrimp lethality assay with 10–100 ppm concentrations and exhibited potent α-amylase and α-glucosidase inhibitory effect with an IC50 of 46.29 ± 0.49 and 47.21 ± 0.19 μg/mL, respectively. Cor-ZnONPs showed moderate radical potency with DPPH, ABTS, hydroxyl radical, nitric oxide, and superoxide radical scavenging assays. Cor-ZnONPs revealed the highest antibacterial activity against Pseudomonas aeruginosa, followed by Shigella flexneri, Proteus vulgaris, and Rhodococcus equi. Moreover, a very low concentration of Cor-ZnONPs was required to inhibit the growth of studied bacterial strains. This study provides an informational insight into the Cordyceps militaris mediated synthesis of ZnONPs, and their antidiabetic, antioxidant, and antibacterial potential. Biosynthesized Cor-ZnONPs indicate a new application of nanoparticles in the development of therapeutic drugs.

Phytochemical analysis by UPLC-QTOF-MS/MS and evaluation of antioxidant and anti-inflammatory activities of the extract and fractions from flowers of Cochlospermum vitifolium

Cochlospermum vitifolium (pacotê) is a medicinal plant used for treatment of hypertension, hepatitis, jaundice, hyperglycemia and inflammatory disorders. This study aimed to identify compounds present in ethanolic extract (EtOH) and hexane (Hex), ethyl acetate (EtOAc) and methanol/water (MeOH) fractions from C. vitifolium flowers and evaluate the antioxidant and anti-inflammatory potential. The phenolic compounds were characterized by UPLC-QTOF-MS/MS and 22 compounds were identified. The antioxidants effect of EtOH, Hex, EtOAc and MeOH fraction were investigated through quantification of total phenolic, diphenylpicryl hydrazine reduction, total antioxidant capacity, iron and cooper-chelating, reducing power, superoxide and hydroxyl radical scavenging assays. The anti-inflammatory potential of EtOH and EtOAc fraction (intra-gastric gavage route, 50, 100 or 150 mg/kg) were assayed by carrageenan-induced paw edema and zymosan-induced air pouch models. The EtOH and EtOAc fraction revealed higher concentration of phenolic compounds and antioxidant action when compared with Hex and MeOH fractions. The extract and fractions showed specific copper chelating effect. The EtOH and EtOAc fraction demonstrated be effective reducing the edema in carrageenan-induced paw edema model. In zymosan-induced air pouch model, the extract and fraction were able to decrease the leukocytes cells, proteins total and cytokines (IL-1β and IL-6) levels. This is the first study that demonstrated the antioxidant and anti-inflammatory effect of EtOH and EtOAc fraction of C. vitifolium flowers, suggesting that its phenolic compounds are, at least in part, responsible for anti-inflammatory effects.

UNVEILING THE PHYTOCHEMICAL PROFILE, SECONDARY METABOLITE QUANTIFICATION AND ANTIOXIDANT ACTIVITY OF CLEMATIS WIGHTIANA WALL. EX WIGHT and ARN.

Traditionally, the leaves of Clematis wightiana have been used in the treatment of rheumatism, indigestion, headaches, varicose veins, bone problems, nasal congestion and sinus. The present study was conducted to evaluate the phytochemical profile, quantification of secondary metabolites and free radical scavenging capacity of C. wightiana leaf. The total phenolic, tannin and flavanoid content of C. wightiana leaves were quantified and were found to be higher in the ethyl acetate extract. Subsequently, the extracts were subjected to appraise their antioxidant capacity by availing various in vitro antioxidant assays namely DPPH radical scavenging assay, ABTS assay, Phosphomolybedenum assay, Ferric Reducing assay, Superoxide Radical Scavenging assay and Reducing power assay. The results of the antioxidant assays revealed that the ethyl acetate extract of C. wightiana leaves possess better free radical scavenging activity than other solvent extracts. Thus, the finding of the study elucidates the perception on phytochemical and bioactivity of C. wightiana which could be used in development of phytotherapeutics to enchance human health. Keywords: Clematis wightiana, Antioxidant, Superoxide radical scavenging, In vitro antioxidant assay, DPPH, Ethnomedicine.

Antioxidant and Anti-α-Glucosidase Activities of Various Solvent Extracts and Major Bioactive Components from the Fruits of Crataegus pinnatifida.

Crataegus pinnatifida is used to treat various diseases, including indigestion, congestive heart failure, hypertension, atherosclerosis, and myocardial dysfunction. We evaluated antioxidant and anti-α-glucosidase activities of various solvent extracts and major bioactive components from the fruit of C. pinnatifida. Ethyl acetate extracts showed potent antioxidant activities with IC50 values of 23.26 ± 1.97 and 50.73 ± 8.03 μg/mL, respectively, in DPPH and ABTS radical scavenging assays. Acetone extract exhibited significant anti-α-glucosidase activity with IC50 values of 42.35 ± 2.48 μg/mL. HPLC analysis was used to examine and compare the content of active components in various solvent extracts. We isolated four active compounds and evaluated their antioxidant and anti-α-glucosidase properties. Among the isolated compounds, chlorogenic acid and hyperoside showed potential antioxidant activities in ABTS and superoxide radical scavenging assays. Moreover, hyperoside also displayed stronger anti-α-glucosidase activity than other isolates. The molecular docking model and the hydrophilic interactive mode of anti-α-glucosidase assay revealed that hyperoside might have a higher antagonistic effect than positive control acarbose. The present study suggests that C. pinnatifida and its active extracts and components are worth further investigation and might be expectantly developed as the candidates for the treatment or prevention of oxidative stress-related diseases and hyperglycemia.

A Novel Compound Plumercine from Plumeria alba Exhibits Promising Anti-Leukemic Efficacies against B Cell Acute Lymphoblastic Leukemia

The current study was focused to evaluate the antioxidant and the anti-cancerous properties of Plumeria alba. Plumeria alba was chosen due to its existing medicinal values. Antioxidant assays like Superoxide radical scavenging assay, Nitrous Oxide radical scavenging assay, were performed, on the methanolic and ethyl acetate extracts of the plant, that depicts the pro-oxidant nature of the extract. Further, they were tested to check cell viability on B cell Acute Lymphoblastic Leukemia (ALL) Cell line (NALM 6), human lung cancer cell line (A549), T cell Acute Lymphoblastic Leukemia cell line (MOLT4), and PBMC isolated from normal donors utilizing MTT assay. Robust anti-proliferative activity was observed in the case of NALM 6 followed by A549, MOLT4, whereas negligible activity was observed in the case of PBMC. Intrigued by this finding, in silico docking was performed using three bioactive compounds namely Plumericine, Isoplumericine, and 13-O-p-Coumaroylplumieride, unique to Plumeria sp. They were docked against five different cyclins and Cdk proteins responsible for ALL. The compounds have shown satisfactory results and their druggability and ADMET properties were checked further. Plumercine turned out to be the most competent compound and hence can be considered as a potential leukemic drug candidate in the future.

Phytochemical Analysis and in vitro Antioxidant and Antibacterial Activities of Ethanolic Leaf Extract of Achyranthes aspera L.

The present study was aimed to evaluate the phytochemicals present in the ethanolic extract of Achyranthes aspera leaves (EEAA) and identify the bioactive compounds by GC-MS analysis. In vitro antioxidant activity was measured by using DPPH, metal chelating and superoxide radical scavenging assays. The anti-bacterial activity was assayed by disc diffusion method. The results revealed the presence of phenols, flavonoids, and tannins in significant amount in EEAA [372 ± 2 mg GAE g-1, 22.6 ± 1.34 mg CE g-1 and 242 ± 2 mg TAE g-1, respectively. GC-MS analysis revealed the presence of 20 major bioactive compounds with 74.36% total leaf extract, dominated by phytol (10.67%), palmitic acid (6.56%), pseudo-ephedrine (6.06%) and hexacosane (5.76%). EEAA exhibited a maximum DPPH radical scavenging activity of 46.3% The metal chelation activity in EEAA was 58.8%. The EEAA exhibited a maximum of 46.51% superoxide scavenging activity. In vitro antibacterial activity of EEAA assayed against three human pathogenic bacteria viz., Salmonella typhi, Bacillus subtilis and Escherichia coli. EEAA showed maximum inhibition against B. subtilis (16.33 ± 0.577 mm). The study revealed that A. aspera is a potential source for developing health-oriented products.

Antioxidant activity of ethyl acetate extract of Ipomoea staphylina

The study aimed to estimate phenolic and iflavonoid content and to assess in vitro antioxidant activity of ethyl acetate extract of Ipomoea staphylina. The total phenolic content of the extract was estimated via Folin-Ciocalteu method and aluminium chloride colorimetric procedure was used to guess the total flavonoid content. DPPH and superoxide scavenging assays were performed to determine in vitro antioxidant activity of I. staphylina extract. The study demonstrated that the scavenging properties of I. staphylina extract against DPPH and superoxide radicals were in a dose depending manner. The extract at 100 μg/ml concentrations has shown maximum DPPH and superoxide radical scavenging effect and the obtained values were comparable with the istandard drug ascorbic acid. The IC50 value of the extract was found to be 35.84 and 30.30 μg/ml in DPPH and superoxide radical scavenging assay, respectively. The extract also contains a moderate quantity of phenolic compounds and flavonoids which are probably responsible for the antioxidant activity. Based on the results found it can be concluded that the ethyl acetate extract of I. staphylina exhibits antioxidant properties probably because of the occurrence of a moderate quantity of phenolic and flavonoid compounds.

In vitro antioxidant activity of Elaeocarpus tectorius (Lour.) Poir – an Indian medicinal plant

The study aimed to investigate bioactive phytochemicals and antioxidant activity of Elaeocarpus tectorius (Lour.) Poir leaf extract. The antioxidant properties were evaluated by four antioxidant methods, 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay, hydroxyl radical (HO%) scavenging assay, superoxide anion (O2%) radical scavenging assay, and nitric oxide (NO%) scavenging assay. The free radical scavenging activity of hydroethanolic extract of E. tectorius was found to be high for DPPH, nitric oxide, superoxide, and hydrogen peroxide (H2O2) radicals in a concentration-dependent manner. The content of total phenols, flavonoids, and tannins was also high in the hydroethanolic extract. The antioxidant capacity and total phenolic content were shown to be significantly related, indicating that phenolic chemicals are the primary contributors to plants' antioxidant capabilities. Based on the findings, it can be concluded that the hydroethanolic leaf extract of E. tectorius could serve as a potential source of antioxidants and can be explored as a therapeutic agent in free radical-induced diseases.

In vitro Antioxidant activity and Phytochemical composition of Syringodium isoetifolium

Seagrass are the marine flowering plants found mainly in clear, shallow estuaries and coastal waters. In all temperate and trophical region seagrasses grow both internally and subtidally. One such seagrass namely Syringodium isoetifolium has many medicinal properities. This seagrass have most promising pharmacological activities which may include anti-inflammatory, anticancer, antidiarrheal, antihaemorrhoidal activities. This study is focussed on the phytochemical evaluation and in vitro antioxidant activity of aqueous, ethanol and hydroalcoholic extract of Syringodium isoetifolium. The qualitative analysis of Syringodium isoetifolium shows the presence of tannin, saponin, flavonoids, steroids, terpenoids, alkaloids, anthraquinone, polyphenol and coumarin. In all the three extracts only ethanol shows the high concentration of phytocompounds. Emodins, glycoside and anthocyanin were found to be absent in all the three extracts. Quantitative analysis of total phenol, flavonoid, saponin and tannin were found to be 193.10 ±13.52, 106.11 ± 7.42, 52.96 ± 3.64 and 81.30 ± 5.69. Superoxide anion radical, Nitric oxide and Hydroxy radical scavenging assay showed that Syringodium isoetifolium was an excellent scavenger of these radicals. These results are an indication of the potent antioxidant property of the extract and may be responsible for some of the therapeutic uses of Syringodium isoetifolium.

Assesment of free radical scavenging activity and inhibitory properties of aqueous extract of Cymodocea serrulata segrass towards α- glucosidase and α –amylase enzyme

Aim: The study reports the in vitro free radical scavenging and α-amylase and α-glucosidase inhibition activities of aqueous extract of seagrass Cymodocea serrulata from Gulf of Mannar, Southeast Asia. Methods: The free radical scavenging activity was evaluated by DPPH, Superoxide, Nitric oxide and Hydroxyl radical scavenging assays and α-amylase, α-glucosidase enzyme inhibitory activity. The C. serrulata showed effective DPPH radical scavenging activity of 69.45 μg/mL, Superoxide radical scavenging activity of 91.08.5 ± 0.02%, Nitric oxide radical scavenging activity of 86.89 ± 0.03% and Hydroxyl radical scavenging activity of 81.09 ± 0.3 % at a concentration of 5 μg/mL respectively. It also showed significant inhibitory activity against α- amylase with an IC50 value of 3.0 ± 0.04 (μg/ml) and the α-glucosidase inhibitory activity with an IC50 value of 3.7 ± 1.01 (μg/ml) at concentrations of 1-5 μg/mL. Conclusion: Cymodocea serrulata was found to be a potent free radical scavenger and inhibitor of α-amylase and α-glucosidase enzymes.

Amelioration of sodium fluoride induced oxidative stress by Cynometra travancorica Bedd in mice.

Cynometra travancorica, endemic to Western Ghats of India is pharmacologically similar to Saraca asoca and occasionally used as substitute in a well-known Ayurvedic uterine tonic Asokarishta. S.asoca possess various biological properties, but there are no reports on C.travancorica. The present study evaluated the pharmacological properties of C.travancorica and its efficacy in attenuating the sodium fluoride (NaF) induced oxidative stress in mice. Antioxidant potential of methanolic extract of C. travancorica (CTE) stem bark was evaluated using DPPH, superoxide radical scavenging and total antioxidant assays. The effect of CTE on mitigating NaF deteriorated redox status in the liver tissue of mice was evaluated. Functional groups in CTE were analyzed by FTIR analysis. CTE effectively scavenged the free radicals in in vitro condition. CTE could augment catalase (46.6%), superoxide dismutase (53.8%) activities and GSH level (48.1%) against NaF induced decline in the liver tissue of mice. The peroxidation of lipids was found to be decreased by 44.9% and tissue damage abated as inferred by histopathology. FTIR analysis revealed the presence of biologically active functional groups in CTE. The study revealed the ameliorative effect of C. travancorica against NaF induced deleterious effect in experimental animals by its potent antioxidant potential.

6-Gingerol and Semisynthetic 6-Gingerdione Counteract Oxidative Stress Induced by ROS in Zebrafish.

6-Gingerol (1) is one of the major components in ginger and developing new synthetic methodologies could bring semisynthetic analogs with improved therapeutic properties. Towards this, multigram scale isolation of 6-gingerol with excellent purity was optimized using a simple and robust extraction, followed by column purification. Synthesis of 6-gingerdione, 7 from 6-gingerol was then achieved through selective -OTBDMS protection, DMP oxidation and deprotection reaction sequence for the first time. Compounds 1, 7 and 8 (dehydrozingerone) exhibited excellent cell-free antioxidant properties in DPPH, ABTS, superoxide radical scavenging assay and H2 O2 assay at 10-50 μM concentrations. The hemolytic study suggests that up to 50 μM, all three compounds did not exhibit toxicity to human erythrocytes. When H2 O2 treated zebrafish larvae groups (96hpf) were exposed to compounds 1, 7 and 8, it increases the SOD (19, 19.1 and 18.7 U/mg protein), CAT (18.1, 16.5, and 15.8 μmol/mg levels and decreases the lipid peroxidation level (13, 15 and 18 nmol/mg protein), respectively. In vivo ROS levels and degree of cell death were studied using DCFDA and Acridine orange assays. Compounds 1, 7 and 8 decreases the ROS and cell death level significantly. Taken together, compounds 1, 7 and 8 exhibit excellent antioxidant properties, counteract H2 O2 induced oxidative stress, reduces cell death in zebrafish larvae.

Antioxidant and Antidiabetic Activities of Ethanolic Extract of Hibiscus sabdariffa calyx and Stevia rebaudiana Leaf

The prevalence of diabetes mellitus has increased tremendously in developing countries of tropical regions. The need for an effective and safe alternative is of importance as oral hypoglycaemic drugs have reported to cause side effects on prolonged use. In the present study two tropical plants, Hibiscus sabdariffa calyx and Stevia rebaudiana leaves were assessed for their in vitro antioxidant and antidiabetic activities. Total phenol and flavonoids of ethanolic extracts were quantified. Bioactive compounds were screened by Gas Chromatography Mass Spectrometry (GC-MS) analysis. Antioxidant activity was assessed by 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) and superoxide radical scavenging assays. Antidiabetic ability was evaluated by inhibition of enzymes involved in carbohydrate metabolism. Glucose uptake by 3T3-L1 cells was also assessed. Ethanolic extract of Stevia leaf (EtSL) had a higher percentage of phenol and flavonoids. The GCMS analysis showed the presence of phytochemicals like Phenol-2,4-bis (1,1-dimethylethyl) in Roselle calyx and 6-methoxyflavone in Stevia leaves. The antioxidant assessment showed that EtSL significantly inhibited superoxide radical (IC50=45.81±1.21 μg/mL). The antidiabetic assessment revealed that Ethanolic extract of Roselle calyx (EtRC) showed strong inhibition of alpha amylase (IC50=27.95±0.32 μg/mL) and alpha glucosidase (IC50=6.21±0.18 μg/mL). Glucose uptake in 3T3-L1 cells demonstrated that both plants had significant insulin sensitizing ability. It was also revealed that the phenol and flavonoid content strongly correlated with IC50 values of antioxidant and antidiabetic assays. Results of this study show that both plants are a potential source of bioactive phytochemicals and can be used as a plant-based antioxidant and antidiabetic agent.