The Experts below are selected from a list of 2043 Experts worldwide ranked by ideXlab platform

K Ishida - One of the best experts on this subject based on the ideXlab platform.

  • Drug sensitivity testing for clinical samples from oesophageal cancer using adhesive tumour cell culture system
    British Journal of Cancer, 1996
    Co-Authors: M Terashima, M Fukushima, K Hayashi, T Iizuka, T Kakegawa, N Ando, O Tanaka, M Shinoda, K Isono, K Ishida
    Abstract:

    A total of 83 specimens of surgically resected tumours from 78 patients with oesophageal cancer were assayed for drug sensitivity using an adhesive tumour cell culture system (LifeTrac CSA assay). Seventyone of 83 specimens had a sufficient number of cells to permit growth in culture and 57 of 71 (80%) were evaluable for drug response. Cells (3 x 10(3) ml-1 well-1) were cultured for 14 days and exposed to drugs on days 3-8. Growing cells were confirmed as cancer cells by immunohistochemical staining. IC90 values against several anti-cancer drugs were determined and population distributions of IC90 for each drug served as the basis for judging sensitivity. The 10th percentiles of IC90 (microgram ml-1) for CDDP, 5-FU, DOX, CPM, MTX, VP16, IFOS, VDS, BLM and CDDP + 5-FU were 0.3, 0.16, 0.005, 0.9, 0.006, 0.09, 0.8, 0.006, 0.04 and 0.15 + 0.09 respectively. The population distribution of IC90 against each drug showed a specific pattern that was very similar among histopathological gradings and stages of the disease. This system appeared to be a clinically applicable drug sensitivity test for human oesophageal cancer.

Harald Noedl - One of the best experts on this subject based on the ideXlab platform.

  • In vitro antimalarial drug resistance in Southeastern Bangladesh
    Wiener klinische Wochenschrift, 2020
    Co-Authors: Bernhard Attlmayr, Kamala Thriemer, Rashidul Haque, Yukiko Wagatsuma, Mohammed Abdus Salam, Selim Akhter, Mark Fukuda, Kurt Schaecher, Robert Scott Miller, Harald Noedl
    Abstract:

    Particularly in Southeast Asia drug resistance has become a major constraint in the treatment of falciparum malaria. So far relatively little is known about the current status of drug resistance in Bangladesh. The aim of this study was therefore to determine the in vitro drug susceptibility of Plasmodium falciparum in south-eastern Bangladesh. In the HRP2 in vitro drug sensitivity assay the tested isolates demonstrated a relatively high sensitivity to dihydroartemisinine (IC50 = 1.33 nM; 95% CI: 1.08-1.63; IC90 = 2.65 nM; 95% CI: 2.13-3.29), mefloquine (IC50 = 11.26 nM, 95% CI: 9.75-13.0; IC90 = 19.55 nM, 95% CI: 15.73-24.29) and quinine (IC50 = 73.24 nM, 95% CI: 65.26-82.21; IC90 = 157.75 nM, (95% CI: 134.16-185.5) thus being significantly more sensitive to mefloquine and quinine than isolates from Thailand. Chloroquine (IC50 = 93.06 nM, 95% CI: 80.38-107.76; IC90 = 214.76 nM, 95% CI: 175.64-262.62) sensitivity was highly compromised with inhibitory concentrations reaching levels comparable to Thailand. Therefore this drug should not be used in the treatment of falciparum malaria in this region. Despite compromised in vitro drug sensitivity to sulfadoxine/pyrimethamine, in clinical studies the combination of sulfadoxine (IC50 = 40.46 microM, 95% CI: 31.15-51.97; IC90 = 173.48 microM, 95% CI: 120.78-249.17) and pyrimethamine (IC50 = 1.7 microM, 95% CI: 1.25-2.3; IC90 = 4.83 microM, 95% CI: 3.17-7.37) with quinine proved to be an interesting option for treating uncomplicated falciparum malaria in Bangladesh.

  • In vitro antimalarial drug resistance in Southeastern Bangladesh
    Wiener Klinische Wochenschrift, 2020
    Co-Authors: Bernhard Attlmayr, Kamala Thriemer, Rashidul Haque, Yukiko Wagatsuma, Selim Akhter, Kurt Schaecher, Robert Scott Miller, Mohammed Abdus Salam, Mark M. Fukuda, Harald Noedl
    Abstract:

    Die effektive Behandlung der Malaria tropica wird vor allem in Sudostasien durch Medikamentenresistenzen zunehmend erschwert. Uber den genauen Resistenzstatus in Bangladesch ist jedoch bisher nur wenig bekannt. Ziel der vorliegenden Studie war daher die Bestimmung der in vitro Sensibilitat von Plasmodium falciparum im Sudosten von Bangladesch, unweit der Grenze zu Myanmar. Die Medikamente Dihydroartemisinin (IC50 = 1,33 nM; 95% CI: 1,08–1,63; IC90 = 2,65 nM; 95% CI: 2,13–3,29), Mefloquin (IC50 = 11,26 nM, 95% CI: 9,75–13,0; IC90 = 19,55 nM, 95% CI: 15,73–24,29) und Chinin (IC50 = 73,24 nM, 95% CI: 65,26–82,21; IC90 = 157,75 nM, 95% CI: 134,16–185,5) zeigten im HRP2 in vitro Medikamentensensibilitatstest dabei adaquate, im Falle von Mefloquin und Chinin sogar eine deutlich bessere Wirksamkeit als in Thailand. Bei Chloroquin (IC50 = 93,06 nM, 95% CI: 80,38–107,76; IC90 = 214,76 nM, 95% CI: 175,64–262,62) fanden sich dagegen ausgepragte Resistenzen, vergleichbar jenen in Thailand, die eine weitere sinnvolle Verwendung von Chloroquin in der Therapie der falciparum Malaria in dieser Region ausschliesen. Trotz offensichtlich verminderter Empfindlichkeit gegenuber Sulfadoxin/Pyrimethamin erwies sich in parallel durchgefuhrten klinischen Untersuchungen die Kombination von Sulfadoxin (IC50 = 40,46 µM, 95% CI: 31,15–51,97; IC90 = 173,48 µM, 95% CI: 120,78–249,17) und Pyrimethamin (IC50 = 1,7 µM, 95% CI: 1,25–2,3; IC90 = 4,83 µM, 95% CI: 3,17–7,37) mit Chinin als interessante Alternative fur die orale Therapie der unkomplizierten falciparum Malaria in Bangladesch.

  • Untersuchungen zur in vitro Arzneimittelresistenz bei Malaria tropica in Bangladesch
    Wiener klinische Wochenschrift, 2006
    Co-Authors: Bernhard Attlmayr, Kamala Thriemer, Rashidul Haque, Yukiko Wagatsuma, Mohammed Abdus Salam, Selim Akhter, Mark Fukuda, Kurt Schaecher, Robert Scott Miller, Harald Noedl
    Abstract:

    Particularly in Southeast Asia drug resistance has become a major constraint in the treatment of falciparum malaria. So far relatively little is known about the current status of drug resistance in Bangladesh. The aim of this study was therefore to determine the in vitro drug susceptibility of Plasmodium falciparum in south-eastern Bangladesh. In the HRP2 in vitro drug sensitivity assay the tested isolates demonstrated a relatively high sensitivity to dihydroartemisinine (IC50 = 1.33 nM; 95% CI: 1.08–1.63; IC90 = 2.65 nM; 95% CI: 2.13–3.29), mefloquine (IC50 = 11.26 nM, 95% CI: 9.75–13.0; IC90 = 19.55 nM, 95% CI: 15.73–24.29) and quinine (IC50 = 73.24 nM, 95% CI: 65.26–82.21; IC90 = 157.75 nM, (95% CI: 134.16–185.5) thus being significantly more sensitive to mefloquine and quinine than isolates from Thailand. Chloroquine (IC50 = 93.06 nM, 95% CI: 80.38–107.76; IC90 = 214.76 nM, 95% CI: 175.64–262.62) sensitivity was highly compromised with inhibitory concentrations reaching levels comparable to Thailand. Therefore this drug should not be used in the treatment of falciparum malaria in this region. Despite compromised in vitro drug sensitivity to sulfadoxine/pyrimethamine, in clinical studies the combination of sulfadoxine (IC50 = 40.46 µM, 95% CI: 31.15–51.97; IC90 = 173.48 µM, 95% CI: 120.78–249.17) and pyrimethamine (IC50 = 1.7 µM, 95% CI: 1.25–2.3; IC90 = 4.83 µM, 95% CI: 3.17–7.37) with quinine proved to be an interesting option for treating uncomplicated falciparum malaria in Bangladesh. Die effektive Behandlung der Malaria tropica wird vor allem in Südostasien durch Medikamentenresistenzen zunehmend erschwert. Über den genauen Resistenzstatus in Bangladesch ist jedoch bisher nur wenig bekannt. Ziel der vorliegenden Studie war daher die Bestimmung der in vitro Sensibilität von Plasmodium falciparum im Südosten von Bangladesch, unweit der Grenze zu Myanmar. Die Medikamente Dihydroartemisinin (IC50 = 1,33 nM; 95% CI: 1,08–1,63; IC90 = 2,65 nM; 95% CI: 2,13–3,29), Mefloquin (IC50 = 11,26 nM, 95% CI: 9,75–13,0; IC90 = 19,55 nM, 95% CI: 15,73–24,29) und Chinin (IC50 = 73,24 nM, 95% CI: 65,26–82,21; IC90 = 157,75 nM, 95% CI: 134,16–185,5) zeigten im HRP2 in vitro Medikamentensensibilitätstest dabei adäquate, im Falle von Mefloquin und Chinin sogar eine deutlich bessere Wirksamkeit als in Thailand. Bei Chloroquin (IC50 = 93,06 nM, 95% CI: 80,38–107,76; IC90 = 214,76 nM, 95% CI: 175,64–262,62) fanden sich dagegen ausgeprägte Resistenzen, vergleichbar jenen in Thailand, die eine weitere sinnvolle Verwendung von Chloroquin in der Therapie der falciparum Malaria in dieser Region ausschließen. Trotz offensichtlich verminderter Empfindlichkeit gegenüber Sulfadoxin/Pyrimethamin erwies sich in parallel durchgeführten klinischen Untersuchungen die Kombination von Sulfadoxin (IC50 = 40,46 µM, 95% CI: 31,15–51,97; IC90 = 173,48 µM, 95% CI: 120,78–249,17) und Pyrimethamin (IC50 = 1,7 µM, 95% CI: 1,25–2,3; IC90 = 4,83 µM, 95% CI: 3,17–7,37) mit Chinin als interessante Alternative für die orale Therapie der unkomplizierten falciparum Malaria in Bangladesch.

  • In vitro susceptibility of Plasmodium falciparum isolates from Myanmar to antimalarial drugs.
    American Journal of Tropical Medicine and Hygiene, 2001
    Co-Authors: Chansuda Wongsrichanalai, Harald Noedl, Lorrin W. Pang, M A Faiz, Theera Wimonwattrawatee, Anintita Laoboonchai, Fumihiko Kawamoto
    Abstract:

    In vitro drug susceptibility profiles were assessed in 75 Plasmodium falciparumisolates from 4 sites in Myanmar. Except at Mawlamyine, the site closest to the Thai border, prevalence and degree of resistance to mefloquine were lower among the Myanmar isolates as compared with those from Thailand. Geometric mean concentration that inhibits 50% (IC50) and 90% (IC90) of Mawlamyine isolates were 51 nM (95% confidence interval (CI), 40-65) and 124 nM (95% CI, 104-149), respectively. At the nearest Thai site, Maesod, known for high-level multidrug resistance, the corresponding values for mefloquine IC 50 and IC90 were 92 nM (95% CI, 71-121) and 172 nM (95% CI, 140- 211). Mefloquine susceptibility of P. falciparum in Myanmar, except for Mawlamyine, was consistent with clinical- parasitological efficacy in semi-immune people. High sensitivity to artemisinin compounds was observed in this geographical region. The data suggest that highly mefloquine-resistant P. falciparum is concentrated in a part of the Thai-Myanmar border region.

Ralph E. Parchment - One of the best experts on this subject based on the ideXlab platform.

  • Human CD34(+) progenitor hematopoiesis in liquid culture for in vitro assessment of drug-induced myelotoxicity.
    Toxicology in Vitro, 2015
    Co-Authors: John Hamre, Myrtle Davis, Ralph E. Parchment
    Abstract:

    Abstract Utilization of validated CFU-GM assays for myelotoxicity screening is hampered by its labor-intensive and low-throughput nature. Herein, we transformed the defined CFU-GM assay conditions and IC90 endpoint into a higher throughput format. Human CD34+ hematopoietic progenitors were cultured in a 96-well plate for 14 days with the same cytokine (rhGM-CSF) used in the CFU-GM assay. Expansion and differentiation toward myeloid lineages were manifested by characteristic changes in nuclear and cytoplasmic morphology and by temporal expression patterns of CD34, CD11b and CD13 markers. Inhibition of CD34+ cell myelopoiesis by 12 anticancer drugs known to induce myelotoxicity in the clinic was quantifiable using either general cytotoxicity endpoints (cell growth area or total nucleus count) or lineage specific readouts (count of cells expressing CD11b and/or CD13). The IC50 and IC90 values derived from the concentration-response curves of 14-day drug exposure in CD34+ cell culture were highly correlated with those from the international validation study of the CFU-GM assay, demonstrating capability to assess general cytotoxicity, cell proliferation and myelopoiesis simultaneously. These results suggest that this human CD34+ hematopoietic progenitor cell assay can be used as a direct replacement for the validated, low throughput CFU-GM assay, and could expand application of in vitro myelotoxicity testing.

  • application of the cfu gm assay to predict acute drug induced neutropenia an international blind trial to validate a prediction model for the maximum tolerated dose mtd of myelosuppressive xenobiotics
    Toxicological Sciences, 2003
    Co-Authors: Augusto Pessina, Silvia Casati, B Albella, Maria Bayo, Juan A Bueren, P Brantom, C Croera, G Gagliardi, P Foti, Ralph E. Parchment
    Abstract:

    Abstract In a previous study of prevalidation, a standard operating procedure (SOP) for two independent in vitro tests (human and mouse) had been developed, to evaluate the potential hematotoxicity of xenobiotics from their direct and the adverse effects on granulocyte-macrophages (CFU-GM). A predictive model to calculate the human maximum tolerated dose (MTD) was set up, by adjusting a mouse-derived MTD for the differential interspecies sensitivity. In this paper, we describe an international blind trial designed to apply this model to the clinical neutropenia, by testing 20 drugs, including 14 antineoplastics (Cytosar-U, 5-Fluorouracil, Myleran, Thioguanine, Fludarabine, Bleomycin, Methotrexate, Gemcitabine, Carmustine, Etoposide, Teniposide, Cytoxan, Taxol, Adriamycin); two antivirals (Retrovir, Zovirax,); three drugs for other therapeutic indications (Cyclosporin, Thorazine, Indocin); and one pesticide (Lindane). The results confirmed that the SOP developed generates reproducible IC90 values with both human and murine GM-CFU. For 10 drugs (Adriamycin, Bleomycin, Etoposide, Fludarabine, 5-Fluorouracil, Myleran, Taxol, Teniposide, Thioguanine, and Thorazine), IC90 values were found within the range of the actual drug doses tested (defined as the actual IC90). For the other 10 drugs (Carmustine, Cyclosporin, Cytosar-U, Cytoxan, Gemcitabine, Indocin, Lindane, Methotrexate, Retrovir, and Zovirax) extrapolation on the regression curve out of the range of the actual doses tested was required to derive IC90 values (extrapolated IC90). The model correctly predicted the human MTD for 10 drugs out of 10 that had "actual IC90 values" and 7 drugs out of 10 for those having only an extrapolated IC90. Two of the incorrect predictions (Gemcitabine and Zovirax) were within 6-fold of the correct MTD, instead of the 4-fold range required by the model, whereas the prediction with Cytosar-U was approximately 10-fold in error. A possible explanation for the failure in the prediction of these three drugs, which are pyrimidine analogs, is discussed. We concluded that our model correctly predicted the human MTD for 20 drugs out of 23, since the other three drugs (Topotecan, PZA, and Flavopiridol) were tested in the prevalidation study. The high percentage of predicitivity (87%), as well as the reproducibility of the SOP testing, confirm that the model can be considered scientifically validated in this study, suggesting promising applications to other areas of research in developing validated hematotoxicological in vitro methods.

  • Differential toxicity of camptothecin, topotecan and 9-aminocamptothecin to human, canine, and murine myeloid progenitors (CFU-GM) in vitro
    Cancer Chemotherapy and Pharmacology, 1997
    Co-Authors: Connie L. Erickson-miller, Joseph E. Tomaszewski, Blaire Osborn, Martin J. Murphy, John G. Page, Ralph E. Parchment
    Abstract:

    Purpose: 20(S)-Camptothecin (CAM), topotecan (TPT, active ingredient in Hycamtin) and 9-amino-20(S)-camptothecin (9AC) are topoisomerase I inhibitors that cause similar dose-limiting toxicities to rapidly renewing tissues, such as hematopoietic tissues, in humans, mice, and dogs. However, dose-limiting toxicity occurs at tenfold lower doses in humans than in mice. The purpose of the current study was to determine whether hematopoietic progenitors of the myeloid lineage from humans, mice, and dogs exhibit the differential sensitivity to these compounds that is evident in vivo. Methods: Drug-induced inhibition of in vitro colony formation by a myeloid progenitor in human, murine, and canine marrow colony-forming unit-granulocyte/macrophage (CFU-GM) provided the basis for interspecies comparisons at concentrations which inhibited colony formation by 50% (IC50) and 90% (IC90). Results: Murine IC90 values were 2.6-, 2.3-, 10-, 21-, 5.9-, and 11-fold higher than human values for CAM lactone (NSC-94600) and sodium salt (NSC-100880), TPT (NSC-609699), and racemic (NSC-629971), semisynthetic and synthetic preparations (NSC-603071) of 9AC, respectively. In contrast, canine IC90 values were the same as, or lower than, the human IC90 values for all six compounds. Conclusions: The greater susceptibility of humans and dogs to the myelotoxicity of camptothecins, compared to mice, was evident in vitro at the cellular level. Differential sensitivity between murine and human myeloid progenitors explains why the curative doses of TPT and 9AC in mice with human tumor xenografts are not achievable in patients. Realizing the curative potential of these compounds in humans will require the development of therapies to increase drug tolerance of human CFU-GM at least to a level equal to that of murine CFU-GM. Because these interspecies differences are complicated by species-specific effects of plasma proteins on drug stability, not all in vitro assay conditions will yield results which can contribute to the development of such therapies.

Aiqian Zhang - One of the best experts on this subject based on the ideXlab platform.

  • synergistic effects of perfluoroalkyl acids mixtures with j shaped concentration responses on viability of a human liver cell line
    Chemosphere, 2014
    Co-Authors: Jiayue Hu, Jianshe Wang, Juan Li, Aiqian Zhang
    Abstract:

    Some perfluoroalkyl acids (PFAAs) are highly persistent and bioaccumulative, resulting in their broad coexisting distribution in humans and the environment. Our aim was to investigate the individual and joint effects of PFAAs on cellular viability of a human liver cell line (HL-7702) using the MTT assay. Equipartition ray design and equivalent-effect concentration ratio (EECR) mixtures were used to investigate the binary and multiple effects of PFAAs, respectively. All tested PFAAs mixtures and the individuals (except perfluorododecanoic acid (PFDoDA) and perfluorotetradecanoic acid (PFTeDA)) showed obvious non-monotonic J-shaped concentration–response curves (CRC) on HL-7702. The inhibitory effect of individual PFAAs increased with the elongation of the carbon chain and was dominated by their molecular volume. The three binary mixtures (PFOA/S, PFHxA/S and PFBA/S) showed that synergistic effects occurred under effective inhibitory concentrations (IC) of IC0, IC10, and IC50 in mixtures, while for IC−20 the synergistic effect only occurred under higher PFSA proportion in mixtures. Furthermore, EECR mixtures of the nine individual PFAAs with J-shaped CRC also showed synergistic effects. However, mixtures of the eleven individual PFAAs including those with S-shaped CRC resulted in partial addition effects on HL-7702. Our results indicated that the individual stimulatory responses of HL-7702 to PFAA may produce adverse effects in mixtures at relevant dose levels.

  • Synergistic effects of perfluoroalkyl acids mixtures with J-shaped concentration–responses on viability of a human liver cell line
    Chemosphere, 2013
    Co-Authors: Jiayue Hu, Jianshe Wang, Juan Li, Aiqian Zhang
    Abstract:

    Some perfluoroalkyl acids (PFAAs) are highly persistent and bioaccumulative, resulting in their broad coexisting distribution in humans and the environment. Our aim was to investigate the individual and joint effects of PFAAs on cellular viability of a human liver cell line (HL-7702) using the MTT assay. Equipartition ray design and equivalent-effect concentration ratio (EECR) mixtures were used to investigate the binary and multiple effects of PFAAs, respectively. All tested PFAAs mixtures and the individuals (except perfluorododecanoic acid (PFDoDA) and perfluorotetradecanoic acid (PFTeDA)) showed obvious non-monotonic J-shaped concentration–response curves (CRC) on HL-7702. The inhibitory effect of individual PFAAs increased with the elongation of the carbon chain and was dominated by their molecular volume. The three binary mixtures (PFOA/S, PFHxA/S and PFBA/S) showed that synergistic effects occurred under effective inhibitory concentrations (IC) of IC0, IC10, and IC50 in mixtures, while for IC−20 the synergistic effect only occurred under higher PFSA proportion in mixtures. Furthermore, EECR mixtures of the nine individual PFAAs with J-shaped CRC also showed synergistic effects. However, mixtures of the eleven individual PFAAs including those with S-shaped CRC resulted in partial addition effects on HL-7702. Our results indicated that the individual stimulatory responses of HL-7702 to PFAA may produce adverse effects in mixtures at relevant dose levels.

Kajal Chakraborty - One of the best experts on this subject based on the ideXlab platform.

  • Pharmacological potential of sulfatedpolygalactopyranosyl-fucopyranan from the brownseaweed Sargassum wightii
    2020
    Co-Authors: M Anusree, Kajal Chakraborty
    Abstract:

    A sulfated polygalactopyranosyl-fucopyranan characterized as ∙∙∙∙→1)-α-Fucp-(2SO3 −)-(3→1)-α-Fucp-(2SO3 −)-(4→1)-β- Galp-(4→1)-β-Galp-(4→∙∙∙∙ was isolated from the brown seaweed Sargassum wightii and evaluated for pharmacological properties with reference to antioxidant, anti-inflammatory, antidiabetic, and antihypertensive activities using different in vitro models. The sulfated polygalactopyranosyl-fucopyranan displayed potential di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) radical scavenging, and Fe2+ ion chelating activities (IC90 ~ 1 mg mL−1). The studied polysaccharide displayed higher anti-inflammatory selectivity towards inducive proinflammatory enzyme cyclooxygenase-2 (COX-2, IC90 1.13 mg mL−1) than constitutive cyclooxygenase-1 (COX-1, IC90 > 1.20 mg mL−1) resulting in greater selectivity index (IC90 COX-2/COX-1, 0.93) than synthetic non-steroidal anti-inflammatory drug aspirin (0.88) and also showed potent lipoxygenase-5 inhibition (LOX-5, IC90 1.02 mg mL−1). The studied polysaccharide displayed significantly higher (P < 0.05) antidiabetic properties compared to the antidiabetic agents acarbose and diprotein-A in terms of α-amylase (IC90 0.93 mg mL−1), α-glucosidase (IC90 1.48 mg mL−1), and dipeptidyl peptidase-4 (IC90 0.11 mg mL−1) enzyme inhibition potentials. The sulfated polygalactopyranosyl-fucopyranan also displayed potential antihypertensive activity with reference to angiotensin-converting enzyme-I inhibitory activity (IC90 0.2 mg mL−1). Extensive spectroscopic experiments in conjugation with monosaccharide compositional analysis attributed (1→3)-linked α-fucopyranose units in the polygalactofucan chain with C-2 sulfation and C-4 substituents as O-acetyl/O-methyl/(1→4)-linked β-galactopyranose. The previously undescribed sulfated polygalactopyranosyl-fucopyranan could function as a potential pharmacophore lead against inflammation, type 2 diabetics, hypertension and utilization as natural antioxidant.

  • Pharmacological potential of sulfated polygalactopyranosyl-fucopyranan from the brown seaweed Sargassum wightii
    Journal of Applied Phycology, 2018
    Co-Authors: Anusree Maneesh, Kajal Chakraborty
    Abstract:

    A sulfated polygalactopyranosyl-fucopyranan characterized as ∙∙∙∙ → 1)-α-Fucp-(2SO3−)-(3 → 1)-α-Fucp-(2SO3−)-(4 → 1)-β-Galp-(4 → 1)-β-Galp-(4 → ∙∙∙∙ was isolated from the brown seaweed Sargassum wightii and evaluated for pharmacological properties with reference to antioxidant, anti-inflammatory, antidiabetic, and antihypertensive activities using different in vitro models. The sulfated polygalactopyranosyl-fucopyranan displayed potential di(phenyl)-(2,4,6-trinitrophenyl) iminoazanium (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) radical scavenging, and Fe2+ ion chelating activities (IC90 ~ 1 mg mL−1). The studied polysaccharide displayed higher anti-inflammatory selectivity towards inducive pro-inflammatory enzyme cyclooxygenase-2 (COX-2, IC90 1.13 mg mL−1) than constitutive cyclooxygenase-1 (COX-1, IC90 > 1.20 mg mL−1) resulting in greater selectivity index (IC90 COX-2/COX-1, 0.93) than synthetic non-steroidal anti-inflammatory drug aspirin (0.88) and also showed potent lipoxygenase-5 inhibition (LOX-5, IC90 1.02 mg mL−1). The studied polysaccharide displayed significantly higher (P 

  • Antioxidative sulphated polygalactans from marine macroalgae as angiotensin-I converting enzyme inhibitors.
    Natural Product Research, 2017
    Co-Authors: Fasina Makkar, Kajal Chakraborty
    Abstract:

    AbstractAntioxidant and antihypertensive potential of the sulphated polygalactans isolated from the marine macroalgae Kappaphycus alvarezii and Gracilaria opuntia were assessed by utilising different in vitro systems. The galactans isolated from K. alvarezii possessed significantly greater antioxidative properties as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH IC90 0.97 mg/mL) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS.+ IC90 0.72 mg/mL) scavenging activities than those isolated from G. opuntia (DPPH IC90 1.2 mg/mL and ABTS 0.86 mg/mL). The sulphated polygalactan →4)-4-O-sulphonato-(2-O-methyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-methyl)-α-D-galactopyranan from K. alvarezii showed greater angiotensin-I-converting enzyme (ACE) inhibitory activity (IC50 0.02 μg/mL) than →3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulphonato)-α-D-galactopyranosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-xylosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyran...

  • Angiotensin-I Converting Enzyme Inhibitory Activities of Common Edible Cephalopods and their Antioxidative Effects using different in vitro Models
    Journal of Food Biochemistry, 2016
    Co-Authors: Kajal Chakraborty, Vamshi Krishna Raola, Fasina Makkar
    Abstract:

    Antioxidant and antihypertensive potential of ethyl acetate-methanol (EtOAc-MeOH) extract of cephalopods, Amphioctopus marginatus, Uroteuthis duvaucelii, Sepia pharaonis, Sepiella inermis and Cistopus indicus were evaluated using different in vitro systems. EtOAc-MeOH fractions of S. inermis, A. marinates and C. indicus showed greater ferrous ion chelating ability (IC90 5.01–5.8 mg/mL), and were effective in neutralizing the ABTS (IC90 3.5–4.01 mg/mL), and DPPH radicals (IC90 4.69–5.8 mg/mL). The utilities of deconvolated 1H and 13C-NMR spectroscopy for analyzing the signature peaks and abundance of bioactive functional groups in the extracts of cephalopods were illustrated. The EtOAc-MeOH extract derived from S. inermis showed greater angiotensin-converting enzyme-I (ACE-I) inhibitory activity (IC90 0.45 mg/mL) than other cephalopods (IC90 > 0.50 mg/mL). A significant colinearity was found between the electronegative groups present in the downfield position of NMR spectra vis-a-vis antioxidative and ACE-inhibitory activities of EtOAc-MeOH extracts from C. indicus and S. inermis.