scholarly journals Studies on biological activities of melanin from marine animals. III. Inhibitory effect of SM II (low molecular weight melanoprotein from squid) on phenylbutazone-induced ulceration in gastric mucosa in rats, and its mechanism of action.

1985 ◽  
Vol 33 (5) ◽  
pp. 2052-2060 ◽  
Author(s):  
TSUTOMU MIMURA ◽  
KAZUHIRO MAEDA ◽  
TAICHIROU TERADA ◽  
YASUO ODA ◽  
KANAE MORISHITA ◽  
...  
1987 ◽  
Vol 58 (04) ◽  
pp. 1068-1072 ◽  
Author(s):  
P Toulon ◽  
J F Vitoux ◽  
C Leroy ◽  
T Lecomte ◽  
M Roncato ◽  
...  

SummaryWe compared in six patients successively treated with an unfractionated heparin (UFH) and a low molecular weight heparin (LMWH) the variations in plasma anti-Xa activity, measured in a chromogenic assay, during a 36 h constant infusion. The values varied in a wider range during UHF infusion, but remained in the therapeutic range except once in one patient. No circadian rhythm could be demonstrated in our six patients. LMWH infusion yielded very constant anti-Xa circulating activities. In both cases, there were no significant modifications of three proteins with high heparin affinity (antithrombin III, heparin cofactor II, histidine-rich glycoprotein).Our results suggest that the circadian rhythm of the biological activities previously observed in patients treated with constant heparin infusion using clotting method is due to other factors than heparin itself.


1993 ◽  
Vol 13 (S 01) ◽  
pp. S5-S11 ◽  
Author(s):  
Debra Hoppensteadt ◽  
Jeanine Walenga ◽  
A Ahsan ◽  
O Iqbal ◽  
W Jeske ◽  
...  

SummaryThe introduction of low molecular weight heparins has added a new dimension to the pharmacological management of thrombotic disorders. Because of different chemical and pharmacological characteristics, due to the manufacturing process, each LMWH should be considered as a distinct entitity and only be used for its given indication. A list of commercially available LMWHs is included. The mechanism of action of the LMWHs and their use in various disorders are discussed. Available laboratory tests for monitoring LMWHs are presented and their limitations pointed out.


Author(s):  
Makoto Ogata

Abstract Carbohydrates play important and diverse roles in the fundamental processes of life. We have established a method for accurately and a large scale synthesis of functional carbohydrates with diverse properties using a unique enzymatic method. Furthermore, various artificial glycan-conjugated molecules have been developed by adding these synthetic carbohydrates to macromolecules and to middle and low molecular weight molecules with different properties. These glycan-conjugated molecules have biological activities comparable to or higher than those of natural compounds, and present unique functions. In this review, several synthetic glycan-conjugated molecules are taken as examples to show design, synthesis and function.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jun Ma ◽  
Xiankun Zeng ◽  
Min Zhou ◽  
Le Cheng ◽  
Difeng Ren

AbstractSpirulina platensis protein hydrolysates were prepared by digesting protein extracts with papain, and the hydrolysates were separated into 30, 10, and 3 kDa weights using membrane ultrafiltration. The 0–3 kDa low-molecular-weight Spirulina peptides (LMWSPs) proved the highest chemical antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, hydroxyl radical (·OH) scavenging activities and total antioxidant capacity. Cellular antioxidant ability of LMWPs fractions against 2000 μg/mL H2O2 induced oxidative damage of L02 cells were investigated. The MTT assay results displayed that LMWSPs at different concentrations (0–1000 μg/mL) had proliferation effect on the L02 cells and that treatment of the L02 cells with the 1000 μg/mL LMWSPs (0–3 kDa) significantly prevented H2O2-induced oxidative damage compared with control cells. Moreover, the 2′,7′-dichlorofluorescein diacetate (DCFH-DA) fluorescent probe assay showed that the levels of ROS and NO were significantly lower in the experimental group that was treated with the peptides for 24 h than in the control group. Furthermore, using the corresponding kits, the treatment inhibited the reduction of SOD activity and the increase of MDA contents in the L02 cells. Therefore, LMWSPs (0–3 kDa) may have potential applications in antioxidant and liver health products.


2015 ◽  
Vol 44 (4) ◽  
pp. 553-565
Author(s):  
J. Legocka ◽  
A. Szweykowska

In detached kohlrabi leaves senescing in the dark, the decrease in chlorophyll to was more pronounced than in chlorophyll a. The retardation by kinetin of the chlorophyll loss was also markedly stronger in the case of chlorophyll b. Using the fractionation of nucleic acids on polyacrylamide gels it has been shown that during leaf senescence the level of all RNA species decreased, whereas the amount of DNA was more or less constant. In the presence of kinetin, the loss of RNA was inhibited and the incorporation of precursor into the cytoplasmic rRNA as well as into low molecular weight RNA species was supported. Chloroplast rRNA synthesis has not been detected in mature leaves and kinetin showed no effect in this respect. In young expanding leaves detached and kept in light, the synthesis of cytoplasmic rRNA was strongly stimulated by kinetin, whereas in the case of Chloroplast rRNA only an inhibitory effect of kinetin could be found. The results suggest that the cytokinins are primarily involved in processes of the synthesis of cytoplasmic rRNA and low molecular RNA fractions, and in this way affect the development of plastids, in particular the course of their senescence.


1993 ◽  
Vol 128 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Nobuyoshi Kokawa ◽  
Mareo Yamoto ◽  
Kenichi Furukawa ◽  
Ryosuke Nakano

We performed partial purification of low molecular weight luteinizing hormone binding inhibitor from porcine follicular fluids and examined its biological activities. Following ultrafiltration, gel filtration and anion exchange of the pooled porcine follicular fluids, low molecular weight fractions (500–10,000 MW) inhibited [125I]hLH binding to porcine granulosa cells in a dose-dependent manner. The binding inhibition kinetics study revealed that the luteinizing hormone binding inhibitor may indicate a non-competitive inhibition with [125I]hLH binding. In vitro bioassay using adult mouse testicular interstitial cells revealed that the partially purified luteinizing hormone binding inhibitor reduced ovine LH-stimulated testosterone and cAMP production in a dose-dependent manner, whereas the luteinizing hormone binding inhibitor did not affect basal production of testosterone and cAMP. The inhibitory activity was heat stable and did not disappear with activated charcoal adsorption. The results of the present study suggest that the luteinizing hormone binding inhibitor may play an important role as an ovarian non-steroidal regulator modulating the receptor binding of LH and LH-mediated steroidogenesis.


Marine Drugs ◽  
2019 ◽  
Vol 17 (7) ◽  
pp. 421 ◽  
Author(s):  
Kiichiro Teruya ◽  
Yoshihiro Kusumoto ◽  
Hiroshi Eto ◽  
Noboru Nakamichi ◽  
Sanetaka Shirahata

Low molecular weight fucoidan extract (LMF), prepared by an abalone glycosidase digestion of a crude fucoidan extracted from Cladosiphon novae-caledoniae Kylin, exhibits various biological activities, including anticancer effect. Various cancers express programmed cell death-ligand 1 (PD-L1), which is known to play a significant role in evasion of the host immune surveillance system. PD-L1 is also expressed in many types of normal cells for self-protection. Previous research has revealed that selective inhibition of PD-L1 expressed in cancer cells is critical for successful cancer eradication. In the present study, we analyzed whether LMF could regulate PD-L1 expression in HT1080 fibrosarcoma cells. Our results demonstrated that LMF suppressed PD-L1/PD-L2 expression and the growth of HT1080 cancer cells and had no effect on the growth of normal TIG-1 cells. Thus, LMF differentially regulates PD-L1 expression in normal and cancer cells and could serve as an alternative complementary agent for treatment of cancers with high PD-L1 expression.


Sign in / Sign up

Export Citation Format

Share Document