Browsing by Author "S.K. Trigun"

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Alterations in the sensitivity to endogenous proteolysis due to storage of fructose-1,6-bisphosphatase extracts of liver and muscle of young and old rats.
(1987) S.K. Trigun; S.N. Singh
The sensitivity of fructose-1,6-bisphosphatase (FBPase: EC 3.1.3.11) to endogenous proteolysis was studied in liver and muscle extracts of young (28 weeks) and old (97 weeks) rats (stored at 4 degrees +/- 2 degrees C) by monitoring the alterations in its properties. Apart from the level of total enzyme activity, decrease in activity ratio (at pH 7.0/9.2) and sensitivity to AMP inhibition no age-dependent significant change was found during storage of the liver extract. However, a more significant increase in activity, comparatively less decrease in activity ratio, and retention of sensitivity to AMP inhibition were observed during the storage of muscle enzyme extract from old rats than from young rats. Using gel electrophoresis, an extra degradative active product was observed in all samples except those of old rat muscle. These results may indicate tissue-specific alterations in the susceptibility of FBPase to endogenous proteolysis during old age in the rat.
Anti-HIV and cytotoxic ruthenium(II) complexes containing flavones: Biochemical evaluation in mice
(2004) L. Mishra; A.K. Singh; S.K. Trigun; S.K. Singh; S.M. Pandey
Ru(II) polypyridyl complexes containing 3-hydroxyflavone derivatives as coligands were screened for anti-HIV and cytotoxic activities against eleven tumor cell lines. In order to check the effect of flavones containing Ru(II) complexes in vivo on a mammal, a representative complex Ru(L) 2(DMSO)2.5H2O (LH-3-Hdroxy-4′- benzyloxyflavone; M5) was orally administered to adult male mice. Its effects on protein content and LDH were studied in different tissues of the animal. The compound got absorbed and retained in the blood between 1-3 hr after feeding. As compared to the normal and DMSO control sets, tissue specific significant reversible changes in the protein content as well as in LDH activity were observed between 1-4 hr of treatment. However, on polyacrylamide gel electrophoresis, except some tissue specific transitory alterations, expression patterns of five LDH isozymes were unchanged after feeding the compound. The present results suggested that in addition to its potent cytotoxic and anti-HIV effects on cell lines in vitro, M5 inhibited LDH activity, but reversibly with a little effect on biosynthetic status of the enzyme in mice.
Assesment of bioactivity of a Fischerella species colonizing Azadirachta indica (neem) bark
(Corvinus University of Budapest, 2006) S.K. Trigun; A.P. Singh; R.K. Asthana; S.M. Pandey; P. Pandey; S.K. Singh; S.P. Singh
In order to investigate whether a. Fischerella sp. colonizing Azadirachta indica (neem) bark is able to show, like neem derived extracts/products, bioactivity with respect to glucose metabolizing potential in animal models, laboratory cultivated neem colonized cyanobacterial biomass was fed to mice and its effects on liver lactate dehydrogenase (LDH: a key enzyme of glucose metabolism) vis a vis blood glucose level was monitored. Neem bark extract and purified azadirachtin (a bioactive neem product) were also tested simultaneously for comparison. As compared to the control, none of the samples could produce much variation in blood glucose levels except a transitory decline, 34% and 26% at 2nd & 12th h, in azadirachtin and Fischerella (isolated from neem) fed mice respectively. However, all the test samples showed significant increase in liver LDH activity after 2nd h of treatment (p< 0.01) followed by a decline at 6th h. Thereafter, the enzyme activity increased progressively up to 24th h in mice fed with azadirachtin and neem colonized Fischerella only (p < 0.001 at 24th h). Expression pattern of the enzyme was also studied using polyacrylamide gel electrophoresis. Liver specific M4-LDH (homo-tetramer of M sub-unit) was detected in all the cases and time-dependent changes in expression of the enzyme paralleled the alterations observed in its activities. To ascertain whether such a bioactivity is common with Fischerella sp. colonizing other trees also, liver LDH profile was compared between mice fed with Fischerella isolated from neem and jamun (Eugenia jambolana) barks separately. Though Fischerella from jamun did not alter liver LDH profile, Fischerella isolated from neem could produce significant increase in the enzyme activity (p < 0.001) and corresponding changes in the expression of LDH isozymes. The results suggest that Fischerella sp. inhabiting neem bark, like bioactivity of its host plant products, modulates activity and expression of liver LDH in mice. © 2005, Penkala Bt.
Changes in the modulations of kinetics and allosteric properties of muscle phosphofructokinase of young and old rats
(1988) S.K. Trigun; S.N. Singh
In vitro studies on various modulations in kinetics and allosteric properties of muscle phosphofructokinase (EC 2.7.1.11) were undertaken, using purified enzyme from young (25-weeks) and old (100-weeks) albino rats. In comparison to normal K0.5 values for fructose-6-phosphate, increase in this value in response to ATP and citrate inhibition, decrease in K0.5 due to AMP activation and extent of ATP inhibition with increase in pH, were observed to be decreased more markedly with the enzyme of old than with that of young rats. Extent of citrate inhibition, reversals of ATP and citrate effects in response to AMP activation, and synergism of citrate and ATP inhibitions were also seen to be decreased considerably with muscle PFK of old in comparison to that of young rats. Such age-related changes in muscle PFK suggest the alterations in allosteric regulation of this enzyme during aging of the animal. © 1988.
Comparison of the molecular properties of muscle phosphofructokinase of young and old rats
(1988) S.K. Trigun; S.N. Singh
[No abstract available]
Developing brain of moderately hypothyroid mice shows adaptive changes in the key enzymes of glucose metabolism
(2005) P. Pandey; S.K. Singh; S.K. Trigun
This study was undertaken to investigate whether the developing brain adapts at biochemical level against neonatal hypothyroidism, as it does so against a variety of physiological disturbances. A moderate hypothyroid state in mice neonates was induced by supplementing 0.05% methimazole in drinking water to the mothers up to suckling period, and its effect on concerted development of the enzymes regulating metabolic channeling of glucose vis a vis glucose phosphorylating activity were studied. In the brain of control mice, the activity of glucose-6-phosphate dehydrogenase (G6PDH), that channels glucose in biosynthetic route (Pentose phosphate pathway, PPP), increased slightly (∼ 1.3 times) from day1 to 10w age. However, glucose phosphorylating activity and the enzymes that commit glucose for energy production, viz phosphofructokinase1 (PFK1), pyruvate kinase (PK) and lactate dehydrogenase (LDH) showed a progressive postnatal increase to attain their respective adult levels (∼ 5-10 times higher than 1day value) by 3-10w ages of mice. In comparison to the control, in the brain of age matched neonatal hypothyroid mice, glucose phosphorylating activity, G6PDH and PFK1 increased significantly (p<0.001) at day1. Thereafter, though, glucose phosphorylating activity continued to increase up to 1w age and remained static thereafter, G6PDH declined significantly (p<0.001) from 1w onward ages. On the other hand, as PFK1 activity increased significantly up to 10w age (p<0.001), the ratio of G6PDH/PFK1 showed a marked decline from 1w onward ages. PK and LDH also showed increasing trend up to 3w age in the brain of hypothyroid mice pups. The results suggest that a moderate hypothyroid state, during the period of rapid brain growth (day 1-1w age), stimulates all the enzymes that regulate channeling of glucose in both, the energy yielding and biosynthetic paths. However, the later postnatal ages, it modulates these enzymes in a metabolic path dependent manner. © Universitätsverlag Ulm GmbH 2004.
Evidence for tissue specific alterations in Zn2+-induced conformational changes in fructose-bisphosphatase of senescent rats
(1989) S.K. Trigun; S.N. Singh
In vitro studies on Zn2+-induced modulations in certain allosteric control of fructose-1,6-bisphosphatase (FBPase: EC 3.1.3.11), isolated from liver and muscle of 28- and 97-wk old rats were carried out in parallel. Similar Chromatographic elution on ion-exchanger and electrophoretic mobility on polyacrylamide gels revealed similarity in charge and molecular size of the enzyme proteins from the two ages of rats. Regarding Zn2+ induced modulations, almost all the parameters used did not show any age-dependent significant alteration with liver enzyme. However, in case of muscle PBPase, apart from a significant increase in Ki for ZnCl2, Zn+-induced modulations in substrate affinity and AMP inhibition were observed to be altered markedly with the enzyme of 97-wk-old rats in comparison to that of 28-wk- old rats. Thus, it suggests age-associated alterations in Zn2+-mediated conformational modification in the muscle enzyme. This has been further supported by tissue-specific usual pattern of substrate affinity in the absence of Zn+ and exhibition of normal AMP inhibition after replacement of Zn2+ by EDTA. Such age-dependent changes induced by Zn+ in muscle FBPase may be of high physiological significance with advancing age of the animal. © 1989.
Low grade cirrhosis induces cognitive impairment and motor dysfunction in rats: Could be a model for minimal hepatic encephalopathy
(Elsevier Ireland Ltd, 2014) Santosh Singh; S.K. Trigun
Hepatic encephalopathy (HE) is a nervous system disorder developed in the patients with liver cirrhosis. The low grade cirrhosis is of common occurrence, however, whether and the extent to which it affects brain function is not clearly understood. The present article examines certain neurobehavioral parameters in the rats with low grade chronic liver failure (CLF) induced by intraperitoneal administration of 50. mg/kg. b.w. thioacetamide up to 14 days. During Morris Water Maze tasks, the CLF rats, as compared to the control, showed insignificant decline in the escape latency score to find out the hidden platform throughout the learning days and also stayed for a significantly declined (p<. 0.01) time period at the place of the hidden platform during the retrieval test. They also showed impairment in the conditional discrimination ability, reflected by a significant decline in the active avoidance score (p<. 0.05) and increment in the number of non-response (p<. 0.05) during shuttle box tests. On rotarod performance, they exhibited significant decline in their riding time (p<. 0.01-001) on the rotating rod as a function of increasing speed. The findings suggest a moderate level cognitive impairment and motor dysfunction in the low grade CLF rats. Since, these impairments correlate with the early stage manifestation of HE in the patients, these CLF rats could serve as a model to study the pathogenesis of minimal hepatic encephalopathy. © 2013 Elsevier Ireland Ltd.
One pot synthesis of Cu(II) 2,2′-bipyridyl complexes of 5-hydroxy-hydurilic acid and alloxanic acid: Synthesis, crystal structure, chemical nuclease activity and cytotoxicity
(2011) Namrata Dixit; R.K. Koiri; B.K. Maurya; S.K. Trigun; Claudia Höbartner; Lallan Mishra
A barbiturate derivative [1,5-dihydro-5-[5-pyrimidine-2,4(1H,3H)-dionyl]- 2H-chromeno[2,3-d] pyrimidine-2,4(3H)-dione] (LH4) was allowed to react with 2,2′-bipyridyl-dinitrato-Copper(II)-dihydrate which provides two complexes, characterized as [Cu(bpy)(L1)]•3H2O (1) and [Cu(bpy)(L2)]•H2O (2), where bpy = 2,2′-bipyridine, L1 = 5-hydroxy-hydurilic acid and L2 = alloxanic acid. In a separate reaction of LH4 with Cu(NO3)2•H2O another type of complex [Cu(LH3)2•(H2O) 2]•4H2O (3) is formed. The complexes were characterized by single crystal X-ray crystallography, physicochemical and electrochemical studies. The interaction of complexes 1 and 3 with DNA was monitored using absorption and emission titrations as well as circular dichroism spectroscopy. The complexes were found to cleave supercoiled plasmid DNA to nicked circular and linear DNA. Complexes 1 and 3 were also tested against T-cell lymphoma (Dalton lymphoma DL) and showed significant cytotoxic activity with IC50 values of ∼ 9.0 nM and 0.6 nM. © 2010 Elsevier Inc.
Pharmaceutical characterization and exploration of Arkeshwara rasa in MDA-MB-231 cells
(Elsevier B.V., 2024) Remya Jayakumar; Manoj Kumar Dash; Pankaj Kumar; Shiwakshi Sharma; Saumya Gulati; Akanksha Pandey; Kaushavi Cholke; Zeeshan Fatima; S.K. Trigun; Namrata Joshi
Background: The diverse specificity mode of cancer treatment targets and chemo resistance demands the necessity of drug entities which can address the devastating dynamicity of the disease. Objectives: To check the anti-tumour potential of traditional medicine rich in polyherbal components and metal nanoparticle namely Arkeshwara rasa (AR). Material methods: The AR was prepared in a modified version with reference from Rasaratna Samuchaya and characterized using sophisticated instrumental analysis including XRD, SEM-EDAX, TEM, TGA-DSC, and LC-MS and tested against the MDA-MB-231 cell line to screen cell viability and the cytotoxicity with MTT, SRB and the AO assay. Results: XRD pattern shows cubic tetrahedrite structure with Sb, Cu, S peaks and trace elements like Fe, Mg, etc. The particle size of AR ranges between 20 and 30 nm. The TGA points thermal decomposition at 210 °C and the metal sulphide peaks in DSC. LC-MS analysis reveals the components of the formulation more on the flavonoid portion. The IC50 value of MTT and SRB are 25.28 μg/mL and 31.7 μg/mL respectively. The AO colorimeter substantiated the cell viability and the apoptosis figures of the same cell line. The AR exhibits cytotoxicity and reaffirms the apoptosis fraction with SRB assay. Conclusions: The Hesperidine, Neohesperidin, Rutin components in the phytochemical pool can synergize the anti-tumour potential with either influencing cellular pathways or decreasing chemo resistance to conventional treatment. AR need to be further experimented with reverse transcription, flow cytometry, western blotting, etc. © 2023 The Authors