Browsing by Author "Pratibha Tripathi"

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4-[5-(benzylsulfanyl)-1,3,4-oxadiazol-2-yl]pyridine from a single-pot reaction
(2006) N.K. Singh; Ray J. Butcher; Manoj Kumar Bharty; Ajay K. Srivastava; Pratibha Tripathi
The asymmetric unit of the title compound, C14H 11N3OS, obtained from the one-pot reaction of isonicotinic acid hydrazide, CS2 and benzyl chloride in the presence of triethylamine, contains two crystallographically independent molecules with similar geometry. The dihedral angles between the pyridine and 1,3,4-oxadiazole rings are 6.3 (1) and 7.0 (1)°, while those between the phenyl and oxadiazole rings are 69.61 (5) and 67.78 (6)°. © 2006 International Union of Crystallography. All rights reserved.
5-Phenyl-1,3,4-oxadiazole-2(3H)-thione
(2007) N.K. Singh; Ray J. Butcher; Pratibha Tripathi; Ajay K. Srivastava; Manoj Kumar Bharty
In the title compound, C8H6N2OS, the planar oxadiazole ring is effectively coplanar with the phenyl ring. This facilitates the formation of N-H⋯S interactions, leading to a thione tautomer in the solid state, and the formation of centrosymmetric dimers. © 2007 International Union of Crystallography All rights reserved.
Assessment of the adrenergic beta-blocking activity of inula racemosa
(1988) Y.B. Tripathi; Pratibha Tripathi; B.N. Upadhyay
Inula racemosa root powder was investigated in patients with proven ischaemic heart disease. The powder prevented ST-segment depression and T-wave inversion as observed in the post-exercise electrocardiogram. The petroleum ether extract of roots lowered plasma insulin and glucose levels within 75 min of oral administration to albino rats and it significantly counteracted adrenaline-induced hyperglycaemia in rats. The extract further showed negative inotropic and negative chronotropic effects on frog heart. All these findings indicate that one of the constituents of Inula racemosa may have adrenergic beta-blocking activity. © 1988.
Bioactivity of novel transition metal complexes of N′-[(4-methoxy)thiobenzoyl]benzoic acid hydrazide
(Elsevier Masson SAS, 2008) Anuraag Shrivastav; Pratibha Tripathi; Ajay K. Srivastava; Nand K. Singh; Rajendra K. Sharma
Cu(II), Fe(III), and Mn(II) complexes of a novel ligand N′-[(4-methoxy)thiobenzoyl]benzoic acid hydrazide (H2mtbh) have been synthesized and characterized by elemental analyses, IR, UV-vis, NMR, mass, EPR and Mössbauer spectroscopy. The results suggest a square planar structure for [Cu(Hmtbh)Cl] and [Cu(mtbh)] whereas an octahedral structure for [Mn(Hmtbh)2] and [Fe(Hmtbh)(mtbh)]. Mn(II) and Fe(III) complexes were found to inhibit proliferation of HT29 cells. [Mn(Hmtbh)2] and [Fe(Hmtbh)(mtbh)] inhibited proliferation of HT29 cells with half maximal inhibition (IC50) of 8.15 ± 0.87 and 68.1 ± 4.8 μM, respectively, whereas H2mtbh showed growth inhibition with IC50 of 90.9 ± 7.8 μM and were able to inhibit NMT activity in vitro. Mn(II) and Fe(III) complexes inhibited NMT activity in a dose dependent manner with IC50 values of 20 ± 2.2 and 60 ± 7.2 μM, respectively, whereas ligand (H2mtbh) displayed IC50 of 3.2 ± 0.5 mM. © 2007 Elsevier Masson SAS. All rights reserved.
Copper(II) and manganese(III) complexes of N′-[(2-hydroxy phenyl) carbonothioyl] pyridine-2-carbohydrazide: novel therapeutic agents for cancer
(2006) Anuraag Shrivastav; Nand K. Singh; Pratibha Tripathi; Theresa George; Jonathan R. Dimmock; Rajendra K. Sharma
c-Src is a non-receptor tyrosine kinase which plays a significant role in the growth mediated signaling pathway impacting cellular proliferation, differentiation, mobility, survival and transformation. Myristoylation of pp60c-src leads to its membrane association and activation, a process catalyzed by N-myristoyltransferase (NMT). We have shown earlier increased NMT activity in the early stages of colon cancer. A novel sulfur nitrogen donor ligand and its Cu(II) and Mn(III) complexes have been prepared and characterized using various physicochemical analyses. These Cu(II) and Mn(III) complexes showed cytotoxicity against the colon cancer cell line HT29. The IC50 for Cu(II) and Mn(III) complexes were 12.2 and 16.1 μM, respectively. HT29 cells treated with Cu(II) and Mn(III) complexes induced apoptosis and inhibited endogenous NMT activity. Furthermore, they induced higher levels of hsc70 and inhibited the expression of c-Src. Inhibition of endogenous NMT activity by metal complexes was demonstrated for the first time. This study also suggested that NMT activity is crucial for cell survival and demonstrated that cessation in activity results in apoptosis. These metal complexes may prove to be novel therapeutic agents for cancer targeting NMT. © 2006 Elsevier SAS. All rights reserved.
Cypermethrin alters the status of oxidative stress in the peripheral blood: relevance to Parkinsonism
(Kluwer Academic Publishers, 2014) Pratibha Tripathi; Ashish Singh; Sonal Agrawal; Om Prakash; Mahendra Pratap Singh
Parkinson’s disease (PD) is a motor scarcity disorder characterized by the striatal dopamine deficiency owing to the selective degeneration of the nigrostriatal dopaminergic neurons. While oxidative stress is implicated in PD, prolonged exposure to moderate dose of cypermethrin induces Parkinsonism. The study aimed to investigate the status of oxidative stress indicators and antioxidant defence system of the polymorphonuclear leukocytes (PMNs), platelets and plasma to delineate the effect of Parkinsonian dose of cypermethrin in the peripheral blood of rats and its subsequent relevance to Parkinsonism. Nitrite content, lipid peroxidation (LPO) and activity of superoxide dismutase (SOD), catalase, glutathione reductase (GR) and glutathione-S-transferase (GST) were measured in the PMNs, platelets and plasma of control and cypermethrin-treated rats in the presence or absence of a microglial activation inhibitor, minocycline or a dopamine precursor containing the peripheral 3,4-dihydroxyphenylalanine decarboxylase inhibitor, named syndopa, employing the standard procedures. The striatal dopamine was measured to assess the degree of neurodegeneration/neuroprotection. Cypermethrin increased nitrite and LPO in the plasma, platelets and PMNs while it reduced the striatal dopamine content. Catalase and GST activity were increased in the PMNs and platelets; however, it was reduced in the plasma. Conversely, SOD and GR activities were reduced in the PMNs and platelets but increased in the plasma. Minocycline or syndopa reduced the cypermethrin-mediated changes towards normalcy. The results demonstrate that cypermethrin alters the status of oxidative stress indicators and impairs antioxidant defence system of the peripheral blood, which could be effectively salvaged by minocycline or syndopa. The results could be of value for predicting the nigrostriatal toxicity relevant to Parkinsonism. © 2014, University of Navarra.
Ibuprofen abates cypermethrin-induced expression of pro-inflammatory mediators and mitogen-activated protein kinases and averts the nigrostriatal dopaminergic neurodegeneration
(Humana Press Inc., 2016) Ashish Singh; Pratibha Tripathi; Om Prakash; Mahendra Pratap Singh
Cypermethrin induces oxidative stress, microglial activation, inflammation and apoptosis leading to Parkinsonism in rats. While ibuprofen, a non-steroidal anti-inflammatory drug, relieves from inflammation, its efficacy against cypermethrin-induced Parkinsonism has not yet been investigated. The study aimed to explore the protective role of ibuprofen in cypermethrin-induced Parkinsonism, an environmentally relevant model of Parkinson’s disease (PD), along with its underlying mechanism. Animals were treated with/without cypermethrin in the presence/absence of ibuprofen. Behavioural, immunohistochemical and biochemical parameters of Parkinsonism and expression of pro-inflammatory and pro-apoptotic proteins along with mitogen-activated protein kinases (MAPKs) were determined. Ibuprofen resisted cypermethrin-induced behavioural impairments, striatal dopamine depletion, oxidative stress in the nigrostriatal tissues and loss of the nigral dopamine producing cells and increase in microglial activation along with atypical expression of pro-inflammatory and apoptotic proteins that include cyclooxygenase-2, tumour necrosis factor-α, MAPKs (c-Jun N-terminal kinase, p38 and extracellular signal-regulated kinase), B cell lymphoma 2-associated protein X, tumour suppressor protein p53, cytochrome c and caspase-3 in the nigrostriatal tissue. The results obtained thus demonstrate that ibuprofen lessens inflammation and regulates MAPKs expression thereby averts cypermethrin-induced Parkinsonism. © 2015, Springer Science+Business Media New York.
Metal-assisted transformation of N-benzoyldithiocarbazate to 5-phenyl-1,3,4-oxadiazole-2-thiol in the presence of ethylenediamine, and its first row transition metal complexes
(Elsevier Ltd, 2007) Pratibha Tripathi; Aritra Pal; Vojtech Jancik; A.K. Pandey; J. Singh; N.K. Singh
The reaction of metal complexes of the type [M(HL)Cl] or [M(HL)2] [where M = Cu(II), Ni(II), Mn(II), Co(II) and Zn(II) and H2L = N-benzoyldithiocarbazate] with an excess of ethylenediamine (en) in CHCl3-MeOH medium leads to ring closure by desulfurisation to yield unique mixed-ligand complexes 1-4, [Cu(en)2](pot)2(pot = 5-phenyl-1,3,4-oxadiazole-2-thiol), [M(en)2(pot)2] [M = Ni(II), Mn(II)] and [Zn(en)(pot)2]. The metal complexes have been characterized by various physicochemical methods. The molecular structure of [Cu(en)2](pot)2 has been determined by a single crystal X-ray diffraction study. In the centrosymmetric unit of [Cu(en)2](pot)2, the metal ion has a square planar arrangement of four symmetry related N-atoms of two en groups and is ionically bonded to two pot anions. Weak interaction studies on the complex reveal the presence of a hydrogen-bonded network in the molecule involving non-coordinating donor atoms of the pot anion with en resulting in the formation of an extended three-dimensional network. The arrangement of the [Cu(en)2]2+ units, at a dihedral angle of 49.43° to pot-, provides a network of intermingled chains leading to a π-π stacked 3-dimensional framework. © 2007 Elsevier Ltd. All rights reserved.
N′-(2-Methoxythiobenzoyl)pyridine-2-carbohydrazide
(2006) N.K. Singh; Ray J. Butcher; Pratibha Tripathi
In the crystal structure of the title compound, C14H 13N3O2S, intermolecular N-H⋯O (H⋯O = 2.03 Å) and C-H⋯S (H⋯S = 2.77 Å) hydrogen bonds link molecules into a two-dimensional framework. © 2006 International Union of Crystallography All rights reserved.
Nutraceuticals and cancer management
(Bioscience Research Institute, 2005) Yamini B. Tripathi; Pratibha Tripathi; Behram H. Arjmandi
The use of complementary and alternative medicine (CAM) is increasing rapidly in developed countries, which is already in use as traditional medicines in various Asian countries. The Indian system of medicine, named as Ayurveda has an edge in this field. Many plant products are in use as herbal medicine, as food supplement or as spices, in every day cooking. Some of them have been well studied in various experimental models of cancer, both in vivo and in vitro models. They have shown significant inhibition of cell proliferation. Some of them are in the phase of clinical trial or already available as food supplement. Cancer patients are specially exploring the use of CAM, because of the high risk of mortality and long-term morbidity associated with surgical procedures of cancer management and high side effects of chemotherapy. This paper reviews different class of phytomedicines, used in Indian system of medicine, and also in Europe, which have shown positive results in preventing cancer progression. It also covers the role of vitamins, minerals, dietary fat in relation to cancer control. The mechanisms of action of these phytomolecules have also been discussed.
Oily fraction of Semecarpus anacardium Linn nuts involves protein kinase C activation for its pro-inflammatory response
(2010) Yamini B Tripathi; Nidhi Pandey; Deepshikha Tripathi; Pratibha Tripathi
The oily fraction (non polar fraction-NPF) of S. anacardium (SA) significantly increased the expression of protein kinase C-δ (PKC-δ) in macrophages in concentration dependent manner, which was similar to phorbol myristate acetate (PMA) response. Further, H-7 (1-(5-isoquinolinesulphonyl)-2-methylpiperazine), an inhibitor of PKC significantly inhibited this NPF mediated response in a concentration dependent manner. In the post treatment kinetics, H-7 showed this inhibition only up to 6 min post NPF/PMA addition, but in similar condition, quercetin, a flavone with reported antioxidant property, showed this inhibition only up to 2 min. The results clearly suggest that oily fraction of SA nuts enhances the expression of PKC protein, which may be responsible for its reported pro-inflammatory property.
Purification of nuts of Semecarpus anacardium Linn., a herbal drug for arthritis
(2008) Yamini B. Tripathi; Nidhi Pandey; Pratibha Tripathi
Although nuts of Semecarpus anacardium Linn. (Anacardiaceae) (SA nuts) are used in the Ayurveda and Siddha systems of medicine for the management of arthritis and other inflammatory diseases, they are always associated with several side effects, if used unpurified. Several traditional methods for purification are available, but they are not free from toxicity and also the scientific basis behind these purification steps is not known. Here, we have hypothesized that the oily part of the nut is toxic and its degree of removal is proportional to its safety margin. To test this hypothesis, we treated the SA nuts with brick powders (traditional method of Ayurveda), silica gel and hexane solvent for various time periods. These defatted nuts were washed and extracted with ethanol and the solvent-free extract was tested on rat peritoneal macrophages in terms of NO production, both in the absence and presence of lipopolysaccharides (LPS). Results suggest that the hexane fraction (oily part) is highly toxic and produces free radicals (FR) in a concentration-dependent manner without affecting the cell viability and the hexane fraction works as a prooxidant, similar to that of LPS. Contrary to this, the alcoholic fraction of hexane-washed SA nuts (defatted nuts) significantly scavenged FR and its yield was directly proportional to the removal of the oily part. Thus it is suggested that the oily part of the nuts is prooxidant, whereas the alcoholic fraction is antioxidant, and that the use of hexane is better for purification of SA nuts than the traditional methods, as it enhances the therapeutic value.
Role of Sandhika: A polyherbal formulation on MC3T3-E1 osteoblast-like cells
(2008) Yamini B. Tripathi; Pratibha Tripathi; Kiranmayi Korlagunta; Sheau Ching Chai; Brenda J. Smith; Bahram H. Arjmandi
Sandhika is a polyherbal formulation, (water soluble fraction of Commiphora mukul, Boswellia serrata, Semecarpus anacardium and Strychnos nux vomica), which has been in clinical use in India for last 20 years. Its modified formulation BHUx has shown specific inhibition of cyclooxygenase (COX)-2 and lipoxygenase (LOX)-15 and has prevented diet-induced atherosclerosis in rabbits. In order to explore the possibility of the use of Sandhika for the management of osteoporosis, we have examined its influence on MC3T3-E1 osteoblast-like cells in presence of lipopolysaccharide (1 μg/ml) in terms of calcium nodule formation and alkaline phosphatase activity. MC3T3-E1 osteoblast-like cells (80% confluence in 6-well plates) were treated with water extract of Sandhika, for 10 days, in the concentration range of 0.5 to 16 mg/ml final concentration, in presence of LPS. Media was changed on every third day and culture supernatant was collected after every change to assess the alkaline phosphatase activity and on the tenth day, cells were washed and stained with "Alizarin S" for visualization of calcium nodules by using Meta Morph software (Universal Imaging, Downingtown, PA). The results showed significant enhancement in calcium nodule formation in the dose dependent manner up to 2 mg/ml, followed by gradual decrease at higher concentrations. This change was accompanied with the increase in the alkaline phosphatase activity in these plates, indicating a potential anabolic effect of this polyherbal formulation on osteoblast-like cells under inflammatory conditions induced by LPS. © 2007 Springer Science+Business Media, LLC.
Synthesis of a new N,N′-ethane-1,2-bis(4-methoxyphenyl)carbothioamide ligand and its Cu(I) and Ag(I) complexes
(Elsevier Ltd, 2008) Nand K. Singh; Mamata Singh; Pratibha Tripathi; Ajay K. Srivastava; Ray J. Butcher
[Cu(H2L)(PPh3)2]NO3 · 0.5H2O (2) and [Ag(H2L)(PPh3)2]NO3 · 0.5H2O (3) complexes of a new flexible thioamide ligand; N,N′-ethane-1,2-bis(4-methoxyphenyl)carbothioamide H2L (1) have been synthesized using PPh3 as a coligand. The synthesized compounds have been characterized with the help of elemental analyses, IR, 1H, 13C and 31P NMR spectroscopy. The ligand and its Cu(I) complex have been studied by single crystal X-ray crystallography. The ligand acts as a neutral S-donor and forms a nine-membered chelate ring in [Cu(H2L)(PPh3)2]NO3 · 0.5H2O. The molecular packing is stabilized by an anionic cavity formed by intermolecular hydrogen bonding between the basal plane of the complex molecule and the nitrate ions. The square shaped columnar channel has dimensions of 5.489(25) [N(11)-H(11A)⋯O(13)⋯H(21A)N(21)] × 3.693(7) [N(11)-C(11)-C(21)-N(21)] Å. © 2007 Elsevier Ltd. All rights reserved.