IR@IIIM - Indian Institute of Integrative Medicine (CSIR)
Not a member yet
200 research outputs found
Sort by
Isolation, purification and characterization of an N-acetyl-D-lactosamine binding mitogenic and anti-proliferative lectin from tubers of a cobra lily Arisaema utile Schott
No full textLectins are the carbohydrate-binding proteins of
non-immune origin which have been the subject of
intense investigation over the last few decades owing
to the variety of interesting biological properties.
Most of the lectins which have been purified and
characterized from plants have been obtained from
dicotyledons. In the present study a lectin was purified
from tubers of a monocot plant Arisaema utile
(AUL) Schott by affinity chromatography on asialofetuin-
linked amino activated silica beads. AUL
gave a single band in SDS-PAGE at pH 8.3 corresponding
to subunit Mr 13.5 kDa. The native molecular
mass of AUL was 54 kDa suggesting a homotetrameric
structure. AUL gave multiple bands in
isoelectric focusing and in native PAGE at pH 8.3.
AUL was inhibited by N-acetyl-D-lactosamine (Lac
NAc), a disaccharide and asialofetuin, a complex desialylated
serum glycoprotein. When treated with
denaturing agents, the lectin was stable in the presence
of urea (3 M), thiourea (4 M) and guanidine HCl
(4 M). AUL was a glycoprotein with a carbohydrate
content of 1.2%. Complete loss of activity was observed
upon modification of tryptophan residues of
the lectin. The activity was reduced to 25% after
modification of tyrosine. Chemical modification of
arginine, histidine, serine and cysteine residues of
AUL did not affect its activity. Using Far UV CD
spectra the estimated secondary structure was 37%
α-helix, 25% β-sheet and 38% random contributions.
The lectin showed potent mitogenic response towards
human lymphocytes. In vitro anti-proliferative assay
using 11 human cancer cell lines resulted in 50% inhibition
of six cell lines viz. SW-620, HCT-15,
SK-N-SH, IMR-32, Colo-205 and HT-29 at 38, 42, 43,
49, 50 and 89 μg/ml, respectively
Substituted dihydronaphthalenes as efflux pump inhibitors of Staphylococcus aureus
No full textA new series of 3-(substituted-3,4-dihydronaphthyl)-2-propenoic acid amides has been prepared through convergent synthetic strategies and tested in combination with ciprofloxacin against NorA overexpressing Staphylococcus aureus 1199B as test strain for potentiating of the drug activity. Out of 24 compounds evaluated, 12 compounds potentiated the activity of ciprofloxacin and resulted in 2e16 fold reduction in the MIC (4e0.5 mg/mL) of the drug. The failure of these efflux pump inhibitors (EPIs) to
potentiate the activity of ciprofloxacin when tested against NorA knock out S. aureus SA-K1758 established
their identity as NorA inhibitors. The structure of all these newly synthesised compounds was confirmed by spectral data. The present communication describes the synthesis, bioevaluation, structure activity relationship and mechanism of action of these EPIs
Diminution of free radical induced DNA damage by extracts/fractions from bark ofSchleichera oleosa(Lour.) Oken
No full textThe present study was undertaken to investigate the effect of extracts of Schleichera oleosa (Sapindaceae)
for its cytotoxic and hydroxyl radical-scavenging activities. The bark of the tree was used to prepare extracts with different solvents (i.e., hexane, chloroform, ethyl acetate, methanol, and water). The extracts were
initially assessed for their in vitro cytotoxicity potential in the sulforhodamine B dye assay against cell lines,such as 502713 (colon), SW-620 (colon), HCT-15 (colon), A-549 (lung), HEP-2 (liver), SK-NS-H (central nervous system), and IMR-32 (neuroblastoma). It was observed that the water extract was effective against all the three colon cancer cell lines, while only methanol and water extracts were effective against A-549 (lung)
and HEP-2 (liver), respectively. As DNA damage is one of the hallmarks of cell death, so the extracts were
assessed for their ability to scavenge hydroxyl radicals, in the deoxyribose degradation assay (site- and
nonsite specific) as well as their protective effect against the hydroxyl radical–induced DNA damage in
the plasmid nicking assay, using pBR322. It was observed that all the extracts, except chloroform and hexane,
exhibited relatively greater antioxidant activity in the nonsite-specific than in the site-specific assay.
Similarly, the extracts were also found to be effective in inhibiting the hydroxyl radical–induced unwinding
of supercoiled DNA, which further confirmed the hydroxyl radical–scavenging ability of the extracts in the
deoxyribose degradation method
Genetic diversity in Acorus calamus L. as revealed by RAPD markers and its relationship with β-asarone content and ploidy level
No full textb-Asarone content in Acorus calamus is a paramount issue because it limits the usage of plant for medicinal purpose. In the present study A. calamus L. accessions based on RAPDmarker, ploidy level and b-asarone content were characterized and correlated on the basis of b-asarone content/ploidy level. Of the 40 random primers used, 6 primers generated polymorphism. Genetic relatedness among accessions evaluated by a similarity matrix based on Dice’s coefficient ranged from 0.72 to 0.97. A phenetic
dendrogram based on UPGMA analysis grouped accessions into two clusters. A. calamus L. accessions were found to be triploid and tetraploid and their b-asarone content was found in two ranges 6.92–8.0% and 73–88%. The study clustered the accessions as per their ploidy level, b-asarone content and geographical locations. This study would have extensive application in quality control of raw materials
In vitro antifungal activity of hydroxychavicol isolated from Piper betle L
No full textBackground: Hydroxychavicol, isolated from the chloroform extraction of the aqueous leaf extract of Piper betle L.,
(Piperaceae) was investigated for its antifungal activity against 124 strains of selected fungi. The leaves of this plant have been long in use tropical countries for the preparation of traditional herbal remedies.
Methods: The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of hydroxychavicol were determined by using broth microdilution method following CLSI guidelines. Time kill curve studies,post-antifungal effects and mutation prevention concentrations were determined against Candida species and Aspergillus species “respectively”. Hydroxychavicol was also tested for its potential to inhibit and reduce the formation of Candida albicans biofilms. The membrane permeability was measured by the uptake of propidium iodide.
Results: Hydroxychavicol exhibited inhibitory effect on fungal species of clinical significance, with the MICs ranging from 15.62 to 500 μg/ml for yeasts, 125 to 500 μg/ml for Aspergillus species, and 7.81 to 62.5 μg/ml for
dermatophytes where as the MFCs were found to be similar or two fold greater than the MICs. There was concentration-dependent killing of Candida albicans and Candida glabrata up to 8 × MIC. Hydroxychavicol also exhibited an extended post antifungal effect of 6.25 to 8.70 h at 4 × MIC for Candida species and suppressed the emergence of mutants of the fungal species tested at 2 × to 8 × MIC concentration. Furthermore, it also inhibited the growth of biofilm generated by C. albicans and reduced the preformed biofilms. There was increased uptake of propidium iodide by C. albicans cells when exposed to hydroxychavicol thus indicating that the membrane disruption could be the probable mode of action of hydroxychavicol.
Conclusions: The antifungal activity exhibited by this compound warrants its use as an antifungal agent particularly for treating topical infections, as well as gargle mouthwash against oral Candida infections
Isolation, characterisation and antibacterial activity studies of coumarins from Rhododendron lepidotum Wall. ex G. Don, Ericaceae
No full textRESUMO: “Estudos de isolamento, caracterização e atividade antibacteriana de cumarinas de Rhododendron lepidotum Wall. ex G. Don, Ericaceae”. Seis cumarinas dafinina (1), dafinetina (2), dafinetina glicosídeo (3), rodonetina (4), rodonina (5) eumbeliferona (6) foram isoladas do extrato metanólico das partes aéreas de Rhododendron lepidotum Wall. ex G. Don, Ericaceae. Os compostos e seus derivados acetilados foram testados para verificar sua atividade antibacteriana contra Staphylococcus aureus ATCC-29213,
Escherichia coli resistente à meticilina, Staphylococcus aureus ATCC-15187, ATCC-8739,Pseudomonas aeruginosa ATCC-9027, pelo método de microdiluição, usando ciprofloxacina como referência. A substância 2 apresentou a melhor atividade antibacteriana com o MIC 125 μg/mL contra S. aureus ATCC-29213 e MRSA ATCC-15187 seguido pela substância 4, que apresentou o valor de CIM de 250 μg/mL contra as quatro cepas testadas. Todas as moléculas
apresentaram melhor atividade antibacteriana do que seus derivados acetilados.
Unitermos: Rhododendron lepidotum, glicosídeos cumarínicos, HMBC, antibacteriano, daphnin,
daphnetin.
ABSTRACT: Six coumarins daphnin (1), daphnetin (2), daphnetin glucoside (3), rhodonetin (4), rhodonin (5) and umbelliferone (6) were isolated from the methanolic extract of Rhododendron lepidotum Wall. ex G. Don, Ericaceae (aerial part). The compounds and their acetyl derivatives were screened for antibacterial activity against Staphylococcus aureus ATCC-29213, methicillin resistant Staphylococcus aureus ATCC-15187, Escherichia coli
ATCC-8739, Pseudomonas aeruginosa ATCC-9027 by microdilution method as compared to the reference ciprofloxacin. Compound 2 displayed the best antibacterial activity with MIC 125 μg/mL against S. aureus ATCC-29213 and MRSA ATCC-15187 followed by 4 which exhibited the MIC value of 250 μg/mL against all the four tested strains. All molecules showed better antibacterial activity than their acyl derivatives
Modulation of P-glycoprotein ATPase activity by some phytoconstituents
No full textIn the present investigation 16 phytoconstituents, which are active moieties found in several medicinal herbs,
have been evaluated for their P-glycoprotein (P-gp) stimulation/inhibition profi les using a P-gp-dependent
ATPase assay in rat jejunal membrane (in vitro). Acteoside, agnuside, catechin, chlorogenic acid, picroside -II
and santonin showed an inhibitory effect. Negundoside, picroside -I and oleanolic acid caused a stimulatory
effect. Andrographolide, apocyanin, berberine,glycyrrhizin, magniferin and piperine produced a biphasic response (stimulation at low concentration and inhibition at high concentration). The results suggested that a possible interaction of these phytoconstituents at the level of P-gp, could be an important parameter in determining
their role in several key pharmacodynamic events
Piperine as an inhibitor of Rv1258c, a putative multidrug efflux pump of Mycobacterium tuberculosis
No full textObjectives: To evaluate the role of piperine as an inhibitor of Rv1258c of Mycobacterium tuberculosis.
Methods: Rifampicin, in combination with piperine, was tested against M. tuberculosis H37Rv and rifampicinresistant
(rifr) M. tuberculosis. A laboratory-generated rifampicin-resistant mutant (rifr) of M. tuberculosis was tested for drug susceptibility and the expression level of the putative efflux protein (Rv1258c) by real-time PCR. The three-dimensional (3D) structure of Rv1258c was also predicted using an in silico approach.
Results: In the present study, rifampicin in combination with piperine, a trans-trans isomer of 1-piperoyl-piperidine,reduced the MIC and mutation prevention concentration (MPC) of rifampicin for M. tuberculosis H37Rv,
including multidrug-resistant (MDR) M. tuberculosis and clinical isolates. Moreover, piperine effectively enhanced
the bactericidal activity of rifampicin in time–kill studies and also significantly extended its post-antibiotic
effect (PAE). In the presence of rifampicin, M.tuberculosis rifr showed a 3.6-fold overexpression of Rv1258c.The 3D structure of Rv1258c, using in silico modelling, was analysed to elucidate the binding of piperine to
the active site.
Conclusions: The results of this study are suggestive of piperine’s involvement in the inhibition of clinically
overexpressed mycobacterial putative efflux protein (Rv1258c). Piperine may be useful in augmenting the antimycobacterial activity of rifampicin in a clinical setting
Effect of Emblica officinalis (fruit) against UVB-induced photo-aging in human skin fibroblasts
No full textEthnopharmacological relevance: Emblica officinalis fruit (EO), commonly known as Amla is a reputed traditional medicine and functional food used in Indian subcontinent. It has long been used in Indian folk medicine to treat liver diseases, stomach ulcers, inflammatory diseases, metabolic disorders, geriatric complaints, skin disorders and beauty care.Aim of the study: Recently, it has been shown to promote pro-collagen content and inhibit matrix metalloproteinase levels in skin fibroblast. The aim of the present study was to investigate the efficacy of EO
to inhibit UVB-induced photo-aging in human skin fibroblasts.Materials and methods: Mitochondrial activity of human skin fibroblasts was measured by MTT-assay.
Quantifications of pro-collagen 1 and matrix metalloproteinase 1 (MMP-1) release were performed
by immunoassay techniques. Hyaluronidase inhibition assay was studied in vitro using bovine testicular
hyaluronidase and human umbilical cord hyaluronic acid. Cell cycle analysis was performed by flowcytometry using propidium iodide.
Results: EO stimulated, the otherwise UVB inhibited cellular proliferation and protected pro-collagen 1
against UVB-induced depletion via inhibition of UVB-induced MMP-1 in skin fibroblasts (10–40�g/mL,p > 0.001). EO exhibited inhibitory activity of hyaluronidase (10–40�g/mL, p > 0.001). Treatment with EO also prevented UVB disturbed cell cycle to normal phase.
Conclusion: The results of the present study suggests that EO effectively inhibits UVB-induced photoaging
in human skin fibroblast via its strong ROS scavenging ability and its therapeutic and cosmetic applications remain to be explored
Synthesis, anti-inflammatory and anticancer activity evaluation of some novel acridine derivatives
No full textCondensation of 9-chloro-2,4-(un)substituted acridines (1a–c) with various amines (2a–e) and 9-isothiocyanato-
2,4-(un)substituted acridines (4a,b) with different amines (2a,b,d,e) gave condensed products 3a–o and 5a–g respectively. Compounds 3a–o and 5a–g were screened for anti-inflammatory activity at a dose of 50 mg/kg p.o. Compound 3e exhibited 41.17% anti-inflammatory activity which is better than most commonly used standard drug ibuprofen which showed 39% anti-inflammatory (at 50 mg/kg p.o.) activity. Anticancer activity evaluation of compounds 3a–o and 5a–g was carried out against a small panel of human cancer cell lines and compounds 3g, 3m and 5g exhibited good anticancer activity against breast (MCF-7), liver (HEP-2), colon (COLO-205, 502713, HCT-15), lung (A-549)and neuroblastoma (IMR-32) cancer cell lines at a concentration of 1� 10�5 M