Satwinderjeet Kaur

Genotoxicity of wastewater samples from sewage and industrial effluent detected by the Allium root anaphase aberration and micronucleus assays

The genotoxicity of wastewater samples from sewage, and industrial effluent from the Amritsar, India, area were investigated using the Allium micronucleus and anaphase aberration assays. Raw sewage samples and acetone extracts of the dehydrated sewage were use for treatment of the Allium roots. Industrial effluents were collected and stored in the form of sludge (semi-dried matter). The acetone extracts of the sludge samples were also used for treatment of the Allium roots. From the Allium root micronuclei tests on the sewage extracts, no significant increase in the number of micronuclei was found in comparison with negative controls. All the other extracts from industrial effluent showed positive responses both in the micronucleus and anaphase aberration assays.

Antimutagenicity of hydrolyzable tannins from Terminalia chebula in Salmonella typhimurium

A tannin fraction (TC-E) from the dried fruit pulp of Terminalia chebula was obtained by successfully extracting with 95% ethyl alcohol and ethyl acetate. TC-E was subjected to silica gel chromatography which yielded four fractions, viz., TC-EI, TC-EII, TC-EIII and TC-EIV. Thin layer chromatography (TLC) and 13C-NMR revealed that TC-EI was gallic acid (GA) derivative while the other fractions were tannin in nature. TC-E and its fractions were evaluated for their antimutagenic potential against two direct-acting mutagens, 4-nitro-o-phenylenediamine (NPD) and 4-nitroquinoline-N-oxide (4NQNO), and S9-dependent mutagen, 2-aminofluorene (2AF) in TA98 and TA100 strains of Salmonella typhimurium. The study revealed that the extract (TC-E) and its fractions were highly significant against S9-dependent mutagen, 2AF. The effect was found to be more or less corresponding with the nature of the fractions, as the monomeric TC-EI (a GA derivative) was least effective as compared to other fractions which were oligomeric, and the order of their effectiveness as per their IbD50 value being TC-EIV (8.9 micrograms)>TC-EIII (17.8 micrograms)>TC-EII (45 micrograms)>TC-EI (320 micrograms) in TA98; TC-EIV being 40 times more effective than TC-EI in inhibiting his+ revertants. A similar effect was noticed in TA100 too, where TC-EI was the least effective and TC-EII had the maximum effect. A similar result was noticed when the antimutagenicity of GA (a monomeric) was compared with tannic acid (TA, an oligomeric). However, chebula tannins were found to be partly effective against NPD but not at all effective against 4NQNO.

Modulatory effects of a tannin fraction isolated from Terminalia arjuna on the genotoxicity of mutagens in Salmonella typhimurium.

A fraction isolated from Terminalia arjuna was studied for its antimutagenic effect against 4-nitro-o-phenylenediamine (NPD) in TA98, sodium azide in TA100 and 2-aminofluorene (2AF, S9-dependent), a promutagen, in both TA98 and TA 100 tester strains of Salmonella typhimurium using the Ames assay. The fraction inhibited the mutagenicity of 2AF very significantly in both strains while the revertant colonies induced by NPD and sodium azide were reduced moderately. 1H-NMR, 13C-NMR, IR and UV-spectroscopic data of the fraction revealed it to be tannin in nature.

Physiological and Biochemical Changes in Brassica juncea Plants under Cd-Induced Stress

Plants of Brassica juncea L. var. RLC-1 were exposed for 30 days to different concentrations (0, 0.2, 0.4, and 0.6 mM) of cadmium (Cd) to analyze the Cd uptake, H2O2 content, hormonal profiling, level of photosynthetic pigments (chlorophyll, carotenoid, and flavonoid), gaseous exchange parameters (photosynthetic rate, vapour pressure deficit, intercellular CO2 concentration, and intrinsic mesophyll rate), antioxidative enzymes (superoxide dismutase, polyphenol oxidase, glutathione-S transferase, and glutathione peroxidase), antioxidant assays (DPPH, ABTS, and total phenolic content), and polyphenols. Results of the present study revealed the increased H2O2 content and Cd uptake with increasing metal doses. UPLC analysis of plants showed the presence of various polyphenols. Gaseous exchange measurements were done by infrared gas analyzer (IRGA), which was negatively affected by metal treatment. In addition, LC/MS study showed the variation in the expression of plant hormones. Level of photosynthetic pigments and activities of antioxidative enzymes were altered significantly in response to metal treatment. In conclusion, the antioxidative defence system of plants got activated due to heavy metal stress, which protects the plants by scavenging free radicals.

Modulatory role of alizarin from Rubia cordifolia L. against genotoxicity of mutagens.

Rubia cordifolia L. (Rubiaceae) is an important medicinal plant used in the Ayurvedic medicinal system. Its use as a traditional therapeutic has been related to the treatment of skin disorders and cancer. Besides its medicinal value, anthraquinones from this plant are used as natural food colourants and as natural hair dyes. Dyes derived from natural sources have emerged as important alternatives to synthetic dyes. Alizarin (1,2-dihydroxyanthraquinone) was isolated and characterized from R. cordifolia L. and evaluated for its antigenotoxic potential against a battery of mutagens viz. 4-nitro-o-phenylenediamine (NPD) and 2-aminofluorene (2-AF) in Ames assay using TA98 tester strain of Salmonella typhimurium; hydrogen peroxide (H(2)O(2)) and 4-nitroquinoline-1-oxide (4NQO) in SOS chromotest using PQ37 strain of Escherichia coli and in Comet assay using human blood lymphocytes. Our results showed that alizarin possessed significant modulatory role against the genotoxicity of mutagens.

Isolation and Characterization of Brassinosteroids from Leaves of Camellia sinensis (L.) O. Kuntze

Brassinosteroids are of ubiquitous occurrence in plants and elicit a wide spectrum of physiological responses. In our study, brassinosteroids were isolated and identified in topmost dormant leaves of tea plants. Six brassinosteriods, i.e. 6-deoxocastasterone, 24-epibrassinolide,3-dehydroteasterone, typhasterol, 3-deoxotyphasterol and 28-homodolicholide, were isolated and identified by GC–MS. All the brassinosteroids identified belong to important components of early and late C6 oxidation pathways proposed for brassinosteroids biosynthesis in plants. It suggests that both pathways are operating in tea to produce brassinolide, the most active brassinosteroid biologically.

Search for MDR modulators: Design, syntheses and evaluations of N-substituted acridones for interactions with p-glycoprotein and Mg2+

By combining the structural features of acridone based anti-cancer drugs (like amsacrine) and MDR modulator propafenone, acridones with hydroxyl amine chain at N-10 have been designed and synthesized. These molecules exhibit appreciable interactions with p-gp and Mg(2+) indicating their suitability to modulate p-gp mediated multi drug resistance.

GROWTH SUPPRESSION OF HUMAN TRANSFORMED CELLS BY TREATMENT WITH BARK EXTRACTS FROM A MEDICINAL PLANT, TERMINALIA ARJUNA

SummaryWe have investigated the effects of acetone and methanol extracts of a medicinal plant, Terminalia arjuna, on the growth of human normal fibroblasts (WI-38), osteosarcoma (U2OS), and glioblastoma (U251) cells in vitro. We found that both extracts at 30 μg and 60 μg/ml concentrations inhibit the growth of transformed cells; the growth of normal cells was least affected. Although the transformed cells appeared to have fragmented nucleus by Hoechst staining, no deoxyribonucleic acid laddering effect was observed. In response to the extract treatment, the tumor suppressor protein, p53, was induced in U2OS but not in U251 and WI-38 cells. A cyclin-dependent kinase inhibitor, p21WAF1, was induced in transformed cells only. The study suggests that the bark extract of medicinal plant, T. arjuna, has components that can induce growth arrest of transformed cells by p53-dependent and-independent pathways.

Antioxidant activity and identification of bioactive compounds from leaves of Anthocephalus cadamba by ultra–performance liquid chromatography/electrospray ionization quadrupole time of flight mass spectrometry

OBJECTIVE To evaluate the antioxidant potential of different extract/fractions of Anthocephalus cadamba (A. cadamba) (Roxb.) Miq. (Rubiaceae) and study the tentative identification of their active constituents. METHODS The extract/fractions were screened for antioxidant activity using various in vitro assays viz. DPPH assay, ABTS assay, superoxide anion radical scavenging assay, reducing power assay and plasmid DNA nicking assay. Total phenolic content of extract/fractions was determined by colorimetric method. An ultra-performance LC-electrospray-quadrupole-time of flight mass spectrometry method was used to analyse the active constituents of extract/fractions of A. cadamba. RESULTS The ethyl acetate fraction was found to be most active fraction in all the assays as compared to other extract/fractions. The IC(50) value of ethyl acetate fraction (ETAC fraction) was 21.24 μg/mL, 1.12 μg/mL, 9.68 μg/mL and 57.81 μg/mL in DPPH assay, ABTS assay, reducing power assay and superoxide scavenging assay respectively. All the extract/fractions also showed the potential to protect the plasmid DNA (pBR322) against the attack of hydroxyl radicals generated by Fentońs reagent. The bioactive compounds were identified by UPLC-ESI-QTOF-MS, by comparing the mass and λ(max) with literature values. CONCLUSIONS The potential of the extract/fractions to scavenge different free radicals in different systems indicated that they may be useful therapeutic agents for treating radical-related pathologic damage.

Design, synthesis and evaluation of tetrahydropyran based COX-1/-2 inhibitors

Chiral tetrahydropyrans were designed and synthesized by allylations of enantiomerically enriched beta-hydroxy ketones followed by iodocyclisations and nucleophilic replacement of iodo group with C(2)H(5)S(-) and SCN-. In vitro COX-1/-2 inhibitory activities and the docking studies of these compounds identify some of them as moderate inhibitors of COX-1 and COX-2 enzymes.