Isolation of thymoquinone from Nigella sativa L. and Thymus vulgaris L., and its anti-proliferative effect on HeLa cancer cell lines

Purpose: To isolate thymoquinone (TQ) from Nigella sativa L. and Thymus vulgaris L., and investigate its anti-proliferative effect on HeLa cancer cells.Method: Pulverized dried samples of N. sativa seed (100 g) and aerial parts of T. vulgaris (1000 g) were subjected to Soxhlet extraction using methanol and n-hexane combined in different proportions. Thymoquinone (TQ) was then isolated from the extracts using high performance liquid chromatography (HPLC). The isolated TQ was further subjected to Fourier Transform Infrared (FTIR) spectroscopy to identify its functional groups. The anti-proliferative effect of TQ on HeLa cancer cells was evaluated using 3-[4, 5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay.Results: Extract yield from N. sativa was significantly higher than from T. vulgaris, and also increased with increase in the proportion of methanol in the extraction solvent (p < 0.05). Methanol and n-hexane (4:1, v:v) yielded the highest amount of oil, with yields of 15.8 and 9.7 ml/25 g dry weight (d.wt.) from N. sativa and T. vulgaris, respectively. The results obtained from HPLC showed that the concentration of TQ isolated from N. sativa (388.61 μg/ml) was significantly higher than that from T. vulgaris (357.03 μg/ml, p < 0.05). The anti-proliferative effects of TQ standard and TQ isolated from N. sativa on HeLa cancer cells were dose-dependent, and was highest at the lowest concentration. The number of viable cells significantly decreased with increase in TQ concentration (p < 0.01). TQ from N. sativa significantly reduced the number of viable cells even at the lowest concentration when compared to TQ standard (p < 0.05). Cell death was significantly higher in TQ-treated groups than in untreated cancer cells.Conclusion: The results obtained in this study show that N. sativa is a potential source of TQ, with the yield enhanced by modifying the extraction procedure or solvent used. Furthermore, TQ isolated from N. sativa exerts a dose-dependent anti-proliferative effect on HeLa cancer cells.Keywords: Thymoquinone, Nigella sativa, Thymus vulgaris, Anti-proliferative effec

Uptake and metabolism of four isomers of dinitrotoluene in A. thaliana and their sequestration in feeding aphids: a phytoremediation perspective

Plants, being sessile, have wide variety of metabolic pathways to detoxify hazardous compounds therefore ensuring the success of phytoremediation of a wide variety of xenobiotics. One such a compound is dinitrotoluene (DNT) that is available as a mixture of six different isomers. Phytoremediation of DNTs is a cost effective, eco friendly and preferable approach compared to commercially available chemical and physical remediation systems. DNTs are toxic to plants at higher concentrations, however lower concentrations are tolerable. The present study considers the uptake of DNTs in the model plant Arabidopsis thaliana to observe the potential of phytoremediation and considers the metabolites during different phases of detoxification. Further it evaluates the possible propagation of DNT and its metabolites in ecosystem through a model system of plant-aphid interaction. The first step in the study included establishment of the toxicity of four different available isomers of DNT (2,6-DNT, 2,3-DNT, 3,4-DNT and 2,4-DNT) in A. thaliana. This was achieved by root growth analysis in Phytagel (axenic) and hydroponic media (non axenic), root and shoot ratio in Phytagel and hydroponic media and finally a time course reduction in root length in hydroponic media. The results obtained from the study showed that all isomers of DNT have different toxicities (EC50 for 2,6-DNT, 2,4-DNT, 3,4-DNT and 2,3-DNT was 13.3 mg /L ,0.33 mg /L 0.23 mg /L and 0.13 mg /L of Phytagel media). At lower concentrations these DNTs were tolerable but at higher concentration they induced biomass inhibition. The uptake and metabolism of different DNT isomers was analysed by GC-MS in A. thaliana cultivated in Phytagel and hydroponic media amended with different concentrations of DNT isomers. The analysis of metabolites showed that the major metabolites of DNT were aminonitrotoluenes (ANTs), the concentration of which varied with the concentration of DNTs in the media (ranged from 0.54-5.2 μg /g dry tissue wt. of A. thaliana for 2A6NT; 20.03 to 280.3 ng /g dry tissue wt. of A. thaliana for 2A4NT and 11.34 to 508.39 ng /g dry tissue wt. of A. thaliana for 4A2NT; 32.8 to 675.22 ng/g dry tissue wt. of A. thaliana for 2A3NT; 41.23 to 564.32 ng /g dry tissue wt. of A. thaliana for 3A4NT). The qualitative and quantitative analysis of possible DNT based conjugates was carried out by LC-MS/MS analysis for A. thaliana cultivated in liquid MS media (axenic). The quantitative analysis of DNT based conjugates indicated ten significant conjugates with higher concentrations of O- and C- glucosides, mostly with hydroxylaminonitrotoluene. The abundant metabolites of DNT (aminonitrotoluene) have been observed to have lesser conjugation. The concentration of DNT based conjugates were observed to be indirectly related to the concentration of metabolites (increase with the decrease in the concentration of metabolites) and their concentrations were 102 times higher than aminonitrotoluenes. The concentration of conjugates varied with the type of isomer in the media. The effect of DNT treatment to herbivore feeders was evaluated through analysis of survival, fecundity and growth of Brevicoryne brassicae (specialist) and Myzus persicae (generalist) aphids on DNT treated A. thaliana at different concentrations. The DNT based metabolites were evaluated in the feeding aphid species to observe the possible propagation. Finally, the aphids were observed to tolerate lower concentrations of DNT treatments and their survival, fecundity and growth was highly compromised with high concentrations of DNT in the medium with B. brassicae showed higher sensitivity than M. persicae (in M. persicae LC50 for 2,6-DNT, 2,4-DNT, 3,4-DNT and 2,3-DNT was 13.9 mg /L , 0.34 mg /L , 0.138 mg /L and 0.14 mg /L of Phytagel media and in B. brassicae LC50 for 2,6-DNT , 2,4-DNT, 3,4-DNT and 2,3-DNT was 11.48 mg /L , 0.24 mg /L , 0.1 mg /L and 0.08 mg /L of Phytagel media). Both aminonitrotoluenes and glucosyl conjugates were present in both aphid species and their concentrations were directly related with the concentration of metabolites in the plants on which they were reared. GC-MS analysis showed that B. brassicae managed to accumulate more metabolites than M. persicae. LC-MS analysis showed that the type of conjugates varied with the type of isomer. Therefore this study shows that if Phytoremediation of DNTs is considered then plants convert the toxic DNTs to their polar (less toxic) reduced metabolites and glucosides which could potentially be transported to the feeding aphids.Open acces

Isolation and Biochemical Characterization of Chromium Reducing Bacteria from Hudiara Drain Sludge

Abstract In the past few decades, the environmental pollution of toxic heavy metals is the major issue throughout the world since industrial evolution

Low-temperature health hazards among workers of cold storage facilities in Lahore, Pakistan

BackgroundCold storage facilities are the most common workplaces that produce artificially cold work environments and are associated with different adverse effects on human health, work productivity and the occurrence of accidents and injuries. The aim of this study was to measure the antagonistic health effects on workers, so that common factors causing abnormal symptoms could be determined, and to gather basic information to monitor the associated health risks from the exposure to cold work environments.Material and MethodsA cross-sectional analytical study was conducted to investigate the occurrence of cold-related adverse health effects, musculoskeletal symptoms, skin problems, injuries, respiratory illnesses, general hygiene and occupational environment related to cold indoor workplaces, using the Standardized Nordic Questionnaire. A total of 200 subjects took part in this study, including 100 exposed and 100 unexposed to cold environments. A 1-way analysis of variance (ANOVA) and a t-test were applied to measure statistical differences and to differentiate the cases where variations occurred, using SPSS 16.ResultsThe study revealed that a longer and constant exposure to extremely cold indoor work environments significantly increased (p < 0.001) the cold-related symptoms and musculoskeletal disorders which ultimately reduced (p < 0.01) the efficiency, effectiveness, performance and work ability of the exposed workers.ConclusionsThe study disclosed various adverse cold-related complaints of the studied subjects who were exposed to extreme cold conditions during a maximum number of working hours. The most consistent problems were related to musculoskeletal discomfort, skin problems and respiratory abnormalities. Med Pr. 2020;71(1):1–

Green synthesis, characterization and photocatalytic applications of silver nanoparticles using Diospyros lotus

Currently, the green route for synthesis of silver nanoparticles (Ag NPs) using plants leaf extract is an emerging research area in nanotechnology. The present study was explored for synthesis, characterization and catalytic application of Ag NPs using Diospyros lotus fresh leaf extracts. Factors affecting the synthesis were optimized and optimum conditions were pH of 8.6, silver nitrate (AgNO3) concentration of 1.5 mM and 10 mL leaf extract. Formation of Ag NPs was observed by change in color of reaction mixture from pale yellow to reddish brown. The synthesized Ag NPs were characterized using UV-Vis spectrophotometer, EDX, XRD and SEM analyses. UV-Vis spectrophotometer showed maximum absorbance peak in the range of 407 nm at different time intervals indicating formation of Ag NPs. SEM and XRD analysis confirmed face centered cubic structure and crystalline nature of biologically synthesized Ag NPs with average particle size of 27 nm. The purity of synthesized Ag NPs was revealed by EDX. Finally, photo catalytic activity (PCA) of Ag NPs was studied and 72.91% decolorization of industrial waste water was obtained at 54 h. Some important parameters like pH, turbidity, conductance; TSS, TDS, sulphide, sulphates, etc. were also monitored before and after treatment with Ag NPs

Reduction of reactive red 241 by oxygen insensitive azoreductase purified from a novel strain Staphylococcus KU898286.

An oxygen insensitive azoreductase was purified from a novel bacterial strain (Staphylococcus sp. KU898286) that was isolated from an abandoned site of the textile waste discharge unit. The isolated enzyme had efficiently cleaved the azo-bonds through reductive transformation under aerobic conditions. Initial phenotypic characterization and final construction of phylogenetic tree on the basis of 16s rDNA demonstrated 99% resemblance of the isolate to Staphylococcus aureus. The purified azoreductase was found to have a broad spectrum activity that reduced RR241 at a concentration of 50mg/L with pH between 6-8 and 30°C temperature). Besides, the reactive red 241 (RR241) was reduced at extracellular level as well as NADH dependent intracellular level. Complete reduction/ decolourization of RR241 were achieved after 18 hrs of exposure. The final degradation product observed to be 2-nephthol was purified by High Pressure Liquid Chromatography (HPLC) and the molecular mass was computed by Gas Chromatography-Mass spectroscopy (GC-MS). The study revealed a cost effective and eco-friendly approach to degrade the toxic dyes into less toxic products by Staphylococcus sp. KU898286

A Novel Route of Mixed Catalysis for Production of Fatty Acid Methyl Esters from Potential Seed Oil Sources

Depleting petroleum resources coupled with the environmental consequences of fossil fuel combustion have led to the search for renewable alternatives, such as biodiesel. In this study, sunflower (Helianthus annus), mustard (Brassica compestres) and pearl millet (Pennisetum americanum) seed oils were converted into biodiesel (fatty acid methyl esters) by acid-, base- and lipase-catalyzed transesterification, and the resultant fuel properties were determined. The methyl esters displayed superior iodine values (102–139), low densities, and a high cetane number (CN). The highest yield of biodiesel was obtained from mustard seed oil, which provided cloud (CP) and pour (PP) points of −3.5 and 5 °C, respectively, and a CN of 53. The sunflower seed oil methyl esters had a density of 0.81–0.86 kg/L at 16 °C, CP of 2 °C, PP of −8 °C, and a CN of 47. The pearl millet seed oil methyl esters yielded a density 0.87–0.89 kg/L, CP and PP of 4 °C and −5 °C, respectively, and a CN of 46. The major fatty acids identified in the sunflower, mustard, and pearl millet seed oils were linolenic (49.2%), oleic acid (82.2%), and linoleic acid (73.9%), respectively. The present study reports biodiesel with ideal values of CP and PP, to extend the use of biodiesel at the commercial level