Green synthesis of silver nanoparticles using Carum copticum: Assessment of its quorum sensing and biofilm inhibitory potential against gram negative bacterial pathogens.

Antimicrobial resistance among pathogenic bacteria has become a global threat to human health. Due to poor progress in development of new antimicrobial drugs, there is a need for the development of novel alternative strategies to combat the problem of multidrug resistance. Moreover, there is focus on ecofriendly approach for the synthesis nanoparticles having efficient medicinal properties including antivirulence properties to tackle the emergence of multi-drug resistance. Targeting quorum sensing controlled virulence factors and biofilms has come out to be a novel anti-infective drug target. The silver nanoparticles (Ag@CC-NPs) were synthesized from aqueous extract of Carum copticum and characterized using UV-vis absorption spectroscopy, fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Ag@CC-NPs were checked for its ability to inhibit quorum sensing-mediated virulence factors and biofilms against three test pathogens at sub-MIC values. There was ~75% inhibition of violacein production by Ag@CC-NPs against C. violaceum. The P. aeruginosa virulence factors such as pyocyanin production, pyoverdin production, exoprotease activity, elastase activity, swimming motility and rhamnolipid production were inhibited by 76.9, 49.0, 71.1, 53.3, 89.5, and 60.0% at sub-MIC. Moreover, virulence factors of S. marcescens viz. prodigiosin production, exoprotease activity, and swarming motility was reduced by 78.4, 67.8, and 90.7%. Ag@CC-NPs also exhibited broad-spectrum antibiofilm activity with 77.6, 86.3, and 75.1% inhibition of biofilms of P. aeruginosa, S. marcescens, and C. violaceum respectively. The biofilm formation on glass coverslip was reduced remarkably as evident from SEM and CLSM analysis. The findings revealed the in vitro efficacy of Ag@CC-NPs against bacterial pathogens and can be exploited in the development of alternative therapeutic agent in management of bacterial infections for topical application, mainly wound infection, or coating of surfaces to prevent bacterial adherence on medical devices.

Structural and functional characterization of a novel immunomodulatory glycoprotein isolated from ajowan (Trachyspermum ammi L.).

Ajowan (Trachyspermum ammi L.) spice has been used in food preparations and also as a traditional medicine in Ayurveda. Although a number of pharmacological activities have been attributed to ajowan, its role in immunomodulation is not known. The main objective of the present study is to examine the macromolecular immunomodulatory components. Macrophage activation was studied by nitric oxide (NO) release, phagocytosis and secretion of pro-inflammatory cytokines as the markers. Ethanol precipitate (fractional) of ajowan aqueous extract was subjected to conventional chromatography (Q Sepharose followed by Bio-Gel P-100). One of the proteins (30.7 kDa; ajowan glycoprotein or Agp) showed effective mitogenic activity towards splenocytes. Agp is a O-linked glycoprotein with the glycans contributing to one-third of the molecular mass. It has a high content of glutamic acid, serine, aspartic acid and proline whereas galactose (45.7%), arabinose (34.5%), glucose (7%), mannose (5%) and xylose (4%) are the constituent sugars. Secondary structure analysis indicated that Agp contains 79% α-helices and 21% random coil. Internal sequencing of the tryptic peptides did not show homology with the existing proteins in the database (BLAST). Agp at 1 µg/mL induced proliferation of B-cell enriched murine splenocytes and activated macrophages in releasing NO and promoted phagocytosis (p < 0.01). RAW 264.7 cells produced pro-inflammatory cytokines (IL-12, TNF-α and IFN-γ) at 1 µg/mL Agp (p < 0.01). Deproteinized Agp (dpAgp) failed to elicit activation of murine immune cells, whereas deglycosylated Agp (20 kDa; dgAgp) showed compromised efficiency. This is the first report of an immunomodulatory protein from ajowan.

Volatile emission in dry seeds as a way to probe chemical reactions during initial asymptomatic deterioration.

The nature and kinetics of reactions in dry seeds determines how long the seeds survive. We used gas chromatography to assay volatile organic compounds (VOCs) emitted from seeds of three unrelated species as a means to non-invasively probe chemical changes during very dry, dry, and humid storage (seeds were dried to 5.5, 33, and 75% relative humidity at room temperature). VOCs emitted from seeds stored in humid conditions reflected fermentation-type reactions, with methanol and ethanol being predominant in Lactuca sativa and Carum carvi, and acetaldehyde and acetone being predominant in Eruca vesicaria. Dried C. carvi seeds continued to emit fermentation-type products, although at slower rates than the seeds stored in humid conditions. In contrast, drying caused a switch in VOC emission in L. sativa and E. vesicaria seeds towards higher emission of pentane and hexanal, molecules considered to be byproducts from the peroxidation of polyunsaturated fatty acids. Longevity correlated best with the rate of fermentation-type reactions and appeared unrelated to the rate of lipid peroxidation. Emission of VOCs decreased when seed species were mixed together, indicating that seeds adsorbed VOCs. Adsorption of VOCs did not appear to damage seeds, as longevity was not affected in seed mixtures. Collectively, the study shows similarity among species in the types of reactions that occur in dry seeds, but high diversity in the substrates, and hence the byproducts, of the reactions. Moreover, the study suggests that the most abundant VOCs arise from degradation of storage reserves within seed cells, and that these reactions and their byproducts are not, in themselves, damaging.

Morphology, physiology, and biochemistry of zinc-stressed caraway plants.

A greenhouse pot experiment was conducted to evaluate the impact of zinc supply (0, 1, and 2 mM Zn as ZnSO4) on morpho-physiological and biochemical parameters of caraway (Carum carvi L.). Exposure to different Zn concentrations for 12 weeks compromised severely all growth parameters (plant height, number of secondary branches, diameter of primary and secondary branches, fresh and dry weight of aerial parts and roots) yield and its components (number of umbels per primary branches and secondary branches; number of umbel per plant; number of seeds per plant; and the weight of 1000 seeds). These manifestations were intimately linked with excessive accumulation of Zn in roots and leaves, alteration of the content of photosynthetic pigments, and extended lipid peroxidation. A manifest increment of proline and soluble sugar content was also observed in response to Zn application. Lipid content in seeds was dropped in Zn-treated plants and the fatty acid profiles were profoundly affected as they were enriched with saturated fatty acids at the expense of unsaturated ones. While improving their oxidative stability as revealed by the reduced values calculated oxidizability and oxidative susceptibility, Zn treatment reduced the lipid nutritional quality of caraway seeds. Moreover, Zn treatment reduced the essential oil yield and its main component carvone while it enhanced the content of its precursor limonene. It also induced alteration of terpene metabolism as revealed in the redirection of the carbon flux to the shikimate/phenylpropanoid pathway resulting in the stimulation of the production of phenolic compounds and their subsequent antioxidant activities.

Antioxidant activities of hot water extracts from various spices.

Recently, the natural spices and herbs such as rosemary, oregano, and caraway have been used for the processing of meat products. This study investigates the antioxidant activity of 13 spices commonly used in meat processing plants. The hot water extracts were then used for evaluation of total phenolic content, total flavonoids content and antioxidant activities. Our results show that the hot water extract of oregano gave the highest extraction yield (41.33%) whereas mace (7.64%) gave the lowest. The DPPH radical scavenging ability of the spice extracts can be ranked against ascorbic acid in the order ascorbic acid > clove > thyme > rosemary > savory > oregano. The values for superoxide anion radical scavenging activities were in the order of marjoram > rosemary > oregano > cumin > savory > basil > thyme > fennel > coriander > ascorbic acid. When compared to ascorbic acid (48.72%), the hydroxyl radical scavenging activities of turmeric and mace were found to be higher (p < 0.001). Clove had the highest total phenolic content (108.28 µg catechin equivalent (CE)/g). The total flavonoid content of the spices varied from 324.08 µg quercetin equivalent (QE)/g for thyme to 3.38 µg QE/g for coriander. Our results indicate that hot water extract of several spices had a high antioxidant activity which is partly due to the phenolic and flavonoid compounds. This provides basic data, having implications for further development of processed food products.

Non-invasive localization of thymol accumulation in Carum copticum (Apiaceae) fruits by chemical shift selective magnetic resonance imaging.

Magnetic resonance imaging was used to localize the site of essential oil accumulation in fruit of Carum copticum L. (Apiaceae). A chemical shift method is described that utilized the spectral properties of the aromatic monoterpene thymol, the major component of the essential oil, to image thymol selectively. The presence of essential oil secretory structures in the fruit and an essential oil containing a high proportion of thymol were confirmed with optical microscopy and gas chromatography-mass spectrometry, respectively. Selective imaging of whole C. copticum fruits showed that thymol accumulation was localized to the secretory structures (canals) situated in the fruit wall. The technique was considered non-invasive as the seeds used in the imaging experiments remained intact and viable.