Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana)

Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential source of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic E. coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analyzed. Among hundreds of compounds, only a few homologous compounds were identified that contained isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole containing analogs, sulfonamides, furanones, flavanones, and known to possess broad-spectrum antimicrobial properties, and possess anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs

Protective role of α-tocopherol on two Vicia faba cultivars against seawater-induced lipid peroxidation by enhancing capacity of anti-oxidative system

To examine the effect of seawater stress on growth, yield, physiological and antioxidant responses of faba bean plant and whether the exogenous application with vitamin E could mitigate the adverse effect of salinity stress or not, a pot experiment was carried out during 2011/12 winter season under green house of the National Research Centre, Dokki, Cairo, Egypt. Two faba bean cultivars (Giza 3 and Giza 843) irrigated with diluted seawater (Tap water, 3.13 or 6.25 dS m−1) and α-tocopherol (0, 50 or 100 mg L−1) were used. At 75 days after sowing, growth sample was taken for vegetative growth measurement, proline, carotenoids, antioxidant enzyme activities (SOD, CAT, POX and PAL), lipid peroxidation, and inorganic ions as well as seed yield and yield attributes were determined. The results revealed that seawater triggered significant inhibitory effects on faba bean growth and yield especially for Giza 3 cultivar with obvious increments in MDA and Na+ ion contents. Foliar application with α-tocopherol at rate of 100 mg L−1 followed by 50 mg L−1 on faba bean plants exerted certain alleviative effects on these indices in particular on Giza 843. α-Tocopherol could play an important role in alleviation of injury of faba bean irrigated with diluted seawater through the enhancement of the protective parameters such as antioxidant enzymes, proline, carotenoids, and inorganic ions (K+ and Ca2+) to be effective in decreasing MDA content, lessening the harmful effect of salinity, and improving faba bean growth, seed yield and seed yield quality

Physiological and biochemical responses of thyme plants to some antioxidants

Orabi SA, Talaat IM, Balbaa LK. 2014. Physiological and biochemical responses of thyme plants to some antioxidants. Nusantara Bioscience 6: 118-125. Two pot experiments were conducted to investigate the effect of tryptophan, nicotinamide and α-tocopherol (each at 50 and 100 mg/L) on plant growth, essential oil yield and its main constituents. All treatments significantly promoted plant height, and increased fresh and dry mass (g/plant) of thyme (Thymus vulgaris L.). The treatment with 100 mg/L nicotinamide showed increasing in total potassium mainly in the first cut. Total soluble sugars, oil percentage and oil yield and protein recorded increments with tryptophan treatments. Treatment of Thymus plants with 100 mg/L nicotinamide observed the highest percentage of thymol (67.61%). Oxygenated compounds recorded the highest value with 50 mg/L α-tocopherol treatment, while the maximum non-oxygenated ones resulted from the application of 100 mg/L nicotinamide. All treatments under study significantly affected the activity of oxidoreductase enzymes (POX and PPO). Nicotinamide at the concentration of 100 mg/L recorded the highest increments in APX and GR and the lowest values in oxidoreductase enzyme activities added to the lowest values of lipid peroxidation to enhance the best protection of thyme plants