Synthesis and Biological Studies of Cationic Organoiron Star-Shaped Dendrimers Attached with Ketoprofen and Mefenamic Acid at the Peripheries.. [DOI: 10.21203/rs.3.rs-2996898/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The design of new star-shaped dendrimers with ketoprofen and mefenamic acid at the periphery was achieved using the divergent method. The use of cationic cyclopentadienyliron moieties coupled with the introduction of ketoprofen and mefenamic acid to the dendrimer allowed to produce dendrimeric materials that possess antimicrobial and anti-inflammatory activities. The dendrimers' compositions were analyzed through FT-IR, 1H-NMR, and 13C-NMR spectroscopic techniques. Furthermore, all synthesized dendrimers exhibited exceptional thermal stability within the 300 – 350oC range, with the cationic iron moieties breaking down at around 200oC. The surface morphology of the dendrimers was examined using Scanning Electron Micrographs (SEM) with no significant change between the three generations in the morphology. In addition, the electrochemical properties were also analyzed by Cyclic voltammetry (CV). The redox wave intensity and broadness showed changes as the dendrimer generation increased. These dendrimers were tested for their in vitro toxicities in mammalian cell lines, antimicrobial and anti-inflammatory activities and displayed positive results.

Aspirin-Based Organoiron Dendrimers as Promising Anti-Inflammatory, Anticancer, and Antimicrobial Drugs

Designing nanocarriers with actions directed at a specific organ or tissue is a very promising strategy since it can significantly reduce the toxicity of a bioactive drug. In this study, an organometallic dendrimer was used to synthesize a biocompatible drug delivery system by attaching aspirin to the periphery of the dendrimer. Our goal is to enhance the bioavailability and anticancer activity of aspirin and reduce its toxicity through successive generations of organoiron dendrimers. The biological activity of aspirin-based dendrimer complexes was evaluated. The result of antimicrobial activity of the synthesized dendrimers also demonstrated an increase in their antimicrobial activity with increased generation of the dendrimers for most types of microorganisms. This study reveals for the first time that organoiron dendrimers linked with aspirin exhibit an excellent Gram-negative activity comparable to the reference drug Gentamicin. All synthesized dendrimers were tested for their anticancer activity against breast cancer cell lines (MCF-7), hepatocellular cell lines (Hep-G2), and a non-cancer cell line, Human Embryonic Kidney (HEK293), using the MTT cell viability assay and compared against a standard anticancer drug, Doxorubicin. Compounds G3-D9-Asp and G4-D12-Asp exhibited noticeable activity against both cell lines, both of which were more effective than aspirin itself. In addition, the in vivo anti-inflammatory activity and histopathology of swollen paws showed that the designed aspirin-based dendrimers displayed significant anti-inflammatory activity; however, G2-D6-Asp showed the best anti-inflammatory activity, which was more potent than the reference drug aspirin during the same period. Moreover, the coupling of aspirin to the periphery of organoiron dendrimers showed a significant reduction in the toxicity of aspirin on the stomach.

Pharmacological Evaluation of Novel Organoiron Dendrimers as Antimicrobial and Anti-Inflammatory Agents

The synthesis of a novel and attractive class of nonsteroidal anti-inflammatory and antimicrobial organoiron dendrimers attached to the well-known drug ibuprofen is achieved. The structures of these dendrimers are established by spectroscopic and analytical techniques. The antimicrobial activity of these dendrimers is investigated and tested against five human pathogenic Gram-positive and Gram-negative bacteria, and minimum inhibitory concentrations are reported. Some of these synthesized dendrimers exhibit higher inhibitory activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and Staphylococcus warneri compare to the reference drugs. As well, the in vitro and in vivo anti-inflammatory activities of these dendrimers are evaluated. The results of in vivo anti-inflammatory activity and histopathology of inflamed paws show that all dendrimers display considerable anti-inflammatory activity; however, second-generation dendrimer (G2-D6) shows the best anti-inflammatory activity, which is more potent than the commercial drug ibuprofen at the same tested dose. Results of the toxicity study reveal that G2-D6 is the safest drug on biological tissues.

Aggregation enhanced excimer emission (AEEE) with efficient blue emission based on pyrene dendrimers

A series of fluorescent dendrimers with pyrene moieties exhibited aggregation enhanced excimer emission (AEEE). Increases in the dendrimer generation caused emission at 480 nm with a high excimer/monomer emission intensity ratio.

Potential health risks from exposure to indoor formaldehyde

An indoor air quality survey was conducted in Southern Louisiana to determine levels of airborne formaldehyde. Gas chromatography analyses of 419 air samples collected from 53 houses revealed levels of formaldehyde ranging from non-detectable to 6.60 mg/m3. Seventy four percent (312/419) of the samples had detectable amounts of airborne formaldehyde. Of the 312 positive samples, approximately 60% exceeded the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) guideline of 0.123 mg/m3. The highest number of samples exceeding the formaldehyde benchmark were collected in winter. It would appear that in some Southern Louisiana houses, a high level of formaldehyde could serve as a potential upper respiratory irritant.

Potential health risks from indoor exposure to chlorpyrifos (O,O-diethyl O-[3,5,6-trichloro-2-pyridyl] phosphorothioate)

A four-season, indoor air quality survey was conducted in Southern Louisiana to determine the indoor air levels of the pesticide chlorpyrifos. Gas chromatographic analysis of 213 air samples collected from 53 houses revealed levels of chlorpyrifos ranging from non-detected to 2.13 micrograms/m3. Using the Florida-Pinella exposure guideline (24-hr exposure to chlorpyrifos at 0.48 microgram/m3), it was noted that 14% of the samples exceeded this guideline. The exposure of occupants to the indoor air concentrations of the pesticide, however, were below either the irritation or the odor thresholds, and effects on acute and chronic health responses remains uncertain.

Health risks from exposure to metals in household dusts

The levels of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), mercury (Hg), and nickel (Ni) were determined in a total of 315 indoor and outdoor dust samples collected from 53 households in Louisiana. Inductively coupled plasma analysis revealed that in many samples, the metal content exceeded the United States Environmental Protection Agency (EPA) Risk-Based Concentration (RBC) guidelines. For example, the number of dust samples above the EPA-RBC included 64 for Cd, 52 for Hg, 43 for As, 4 for Fe, 4 for Cu, 3 for Cr, and 2 for Ni. One-hundred fifty-two samples exceeded the street-dust level for Pb published by the U.S. Agency for Toxic Substances and Disease Registry. The results of this study indicate that exposure to indoor and/or outdoor dust presents a potential health risk for Louisiana residents.

Assessment of potential health risks associated with ingesting heavy metals in fish collected from a hazardous-waste contaminated wetland in Louisiana, USA

Significant adverse effects on environmental quality, ecosystem integrity, and human health have often been associated with improper disposal of hazardous materials. This study ascertains the levels of eight heavy metals in various fish species that were collected from a local hazardous-waste-contaminated wet-land and estimates the potential health risk that may be associated with consuming such fish. We examined a total of 53 fish samples representing 12 different species. The respective mean concentrations (ng/g) of arsenic, cadmium, chromium, copper, iron, lead, mercury, and nickel found in edible tissues were as follows: 72.5 +/- 103.1, 55.4 +/- 34.6, 97.4 +/- 111.7, 177.3 +/- 328.3, 2711.0 +/- 4469.6, 26.0 +/- 119.0, 32.7 +/- 75.3, and 81.5 +/- 178.9. For a 10-kg child eating 6.5 g of fish per day, the computed combined hazard index was 0.475 ; for 70-kg adults with a daily consumption of 6.5 g (general population), 30 g (sport fishermen), and 140 g (subsistence fishermen), the respective computed hazard indices were 0.068, 0.313, and 1.462. The results indicate that subsistence fishermen had the highest risk for systemic effects, with an exposure exceeding the Environmental Protection Agency (EPA) Reference Dose value. In a 10-kg child, such excess exposure would be reached--even with such single metals as arsenic and mercury--when applying the EPA-approved maximum fish consumption rate of 54 g/day to the general population. The cancer risk for arsenic, the only metal with an established cancer potency factor from oral exposure, varied from 8 x 10(-6) to 253 x 10(-6), indicating an exposure exceeding the widely accepted risk level of 1 x 10(-6) (one excess cancer per 10(6) population).

Arsenic levels in blood, urine, and hair of workers applying monosodium methanearsonate (MSMA)

Uptake and excretion of total arsenic from monosodium methanearsonate (MSMA) in workers who applied the herbicide was followed during the spraying season. Urine, blood, and hair samples were collected and air samples were taken from the workers' breathing zone. Arsenic concentrations in air samples ranged from 0.001-1.086 micrograms/m3. Blood and urine arsenic values ranged from 0.0-0.2 mg/L and 0.002-1.725 mg/L, respectively. The geometric mean arsenic concentration in urine increased during the week but returned to base levels on weekends. Hair arsenic concentrations ranged from 0.02-358.0 mg/kg, increased during the spraying season, and returned to pre-season levels once herbicide application ceased. Three workers had higher than normal pre-exposure hair values. However, only one of the three workers had consistently above normal values throughout the study period.

Fate of foreign compounds in the environment

The behavior of a foreign compound, once introduced into the environment, depends upon the nature of the compound and its interaction with the physical, chemical, and biological components of the ecosystem. It is important to understand the interaction of exogenous compounds with the ecosystem, because only in this way can the potential human health effects of these compounds be predicted. This paper outlines the various parameters that must be considered when predicting the fate of a compound in the environment. An example is then given which relates these factors to the distribution and fate of arsenical compounds.

Biotransformation of the pesticide sodium arsenate

Biotransformation is an important parameter in assessing the environmental impact and fate of pesticides since metabolites produced may be either more or less toxic than the parent compound. Sodium arsenate (+5 inorganic), the wood preservative and insecticide, may be converted to both inorganic (+3) and organic compounds (-3) by microorganisms in soil, sediment and water bodies. Biotransformation of sodium arsenate was studied in pure cultures of 5 bacterial species using a mineral salt and limited carbon source medium. Arsenate concentrations were 10 microgram/ml and 100 microgram/ml of arsenic respectively. The rate of biodegradation of the parent compound was described by a first order composite exponential equation of the form Ct = C1e-k1t+C2e-k2t. Rates of production of metabolites (arsenite, monomethylarsine, dimethylarsine and trimethylarsine) were described by a first order exponential equation of the form Ct = Co (1-e-kt).

Accumulation of MSMA in the fruit of the blackberry (Rubus sp.)

The organic arsenical herbicide, MSMA, is used extensively for weed control along highway rights of way. Residues of the herbicide in edible crops growing near roadsides are of health concern since these products are accessible year round for harvesting by the unsuspecting public. This study examined the uptake and concentration of MSMA in the fruit of the blackberry during the various stages of maturation following the recommended application of 3.37 kg MSMA/hectare. MSMA-Aso accumulated with uptake being greatest in the earliest stages of fruit development. Arsenic levels consistently increased to concentrations of 25-30 microgram/g during one week following herbicide application to green fruit. Uptake during the later stages of development reached approximately 12.5 microgram/g in red and ripe fruit respectively. At all stages, uptake of herbicide in berries exceeded concentrations applied topically, indicating a major source of arsenic through transport from stems and leaves. Berries also absorbed herbicide following topical application to the fruit which is a significant source of arsenic following application in the later stages of development. The movement of herbicide to ripening fruit can be described by a three compartment model in which arsenic gains access from the surface of the berry and by translocation from stems and leaves. Parameter estimates for the model appear in the text.