In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax–decyl oleate nanoparticles

2007 ◽  
Vol 65 (1) ◽  
pp. 122-125 ◽  
Author(s):  
J.R. Villalobos-Hernández ◽  
C.C. Müller-Goymann
Keyword(s):  
Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 592 ◽  
Author(s):  
Abraham M. Abraham ◽  
Reem M. Alnemari ◽  
Jana Brüßler ◽  
Cornelia M. Keck

Antioxidants are recommended to prevent and treat oxidative stress diseases. Plants are a balanced source of natural antioxidants, but the poor solubility of plant active molecules in aqueous media can be a problem for the formulation of pharmaceutical products. The potential of PlantCrystal technology is known to improve the extraction efficacy and antioxidant capacity (AOC) of different plants. However, it is not yet proved for plant waste. Black tea (BT) infusion is consumed worldwide and thus a huge amount of waste occurs as a result. Therefore, BT waste was recycled into PlantCrystals using small-scale bead milling. Their characteristics were compared with the bulk-materials and tea infusion, including particle size and antioxidant capacity (AOC) in-vitro. Waste PlantCrystals possessed a size of about 280 nm. Their AOC increased with decreasing size according to the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity) assays. The AOC of the waste increased about nine-fold upon nanonization, leading to a significantly higher AOC than the bulk-waste and showed no significant difference to the infusion and the used standard according to DPPH assay. Based on the results, it is confirmed that the PlantCrystal technology represents a natural, cost-effective plant-waste recycling method and presents an alternative source of antioxidant phenolic compounds.


Heliyon ◽  
2021 ◽  
pp. e07644
Author(s):  
Yugo Uematsu ◽  
Fumihiko Ogata ◽  
Noriaki Nagai ◽  
Chalermpong Saenjum ◽  
Takehiro Nakamura ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Hany Youssef ◽  
Yasir Abdulhamed ◽  
Tarek Yousef ◽  
Gaber Abu El-Reash

Abstract In the current work, a ligand N'1-((E)-2-hydroxy-3H-indol-3-ylidene)-N'3-((E)-2-oxoindolin-3-ylidene)malonohydrazide (H4MDI) and its Cr(III) and Ni(II) complexes have been synthesized and characterized by various conventional methods. For evaluating the optimal ligand structure and its complexes, calculations of DFT were applied. Magnetic measurements inherent to their electronic spectra show that both Cr(III) and Ni(II) chelates have octahedron coordination frameworks. On the other hand, the IR spectral data revealed that the ligand behaves as a binegtive hexadentate in [Cr2(H2MDI)(H2O)2Cl4] and as a tetranegative hexadentate in [Ni2(MDI)(H2O)6].4H2O. In addition, the behavior of thermal decomposition for prepared complexes was discussed. Two comparable methods (Coats-Redfern and Horowitz-Metzger) were used to calculate the kinetic parameters of the resulted thermal decomposition stages. Furthermore, the ion-flotation process was used for the separation of Ni(II) from aqueous media via the prepared ligand as a chelating agent and oleic acid as a surfactant. Moreover, the antimicrobial behavior of the synthesized moieties was investigated against various bacterial and fungal strains. H4MDI has the most activity with minimum inhibitory concentration (MIC) of 0.78 µg/mL for both E. coli, and C. Albicans, while Ni(II) complex shows the activity against S. aureus, E. coli, and C. Albicans with MIC of 2.34, 4.68, and 1.17 µg/mL, respectively. Finally, the in-vitro cytotoxic activity of the prepared compounds against hepatocellular carcinoma human tumor cells (HePG-2) has been examined, and revealed that H4MDI and its Ni(II) complex show very strong activity against HePG-2 with IC50 of 9.7 and 7.7 µmol/L, respectively.


1956 ◽  
Vol 34 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Ann D. Anderson ◽  
Ralph B. March

Carbonic anhydrase activity has been demonstrated in vitro in preparations of the head, fat body, and gut of the American cockroach, Periplaneta americana (L.), and in the adult housefly, Musca domestica L. The insect factor, which is soluble in aqueous media and can be separated from the particulate cell fragments of insect tissue homogenates is heat labile and sensitive to cyanide inactivation. It is strongly inhibited by sulphanilamide, p-aminoethylphenyl-sulphonamide, and p-chlorphenylsulphonamide. No inhibition has been found with N-substituted sulphonamides or with any of the organic insecticides examined, including DDT, lindane, dieldrin, nicotine, rotenone, pyrethrins, and para-oxon. Sensitivity of carbonic anhydrase to sulphonamides having an intact—SO2NH2 group is also characteristic of mammalian preparations. The data indicate that inhibition of insect carbonic anhydrase cannot be an important factor in the mode of action of DDT or other organic insecticides.


2009 ◽  
Vol 4 (5) ◽  
pp. 194-204 ◽  
Author(s):  
Mohammad Mohiuddin ◽  
A.T.M. Zafrul Azam ◽  
Md. Shah Amran ◽  
Md. Amjad Hossain

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 614
Author(s):  
María Melissa Gutiérrez-Pacheco ◽  
Luis Alberto Ortega-Ramírez ◽  
Brenda Adriana Silva-Espinoza ◽  
Manuel Reynaldo Cruz-Valenzuela ◽  
Gustavo Adolfo González-Aguilar ◽  
...  

The objective of the present study is to evaluate the effect of individual and combined coatings of chitosan (0.008 g·mL−1) and carnauba wax (0.1 g·mL−1) with oregano essential oil (OEO, 0.08 g·mL−1) to reduce dehydration and microbial decay of fresh cucumbers stored at 10 °C. Chitosan-OEO-wax films showed the lowest water vapor transmission rate (0.141 g·m−2·h−1), compared to single chitosan films (0.257 g·m−2·h−1). While chitosan-OEO films completely inhibited the in vitro growth of Alternaria alternata and reduced the growth of Salmonella Typhimurium, Escherichia coli O157:H7, mesophilic bacteria, and fungi isolated from decayed cucumbers. Besides, the infrared analysis of chitosan-OEO-wax films showed shifts in O–H and N–H absorption bands, indicating possible hydrogen bonding between the components. Wax and wax-OEO were the most effective coatings to prevent weight loss in cucumbers during 15 days of storage at 10 °C, while the most effective antimicrobial treatments were chitosan and chitosan-OEO. Therefore, these results showed that carnauba wax and carnauba wax-OEO coatings were the most effective in weight loss, whereas chitosan and chitosan-OEO were the most effective to reduce the microbial load of the treated fresh cucumber.


2013 ◽  
Vol 118 (6) ◽  
pp. 1350-1361 ◽  
Author(s):  
Ilin Kuo ◽  
Belinda S. Akpa

Abstract Background: In vitro observations support the lipid sink theory of therapeutic action by confirming the capacity of lipid emulsions to successfully uptake bupivacaine from aqueous media. However, competing hypotheses and some in/ex vivo small animal studies suggest that a metabolic or positive inotropic effect underlies the dramatic effects of lipid therapy. Controlled clinical tests to establish causality and mechanism of action are an impossibility. In an effort to quantitatively probe the merits of a “sink” mechanism, a physiologically based pharmacokinetic model has been developed that considers the binding action of plasma lipid. Methods: The model includes no fitting parameters and accounts for concentration dependence of plasma protein and lipid:anesthetic binding as well as the metabolism of the lipid scavenger. Predicted pharmacokinetics were validated by comparison with data from healthy volunteers administered a nontoxic dose of bupivacaine. The model was augmented to simulate lipid therapy and extended to the case of accidental IV infusion of bupivacaine at levels known to cause systemic toxicity. Results: The model yielded quantitative agreement with available pharmacokinetic data. Simulated lipid infusion following an IV overdose was predicted to yield (1) an increase in total plasma concentration, (2) a decrease in unbound concentration, and (3) a decrease in tissue content of bupivacaine. Conclusions: Results suggest that the timescale on which tissue content is reduced varies from organ to organ, with the concentration in the heart falling by 11% within 3 min. This initial study suggests that, in isolation, the lipid sink is insufficient to guarantee a reversal of systemic toxicity.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Patchara Punyamoonwongsa ◽  
Supattra Klayya ◽  
Warayuth Sajomsang ◽  
Chanikarn Kunyanee ◽  
Sasitorn Aueviriyavit

Silk sericin (SS) from the Bombyx mori silk cocoons has received much attention from biomedical scientists due to its outstanding properties, such as antioxidant, antibacterial, UV-resistant, and ability to release moisturizing factors. Unmodified SS does not self-assemble strongly enough to be used as a hydrogel wound dressing. Therefore, there is a need for suitable stabilization techniques to interlink the SS peptide chains or strengthen their structural cohesion. Here, we reported a method to form a silk semi-interpenetrating network (semi-IPN) structure through reacting with the short-chain poly(ethylene glycol) diacrylate (PEGDA) in the presence of a redox pair. Various hydrogels were prepared in aqueous media at the final SS/PEGDA weight percentages of 8/92, 15/85, and 20/80. Results indicated that all semi-IPN samples underwent a sol-gel transition within 70 min. The equilibrium water content (EWC) for all samples was found to be in the range of 70-80%, depending on the PEGDA content. Both the gelation time and the sol fraction decreased with the increased PEGDA content. This was due to the tightened network structure formed within the hydrogel matrices. Among all hydrogel samples, the 15/85 (SS/PEGDA) hydrogel displayed the maximum compressive strength (0.66 MPa) and strain (7.15%), higher than those of pure PEGDA. This implied a well-balanced molecular interaction within the SS/PEGDA/water systems. Based on the direct and indirect MTS assay, the 15/85 hydrogel showed excellent in vitro biocompatibility towards human dermal fibroblasts, representing a promising material for biomedical wound dressing in the future. A formation of a semi-IPN structure has thus proved to be one of the best strategies to extend a practical limit of using SS hydrogels for wound healing treatment or other biomedical hydrogel matrices in the future.


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