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A Pharmacological Appraisal of Antimalarial Plant Species
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Mahwahwatse J. Bapela, Precious B. Ramontja, Mcebisi J. Mabuza
The leaf water extract of Maytenus arbutifolia (L.) displayed a significantly high parasite selectivity (SI = 3838) for P. falciparum (D6) strain. It showed an IC50 value of 0.95 µg/mL and a cytotoxicity value of 3645.7 µg/mL when tested on Vero E6 cells (Muthaura et al., 2007b). Warburgia ugandensis from the Canellaceae family was reported by Muthaura et al. (2011) to have significant antiplasmodial activity. Its MeOH stem bark extract displayed an IC50 value of 1.4 µg/mL on the KI strain of P. falciparum, with a cytotoxicity value of 0.34 µg/mL on L6 cells. Warburgia ugandensis showed a very low parasite selectivity (SI = 0.24), which does not fall within the acceptable range of potential drug hits (Muthaura et al., 2011). However, there are many different derivatization procedures, techniques and approaches that can be applied to chemically manipulate the plant extract to be clinically safe and more selective.
The Design of Receptor-Binding Radiotracers
Published in Lelio G. Colombetti, Principles of Radiopharmacology, 2019
William C. Eckelman, Raymond E. Gibson, Waclaw J. Rzeszotarski, Victor Jiang, J. Krijn Mazaitis, Chang Paik, Toru Komai, Richard C. Reba
Another approach (for which there is much precedent in the field of pharmaceutical development, chemotherapy, fluorescent labeling, and spin labeling) is derivatization of biochemicals or drugs.8 In the radiotracer context, the derivative will contain the site-directing biochemical or drug linked to a radionuclide carrying group; if the radionuclide carrying group is a chelating agent, the chelating portion will be required to retain high affinity for a metallic radionuclide. If the radionuclide is iodine, an aromatic ring or an ethynyl group will be added to the biologically active compound (Figure 1).
Drug Targeting to the Lung: Chemical and Biochemical Considerations
Published in Anthony J. Hickey, Sandro R.P. da Rocha, Pharmaceutical Inhalation Aerosol Technology, 2019
Peter A. Crooks, Narsimha R. Penthala, Abeer M. Al-Ghananeem
As mentioned previously, a significant reduction in antibody reactivity is often observed after multiple sites of conjugation of drug with antibody. This has led to the development of carriers that, when covalently linked to antibody, are able in turn to covalently bind many drug molecules to appropriate carrier functionalities. Examples of carrier molecules that have been used include dextran (Pimm et al. 1982, Hurwitz et al. 1979, Tsukada et al. 1987), human serum albumin (Garnett et al. 1983), and poly-L-glutamate (Tsukada et al. 1984). Obviously, such a gross molecular modification of the parent antibody may well affect its overall properties, and this often leads to significant differences in biodistribution of an antibody-carrier-drug complex relative to the parent antibody. In addition, for reasons stated previously, such a structural derivatization may also result in lower tissue specificity and increased toxicity. Factors affecting the pharmacology of antibody-drug conjugates (ADCs) and the interaction between ADC carriers and biological systems has recently been reviewed (Lucas et al. 2018).
Overview of analytical methods for determining novel psychoactive substances, drugs and their metabolites in biological samples
Published in Critical Reviews in Toxicology, 2022
Jadwiga Musiał, Jakub Czarny, Renata Gadzała-Kopciuch
GC–MS is characterized by a lower detection limit than immunochemical tests (Papoutsis et al. 2010; Kerrigan, Banuelos, et al. 2011; Kerrigan, Mellon, et al. 2011). However, GC–MS requires a derivatization step to identify a higher number of psychoactive substances (Papoutsis et al. 2010). Derivatization prolongs run time and increases analytical costs, which poses an additional problem for toxicology laboratories. Due to these shortcomings, LC–MS methods are more widely used than GC–MS (Mueller et al. 2005; Wohlfarthet al. 2010; Dalsgaard et al. 2012; Kneisel and Auwärter 2012; Swortwood et al. 2013; Tang et al. 2014; Wicka et al. 2014; Adamowicz and Tokarczyk 2016; Cannaert et al. 2016; Rojek et al. 2017; Salomone et al. 2017; Yeter 2017; Fels et al. 2020). LC–MS supports the determination of numerous compounds (Mueller et al. 2005; Delsgaard et al. 2012; Tang et al. 2014; Adamowicz and Tokarczyk 2016; Yeter 2017). These methods are characterized by lower LOD values, shorter run time, and lower costs. The optimal method for detecting psychoactive substances should eliminate deuterated compounds which increase the cost of the analysis. Particular focus should be placed on chromatographic methods that enable the separation and subsequent determination of substances with the same m/z ratios. Such analytes cannot be identified by multiple reaction monitoring (MRM) alone without proper chromatographic separation of the analyzed substances.
The nanomaterial-induced bystander effects reprogrammed macrophage immune function and metabolic profile
Published in Nanotoxicology, 2020
Peng Yuan, Xiangang Hu, Qixing Zhou
After coculture with A549 cells exposed to WS2 nanosheets for 24 h, the cell culture medium of differentiated THP-1 macrophages was removed, and the cells were washed twice with 1 mL of prewarmed PBS. Then, 1 mL of ice-cold 80:20 (v/v) methanol/water was immediately added, and the cells were scraped and collected in a 2-mL Eppendorf tube. The wells were washed again with an additional 1 mL of a methanol/water solution and combined with the previous solution. The metabolites were extracted using ice bath ultrasound (400 W, 30 min) followed by centrifugation (12 000 × g, 5 min, 4 °C). The supernatant was filtered through a 0.22-μm organic membrane filter, removed via nitrogen blowing, and lyophilized. Methoxamine hydrochloride (20 mg/mL, 50 μL) and N-methyl-N-(trimethylsilyl) trifluoroacetamide (80 μL) were added as derivatives. After derivatization, the samples (1 μL) were injected and analyzed using gas chromatography-mass spectrometry (GC-MS, 6890 N/5973, Agilent, USA). The metabolites were identified using full-scan monitoring with a detection slope of m/z 50-650, based on the National Institute of Standards and Technology (NIST) Mass Spectral Library in ChemStation software.
Comparison of the short-chain fatty acids in normal rat faeces after the treatment of Euphorbia kansui, a traditional Chinese medicine for edoema
Published in Pharmaceutical Biology, 2020
Dongjing Jiang, Sijia Guo, An Kang, Yonghui Ju, Jingxian Li, Sheng Yu, Beihua Bao, Yudan Cao, Yuping Tang, Li Zhang, Weifeng Yao
Pre-experiment was carried out to investigate the contents of acetic, propionic, isopropyl, butyric, 2-methylbutyric, valeric and heptanoic acids in faeces derived from normal rats gavaged with EK. It was found that isopropyl, 2-methylbutyric and heptanoic acids were not detected in the faeces. For this, acetic acid, propionic acid, butyric acid and valeric acid were selected as study subjects in this experiment. There were many methods for detecting SCFAs in biological samples such as serum (Zhao et al. 2007), urine (Jain et al. 2015), saliva, platelets (Bao and Mao 1991), intestinal contents and faecal culture fluid (Lu et al. 2014). These existing methods directly selected aqueous solution to investigate the extraction of SCFAs. The effect of matrix such as faeces on the content of SCFAs were not fully considered in the actual process. Based on the full consideration of biological sample matrix (faeces), propyl chloroformate was taken as an esterified derivatizing reagent. Reaction time of this method was short and volatilization of SCFAs could be effectively avoided in a low temperature environment. The derivatization process was carried out in the aqueous phase, facilitating the processing of biological samples. Moreover, the derivatives were easy to obtain and the testing samples did not need to be re-separated. The operation process became simpler and easier. At the same time, derivatized reagents were relatively inexpensive, which could effectively reduce the costs of this experiment.