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Endocrine Disrupting Chemicals, Obesogens, and the Obesity Epidemic
Published in Nathalie Bergeron, Patty W. Siri-Tarino, George A. Bray, Ronald M. Krauss, Nutrition and Cardiometabolic Health, 2017
Raquel Chamorro-Garcia, Bruce Blumberg, Nathalie Bergeron, Patty W. Siri-Tarino, George A. Bray, Ronald M. Krauss
The organotins tributyltin (TBT) and triphenyltin (TPT) were the first obesogens described and they both activate PPARγ (Grun et al. 2006, Janesick et al. 2016, Kanayama et al. 2005). More recently, the pesticides triflumizole, quinoxyfen, spirodiclofen, and zoxamide have been shown to activate PPARγ and to increase lipid accumulation using in vitro models such as the murine pre-adipocyte 3T3-L1 cell line and mouse and human mesenchymal stem cells (MSCs) (Janesick et al. 2016, Li et al. 2012). In the same study, we found that the fungicide fludioxonil is not a PPARγ activator, but it activates RXR and increases lipid accumulation in 3T3-L1 cells and MSCs (Janesick et al. 2016). MSCs are able to differentiate into a variety of cell types, including adipocytes, osteoblasts, chondrocytes, and myocytes, depending upon the stimuli they receive (Cristancho and Lazar 2011). By exposing 3T3-L1 cells or MSCs to obesogen candidates in the presence of an adipogenic cocktail, it is possible to assess the adipogenic capabilities of individual chemicals by analyzing lipid accumulation and mRNA expression levels of adipogenic marker genes such as those described earlier (Chamorro-Garcia et al. 2012, Grun et al. 2006, Janesick et al. 2016, Kirchner et al. 2010). There is a subset of candidate obesogens whose mechanisms of action remain unknown. One example is bisphenol-A diglycidyl ether (BADGE), which is used in the manufacture of epoxy resins, paints, and as a coating in food cans. BADGE induces lipid accumulation in 3T3-L1 pre-adipocytes and MSCs, but the inhibition of PPARγ with the specific antagonists T0070907 or GW9663 does not interfere with BADGE-induced accumulation of lipids (Chamorro-Garcia et al. 2012). Other potential obesogens whose mechanisms of action remain unknown are imazalil, tebupirimfos, florchlorfenuron, flusilazole, acetamiprid, and pymetrozine, which are not PPARγ or RXR activators but induce adipogenesis in 3T3-L1 cells (Janesick et al. 2016). These studies indicate that further analyses are needed to more fully understand the mechanisms through which obesogens act.
Synthesis of novel pyrroles and fused pyrroles as antifungal and antibacterial agents
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Rania Helmy Abd El-Hameed, Amira Ibrahim Sayed, Shima Mahmoud Ali, Mohamed A. Mosa, Zainab M. Khoder, Samar Said Fatahala
Pyrroles and its fused derivatives, are an important class of naturally22,23 and synthetically24–26 occurring compounds with a wide-range of biological activities; antibacterial27–29, antifungal30–33, antiviral34–39, anticancer40,41 and anti-inflammatory42,43. Pyrrolnitin and fludioxonil, are two naturally secreted pyrroles, reported to bear a broad spectrum antifungal activities44–46. 7-deazapurine, naturally secreted pyrrolopyrimidines antibiotics, toyocamycin, tubercidin and sangivamycin, commonly have antibacterial, antifungal, anticancer, antiviral and anti-inflammatory activities22,47. Due to structural resemblance to purine, 7-deazapurines interfered with various cellular processes; toyocamycin united with tRNA, pyrrolopyrimidine inhibits tRNA aminoacylation. Sangivamycin has lately been revealed to inhibit protein kinases22, as revealed in Figure 2.
Analyzing pesticides and metal(loid)s in imported tobacco to Saudi Arabia and risk assessment of inhalation exposure to certain metals
Published in Inhalation Toxicology, 2022
Mohammed A. Al Mutairi, Hatim A. Al Herbish, Rakan S. Al-Ajmi, Hatim Z. Alhazmi, Reham A. Al-Dhelaan, Abdullah M. Alowaifeer
Out of 407 analyzed pesticides, only 23 pesticide residues were detected in raw tobacco from brands A to H (Table 1). Twelve fungicides were detected in 52.1% of tobacco samples; azoxystrobin, carbendazim, cyprodinil, fludioxonil, flutriafol, metalaxyl, 2-phenylphenol, tebuconazole, thiabendazole, thiophanate-methyl, tridimenol, and trifloxystrobin. Whereas 34.7% of tobacco samples contained eight pesticide residues; acetamiprid, anthraquinone, chlorantraniliprole, imidacloprid, permethrin (trans), piperonyl butoxide, tetramethrin I, and triflumuron. Furthermore, only 13% of tobacco samples contained three pesticide residues belonging to herbicide and acaricide classes (alachlor, bromopropylate, and pendimethalin).
Fungal and mycotoxin occurrence, affecting factors, and prevention in herbal medicines: a review
Published in Toxin Reviews, 2022
Jingsheng Yu, Meihua Yang, Jianping Han, Xiaohui Pang
Compared with the other two prevention strategies, physical prevention methods are nontoxic, broad-spectrum, and environmentally-friendly. The implementation of good agricultural practices has been considered reliable and environmentally sustainable for mycotoxin prevention during preharvest. The agricultural practice methods involve three main ways. Firstly, the genetic engineering can be used to breed new varieties that resist fungal contamination (Miller 2001, Kamle et al. 2019, Logrieco et al. 2021). Secondly, the application of fungicide has been demonstrated as effective to prevent fungal contamination and mycotoxin production. Miguel et al. (2015) found that the application of fludioxonil and metalaxyl-M fungicides exhibited inhibitory effect on the growth and FUB1 production of Fusarium verticillioides 103 F. Thirdly, some common intervention methods had a positive impact on the prevention of fungal contamination, such as hand sorting, maintaining optimal plant densities, and washing (van der Westhuizen et al. 2011, Alberts et al. 2019). During the postharvest, the majority of prevention strategies are performed by regulating the physical conditions to prevent the growth of mycotoxin-producing fungi and mycotoxin synthesis. Numerous studies have focused on regulating air composition to inhibit fungal growth and mycotoxin production. Gallo et al. (2016) indicated that the AFB1 level decreased at 20 °C and aw 0.93. Paola et al. (2008) reported that the AF production of Aspergillus flavus was inhibited, when the carbon dioxide content was increased 20%. In addition, Valero et al. (2008) showed the OTA accumulation produced by Aspergillus carbonarius and Aspergillus niger decreased, when the oxygen and carbon dioxide contents were 1% and 15%, respectively. Cairns-Fuller et al. (2005) studied the effect of carbon dioxide content on Penicillium verrucosum, and observed that OTA synthesis was inhibited at 50% of carbon dioxide or higher. In addition, other physical methods have been reported. Chen et al. (2010b) applied high hydrostatic pressure technology to reduce microbial contamination in roots and flowers of Echinacea purpurea, and found that this technology did not affect the active ingredient in Echinacea purpurea. A study by Scussel et al. (2011) demonstrated that O3 had a significant inhibitory effect on AF production of Aspergillus flavus and Aspergillus parasiticus. The effect of ultraviolet radiation A and B on Aspergillus parasiticus and Aspergillus carbonarius were studied, and the production of AFB2, AFG2, and OTA were suppressed (Esther et al. 2015).