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In Vitro Activity of Quaternary Ammonium Surfactants against Streptococcal, Chlamydial, and Gonococcal Infective Agents

Publication . Inácio, Ângela S.; Nunes, Alexandra; Milho, Catarina; Mota, Luís Jaime; Borrego, Maria J.; Gomes, João P.; Vaz, Winchil L.C.; Vieira, Otília V.

Quaternary ammonium compounds (QAC) are widely used, cheap, and chemically stable disinfectants and topical antiseptics with wide-spectrum antimicrobial activities. Within this group of compounds, we recently showed that there are significant differences between the pharmacodynamics of n-alkyl quaternary ammonium surfactants (QAS) with a short (C12) alkyl chain when in vitro toxicities toward bacterial and mammalian epithelial cells are compared. These differences result in an attractive therapeutic window that justifies studying short-chain QAS as prophylactics for sexually transmitted infections (STI) and perinatal vertically transmitted urogenital infections (UGI). We have evaluated the antimicrobial activities of short-chain (C12) n-alkyl QAS against several STI and UGI pathogens as well as against commensal Lactobacillus species. Inhibition of infection of HeLa cells by Neisseria gonorrhoeae and Chlamydia trachomatis was studied at concentrations that were not toxic to the HeLa cells. We show that the pathogenic bacteria are much more susceptible to QAS toxic effects than the commensal vaginal flora and that QAS significantly attenuate the infectivity of N. gonorrhoeae and C. trachomatis without affecting the viability of epithelial cells of the vaginal mucosa. N-Dodecylpyridinium bromide (C12PB) was found to be the most effective QAS. Our results strongly suggest that short-chain (C12) n-alkyl pyridinium bromides and structurally similar compounds are promising microbicide candidates for topical application in the prophylaxis of STI and perinatal vertical transmission of UGI.

2016-05-23Journal article

Open access

The harmonized INFOGEST in vitro digestion method: From knowledge to action

Publication . Egger, Lotti; Menard, Olivia; Delgado-Andrade, Cristina; Alvito, Paula; Assunção, Ricardo; Balance, Simon; Barberá, Reyes; Brodkorb, Andre; Cattenozh, Thomas; Clemente, Alfonso; Comi, Irene; Dupont, Didier; Garcia-Llatas, Guadalupe; Lagarda, María Jesús; Le Feunteun, Steven; JanssenDuijghuijsen, Lonneke; Karakaya, Sibel; Lesmes, Uri; Mackie, Alan R.; Martins, Carla; Meynier, Anne; Miralles, Beatriz; Murray, Brent S.; Pihlanto, Anne; Picariello, Gianluca; Santos, Claudia N.; Simsekm, Sebnem; Recio, Isidra; Rigby, Neil; Rioux, Laurie-Eve; Stoffers, Helena; Tavares, Ana; Tavares, Lucelia; Turgeon, Sylvie; Ulleberg, Ellen K.; Vegarud, Gerd E.; Vergères, Guy; Portmann, Reto

Within the active field of in vitro digestion in food research, the COST Action INFOGEST aimed to harmonize in vitro protocols simulating human digestion on the basis of physiologically inferred conditions. A harmonized static in vitro digestion (IVD) method was recently published as a primary output from this network. To validate this protocol, inter-laboratory trials were conducted within the INFOGEST network. A first study was performed using skimmilk powder (SMP) as amodel food and served to compare the different in-house digestion protocols used among the INFOGEST members. In a second inter-laboratory study applying the harmonized protocol, the degree of consistency in protein hydrolysis was investigated. Analysis of the hydrolyzed proteins, after the gastric and intestinal phases, showed that caseins were mainly hydrolyzed during the gastric phase, whereas β- lactoglobulin was, as previously shown, resistant to pepsin. Moreover, generation of free amino acids occurred mainly during the intestinal phase. The study also showed that a few critical steps were responsible for the remaining inter-laboratory variability. The largest deviations arose from the determination of pepsin activity. Therefore, this step was further clarified, harmonized, and implemented in a third inter-laboratory study. The presentwork gives an overviewof all three inter-laboratory studies, showing that the IVD INFOGEST method has led to an increased consistency that enables a better comparability of in vitro digestion studies in the future.

2015-12-08Journal article

Restricted access

The 2-hydroxy-nevirapine metabolite as a candidate for boosting apolipoprotein A1 and for modulating anti-HDL antibodies

Publication . Marinho, Aline T.; Batuca, Joana R.; Miranda, Joana P.; Caixas, Umbelina; Dias, Clara G.; Branco, Teresa; Soto, Karina; Pinheiro, Pedro; Bourbon, Mafalda; Marques, M. Matilde; Antunes, Alexandra M.; Monteiro, Emília C.; Pereira, Sofia A.

The antiretroviral nevirapine (NVP) is associated to a reduction of atherosclerotic lesions and increases in high-density lipoprotein (HDL)-cholesterol. Despite being a hepatotoxic drug, which forbids its re-purposing to other therapeutic areas, not all NVP metabolites have the same potential to induce toxicity. Our aim was to investigate the effects of NVP and its metabolites in an exploratory study, towards the identification of a candidate to boost HDL. A pilot prospective (n = 11) and a cross-sectional (n = 332) clinical study were performed with the following endpoints: HDL-cholesterol and apolipoprotein A1 (ApoA1) levels, anti-HDL and anti-ApoA1 antibodies titers, paraoxonase, arylesterase and lactonase activities of paraoxonase-1, and NVP's metabolite profile. NVP treatment increased HDL-cholesterol, ApoA1 and paraoxonase-1 activities, and lowered anti-HDL and anti-ApoA1 titers. In the prospective study, the temporal modulation induced by NVP was different for each HDL-related endpoint. The first observation was a decrease in the anti-HDL antibodies titers. In the cross-sectional study, the lower titers of anti-HDL antibodies were associated to the proportion of 2-hydroxy-NVP (p = 0.03). In vitro models of hepatocytes were employed to clarify the individual contribution of NVP's metabolites for ApoA1 modulation. Long-term incubations of NVP and 2-hydroxy-NVP in the metabolically competent 3D model caused an increase in ApoA1 reaching 43 % (p < 0.05) and 86 % (p < 0.001), respectively. These results support the contribution of drug biotransformation for NVP-induced HDL modulation, highlighting the role of 2-hydroxy-NVP as ApoA1 booster and its association to lower anti-HDL titers. This biotransformation-guided approach allowed us to identify a non-toxic NVP metabolite as a candidate for targeting HDL.

2021-03-16Journal article

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