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A major revision of the importance of solute carrier (SLC) transporters in human physiology and pathology has taken place in recent years. SLCs comprise the largest family of transporters, and there is significant evidence of their implication in health and several pathologies, leading to a growing interest in these transporters as novel targets for drug discovery. Since SLCs transport a broad range of endogenous and exogenous compounds, including drugs, they are the basis of significant drug-drug interactions and can cause potential drug toxicity or a lack of efficacy. This review compiles the up-to-date knowledge on the natural occurrence of the principal SLC families in human organs and tissues, in particular, highlighting their biological function and dysfunction in disease. Moreover, SLC implications in pharmacokinetics and drug-drug interactions are reviewed, concepts that can be useful in drug design.

The Biopharmaceutics Drug Disposition Classification System (BDDCS) predicts intestinal transporter effects to be clinically insignificant following oral dosing for highly soluble and highly permeable/metabolized drugs (class 1 drugs). We investigated the effect of inhibiting P-glycoprotein (P-gp) on the in vitro rat intestinal permeability (Papp) and metabolism of the class 1 drug verapamil. Jejunal segments from Sprague-Dawley rats fasted overnight were mounted in Ussing chambers filled with 10 mL of Krebs-Ringer buffer (KRB). For P-gp inhibition studies, GG918 0.5 μM was added to the KRB solution. The experiment started by the addition of verapamil (1 or 10 μM) to either apical or basolateral sides. Samples from verapamil donor and receiver compartments were collected at 30 s and 0.166, 0.5, 1, 1.83 and 3 h after the start of the experiment. Analysis of verapamil and its major metabolite, norverapamil, in the samples and intracellularly at 3 h was performed by HPLC. The same experiment was repeated with norverapamil 10 μM (verapamil metabolite), digoxin 100 nM (positive control for P-gp activity) and atorvastatin 1 and 10 μM (example of a class 2 drug). For 1 μM verapamil, efflux ratio (B to A Papp/A to B Papp) was 4.6 and markedly decreased by GG918 (efflux ratio = 1.1). For 10 μM verapamil efflux ratio was 4.1 (control) vs 1.8 (GG918), comparable to the change seen for digoxin 100 nM with an efflux ratio of 3.6 (control) vs 1.6 (with GG918) and atorvastatin (efflux ratio of 5.2 and 3.0 for atorvastatin 1.0 and 10 μM, respectively, changed to 1.0 and 0.65 with GG918). The changes observed in the norverapamil 10 μM experiment were also significant, where efflux ratio decreased from 13.5 (control) to 1.5 (GG918). The extraction ratio (ER) of 10 μM verapamil to norverapamil decreased from 0.41 after an apical dose to 0.21 after a basolateral dose, but was unaffected by the incubation with GG918. The results suggest that P-gp inhibition has an effect on class 1 drug verapamil and class 2 drug atorvastatin Papp in the rat intestine. Moreover, a stronger P-gp effect on the Papp of the more polar norverapamil metabolite was observed. Papp changes caused by the P-gp inhibitor GG918 do not affect the extent of verapamil metabolism.

117 Biomedical and Biopharmaceutical Research J o r n a l d e I n v e s t i g a ç ã o B i o m é d i c a e B i o f a r m a c ê u t i c aThe utility of in vitro trials that use Caco-2 cell systems as a replacement for animal intestinal permeability and human bioequivalence measurements in drug development AbstractCaco-2 cells have been widely used for in vitro intestinal permeability screening of new molecules in drug development but with some pitfalls. Limiting the application of Caco-2 permeability screening to passive compounds is difficult as the majority of approved drugs include both passive diffusion and active transport. The aim of this study was to evaluate Caco-2 cells utility in assessing effects of P-gp mediated efflux. For that purpose the study design included the highly soluble, highly permeable (class 1), verapamil and diltiazem, the highly soluble and poorly permeable drug (class 3) digoxin and the P-gp inhibitor GG918. The apparent permeability and efflux ratio (ER) were calculated. Digoxin, a positive control for P-gp, presented an ER of 4, which decreased to around 1 by GG918 addition, consistent with a P-gp effect in Caco-2 cells. ER for verapamil and diltiazem was nearly 1 and the presence of GG918 resulted in no ERs changes. These results suggest that P-gp apparently plays a minimal role in transport of class 1 drugs across Caco-2 cells while class 3 drugs should be significantly affected by P-gp. It is suggested that Caco-2 cells may be useful to determine whether P-gp plays a relevant role in intestinal absorption.Key words: Caco-2, intestinal permeability, P-glycoprotein, diltiazem, verapamil, digoxin. ResumoAs células Caco-2 são amplamente utilizadas no rastreio da permeabilidade intestinal de novas moléculas, embora com algumas limitações. A utilização de Caco-2 apenas para compostos com permeabilidade passiva elevada é difícil, uma vez que a maioria dos medicamentos aprovados incluem difusão passiva e transporte ativo. Este trabalho avalia a utilidade das células Caco-2 para previsão dos efeitos de efluxo mediados pela P-gp. O protocolo experimental incluiu fármacos altamente solúveis e permeáveis (classe 1), verapamilo e diltiazem, um fármaco altamente solúvel e pouco permeável (classe 3), digoxina e um inibidor da P-gp, GG918. Calcularam-se as permeabilidades aparentes e as razões de efluxo (ER). A digoxina, controlo positivo para a P-gp, apresentou uma ER de 4, que diminuiu para aproximadamente 1 por adição de GG918, consistente com um efeito da P-gp nestas células. As ER para o verapamilo/ diltiazem situaram-se próximo da unidade na ausência e presença de GG918. Estes resultados sugerem que a P-gp poderá desempenhar um papel irrelevante no transporte de fármacos de classe 1 em células Caco-2, enquanto o transporte de fármacos de classe 3 poderá ser significativamente afectado pela P-gp. É proposto que as células Caco-2 podem ser úteis para determinar o papel da P-gp na absorção intestinal. a Palavras-Chave: Permeabilidade intestinal, Caco-2, glicoproteína-P, diltiazem, verapamilo,...

8 Biomedical and Biopharmaceutical Research J o r n a l d e I n v e s t i g a ç ã o B i o m é d i c a e B i o f a r m a c ê u t i c a Panel of evironmental health indicators for oncological diseases Painel de indicadores de saúde ambiental para doenças oncológicasKeywords: DPSEEA, indicators, oncology, environmental health, public health. ResumoEm Portugal o cancro é a primeira causa de morte prematura e a segunda em todas as idades. Mundialmente a proporção de casos de cancro atribuíveis a fatores de risco modificáveis excede um terço dos mesmos. Estes são casos evitáveis. O modelo de organização de indicadores de saúde ambiental DPSEEA: Força Motriz-Pressão-Situação-Exposição-Efeito-Ação simplifica a descrição e a análise das relações entre desenvolvimento, ambiente e saúde, visando auxiliar a tomada de decisões. Através de uma pesquisa aplicada, descritiva e documental elaborou-se um quadro de 18 indicadores alicerçado no modelo DPSEEA, visando a leitura da situação e evolução da saúde ambiental em Portugal com impacto na área das doenças oncológicas.Foram consultados os sites de 41 entidades e identificados 81 indicadores. A seleção dos 18 indicadores mais adequados, 3 por cada dimensão do modelo, foi efetuada através dum painel de 21 peritos, organizados de forma aleatória e estratificada por áreas de formação. Os indicadores foram classificados numa escala de Likert quanto à validez, solidez, relevância, sensibilidade e qualidade estatística. Estatisticamente as diferenças nas pontuações observadas para os diferentes indicadores em todas as dimensões são significativas e o conjunto de 3 indicadores escolhidos para cada dimensão é igualmente relevante em 95% dos mesmos (p<0,05).Palavras-chave: DPSEEA, indicadores, oncologia, saúde ambiental, saúde pública.

The Pharmacovigilance Risk Assessment Committee (PRAC) is responsible for medicines safety monitoring in Europe. Biologic drugs (BDs) have more recently been developed and reinforced the treatment of serious and chronic diseases. Because of their specificities, BDs have become a new challenge for pharmacovigilance. This work evaluates safety signals generated by PRAC for BDs vs. conventional therapy (CT) between September 2012 and December 2018 (819 signals). Normalizing the results by the number of molecules (INN) in each drug class we found the proportion of safety signals by therapy type to be 4 for BDs vs. 2.5 for CT. The System Organ Classes (SOCs) affected by safety signals triggered for BDs and CT were compared. The three most relevant System Organ Classes (SOCs) found to be related to CT signals are general disorders and administration site conditions (14%), skin and subcutaneous tissue disorders (7%) and gastrointestinal disorders (6%). Signals related to BDs are mainly associated with blood and lymphatic system disorders (14%), skin and subcutaneous tissue disorders (13%) and nervous system disorders (10%). During the study period safety signals for BDs were proportionally 1.6 higher than safety signals for CT.

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