Abstract Background Cnidarian venoms and extracts have shown a broad variety of biological activities including cytotoxic, antibacterial and antitumoral effects. Most of these studied extracts were obtained from sea anemones or jellyfish. The present study aimed to determine the toxic activity and assess the antitumor and antiparasitic potential of Palythoa caribaeorum venom by evaluating its in vitro toxicity on several models including human tumor cell lines and against the parasite Giardia intestinalis. Methods The presence of cytolysins and vasoconstrictor activity of P. caribaeorum venom were determined by hemolysis, PLA2 and isolated rat aortic ring assays, respectively. The cytotoxic effect was tested on HCT-15 (human colorectal adenocarcinoma), MCF-7 (human mammary adenocarcinoma), K562 (human chronic myelogenous leukemia), U251 (human glyoblastoma), PC-3 (human prostatic adenocarcinoma) and SKLU-1 (human lung adenocarcinoma). An in vivo toxicity assay was performed with crickets and the antiparasitic assay was performed against G. intestinalis at 24 h of incubation. Results P. caribaeorum venom produced hemolytic and PLA2 activity and showed specific cytotoxicity against U251 and SKLU-1 cell lines, with approximately 50% growing inhibition. The venom was toxic to insects and showed activity against G. intestinalis in a dose-dependent manner by possibly altering its membrane osmotic equilibrium. Conclusion These results suggest that P. caribaeorum venom contains compounds with potential therapeutic value against microorganisms and cancer.

A deficiência da Glicose-6-fosfato desidrogenase (G6PD) é a enzimopatia mais frequente, com uma prevalência global do 4,9%, e com aproximadamente 330 a 400 milhões de pessoas afetadas no mundo. A G6PD tem um importante papel no equilíbrio celular redox intracelular, especialmente nos eritrócitos; em condições de estresse oxidativo induzido, (por exemplo, pela exposição a agentes externos como fármacos, alimentos, ou infecções) as hemácias portadoras da variante enzimática e com deficiência da atividade enzimática, sofrem danos irreversíveis que condicionam a sua destruição acelerada. A hemólise explica o espectro de manifestações clínicas desta doença, que incluem icterícia neonatal, episódios de hemólise aguda induzida por agentes externos ou anemia hemolítica crônica. Este trabalho faz uma resenha dos aspectos epidemiológicos e clínicos desta doença, e revisa os aspectos fisiopatológicos no nível bioquímico-molecular, com ênfase especial na caracterização genética, estrutural e funcional das variantes associadas à deficiência de G6PD.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most frequent enzymopathy in humans with a global prevalence of 4.9 % and around 330 to 400 million patients affected worldwide. G6PD plays a fundamental role in the intracellular redox equilibrium, especially in red blood cells (RBC). Under oxidative stress (induced by exposure to external agents like drugs, infections or diet) RBC carrying the deficient variant suffer irreversible damage resulting in their accelerated destruction. This hemolysis explains the clinical manifestations of the disease that include neonatal jaundice, induced acute hemolysis or chronic hemolytic anemia. This work summarizes the epidemiologic and clinical features of G6PD deficiency, and reviews the molecular pathophysiology of this disease with special emphasis on the genetical, structural and functional characterization of variants causing this pathology.

La deficiencia de Glucosa-6-fosfato deshidrogenasa (G6PD) es la enzimopatía más frecuente, con una prevalencia global del 4,9% y con alrededor de 330 a 400 millones de personas afectadas en el mundo. La G6PD desempeña un papel fundamental en el equilibrio redox intracelular, especialmente en los eritrocitos; en condiciones de estrés oxidativo inducido (por ejemplo, por exposición a agentes externos como fármacos, alimentos o infecciones), los hematíes portadores de la variante enzimática y con deficiencia de la actividad enzimática, sufren daños irreversibles que condicionan su destrucción acelerada. La hemólisis explica el espectro de manifestaciones clínicas de esta enfermedad, que incluyen ictericia neonatal, episodios de hemólisis aguda inducida por agentes externos o anemia hemolítica crónica. El presente trabajo hace una reseña de los aspectos epidemiológicos y clínicos de esta enfermedad y revisa los aspectos fisiopatológicos a nivel bioquímico-molecular, con particular énfasis en la caracterización genética, estructural y funcional de las variantes asociadas a la deficiencia de G6PD.

Abstract Microbial alcohol oxidoreductases constitute a very diverse group. They can be divided into three major categories. (a) NAD(P)-dependent dehydrogenases. (b) NAD(P)-independent enzymes that use pirroloquinoline quinone (PQQ), heme C as cofactor. (c) FAD-dependent oxidases that catalyze an essentially irreversible oxidation of alcohols. The ADHs that have PQQ as the prosthetic group are divided into 3 groups; types I, II and III. Type I ADH is a simple quinoprotein having PQQ as the prosthetic group; while type II and type III ADHs are quinohemoprotein having heme C as well as PQQ. Type II are soluble periplasmic enzymes and are widely distributed in Proteobacterias such as Pseudomonas putida, Ralstonia eutropha and Comamonas testosteroni. Type III ADHs are membrane-bound enzymes and oriented towards the periplasmic surface. They have been identified and characterized solely in acetic acid bacteria. Type III ADH consists of three subunits. The intramolecular electron transfer in the type II and III ADHs is the PQQ to heme C of the first subunit and there, from heme to heme in the second subunit until arriving at ubiquinone. The three types of PQQ-ADHs are discussed in this paper.

Resumen Existe una gran diversidad de alcohol deshidrogenasas (ADHs) microbianas; las cuales son divididas en tres grandes grupos: (a) Las que son dependientes de las coenzimas NAD o NADP, (b) Las que son independientes de estas coenzimas; sin embargo, utilizan pirroloquinolina quinona (PQQ) y hemo tipo C como grupo prostético y (c) Las oxidasas dependientes de FAD que catalizan la reacción irreversible de alcoholes. Las ADHs que utilizan el PQQ, se encuentran a su vez divididas en tres tipos. Las ADHs tipo I que contienen sólo PQQ como grupo prostético y se les conoce como quinoproteínas; mientras que las ADHs tipo II y tipo III además del PQQ contienen hemo tipo C y se les conoce como quinohemoproteínas. Las ADHs tipo II son enzimas solubles que se encuentran en el espacio periplásmico y están presentes en proteobacterias como Pseudomonas putida, Ralstonia eutropha y Comamonas testosteroni. Las ADHs tipo Ill son enzimas que se encuentran ancladas a la membrana y trabajan orientadas hacia el espacio periplásmico. se les ha identificado y caracterizado únicamente en bacterias ácido acéticas. Las ADH tipo III, por lo general contienen tres subunidades. El transporte intramolecular de electrones en las ADHs tipo II y IIII se propone que es del PQQ al hemo C de la primera subunidad y de ahí, de hemo en hemo en la segunda subunidad hasta llegar a la quinona endógena. Los tres tipos de PQQ-ADHs son discutidas en esta revisión.