FOSFATASA ALCALINA DE CAMARÓN: ESTRUCTURA, CARACTERÍSTICAS Y FUNCIONES/ SHRIMP ALKALINE PHOSPHATASE: STRUCTURE, CHARACTERISTICS, AND FUNCTIONS

Los estudios sobre la fosfatasa alcalina (FA) son escasos en especies de origen terrestre; existe poca información de esta enzima con respecto a las especies marinas, como el camarón. Los principales aspectos considerados en esta revisión son: la estructura, características y funciones de la fosfatasa alcalina presente en camarones (FAC), comparadas con sus homólogos de diferentes orígenes. Las tríadas del sitio activo de la FAC son muy similares a los de FA de origen bacteriano. Diversos agentes que actúan como inhibidores de la FA comercial, también pueden inhibir a la FAC. Las principales funciones de la FA en crustáceos, como el camarón, se relacionan con el proceso digestivo del organismo, participando en reacciones de transfosforilación, así como en el sistema inmunológico, en la que se ha asociado a la activación de los efectores celulares responsables del sistema de defensa del camarón, por lo que puede ser utilizado cómo un agente indicador de enfermedades en estos organismos. Por otro lado, debido a que las características químicas y estructurales de la FAC son similares a las de sus homólogos de origen bacteriano, se infiere que los usos y aplicaciones de la FAC pueden ser semejantes a las de origen bacteriano. ABSTRACT Studies on alkaline phosphatase (AP) are few on terrestrial species; there is little information of this enzyme with respect to marine species, especially shrimp. The main aspects considered in this review are structure, characteristics and functions present in shrimp alkaline phosphatase (SAP) compared with their equivalents from different sources. The triads of the SAP active site are very similar to those of AP of bacterial origin, these last being widely studied and used as a model. Several agents that act as inhibitors of the commercial AP, also can inhibit the SAP. Of the main functions of the AP in crustaceans, such as shrimp, are those related to the digestive process of the organism, participating in transphosphorylation reactions and the immune system, which has been associated with activation of cellular effectors responsible of shrimp defense system, so it can be used as an indicator of disease agent in this organism. Moreover, because the chemical and structural characteristics of the SAP are similar to those of their bacterial homologues, uses and applications of SAP can be similar to those of bacterial origin

Physicochemical properties of cowpea (Vigna unguiculata L. Walp.) meals and their apparent digestibility in white shrimp (Litopenaeus vannamei Boone).

The effect of different feed processing methods on the physicochemical properties, and apparent digestibility of cowpea (Vigna unguiculata) meals as ingredients in diets for white shrimp ( Litopenaeus vannamei ) was investigated. Five experimental cowpea meals were prepared: whole raw (WRC), dehulled (DC), cooked (CC), germinated (GC) and extruded (EXC). The physicochemical properties of the meals were evaluated using differential scanning calorimetry. The meals were included at 15 % in diets for L. vannamei (15.4 g) to determine firmness of pellets and in vivo digestibility of nutrients by using chromic oxide as inert marker. Six diets were evaluated: a control diet, and five diets containing the different cowpea meals. Transition enthalpy significantly decreased after thermal treatment, from 6.1 J/g in WRC to 1.4 J/g in CC, and disappeared in EXC. Firmness of pellets varied from 1.1 N in the EXC diet to 2.8 N in the WRC diet. A significant negative correlation between transition enthalpy and carbohydrate digestibility was found. Dry matter, protein, carbohydrate and lipid digestibility of cowpea meals significantly increased after germinating, cooking or extruding. It is concluded that germinated, cooked and extruded cowpea meals are highly digestible for shrimp and that enthalpy of transition is negatively correlated with the digestibility of carbohydrates

Antimutagenicity and Antiproliferative Studies of Lipidic Extracts from White Shrimp (Litopenaeus vannamei)

An organic extract from fresh shrimp (Litopenaeus vannamei) was studied for antimutagenic and antiproliferative properties using Salmonella typhimurium tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line (B-cell lymphoma), respectively. Shrimp extract was sequentially fractionated by thin layer chromatography (TLC) and each fraction was tested for antimutagenic and antiproliferative activities. Crude organic extracts obtained from shrimp reduced the number of revertants caused by aflatoxina B1, showing a dose-response type of relationship. Sequential TLC fractionation of the active extracts produced several antimutagenic and/or antiproliferative fractions. These results suggested that the lipid fraction of the tested species contained compounds with chemoprotective properties that reduce the mutagenicity of AFB1 and proliferation of a cancer cell line

Properties of Cephalopod Skin Ommochromes to Inhibit Free Radicals, and the Maillard Reaction and Retino-Protective Mechanisms in Cellular Models Concerning Oxidative Stress, Angiogenesis, and Inflammation

Ommochromes are pigments of invertebrates that exhibit oxidative stress protection. The aim of this study was to investigate ommochromes extracted from cephalopod's skin for their ability to inhibit age-related-macular degeneration (AMD)-related factors such as H2O2-induced and iron-dependent oxidative stress (ferroptosis and erastin), accumulation of advanced glycation end-products (AGEs), as well as vascular endothelial growth factor (VEGF), and inflammatory cytokines (interleukin 6 and interleukin 8) secretion. As cell systems, we used primary porcine retinal pigment epithelium (RPE), human retinal pigment epithelium cell line ARPE-19 and uveal melanoma cell line OMM-1. In vitro, ommochromes produced an antiglycation effect by the inhibition of fructosylation reaction. The ommochromes showed protective effects against erastin- induced cell death in ARPE-19. In addition, in long-term stimulation (7 days) ommochromes decreased constitutively secreted VEGF, as well as interleukin 6 and interleukin 8 induced by Poly I:C in primary RPE. No relevant effects were detected in OMM-1 cells. The effects are dependent on the cell system, time of exposition, and concentration. This substance is of interest for further research concerning age-related macular degeneration

Capacidad antioxidante y mecanismo de acción de pigmentos en organismos marinos

Marine organisms have wonderful colors that make them very attractive. The unique characteristics of the compounds synthesized by species of marine origin go beyond their appearance. The pigments responsible for these colors are also capable of exerting biological activities, including the antioxidant capacity, which can be performed by different mechanisms. This has led to an increase in research attention due to their potential application in the pharmaceutical, cosmetics and food industries, and has expanded from in vitro studies to in vivo tests. The objective of this review is to compile and describe the studies aimed at establishing and elucidating the mechanisms of action of different biochemical compounds with antioxidant activities from marine species. In order to achieve that objective, the Scopus®, Web of Science™ and Microsoft Academic databases were used. Marine pigments represent a promising alternative to the antioxidants and synthetic additives used today. By establishing and understanding the mechanisms of action of the bioactive pigmented compounds isolated from marine organisms, it is possible to determine with greater precision their possible application in the industry.Los organismos marinos poseen maravillosos colores que los hacen muy atractivos. Las características únicas de los compuestos sintetizados por especies de origen marino van más allá de su apariencia. Los pigmentos responsables de esos colores son capaces también de generar diversas actividades biológicas, como la capacidad antioxidante, la cual puede ocurrir a través de diversos mecanismos. Esto ha propiciado un aumento de su investigación, debido a su amplia aplicación en la biotecnología, farmacéutica, cosmética y alimentación de organismos vivos, expandiendo los estudios tanto in vitro como en ensayos in vivo. El objetivo de este trabajo fue compilar y describir diversos estudios recientes, enfocados en demostrar y elucidar los mecanismos de acción de los diferentes compuestos bioquímicos con actividad antioxidante, provenientes de algunos organismos marinos. Para ello, se utilizaron las bases de datos Scopus®, Web of Science™ y Microsoft Academic. Los pigmentos provenientes de organismos marinos representan una alternativa promisoria frente a los antioxidantes y aditivos sintéticos utilizados en la actualidad. El establecimiento y comprensión de los mecanismos de acción de los componentes pigmentados bioactivos, aislados de los organismos marinos, permitirá determinar con mayor precisión su posible aplicación en la industria