Comparison of the phenolic contents and epigenetic and genetic variability of wild and cultivated watercress (Rorippa nasturtium var. aquaticum L.)

Background: Epigenetic modifications are key factors modulating the expression of genes involved in the synthesis of phytochemicals. The knowledge of plant epigenetic and genetic variations can contribute to enhance the production of bioactive compounds. These issues have been little explored thus far in Rorippa nasturtium var. aquaticum L. (watercress), an edible and medicinal plant. The aim of the current study was to determine and compare the phenolic composition and epigenetic and genetic variations between wild and cultivated watercress. Results: Significant differences were found in the quantitative phenolic composition between wild and cultivated watercress. The eight primer combinations used in the methylation-sensitive amplification polymorphism (MSAP) method revealed different epigenetic status for each watercress type, the cultivated one being the most epigenetically variable. The genetic variability revealed by the EcoRI/MspI amplification profile and also by eight inter-simple sequence repeat (ISSR) primers was different between the two types of watercress. The results of the Mantel test showed that the correlation between genetic and epigenetic variations has diminished in the cultivated type. Cluster analyses showed that the epigenetic and genetic characterizations clearly discriminated between wild and cultivated watercress. Conclusions: Relevant chemical, epigenetic, and genetic differences have emerged between wild and cultivated watercress. These differences can contribute to fingerprint and develop quality control tools for the integral and safety use and the commercialization of watercress. The richness of epialleles could support the development of tools to manipulate the watercress epigenome to develop high bioproduct­producing cultivars

Modulator effect of watercress against cyclophosphamide-induced oxidative stress in mice

Watercress (Nasturtium officinale, Cruciferae; W. Aiton) is a vegetable widely consumed in our country, with nutritional and potentially chemopreventive properties. Previous reports from our laboratory demonstrated the protective effect of watercress juice against DNA damage induced by cyclophosphamide in vivo. In this study, we evaluated the in vivo effect of cress plant on the oxidative stress in mice. Animals were treated by gavage with different doses of watercress juice (0.5 and 1g/kg body weight) for 15 consecutive days before intraperitoneal injection of cyclophosphamide (100 mg/kg body weight). After 24 h, mice were killed by cervical dislocation. The effect of watercress was investigated by assessing the following oxidative stress biomarkers: catalase activity, superoxide dismutase activity, lipid peroxidation, and glutathione balance. Intake of watercress prior to cyclophosphamide administration enhanced superoxide dismutase activity in erythrocytes with no effect on catalase activity. In bone marrow and liver tissues, watercress juice counteracted the effect of cyclophosphamide. Glutathione balance rose by watercress supplementation and lipid oxidation diminished in all matrixes when compared to the respective control groups. Our results support the role of watercress as a diet component with promising properties to be used as health promoter or protective agent against oxidative damage.

El berro (Nasturtium officinale, crucíferas; W. Aiton) es una hortaliza ampliamente consumida en nuestro país, con valor nutricional y propiedades potencialmente quimiopreventivas. En trabajos previos demostramos que el jugo de berro tiene efecto protector in vivo contra el daño del ADN inducido por ciclofosfamida en tejidos del ratón. En el presente trabajo evaluamos, también in vivo, los efectos del jugo sobre el estrés oxidativo en diferentes tejidos del ratón. Los siguientes biomarcadores fueron investigados: actividad de superóxido dismutasa, actividad de catalasa, peroxidación lipídica y balance de glutatión. Los animales fueron tratados con diferentes dosis de jugo (0.5 y 1 g/kg de peso corporal) por alimentación forzada durante 15 días consecutivos antes de la inyección intraperitoneal con ciclofosfamida (100 mg/kg). La ingesta de berro antes de la administración de ciclofosfamida mejoró la actividad de superóxido dismutasa en los eritrocitos sin efecto sobre la actividad de la catalasa. En médula ósea e hígado, el jugo de berro contrarrestó el efecto deletéreo de la ciclofosfamida. En todas las matrices, el balance de glutatión fue mayor y la oxidación de lípidos menor que los valores encontrados en los grupos control. Nuestros resultados demuestran que el berro es un componente de la dieta con propiedades prometedoras como promotor de la salud o como agente protector contra el daño oxidativo.