A Comparative Evaluation of the Actions of Different Secondary Metabolites of Marine Hydrobionts on the Redox Status of Tumor and Immune Cells

Abstract

Abstract—We performed a comparative analysis of the ability of a number of pharmacologically active natural compounds that are often considered as antioxidants to affect the redox status of the tumor (Ehrlich adenocarcinoma) and immune (splenocytes) cells. The following substances were studied: flavone luteolin and its sulfated derivative, 7,3'-luteolin disulfate from the eelgrass Zostera asiatica; oxycarotenoid astaxanthin from microalgae Haematococcus pluvialis, and a medicinal agent, Gistokhrom, whose active ingredient is hydroxy-1,4-naphthoquinone, echinochrome A from the flat sea urchin Scaphechinus mirabilis. The redox properties of the test compounds were evaluated in vitro by measuring the intracellular content of reactive oxygen species (ROS) using a selective fluorescent indicator, 2',7'-dihydrochlorofluorescein diacetate. The effect of the test substances on the intracellular level of ROS was determined at low (1 μg/mL) and high (10 μg/mL) doses, and in the presence or absence of a strong ROS inducer, the known antitumor agent doxorubicin, at a 10 μg/mL dose in an incubation medium. It has been shown that luteolin possesses the greatest antioxidant activity against both tumor and immune cells; luteolin disulfate and astaxanthin, which at the above doses reduce the ROS level both in the presence and absence of an inducer, have a lower antioxidant activity. Interestingly, unlike them, the drug Gistokhrom has a slight antioxidant effect on tumor cells only at a high dose and a weak effect on the redox status of splenocytes. In this work, we analyzed the possible role of ROS in biological activity and the mechanisms of action of the studied substances.