Xenopus Oocyte's Conductance for Bioactive Compounds Screening and Characterization.

Amani Cheikh,Yassine Tlili,Andrea Santulli,Balkiss Bouhaouala-Zahar,Hager Tabka,Rym Benkhalifa,Noureddine Bouzouaya

doi:10.3390/ijms20092083

Abstract

Background: Astaxanthin (ATX) is a lipophilic compound found in many marine organisms. Studies have shown that ATX has many strong biological properties, including antioxidant, antiviral, anticancer, cardiovascular, anti-inflammatory, neuro-protective and anti-diabetic activities. However, no research has elucidated the effect of ATX on ionic channels. ATX can be extracted from shrimp by-products. Our work aims to characterize ATX cell targets to lend value to marine by-products. Methods: We used the Xenopus oocytes cell model to characterize the pharmacological target of ATX among endogenous Xenopus oocytes’ ionic channels and to analyze the effects of all carotenoid-extract samples prepared from shrimp by-products using a supercritical fluid extraction (SFE) method. Results: ATX inhibits amiloride-sensitive sodium conductance, xINa, in a dose-dependent manner with an IC50 of 0.14 µg, a maximum inhibition of 75% and a Hill coefficient of 0.68. It does not affect the potential of half activation, but significantly changes the kinetics, according to the slope factor values. The marine extract prepared from shrimp waste at 10 µg inhibits xINa in the same way as ATX 0.1 µg does. When ATX was added to the entire extract at 10 µg, inhibition reached that induced with ATX 1 µg. Conclusions: ATX and the shrimp Extract inhibit amiloride-sensitive sodium channels in Xenopus oocytes and the TEVC method makes it possible to measure the ATX inhibitory effect in bioactive SFE-Extract samples.

Highlights

ATX is a ketocarotenoid in a variety of living organisms, many of which are found in the marine environment [1]
Xenopus oocytes extracted from the South African clawed frog Xenopus laevis, the most commonly used model for studying the properties, organization, and cellular roles of ionic channels and transporters [22]
To characterize the presence of ATX in crude extracts, we explore the effect of pure ATX and/or supercritical fluid extraction (SFE)-Extract on endogenous currents, both separately and concomitantly

Summary

Introduction

ATX is a ketocarotenoid in a variety of living organisms, many of which are found in the marine environment [1]. What’s more, multiple studies have reported the involvement of calcium [7,8], potassium [9,10,11,12], sodium [13], and chloride channels [14] in the development of pathologies in which oxidative stress plays a major role These channels represent very important pharmacological targets for several pathologies. Methods: We used the Xenopus oocytes cell model to characterize the pharmacological target of ATX among endogenous Xenopus oocytes’ ionic channels and to analyze the effects of all carotenoid-extract samples prepared from shrimp by-products using a supercritical fluid extraction (SFE) method. Results: ATX inhibits amiloride-sensitive sodium conductance, xINa, in a dose-dependent manner with an IC50 of 0.14 μg, a maximum inhibition of 75% and a Hill coefficient of 0.68 It does not affect the potential of half activation, but significantly changes the kinetics, according to the slope factor values. Conclusions: ATX and the shrimp Extract inhibit amiloride-sensitive sodium channels in Xenopus oocytes and the TEVC method makes it possible to measure the ATX inhibitory effect in bioactive SFE-Extract samples

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Conclusion