Black sea cucumber (Holothuria atra Jaeger, 1833) protects Caenorhabditis elegans against Pseudomonas aeruginosa infection

Abstract

A strategy to circumvent the problem of multidrug resistant pathogen is consumption of functional food rich in anti-infectives targeting bacterial virulence or host immunity. The black sea cucumber (Holothuria atra) is a tropical marine sea cucumer species traditionally consumed as remedy for many ailments. There is a paucity of knowledge the anti-infectives capacity of H. atra and the underlying mechanisms involved. The objectives of this study were to utilize the Caenorhabditis elegans-P. aeruginosa infection model to assess the anti-infective properties of H. atra. We first showed the capacity of a H. atra extract and fraction in promoting survival of C. elegans during a customarily lethal P. aeruginosa infection. The same chemical entities also attenuate the production of several P. aeruginosa virulence factors and biofilm. Treatment of infected transgenic lys-7::GFP worms with H. atra fraction restored the repressed expression of lys-7, a defense enzyme, indicating improved host immunity. QTOF-LCMS analysis revealed the presence of aspidospermatidine, an indole alkaloid and inosine. Collectively, our finding shows that H. atra confers survival advantage in C. elegans against P. aeruginosa infection through inhibition of pathogen virulence and eventually, the restitution of host lys-7 expression.