The latex of Euphorbia tirucalli inhibits staphyloxanthin production and protects Tenebrio molitor larvae against Staphylococcus aureus infection

Abstract

The latex of Euphorbia tirucalli L. (LET) has great etnopharmacological relevance for several traditional communities. In this study, the in vitro and in vivo (using Tenebrio molitor larvae) antimicrobial effects of LET were evaluated. LET did not inhibit the growth of S. aureus, however, a reduction on staphyloxanthin production (an important virulence factor of S. aureus) was observed. LET (at 10 μL/kg) was also able to enhance the survival of larvae infected with a lethal dose of S. aureus, an effect associated with reduction in the numbers of haemocytes. Furthermore, haemocytes from LET-treated larvae exhibited dysfunctional lysosome activity. These results indicate the effectiveness of LET as an anti-infective agent which could be useful as source of lead molecules for the development of new therapies against S. aureus-induced infections.

Graphical abstract

Keywords:

• Virulence factors
• bacterial infections
• haemocytes

Acknowledgments

This work was funded by Fundação de Amparo à Pesquisa e Desenvolvimento Científico do Maranhão (Grant nos. UNIVERSAL-00998/16, COOPI-02860/16, BIC-07392/16, BIC-00111/18, BEPP-02241/18), Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior (Grant no. 3325/2013) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (Grant no. 309046/2016-5).

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships.

Additional information

Funding

This work was kindly supported by the "Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão" (COOPI-02860/16, UNIVERSAL-00998/16) and "Conselho Nacional de Desenvolvimento Científico e Tecnológico" (Grant no. 309046/2016-5).