Grandiflorenic acid isolated from Sphagneticola trilobata against Trypanosoma cruzi: Toxicity, mechanisms of action and immunomodulation

Toxicol In Vitro. 2022 Feb:78:105267. doi: 10.1016/j.tiv.2021.105267. Epub 2021 Oct 22.

Abstract

Grandiflorenic acid (GFA) is one of the main kaurane diterpenes found in different parts of Sphagneticola trilobata. It has several biological activities, especially antiprotozoal action. In turn, Chagas disease is a complex systemic disease caused by the protozoan Trypanosoma cruzi, and the drugs available to treat it involve significant side effects and impose an urgent need to search for therapeutic alternatives. In this context, our goal was to determine the effect of GFA on trypomastigote and intracellular amastigote forms. Our results showed that GFA treatment led to significantly less viability of trypomastigote forms, with morphological and ultrastructural changes in the parasites treated with IC50 of GFA (24.60 nM), and larger levels of reactive oxygen species (ROS), mitochondrial depolarization, lipid droplets accumulation, presence of autophagic vacuoles, phosphatidylserine exposure, and plasma membrane damage. In addition, the GFA treatment was able to reduce the percentage of infected cells and the number of amastigotes per macrophage (J774A.1) without showing cytotoxicity in mammalian cell lines (J774A.1, LLCMK2, THP-1, AMJ2-C11), in addition to increasing TNF-α and reducing IL-6 levels in infected macrophages. In conclusion, the GFA treatment exerted influence on trypomastigote forms through an apoptosis-like mechanism and by eliminating intracellular parasites via TNF-α/ROS pathway, without generating cellular cytotoxicity.

Keywords: Apoptosis; Kaurane diterpene; ROS; TNF-α; Tripanocidal activity; Wedelia paludosa.

MeSH terms

  • Animals
  • Antiprotozoal Agents / pharmacology*
  • Antiprotozoal Agents / toxicity
  • Asteraceae / chemistry
  • Cell Line
  • Chagas Disease / drug therapy
  • Diterpenes / pharmacology*
  • Diterpenes / toxicity
  • Humans
  • Immunomodulation / drug effects
  • Macaca mulatta
  • Macrophages / parasitology
  • Mice
  • Reactive Oxygen Species / metabolism
  • Trypanosoma cruzi / drug effects*
  • Trypanosoma cruzi / growth & development
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Antiprotozoal Agents
  • Diterpenes
  • Reactive Oxygen Species
  • Tumor Necrosis Factor-alpha
  • grandiflorenic acid