Photodynamic effect of palladium porphyrin derived from cashew nut shell liquid against promastigote forms of Leishmania braziliensis

Photodiagnosis Photodyn Ther. 2021 Mar:33:102083. doi: 10.1016/j.pdpdt.2020.102083. Epub 2020 Nov 4.

Abstract

Cutaneous leishmaniasis (CL) is a neglected tropical disease (NTD), endemic mainly in low-income countries that lack adequate basic health care. The emergence of resistant parasites to pentavalent antimonials has led to the search for new treatments for CL. Photodynamic therapy (PDT) is a promising non-invasive and less toxic alternative for the treatment of CL. The present work describes the synthesis, characterization and photodynamic effect against CL of a new metalloporphyrin Pd (II) meso-tetra[4-(2-(3-n-pentadecylphenoxy)ethoxy]phenylporphyrin (PdP) derived from the cashew nut shell liquid (CNSL). The PdP complex presented a singlet oxygen quantum yield of 0.49, favoring a type II photochemical reaction. The results of the photodynamic experiment carried out with PdP on the promastigote forms of Leishmania braziliensis indicated a mortality percentage of 70 % of the cells when compared to the control after exposure to blue light (λ = 420 nm). Besides this, the metalloporphyrin PdP did not show considerable toxicity to macrophages, indicating the cell viability of the compound. Therefore, this metalloporphyrin derived from biomass represents an interesting alternative as a potential therapeutic drug for the treatment of CL through PDT, especially for patients with intolerance to the chemotherapeutic drugs currently available.

Keywords: CNSL; Cutaneous leishmaniasis; Metalloporphyrin; Photodynamic therapy.

MeSH terms

  • Anacardium*
  • Humans
  • Leishmania braziliensis*
  • Leishmaniasis, Cutaneous* / drug therapy
  • Nuts
  • Palladium / therapeutic use
  • Photochemotherapy* / methods
  • Photosensitizing Agents / pharmacology
  • Photosensitizing Agents / therapeutic use
  • Porphyrins* / pharmacology
  • Porphyrins* / therapeutic use

Substances

  • Photosensitizing Agents
  • Porphyrins
  • Palladium