Trichomonicidal activity of a new anthraquinone isolated from the roots of Morinda panamensis Seem

Abstract

Trichomoniasis, caused by the protozoan parasite Trichomonas vaginalis, is the most common nonviral sexually transmitted infection worldwide. Although drug treatment is available, unpleasant side effects and increased resistance to the nitroimidazole family have been documented. Hence, there is a need for the identification of new and safe therapeutic agents against T. vaginalis. Antimicrobial activity of anthraquinone compounds has been reported by a number of authors. The genus Morinda is well known for the diversity of anthraquinones with numerous biological activities. A new anthraquinone, lucidin‐ω‐isopropyl ether, was isolated from the roots of Morinda panamensis Seem. The structure of the compound was determined by 1H and 13C Nuclear Magnetic Resonance (NMR) analyses, in addition to comparison with literature reports. Using in vitro susceptibility assay, the half inhibitory concentration (IC50) of lucidin‐ω‐isopropyl ether for T. vaginalis (1.32 μg/mL) was found similar to that of metronidazole concentration tested (6 μM = 1.03 μg/mL). In addition, this anthraquinone was capable of inhibiting the parasite's ability to kill HeLa cells and decreased proteolytic activity of the proteinase TvMP50 from T. vaginalis. This was associated with the decreased expression of the mp50 gene. These results demonstrate the trichomonicidal potential by lucidin‐ω‐isopropyl ether. Further action‐mode studies are necessary to elucidate the antiparasitic mechanism of this new anthraquinone to develop a more potent antitrichomonal agent.

Novel Treatment Approaches to Combat Trichomoniasis, a Neglected and Sexually Transmitted Infection Caused by Trichomonas vaginalis: Translational Perspectives

“…The anthraquinone lucidin-ω-isopropyl ether from M. panamensis Seem. roots presented anti-T. vaginalis activity with an IC 50 of 1.32 µg/mL, and its potential as a metallopeptidase inhibitor has been elucidated [87]. The plants traditionally used in Northern Maputaland in South Africa were explored against several STI pathogens, such as T. vaginalis.…”

Bioactive Compounds as Potential Agents for Sexually Transmitted Diseases Management: A Review to Explore Molecular Mechanisms of Action

“…The author reports that although anthraquinone presented anti- T. vaginalis activity, additional mode of action studies is needed to elucidate the antitrichomonal mechanism of action. ( Cáceres-Castillo et al, 2019 ).…”

“…The author reports that although anthraquinone presented anti-T. vaginalis activity, additional mode of action studies is needed to elucidate the antitrichomonal mechanism of action. (Cáceres-Castillo et al, 2019). Tiwari et al (2008) evaluated the anti-T. vaginalis activity of Sapindus saponins, a component of the plant-based contraceptive Consap, where the Sapindus saponins purified sample and MTZ was used.…”

The Inhibitory Activity of Anthraquinones against Pathogenic Protozoa, Bacteria, and Fungi and the Relationship to Structure

“…Figure 1 shows the structures of the seven compounds evaluated against trichomonads in the present study: anthraquinone; anthrarufin (1,5-dihydroxy-9,10-anthraquinone); chrysazin (1,8-dihydroxy-9,10-anthraquinone); purpurin (1,2,4-trihydroxy-9-10-anthraquinone); emodin (1,3,8-trihydroxy-6-methyl-9,10-anthraquinone); aloe-emodin (1,8-dihydroxy-3-hydroxymethyl-9,10-anthraquinone), and rhein from the edible rhubarb plant. The structure of a new anthraquinone (lucidin-isopropyl ether) that has strong anti- Trichomonas vaginalis activity, recently isolated from the roots of Morinda panamensis Seem., is also shown in Figure 1 [ 5 ]. Anthraquinones occur naturally in the plant as glycosides, as illustrated in Figure 1 by the structures of sennoside and rhein-8-glucoside.…”