Extracts of Tectona grandis and Vernonia amygdalina have anti-Toxoplasma and pro-inflammatory properties in vitro

Abstract

Tectona grandis (teak) and Vernonia amygdalina (bitter leaf) are plants used in traditional medicine in West Africa. In this study, we tested ethanolic and hydro-ethanolic extracts of bark and leaves of T. grandis and ethanolic extract of leaves of V. amygdalina for their inhibitory effect on Toxoplasma gondii, a protozoan parasite responsible for toxoplasmosis. Ethanolic extract of V. amygdalina leaves had proportional contents of phenols, tannins, flavonoids, and polysaccharides. This extract presented the highest efficacy against T. gondii, the lowest cytotoxicity to mammalian cells, but moderate anti-oxidant activity compared to other plant extracts. Ethanolic extract of T. grandis bark also had elevated anti-T. gondii activity, low cytotoxicity on mammalian cells, and one of the highest anti-oxidant activities. However, the phytochemical content of this extract was not very different from the hydro-ethanolic extract, which had no anti-T. gondii activity. In addition, ethanolic extract of V. amygdalina leaves, but not of T. grandis bark, significantly increased the production of TNF-α and NO by antigen-presenting cells. Both extracts had the tendency to decrease expression of major histocompatibility complex molecules at the surface of antigen-presenting cells, while they did not modulate the percentage of apoptotic cells. A study of signalling pathways would help to determine the mechanisms of action of these plant extracts.

Copaifera spp. oleoresins impair Toxoplasma gondii infection in both human trophoblastic cells and human placental explants

“…The search for alternative therapeutic tools gathered great interest in the past few decades, where plants with medicinal properties are systematically screened for their potential to treat parasitic diseases [37][38][39][40][41] . Several studies have evaluated the anti-Toxoplasma effects of many plant-based products, and promising results have been published [39][40][41][42][43][44][45][46][47][48] .…”

Antibacterial, anti-inflammatory and antioxidant activities of Mahanintangtong and its constituent herbs, a formula used in Thai traditional medicine for treating pharyngitis

“…Patchoulene epoxide which isolated from patchouli oil also inhibits TNF-α, IL-1β, IL-6, PGE2 and NO and downregulates mRNA expression of COX-2 and inducible nitric oxide synthetase [ 35 ]. Another important component, the ethanol extract from the bark of T. grandis , also inhibits TNF-α in RAW 264.7 cells and immortalized mouse splenic dendritic cells [ 36 ]. Phytochemicals present in T. grandis include naphthoquinone, anthraquinone, monoterpene, diterpene, triterpene, apocarotenoid, phenolic compounds and flavonoids, steroids/saponins, phenylpropanoids and fatty esters [ 37 ].…”

The Mechanism of Action of Ursolic Acid as a Potential Anti-Toxoplasmosis Agent, and Its Immunomodulatory Effects

“…It also effectively induces various activities, including antimicrobial [32,33,34] and anti-parasitic effects [35,36]. Until recently, although studies and compounds regarding anti- T. gondii activity have been reported globally [37,38,39,40,41,42,43], the mechanism of action of ursolic acid on the inhibitory effect of T. gondii and the immunomodulatory activity was not reported yet. From this perspective, this study was performed to evaluate the mechanism of action and the immunomodulatory activity of ursolic acid in terms of anti- T. gondii effects and activity, and to confirm the potential as a potent candidate drug for developing novel anti-toxoplasmosis agents.…”