Evaluation of the Anti-Toxoplasma gondii Efficacy, Cytotoxicity, and GC/MS Profile of Pleopeltis crassinervata Active Subfractions

Abstract

Pleopeltis crassinervata (Pc) is a fern that, according to ethnobotanical records, is used in Mexican traditional medicine to treat gastrointestinal ailments. Recent reports indicate that the hexane fraction (Hf) obtained from Pc methanolic frond extract affects Toxoplasma gondii tachyzoite viability in vitro; therefore, in the present study, the activity of different Pc hexane subfractions (Hsf) obtained by chromatographic methods was evaluated in the same biological model. Gas chromatography/mass spectrometry (GC/MS) analysis was carried out for hexane subfraction number one (Hsf1), as it showed the highest anti-Toxoplasma activity with a half-maximal inhibitory concentration (IC50) of 23.6 µg/mL, a 50% cytotoxic concentration (CC50) of 398.7 µg/mL in Vero cells, and a selective index (SI) of 16.89. Eighteen compounds were identified by Hsf1 GC/MS analysis, with the majority being fatty acids and terpenes. Hexadecanoic acid, methyl ester was the most commonly found compound (18.05%) followed by olean-13(18)-ene, 2,2,4a,8a,9,12b,14a-octamethyl-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,12,12a,12b,13,14,14a,14b-eicosahydropicene, and 8-octadecenoid acid, methyl ester, which were detected at 16.19%, 12.53%, and 12.99%, respectively. Based on the mechanisms of action reported for these molecules, Hsf1 could exert its anti-Toxoplasma activity mainly on T. gondii lipidomes and membranes.

Antibacterial, Trichomonacidal, and Cytotoxic Activities of Pleopeltis crassinervata Extracts

“…These results agree with the ethnobotanical record of P. crassinervata which reported that the frond harbors curative properties [6]. For these reasons we decided to perform the fractionation of FMeOHe according to the methodology established in our previous research, with the aim of elucidating its antibacterial activity [20]. After FMeOHe partition, a second antibacterial assay was performed wherein FMeOHe and its three fractions were evaluated.…”

“…Additionally, an investigation revealed that Hf from P. crassinervata exerted an effect on T. gondii tachyzoites with an IC 50 value as low as 16.9 µg/mL. This finding is particularly noteworthy given the taxonomic similarities between T. vaginalis and T. gondii, as both protozoan parasites are affected by the same fractions [19,20]. This study showed that Hsf6 with trichomonacidal activity is primarily composed of terpenes.…”

“…These compounds are known for their diverse range of biological activities. Notably, terpenoid compounds such as phytol have been identified in the Hsf1 subfraction [20]. Additionally, an investigation revealed that Hf from P. crassinervata exerted an effect on T. gondii tachyzoites with an IC 50 value as low as 16.9 µg/mL.…”

“…Due to its biological efficacy, hexane fraction (Hf) was subjected to a chromatographic separation in a glass column packed with gel silica, and seven subfractions were obtained. The subfractions were named Hsf1-Hsf7 in accordance with the elution order, as described in our previous study [20].…”

“…Based on the antimicrobial properties coupled with the antiparasitic activity exposed in previous studies, evaluations of extracts, fractions, and subfractions of the plant were carried out through a bioguided approach [19,20]. In vitro models with pathogenic bacteria, including both Gram-positive and Gram-negative strains that are commonly associated with gastric disorders and mouth ulcers, were employed for these investigations.…”