In vitro inhibitory effect of Hydrocotyle bonariensis Lam. extracts over Chlamydia trachomatis and Chlamydia pneumoniae on different stages of the chlamydial life cycle

Andrea Carolina Entrocassi; Alejandra Vanina Catalano; Adriana Graciela Ouviña; Erica Georgina Wilson; Paula Gladys López; Marcelo Rodríguez Fermepin

doi:10.1016/j.heliyon.2021.e06947

In vitro inhibitory effect of Hydrocotyle bonariensis Lam. extracts over Chlamydia trachomatis and Chlamydia pneumoniae on different stages of the chlamydial life cycle

Heliyon. 2021 May 18;7(5):e06947. doi: 10.1016/j.heliyon.2021.e06947. eCollection 2021 May.

Authors

Andrea Carolina Entrocassi^{1

2}, Alejandra Vanina Catalano^{3

4}, Adriana Graciela Ouviña^{3

4}, Erica Georgina Wilson^{3

4}, Paula Gladys López^{3

4}, Marcelo Rodríguez Fermepin^{1

2}

Affiliations

¹ Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Microbiología Clínica, Ciudad Autónoma de Buenos Aires, Argentina.
² Universidad de Buenos Aires, Instituto de Fisiopatología y Bioquímica Clínica (INFIBIOC), Ciudad Autónoma de Buenos Aires, Argentina.
³ Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Farmacognosia, Ciudad Autónoma de Buenos Aires, Argentina.
⁴ CONICET - Universidad de Buenos Aires, Instituto de Química y Metabolismo del Fármaco (IQUIMEFA), Ciudad Autónoma de Buenos Aires, Argentina.

Abstract

Chlamydial infections in humans are widely distributed and are responsible for a variety of acute and chronic diseases. Both Chlamydia trachomatis and Chlamydia pneumoniae can lead to chronic conditions that have been linked to complications and sequelae. This study aimed to develop a culture method in order to detect in vitro antichlamydial activity of different extracts obtained from native Argentinian plants used as antimicrobials in local ethnomedicine and to evaluate their inhibitory activity over Chlamydia trachomatis and Chlamydia pneumoniae growth. The inhibitory activity over different stages of the chlamydial life cycle on cell culture was assessed: the entry, the inclusion developing after entry, and the exponential growth stage. Also, the capability of rendering the cell refractory to chlamydial infection by pre-incubation with the extracts was assayed. Inhibitory activity of water-based and organic-based extracts obtained from Hydrocotyle bonariensis Lam. (Araliaceae), Lithraea molleoides (Vell.) Engl. (Anacardiaceae) and Hybanthus parviflorus (Mutis ex L.f.) Baill. (Violaceae) were tested against five strains of Chlamydia trachomatis (L2/434/BU and four clinical isolates form both neonatal conjunctivitis and adult genital infections, genotypes D, E, and K) and against Chlamydia pneumoniae AR39. The Hydrocotyle bonariensis dichloromethane extract showed a broad inhibitory activity over the exponential growth stage of Chlamydia trachomatis and Chlamydia pneumoniae independently from the chlamydial strain and the cell line. These results suggest a high inhibitory potential on both Chlamydiae species. In order to characterize the Hydrocotyle bonariensis dichloromethane active extract, an ¹H-NMR was performed. The ¹H-NMR characterization showed a spectrum with characteristic signals of the fatty acid moiety of lipids or cerebrosides, volatile phenolics, phytosterols, methyl triterpenes signals, and glucose moiety of the cerebrosides.

Keywords: Antichlamydial activity; Argentinian medicinal plant; Chlamydia pneumoniae; Chlamydia trachomatis; Hydrocotyle bonariensis.