Trypanocidal Effects of Essential Oils from Selected Medicinal Plants. Synergy among the Main Components

Abstract

Fourteen essential oils (EOs) from selected live germplasm of medicinal plants have been tested for their antitrypanosomal and cytotoxic activity. These plants have been domesticated and maintained under experimental cultivation. Their EOs were tested on epimastigote forms of Trypanosoma cruzi strain Y and human lung fibroblasts LC5 cell line, along with the major components of the active oils, both separately and in binary combinations. Mentha rotundifolia, Thymus zygis, T. vulgaris and Hyssopus officinalis were the most active EOs against T. cruzi. Among the main components of these EOs (1-8-cineole, thymol, p-cymene, piperitenone oxide, β-pinene, γ-terpinene, carvacrol and linalool), the most active against the parasite and less toxic to human cells was thymol. In general, the activity of the main components did not exceed that of their origin EO, and the study of the activity of these compounds in combination indicates the existence of antagonistic and synergistic effects depending on the concentration tested.

Effect of salinity on the antiparasitic activity of hyssop essential oil

“…Guardo et al (26) reported moderate trypanocidal effects of an H. officinalis EO from a Spanish hyssop population on T. cruzi with activity levels similar to the ones found here.…”

“…Among other hyssop EO components, α-pinene showed a moderate effect on T. cruzi (70) and strong effect on T. brucei, while α-phellandrene showed a moderate effect (71). β-Pinene was active against T. cruzi and showed synergistic effect with carvacrol (26). Germacrene D inhibited the enzyme cruzain, a cysteine protease from T. cruzi (72,73) and this compound showed moderate activity against trypomastigote forms (74).…”

“…The increasing demand for bio pesticides, safer antibiotics and drugs (nontoxic to humans or environment and easily biodegradable) have resulted in new medicinal and agricultural applications of hyssop EOs based on their effects on human resistant pathogenic bacteria, food-borne fungal pathogens, insect pests and phytopathogenic fungi (6,20,21,22,23,(24)(25). However, despite its traditional use as an anthelmintic (5), little is known on the antiparasitic effects on hyssop EO except for one record on an EO from H. officinalis grown in Spain reported as trypanocidal (26), with moderate effects on the plant parasitic nematode Meloidogyne javanica (27).…”

Biological Evaluation of Essential Oils from Selected Medicinal Plants and Their Main Components against Phytomonas davidi (Kinetoplastea: Trypanosomatidae)

“…In the case of thymol, it is demonstrated that it disrupts the permeability of the cell membrane, by increasing the size and number of pores or by disorganization of anionic lipopolysaccharides and, therefore, allows antibiotics, or any substance in combination, penetrate inside the cell and cause the desired effect. [32] Furthermore, previous study on the effects of EO components on T. cruzi, including several tested here (1,8-cineole, p-cymene, β-pinene, linalool, γ-terpinene, thymol), [27] also showed synergistic combinations for the lower concentrations tested (7 combinations at 10 μg/ml) and antagonistic ones at the highest dose (9 combinations at 100 μg/ml). Among the antagonistic combinations, six included 1,8-cineole and five γterpinene, and among the synergistic, four included carvacrol (not tested in the present work) and four terpinene, but no β-pinene.…”

Genetic and flower volatile diversity in two natural populations of Hyssopus officinalis L. in Bulgaria

“…At the same time Semerdjieva et al [28] identified eucalyptol as a major compound in the essential oil of H. officinalis accounting for 25-59% in the samples. Guardo et al [29] also reported eucalyptol as a major component of the H. officinalis essential oil accounting for 53% of its composition. The composition of the essential oil from H. officinalis could be influenced by a number of factors including climatic conditions and the application of different agronomic practices [30], the use of different subspecies or genotypes as a biomass for essential oil distillation [31] and even the application of different distillation conditions [28].…”