Evaluation of the cytotoxic effect and antibacterial, antifungal, and antiviral activities of Hypericum triquetrifolium Turra essential oils from Tunisia

Abstract

BackgroundA number of bio-active secondary metabolites have been identified and reported for several Hypericum species. Many studies have reported the potential use of the plant extracts against several pathogens. However, Hypericum triquetrifolium is one of the least studied species for its antimicrobial activity. The aim of the present study was to evaluate the cytotoxic effect of the essential oils of Hypericum triquetrifolium as well as their antimicrobial potential against coxsakievirus B3 and a range of bacterial and fungal strains.MethodsThe essential oils of Hypericum triquetrifolium harvested from five different Tunisian localities (Fondouk DJedid, Bou Arada, Bahra, Fernana and Dhrea Ben Jouder) were evaluated for their antimicrobial activities by micro-broth dilution methods against bacterial and fungal strains. In addition, the cytotoxic effect and the antiviral activity of these oils were carried out using Vero cell lines and coxsakievirus B3.ResultsThe results showed a good antibacterial activities against a wide range of bacterial strains, MIC values ranging between 0.39-12.50 mg/ml and MBC values between 1.56-25.0 mg/ml. In addition, the essential oils showed promising antifungal activity with MIC values ranging between 0.39 μg/mL and 12.50 μg/mL; MFC values ranged between 3.12 μg/mL and 25.00 μg/mL; a significant anticandidal activity was noted (MIC values comprised between 0.39 μg/mL and 12.50 μg/mL). Although their low cytotoxic effect (CC50 ranged between 0.58 mg/mL and 12.00 mg/mL), the essential oils did not show antiviral activity against coxsakievirus B3.ConclusionThe essential oils obtained from Hypericum triquetrifolium can be used as antimicrobial agents and could be safe at non cytotoxic doses. As shown for the tested essential oils, comparative analysis need to be undertaken to better characterize also the antimicrobial activities of Hypericum triquetrifolium extracts with different solvents as well as their purified fractions and their pure secondary metabolites.

Evaluation of the in vitro antibacterial activity of the solvent fractions of the leaves of Rhamnus prinoides L’Herit (Rhamnaceae) against pathogenic bacteria

“…The crude extract and solvent fractions that showed antibacterial activity by agar well diffusion method were subjected to serial resazurin based microtitre dilution technique on 96 well plates (Greiner Bio-One, Germany) as described by previous studies [ 25 , 26 ]. The first column of microtiter plate was filled with 100 μl stock solution (390 mg/ml) of the crude or each active solvent fraction of test material except the last well in which equal amount of the respective solvent was added.…”

“…MBC was determined by a method described in different studies [ 26 ]. In this technique, the contents of all wells containing a concentration of test material above the MIC value from each triplicate, in the MIC determination test, was streaked on MHA or MHA supplemented with 5 % sheep blood (for streptococcus species) with wire loop aseptically and incubated at 37 °C for 24 h. The lowest concentration of the extract which showed no bacterial growth after incubation was observed for each triplicate and noted as the MBC.…”

Local knowledge about sustainable harvesting and availability of wild medicinal plant species in Lemnos island, Greece

“…Some of our informants assigned the exact same properties to these plants or suggested their use against diseases or health issues of bacterial or viral etiology (for example, common cold [69], urinary tract infection [70], diarrhea [71]). Similarly, the cited antidepressant, wound healing, and anti-inflammatory properties of Saint John's Worts (H. perfoliatum, H. perforatum, H. triquetrifolium) have been justified in literature [72][73][74][75][76]. Equally, for the antioxidant activity of Crithmum maritimum [77], the kidney protective properties of Taraxacum and Cichorium species [78,79], the nutritional value of P. oleracea [80], the nephroprotective properties of S. oleraceus [81], and the galactagogue action of F. vulgare [82] (Additional file 2).…”

Modulation of cytokine production from cultured mononuclear cells of leukemia patients by Hypericum triquetrifolium Turra methanolic extract

“…This species also has healing and diuretic properties and is used to treat kidney, urinary bladder, liver and migraine complications (Conforti, Loizzo, Statti, & Menichini, 2007). In addition, several biological potentials have described for different extracts of H. triquetrifolium or its natural products; for instance, anti-oxidant, anti-microbial, immunological, anti-mutagenic and anti-tumor potentials (Rouis et al, 2013;Saad et al, 2011).…”