Antibacterial effect of Libanstine from Ilex paraguariensis (Yerba Mate)
Antibacterial effect
Lebanon from Ilex paraguariensis (Yerba Mate)
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Link do źródła –https://www.sciencedirect.com/science/article/abs/pii/S0367326X21001374
Abstract
According to reports, infectious diseases are one of the leading causes of death in the world. The World Health Organization (WHO) warns of an increase in deaths due to antimicrobial resistance. Recently, there has been a tendency to search for new active antibacterial compounds in plants. Ilex paraguariensis , known as Yerba Mate, is a plant known for being rich in numerous bioactive compounds that play an important role in human health. In this study, Yerba Mate was extracted with a mixture of acetone : water (1:1) and then fractionated with hexane , chloroform and ethyl acetate . The obtained fractions were tested for antibacterial activity against Staphylococcus aureus and Salmonella species . Minimum inhibitory concentration (MIC) values for S. aureus S. aureus and 1.56 mg/mL to 3.12 mg/mL for Salmonella species. The aqueous fraction was further treated with various enzymes to mimic in vivo digestion . The active metabolite ranged from 1.56 to 3.12 mg/mL for both the chloroform and ethyl acetate fractions. For the water fraction, the MIC values ranged from 0.78 to 3.12 mg/mL on digestion and the fractions obtained were then tested for antibacterial activity . Furthermore, the Yerba Mate aqueous fraction was run on High Performance Liquid Chromatography (HPLC) and collected fractions were tested for antibacterial activity, to identify the . Fraction 3 was tested on various S. aureus strains and the MIC values ranged from 0.19 to 1.56 μg/ml. A new pyrazinone, Libanstin, was identified from Ilex paraguariensis using NMR spectroscopy .
Graphical summary
Introduction
Staphylococcus aureus is a Gram-positive bacterium. It is a human pathogen that causes minor and major diseases. This bacterium is resistant to many antibiotics due to mutations leading to changes in antibiotic binding sites and high expression of efflux pumps [10]. Salmonella species are Gram-negative bacteria. They cause infections leading to many clinical syndromes. The risk of infection with multidrug-resistant Salmonella occurs when antibacterial agents are used against these bacteria [7].
Herbal medicines are widely used as therapeutic agents due to their availability, increasing demand for natural and organic products, and proven synergistic effects [26]. Ilex paraguariensis is a herb commonly used in Latin American countries. The leaves of this plant contain high concentrations of many bioactive molecules: phenolic compounds, mainly tannins, flavonoids and phenolic acids [2]. It is also rich in theobromine, caffeine, caffeoylquinic acid and dicaffeoylquinic acid derivatives [18].
Polyphenols present in Yerba Mate contribute to its antioxidant effect [5] and protect body tissues against oxidative stress [20]. Saponins are glycoside compounds that have both hydrophobic and hydrophilic parts. Metasaponins from Ilex paraguariensis have anticancer [19], antiparasitic [23,24] and anti-inflammatory effects [18]. A synergistic anti-inflammatory effect is also observed between Yerba Mate saponins and quercetin [18].
Xanthines are purine alkaloids found in various plant extracts. Caffeine, theobromine and theophylline are the three xanthines found in Yerba Mate [27]. These alkaloids constitute a source of “energy dietary supplements” for the plant [21].
In this study, the antibacterial activity of Ilex paraguariensis was investigated after liquid-liquid partitioning into S. aureus and Salmonella species. Furthermore, the bioactive compound(s) responsible for this antibacterial activity were investigated.
Fragments of sections
General experimental
All 1D ( 1H and 13C ) and 2D (COSY, HSQC-DEPT and HMBC) NMR spectra were recorded on a Bruker 500 MHz Avance HD spectrometer with a 5-mm BBFO Smart probe with a Z gradient ( 1H at 500 MHz, 13 °C at 125, 7MHz). 2D experiments were recorded using standard pulse programs. The samples were dissolved in CDCl3 and the chemical shifts of the solvent signals at 7.24 ppm (δH) and 77.0 ppm (δC ) were considered as the internal standard (reference signal). Observed chemical shift (δ) values are given in ppm i
MIC values of the Yerba Mate fraction against S. aureus and Salmonella strains
Yerba Mate leaves were first extracted with various solvents to test the strongest antibacterial activity against several strains of bacteria. It was extracted with ethanol and further subfractionated with hexane, chloroform, ethyl acetate and water. MIC values were not detected in these extracts at the highest concentration tested (4.375 mg/ml). Yerba Mate was then extracted with pure acetone and then subfractionated. Comparison of MIC values (2.5 mg/ml) of fractions with their fractions
Discussion
Plant extracts or their bioactive compounds have been extensively studied for their antimicrobial activity, especially for the growth of multidrug-resistant bacteria [16]. Ilex paraguariensis (Yerba Mate) has recently gained popularity due to increased consumption and biological activity. Marcin et al. [15] tested methanolic and ethanolic extracts of Yerba Mate against S. aureus , S. enteritidis , L. monocytogenes and E. coli [15]. The ethanol extract had a lower MIC value than
Application
Plants have been used to treat many infectious diseases since ancient times. Numerous studies demonstrate the antiproliferative, antioxidant, anti-inflammatory, antifungal and antibacterial effects of various plant extracts. In this study, the aqueous fraction, after liquid-liquid separation of acetone:water (1:1) extract from Ilex paraguariensis stems and leaves , showed the highest antibacterial activity. Moreover, a bioactive compound responsible for this effect has been demonstrated
Financing
This research received no specific grant from funding agencies in the public, commercial or not-for-profit sectors.
Author contributions
SE-S and EF performed the experimental procedures and helped prepare the manuscript. GP and AAF helped with compound identification, NMR analysis, and manuscript revision. RAM conceived the design of the work and was involved in the interpretation of results and revision of the manuscript. All authors have read and approved the final version of the manuscript.
The content on the website comes from the National Library of Medicine and has been translated into Polish.
Link to source – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9516501/