Correlation Among Metallic Ions, Phenolic Compounds and Antimicrobial Action in Medicinal Plants Extracts

Abstract

The extracts of three different medicinal plants –Calendula officinalis L., Maytenus ilicifolia Martius ex Reissek and Cymbopogon citratus (DC) Stapf – obtained with 70% and 95% v/v ethanol had their antimicrobial activity tested against five pathogenic microorganisms. A quantitative analysis of total phenols, flavonoids and mineral species was performed on the extracts using UV‐vis spectroscopy and atomic absorption spectroscopy. Klebsiella pneumoniae showed the greatest sensibility to the extracts tested. The mineral content of the medicinal herbs varied according to the type of plant (Cu = not detected to 10.90; Zn = 0.85 to 10.04; Na = 24.94 to 153.62; Al = 90.04 to 420.39; Mg = 9.62 to 1,129.15; Ca = 7.15 to 167.27 and K = 913.85 to 9,578.94 µg/g); however, the concentration of heavy elements (Pb, Cd and Cr) was null in the extracts. The concentrations of flavonoids ranged from 13.55 to 41.54 mg/g and 92.35 to 518.28 mg/g for phenolic acids. PRACTICAL APPLICATIONS The use of plants with pharmacological activities has increased significantly because of their functional properties in the diet for the promotion of human health and antimicrobial effects. Moreover, medicinal herbs play an important role in public health, especially in developing countries. In Brazil, the use of plant extracts in the treatment of certain diseases is very common. This habit can be explained, at least in part, by the belief that herbs with therapeutic effects do not have toxic effects on the organism. In this paper, ethanolic extracts of three medicinal plants, widely cultivated and used by the population of Brazil and worldwide, had their levels of metals ions and total phenolic compounds determined. Antimicrobial activity of the extracts was evaluated against foodborne pathogens or food spoilage organisms or clinically isolates microorganisms.

Actividad antibacteriana in vitro de Maytenus ilicifolia Martius sobre Streptococcus mutans y Staphylococcus aureus

“…Nuestras pruebas fueron realizadas teniendo como control negativo una solución fisiológica 0,9% al igual que Ojeda Pereda & Beltrán Orbegoso (2019), sin embargo, Ducat et al, (2011), al evaluar la actividad antibacteriana de Maytenus ilicifolia Martius utilizó como control negativo Etanol 70 y 90%, siendo estos los mismos solventes utilizados para la preparación del extracto.…”

“…En cuanto al efecto del extracto etanólico de Maytenus ilicifolia Martius sobre Staphylococcus aureus, en relación al estándar considerado se obtuvo un porcentaje de efecto inhibitorio del 51,82% a una concentración de 47,76 mg/mL, siendo ésta una concentración más alta con respecto a la sugerida efectiva por Ducat et al(2011), quienes en un estudio, obtuvieron extractos etanólicos de Maytenus ilicifolia Martius ex Reissek en concentraciones de 70% (ES70) y 95% (ES95) v/v etanol para determinar la actividad antimicrobiana, encontrándose que el ES70 presentó una zona de inhibición frente al S. aureus. Se observó que el ES70 inhibió el desarrollo del S. aureus en concentraciones de 25; 2,5 y 0,25 mg/mL, obteniéndose como CIM del extracto 0,25 mg/mL y el CBM de 25 mg/mL.…”

“…plantas con actividad antimicrobiana, habiéndose demostrado que la variante de difusión en pozo presenta más alta sensibilidad en relación con los discos de papel de filtro Whatman debido a la presencia de grupos hidroxilo libres de la celulosa que impiden la difusión de compuestos catiónicos de los productos naturales en el agar (Ramírez & Marin, 2009). Por tanto y coincidiendo con los procedimientos empleados por Ducat et al, (2011) optamos por el método de difusión en pozo en agar Mueller Hinton para efectuar las…”

Essential metals and phenolic acids in commercial herbs and spices. Multivariate analysis of correlations among them

“…However, Ducat et al [1] submits a hypothesis that correlations between aluminium, calcium and copper and total flavonoids in medicinal plants are caused by formation of flavonoid chelates with these ions. According to Maisuthisakul et al [13], iron and calcium negatively correlates with total phenolic level expressed as gallic acid equivalent for 28 studied [33] have shown that, with the exception of manganese, no correlation existed between macro-and trace elements and the total antioxidant capacity expressed by a radical scavenging DPPH assay of the banana fresh pulps and peels.…”

“…Various plants have been used since antiquity not only for their culinary benefits but also for their role played in health protection as preventive or supportive therapies of numerous diseases and disorders [1][2][3][4]. Many plants have been used as folk remedies after preparation in traditional way such as cooking, infusions or macerations.…”