Atividade antioxidante e antimicrobiana de extratos de Pereskia Grandfolia Haw

Abstract

The research of new antimicrobial agents is necessary due to the emergence of resistant microorganisms. Thus, there is a need for agents that have mechanisms of action different from drugs and that can contribute significantly to the development of health worldwide, with the objective of finding more effective and less toxic substances. It is known that some substances produced by plants can have action in the human body and, if used correctly, can act with medicinal benefits, be they preventive, palliative or curative. Among so many plant species that are little studied in relation to antioxidant and biological activities, Pereskia grandifolia Haw. belonging to the family Cactaceae, popularly known as ora-pro-nóbis, stands out for having known therapeutic and nutritional properties. The objective of this work was to evaluate the activity of extracts of Pereskia grandifolia Haw.obtained by different methods of extraction in relation to phytochemical and biological analyzes on Staphylococcus aureus and Pseudomonas aeruginosa. As Pereskia grandifolia Haw. Were collected in the Medicinal Plants Garden of the Federal University of Lavras and in the leaves the moisture content was determined. The aqueous refluxing, sonication, ethanolic refluxing and ethanolic sonication extracts were made and subsequently the pH of the extracts and the extractive yield were determined. To evaluate the antioxidant activity of the extracts were carried out analyzes such as determination of total phenols, quantification of total flavonoids, and quantification of total dihydroflavonoids. In addition to these analyzes, total antioxidant capacity was observed by sequestration of the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical and the chelating power and reducing power were determined. To evaluate the in vitro antibacterial activity of extracts of Pereskia grandifolia Haw. Against Pseudomonas aeruginosa and Staphylococcus aureus the Minimum Bactericidal Concentration (CMB) and sensitivity to antibiotics were determined. In relation to the phytochemical analyzes, the ethanol extract obtained by reflux showed a higher amount of phenols and flavonoids and a better antioxidant capacity. And in relation to the antibacterial activity all the extracts obtained from Pereskia grandifolia Haw. inhibited the growth of the microorganisms. Aqueous reflux and sonication extract shows greater inhibition halo. However, when the CMB was determined only the ethanolic extract of ora-pro-nobis was effective. The results of this study indicate the effectiveness of the antioxidant and antibacterial activity of the different extracts obtained from Pereskia grandifolia Haw. reinforcing the medicinal importance of this species, and encouraging the search for new studies.