Inability of 7,8 – Dihydroxy-4- Methylcoumarin antioxidant activity, to prolong longevity and to protect against stress in Caenorhabditis Elegans worms

Despite an increase in life expectancy, it is known that this factor is not necessarily accompanied by a better quality of life, which reflects in longevity. Aspects related to metabolic stress to which cells are subjected can modulate this process, which can lead to various pathologies. Coumarins are secondary metabolites found in several plants, such as guaco, and are part of the polyphenol family capable of producing up to 1300 derivatives, with potential effects against metabolic stress, in addition to being used in the cosmetics industry with the objective of improving fragrance of products. Therefore, it seems necessary to seek to elucidate molecular mechanisms that can regulate this aging process, which can be associated with the gradual loss of physiological functions of cells and tissues, increasing the number of cells in senescence that may be related to increased oxidative stress. PURPOSE: the aim of this study was to identify the influence of the use of the coumarin synthetic compound 7,8-Dihydroxy-4-methylcoumarin (DHMC) on longevity and resistance to different types of stress in vivo. METHODS: free radical scavenging (DPPH) analyzes were performed for the compound, longevity, and stress tests (H2O2, NaCl, Heat) for C. elegans worms. RESULTS: in the first analysis, the compound showed 92% of antioxidant activity already in small concentrations (25ug/ml) through DPPH analysis. In the following tests DHMC did not show antibacterial responses against Escherichia coli, and Caenorhabditis elegans worms did not show stress reduction or significant improvement in longevity with the use of the compound. CONCLUSION: therefore, the DHMC compound expresses a high antioxidant activity and presents several study potentials. However, it has no biological effects in protecting against stress or contributing to longevity in C. elegans worm

Chelating effect of carvacrol and the oregano essential oil

Essential oils are natural products obtained from parts of plants by means of steam distillation. They are also made by expression of citrus fruit pericarp [1]. Because they are a complex mixture of chemical components, they exert innumerable biological activities, such as antimicrobial, antiparasitic, antitumor, antioxidant, among others. Because of the public demand for products of natural origin in different segments of society, essential oils have gained space, mainly in the food industries, where natural preservatives are sought that can replace or be associated with the synthetic additives used. One of the desirable properties of preservatives is their ability to interact with metal ions, such as iron, by exerting a chelating effect to inhibit lipid oxidation reactions catalyzed by these ions [2]. The objective of the present work was to evaluate the chelating effect of oregano essential oil and its major constituent, carvacrol, by cyclic voltammetry. The essential oil was extracted by hydrodistillation over a period of 2 hours using a modified Clevenger apparatus and characterized by gas chromatography coupled to mass spectrometric and flame ionization detectors. For the determination of the chelating effect, an electrochemical cell containing 0.05 mol L-1 of anhydrous Na2SO4 was used as the supporting electrolyte, and FeSO4.5H2O 0.00150 mol L-1 was the source of ferrous ions. Three electrodes were employed: Ag/AgCl (saturated in KCl) electrode was the reference, a platinum wire was the auxiliary, and glassy carbon was the working electrode. The determination of the chelating effect was performed by calculating the variation of the height of the ferrous oxidation peak with the increase in the concentrations of carvacrol and the essential oil. The essential oil from oregano contained terpinen-4-ol, carvacrol, trans-sabinene hydrate and γ-terpinene as the principal constituents. A reduction in the ferrous anodic current of 99.5 and 89% after the addition of 500 μg mL-1 of carvacrol and oregano oil, respectively, was observed, thus indicating the occurrence of a chelating effect of oregano essential oil and its constituent carvacrol

Effect of the essential oil from Cantinoa carpinifolia (Benth.) Harley & J.F.B.Pastore on efflux of potassium ions from Escherichia coli and Staphylococcus aureus strains

Essential oils are secondary metabolites synthesized from glucose via two basic precursors, terpenes and phenylpropanoids. These compounds present diverse biological activities that reflect the very role they play in plants [1]. One of the most important properties is the antibacterial activity, although there are still few studies regarding the mechanism of action. Cantinoa carpinifolia (Benth.) Harley & J.F.B.Pastore, popularly known as rosman, is a plant species belonging to the Lamiaceae family and whose use in popular medicine is described in the treatment of diseases such as colds, flu, and rheumatism [2]. The objectives of the present work were to extract the essential oil from C. carpinifolia and to evaluate its effect on the efflux of potassium ions from strains of Escherichia coli and Staphylococcus aureus. The essential oil was extracted by the hydrodistillation technique using a modified Clevenger apparatus. The effect of the essential oil on the potassium efflux of bacterial strains was determined by flame photometry [3]. The concentrations tested were 6.25 μL mL-1 and 0.39 μL mL-1 for E. coli and S. aureus, respectively. The cell membrane is a barrier between the external and internal environments of the cell, being permeable to the passage of electrolytes that are important for various cellular functions, such as K+ ions. The leakage of these ions indicates that an increase in permeability or rupture of the cell membrane occurred, affecting the functioning of bacterial cell metabolism and causing lysis. There was no significant variation between the five evaluated times (0, 60, 135, 197 and 267 min) for either of the bacteria nor did the concentration of potassium ions differ statistically when the treatments containing the essential oil and the control (bacterial culture) were compared. These results suggest that the essential oil from C. carpinifolia did not influence the cell membrane permeabilities of E. coli and S. aureus to potassium ions because there was no increase in the concentration of this ion at the evaluated times