Antibacterial, antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs

Abstract

Context: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal. Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc. Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48 h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24 h) was tested using HEP G2 cells and fibroblasts. Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90 mg AAE/g dw and 783.48 mg TE/g dw, respectively). CM had the highest zinc concentration (37.21 mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91 mg/100 g dw). LS was rich in rosmarinic acid (301.71 mg/100 g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830 lg/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content. Conclusion: The most promising plants for further studies are CM, LS and GP.ARTICLE HISTORY

Antioxidant, Anti‐inflammatory and Cytotoxic Activities of Polyphenols Extracted from Chroogomphus rutilus

“…Determination of DPPH Radical Scavenging Ability . Radical scavenging capacity for DPPH was estimated according to the method of Nunes et al . with slight modifications.…”

“…The reducing power was determined according to the method with slight modifications established by Nunes et al . The reaction system, containing 1 mL samples (0–0.8 mg/mL), 2.5 mL PBS (pH 6.6, 0.2 m ) and 1.0 mL potassium ferricyanide solution (1 %), was heated in a water bath for 20 min at 50 °C.…”

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“…Flavonoids as ingredients of this formula possess a wide range of bioactive effects including strong antioxidant activity 17 . These antioxidant agents can scavenge free radicals that protect the organism against damage caused by free oxygen species 18,19 . The free radicals are mainly reactive oxygen (ROS) and reactive nitrogen (RNS) species.…”

Ease of Phytochemical Extraction and Analysis from Plants?

“…The organic solvent extraction phase uses either a single solvent (water, ethanol, ethyl acetate and hexane) as solidliquid extraction or an aqueous form of these solvents as a two phase extraction method. In general, ethanol is preferred because at the point of consumption of the molecules obtained, ethanol is considered as "Generally Accepted As Safe (GRAS)" according to American Food and Drug Administration (Azmir et al, 2013;Nunes et al, 2017;Oroian and Escriche, 2015). On the other hand, the studies showed that addition of water to the extraction solvent resulted in increase in the yield of phenolic compound extraction.…”