Hemerson Rosa

Yerba mate (Ilex paraguariensis St. Hill.)-based beverages: How successive extraction influences the extract composition and its capacity to chelate iron and scavenge free radicals

Chimarrão or mate is a popular beverage from South America that is drank with successive infusions. Although yerba mate extracts have been widely studied, few studies have described the extract contents in beverages. Using yerba mate samples from Brazil, Argentina, and Uruguay, we examined the extract chromatographic profiles, total polyphenol content and their capacities to chelate iron. In addition, we analyzed antioxidant activity by examining the ability of the extracts to scavenge DPPH and NO. Our results showed that the amount of extracted compound was highest in yerba mate extract from Uruguay, followed by Argentina, then Brazil. Herbs from all three areas had a significant capacity to inhibit DPPH and NO free radicals. The Brazilian and Uruguayan herbs had an 80% iron chelation capacity (p<0.001), while the iron chelation capacity of the Argentinean herb was lower but still significant (p⩽0.05). We conclude that the compound concentration decreases with successive extractions, while the antioxidant capacity is maintained at significant levels.

Ecdysteroids in Sida tuberculata R.E. Fries (Malvaceae): Chemical composition by LC–ESI-MS and selective anti-Candida krusei activity

Sida tuberculata is found in a region of South America and has traditionally been consumed as an infusion or tea. The chemical composition and antifungal activity of aqueous infusions from leaves and roots were investigated. LC-ESI-MS mass spectra were successfully obtained and used to identify four ecdysteroids: 20-hydroxyecdysone-3-O-β-D-glycopyranoside, 20-hydroxyecdysone, 20-hydroxyecdysone-3-O-β-D-xylose and a hydroxyecdysterone derivative. The in vitro antifungal activity was studied, and the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) were established against Candida krusei isolates. The antibiofilm activity was evaluated by the determination of the biofilm removal efficiency in contaminated central venous catheter (CVC) coupons. The preparations exhibited antifungal activity against the species tested, with MICs ranging from 3.90 to 62.50 μg/ml. The infusion removed the C. krusei biofilm after 90 min of exposure. The observed bioactivity and composition of ecdysteroids will contribute to the future development of antifungal substances for clinical use or as food additives.

Ilex paraguariensis crude extract acts on protection and reversion from damage induced by t-butyl hydroperoxide in human erythrocytes: a comparative study with isolated caffeic and/or chlorogenic acids.

BACKGROUND Studies comparing the effects of phytochemicals under different regimens of exposure are necessary to give a better indication about their mechanism(s) of protection. Hence, in the present study, we investigated the preventive (pre-incubation), protective (co-incubation) and/or remediative (post-incubation) activity of chlorogenic acid and caffeic acids, in comparison with Ilex paraguariensis crude extract, against t-butyl hydroperoxide (t-BHP)-induced damage to human erythrocytes. RESULTS We found that both caffeic and chlorogenic acids were able to prevent and revert the hemolysis associated with t-BHP exposure. By contrast, isolated compounds (alone or in combination) presented no effect on basal and/or t-BHP-induced non-protein thiol (NPSH) oxidation or production of thiobarbituric acid reactive substances (TBBARS). In turn, I. paraguariensis extract was effective to prevent, protect and revert the hemolysis associated with t-BHP exposure. Moreover, I. paraguariensis significantly protects and reverts t-BHP-induced NPSH oxidation and TBARS production. CONCLUSIONS We have found that I. paraguariensis extract acts better with respect to the protection and reversion of t-BHP-associated changes, whereas isolated compounds are more active in preventing and reverting t-BHP pro-hemolytic action. Moreover, our data suggest that the pro-hemolytic activity of t-BHP may occur via mechanism(s) other(s) than lipid peroxidation and/or NPSH oxidation.

Compounds from Ilex paraguariensis extracts confer antioxidant effects in the brains of rats subjected to chronic immobilization stress

Immobilization induces oxidative damage to the brain. Ilex paraguariensis extracts (Mate) and their major natural compound, chlorogenic acid (CGA), exert protective effects against reactive oxygen species formation. Here, the effects of Mate and CGA on oxidative damage induced by chronic immobilization stress (CIS) in the cortex, hippocampus, and striatum were investigated. For CIS, animals were immobilized for 6 h every day for 21 consecutive days. Rats received Mate or CGA by intragastric gavage 30 min before every restraint session. Endpoints of oxidative stress (levels of lipid peroxidation, protein carbonylation, and reduced (GSH) and oxidized (GSSG) forms of glutathione) were evaluated following CIS. While CIS increased oxidized lipid and carbonyl levels in all brain regions, CGA (and Mate to a lesser extent) attenuated lipid and protein oxidation as compared with control groups. GSH/GSSG balance showed a tendency to increase in all regions in response to stress and antioxidants. Taken together, our results support a protective role of dietary antioxidants against the neuronal consequences of stress.

Extraction optimization and UHPLC method development for determination of the 20-hydroxyecdysone in Sida tuberculata leaves

&NA; Sida tuberculata (ST) is a Malvaceae species widely distributed in Southern Brazil. In traditional medicine, ST has been employed as hypoglycemic, hypocholesterolemic, anti‐inflammatory and antimicrobial. Additionally, this species is chemically characterized by flavonoids, alkaloids and phytoecdysteroids mainly. The present work aimed to optimize the extractive technique and to validate an UHPLC method for the determination of 20‐hydroxyecdsone (20HE) in the ST leaves. Box‐Behnken Design (BBD) was used in method optimization. The extractive methods tested were: static and dynamic maceration, ultrasound, ultra‐turrax and reflux. In the Box‐Behnken three parameters were evaluated in three levels (−1, 0, +1), particle size, time and plant:solvent ratio. In validation method, the parameters of selectivity, specificity, linearity, limits of detection and quantification (LOD, LOQ), precision, accuracy and robustness were evaluated. The results indicate static maceration as better technique to obtain 20HE peak area in ST extract. The optimal extraction from surface response methodology was achieved with the parameters granulometry of 710 nm, 9 days of maceration and plant:solvent ratio 1:54 (w/v). The UHPLC‐PDA analytical developed method showed full viability of performance, proving to be selective, linear, precise, accurate and robust for 20HE detection in ST leaves. The average content of 20HE was 0.56% per dry extract. Thus, the optimization of extractive method in ST leaves increased the concentration of 20HE in crude extract, and a reliable method was successfully developed according to validation requirements and in agreement with current legislation.

Predictive antidiabetic activities of plants used by persons with Diabetes mellitus

BACKGROUND There are several ways to identify medicinal power of phytoconstituents, such as in silico evaluations. Furthermore, ethnopharmacological researches are important alternatives for the identification of plants with medicinal potential. Significantly, medicinal plants are widely used by persons with Diabetes mellitus (DM) to treat manifestations of this syndrome. OBJECTIVES i) to investigate the use of medicinal plants for individuals with DM and their health profile; ii) to evaluate in silico possible antidiabetic activities for main phytoconstituents of the commonly used plants. METHODS A questionnaire was used to measure consumption of medicinal plants. The Prediction of Activity Spectra for Substances (PASS) platform was employed to perform in silico evaluations. In silico predictions for antidiabetic activities were performed with the main compounds identified in a literature review which focused on the more utilized plants. RESULTS We interviewed 105 persons with DM, most them women (73.34%). Overall mean age was 59.35 years, and 97.14% of them were diagnosed with type 2 DM. An evaluation of the routine exams of the interviewees showed that they have a poor metabolic control. Among the interviewees, 67.62% confirmed the use medicinal plants. Main forms of consumed plant preparation were infusion of leaves and in association with mate (a typical beverage of southern Brazil). Most interviewees consume five or more cups of infusion per day, and when consumed with the mate, 1.73 liters per day. Forty-six medicinal plants were mentioned, and cows paw (Bauhinia) and jambolan (Syzygium cumini) were the most used. The main informed objective for the plant use was blood glucose control (69.01%). The PASS analysis presented six phytoconstituents with high antidiabetic prediction, especially, vicenin-2, the main phytochemical identified in Passiflora genus (Pa = 0.822). CONCLUSION Our data show that persons with DM use many plants as a complementary treatment to the traditional medicine. Moreover, part of these plants presented phytoconstituents with antidiabetic potential. These data can serve as a basis for future investigations, with the objective of exploring in vitro and in vivo antidiabetic effects of these plants and its compounds.