Migraine Attacks Triggered by Ingestion of Watermelon.

INTRODUCTION: Ingesting some foods can trigger headache attacks in migraine patients. Diet-sourced citrulline activates the l-arginine-nitric oxide pathway, acting on the pathophysiology of migraine. METHODS: The study was a clinical trial, interventional, controlled, and with group comparison. The sample was non-random, composed of 38 volunteers with migraine and 38 without headache (control). Both groups ingested a portion of watermelon to determine the onset of headache attacks. Before and after ingesting watermelon, they underwent blood collections to determine serum nitrite levels. RESULTS: There were 38 volunteers diagnosed with migraine without aura and 38 controls, whose mean age was, respectively, 22.4 ± 1.5 and 22.9 ± 3.1 years (p = 0.791). Headache was triggered by watermelon ingestion after 124.3 ± 20.5 min of ingestion in 23.7% (9/38) of the migraine volunteers and in none of the controls (p = 0.002). There was an increase in serum nitrite levels, both in migraine volunteers (23.4%) and in the control group (24.3%), after watermelon ingestion. This difference was significant (p < 0.001). DISCUSSION: Watermelon ingestion triggered headache attacks in migraine patients and increased serum nitrite levels, attesting to a possible activation of the l-arginine-nitric oxide pathway.

Toxicity, cytotoxicity, mutagenicity and in vitro antioxidant models of 2-oleyl-1,3-dipalmitoyl-glycerol isolated from the hexane extract of Platonia insignis MART seeds.

2-oleyl-1,3-dipalmitoyl-glycerol (ODG) was obtained from Platonia insignis (bacurizeiro) seeds. There are no studies on its toxicity and protective activities against oxidative stress. This study was aimed to evaluate antioxidant effects in vitro, as well as to evaluate the toxicological and mutagenic effects of the ODG. ODG showed a median lethal dose (LD50) greater than 1200 µg mL-1 in A. salina. In the assay of A. cepa (0.2-0.002 mg mL-1) the ODG compound at the highest concentration was slightly cytotoxic with decrease in the size of roots and mitotic indexes, but did not induce chromosomal alterations. ODG (8.75-140.00 µg mL-1) was found to reduce nitric oxide production by 41.6 %, while the antioxidant standard ascorbic acid (AA) reduced 54.14 %. ODG (15.625-250.00 µg mL-1) promoted removal of the hydroxyl radical by 35.69 % at the highest concentration and was able to prevent lipid peroxidation induced by 2,2'-azobis-2-amidinopropane (AAPH), inhibiting the amount of TBARS formed, up to 35.69 %, a result close to that obtained with AA. Thus, ODG moderately reduced the levels of hydroxyl radicals, nitric oxide, and TBARS in vitro and was nontoxic at low concentrations.

In Vitro and Ex Vivo Chemopreventive Action of Mauritia flexuosa Products.

Mauritia flexuosa (Arecaceae), known as "Buriti," is a Brazilian palm tree with high economic potential for local communities. Herein, we investigated the phytochemistry profile and antioxidant potential of M. flexuosa fruits and determined the bioaccessibility of phenolic compounds. Peels revealed upper values for phenols, flavonoids, carotenoids, tannins, and ascorbic acid when compared to the pulps and endocarps. All samples showed capacity to scavenger free radicals (0.5, 1.0, 2.0, 4.0, and 8.0 mg/mL) but peels presented higher scavenger action in all methods explored. Phenolic compounds identified by HPLC displayed reduced bioaccessibility after in vitro simulated gastrointestinal digestion for pulp (38.7%), peel (18.7%), and endocarp (22.3%) extracts (P < 0.05). Buriti fruits also protected rat blood cells against lysis induced by peroxyl radicals. We demonstrated the promising chemopreventive potentialities of M. flexuosa fruits and their by-products and peels with higher quantities of bioactive compounds and phenolic substances before and after in vitro bioaccessibility investigation. In Brazil, these parts are discarded or underused, mainly as feed for ruminant animals. Consequently, it is extremely important to explore nutritional characteristics of these by-products for human/livestock foods and to install biofriendly techniques and sustainable biotechnology handling of natural resources.

Pathophysiological investigations, anxiolytic effects and interaction of a semisynthetic riparin with benzodiazepine receptors.

We have reported Riparin A as a promising antiparasitic molecule ​​against Leishmania amazonensis promastigotes. This work evaluated the acute oral toxicity of Riparin A and its anxiolytic effects using in vivo models and computational tools. Mice were submitted to acute oral toxicity tests (Guideline OECD 423). Later, anxiety assays with Riparin A (50, 100 and 200 mg/kg: elevated plus maze, light/dark box and marble burying) were performed. Theoretical calculations analyzed interaction of Riparin A with gamma-amino butyric acid (GABA) receptors. Only Riparin A at 2000 mg/kg alter body weight, food and water consumption and urine production after 7 and/or 14 days treatment and increased serum triglycerides. There was increase in the time spent in the open arms (TSOA) and number of transitions between compartments (NTC) and decrease in number of hidden balls (NHB) in Riparin A-treated animals at 200 mg/kg (P < 0.05), whose approximate ED50 was 283.1 (156.5-397.1) mg/kg. The functional amide of Riparin A interacted with the GABAA receptor mainly at subunits α2 and ß1 and presented strong interaction with the Asp68 residue, which is part of the pharmacophore group. Riparin A was toxically safe and pharmacologically active for anxiolytic purposes, revealed NOAEL of 200 mg/kg and probably interacts with Asp68 residues of benzodiazepine receptors by hydrogen bonds.

Phytochemistry Profile, Nutritional Properties and Pharmacological Activities of Mauritia flexuosa.

Mauritia flexuosa L. (Arecaceae) is a popular Brazilian fruit known as "buriti" and belonging to the category of functional foods. This work reviewed the phytochemistry profile, nutritional and pharmacological activities of M. flexuosa. The main bioactive compounds reported to buriti were carotenoids, tocopherols, ascorbic acid, phenolic compounds, fiber, phytosterols, and mono- and poly-unsaturated fatty acids. These compounds were mainly related to antioxidant, hypolipemiant, photoprotector, antiaggregant, antithrombotic, anti-inflammatory, hypoglycemiant, antimicrobial, and antitumor activities. Furthermore, some compounds present in buriti fruit and its properties were tested in vitro and in vivo and showed biotechnology applications, especially for extraction of fiber, polysaccharides, pigments, antioxidants, and oil. Howerer, the buriti fruit shows great relevance to the development of new products in food, pharmaceutical and chemical industry, this fruit is still underexploited and it has need to expand its production chain and processing to encourage their consumption and utilization.

In vitro antioxidant, antitumor and leishmanicidal activity of riparin A, an analog of the Amazon alkamides from Aniba riparia (Lauraceae) / Atividade antioxidante, antitumoral e leishmanicida in vitro da riparina A, um análogo das alcamidas amazônicas de Aniba riparia (Lauraceae)

Aniba riparia (Lauraceae) is an important medicinal plant found in the Amazon region and presents alkaloids of the type alkamide known as riparins. Riparin A is structurally represented as the fundamental core of all Amazon riparins. This work aimed to assess the in vitro antioxidant, antitumor and antileishmanial effects of riparin A. Riparin A presented weak antioxidant capacity by tecniques of DPPH• (EC50 of 296.2 μg mL-1) and ABTS•+ (EC50 of 450.1 μg mL-1), showed moderate activity against colon carcinoma (HCT-116: IC50 of 21.7 μg mL-1) and leishmanicidal activity on promastigotes of L. amazonensis (IC50 of 307.0 ± 79.6, 193.7 ± 44.3 and 81.8 ± 11.2 μg mL-1, respectively, after 24, 48 and 72 h of incubation). Then, in addition to its structural simplicity, riparin A revealed promising biological activities and remarkable in vitro leishmanicidal action, an important result in epidemiological point of view to control leishmaniasis in Brazil, including in the Amazon region.

Aniba riparia (Lauraceae) é uma importante planta medicinal encontrada na região amazônica que apresenta alcaloides do tipo alcamida e conhecidos como riparinas. Este trabalho teve como objetivo avaliar os efeitos antioxidantes, antitumorais e leishmanicidas in vitro da riparina A. Riparina A apresentou fraca capacidade antioxidante pelas técnicas do DPPH• (CE50 de 296,2 μg mL-1) e ABTS•+ (CE50 de 450,1 μg mL-1), mostrou moderada atividade contra carcinoma de cólon (HCT-116: CI50 de 21,7 μg mL-1) e atividade leishmanicida sobre formas promastigotas de Leishmania amazonensis (CI50 de 307,0 ± 79,6; 193,7 ± 44,3 e 81,8 ± 11,2 μg mL-1, respectivamente, após 24, 48 e 72 h de incubação). Assim, além de sua simplicidade estrutural, a riparina A revelou atividades biológicas promissoras e significativa ação leishmanicida in vitro, resultado importante diante da relevância epidemiológica para controle da leishmaniose no Brasil, inclusive na região amazônica.