Publications by authors named "Maria Raquel Figueiredo"

Article Synopsis
  • The text discusses the isolation of two cytotoxic compounds, aurelianolides A and B, from a plant in the Solanaceae family, which shows potential as anticancer drugs.
  • Traditional methods for obtaining these compounds are costly and time-consuming, prompting a study to explore a more efficient technique using high-speed countercurrent chromatography (HSCCC).
  • The study achieved a successful separation of the withanolides in a single step, resulting in high-purity yields of aurelianolides A and B, significantly improving the process compared to classical methods.
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Background: , a Brazilian native species from the Solanaceae family, is recognized as a promising source of bioactive withanolides, particularly Aurelianolide A and B, which exhibit significant antitumoral activities. Despite its potential, research on the chemical constituents of this species remains limited. This study aimed to dereplicate extracts and partitions of to streamline the discovery of bioactive withanolides.

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Chagas disease (CD) caused by the protozoan affects more than six million people worldwide. Treatment is restricted to benznidazole (Bz) and nifurtimox (Nf) that display low activity in the later chronic stage besides triggering toxic events that result in treatment abandonment. Therefore, new therapeutic options are necessary.

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(Andiroba, Meliaceae) is considered a multipurpose tree. In Brazil, Indigenous people have used it as insect repellent and in the treatment of various diseases. Most biological activities and popular uses are attributed to limonoids, which are highly oxygenated tetranortriterpenoids.

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Background/aim: Aurelianolide A and B were identified and isolated from Aureliana fasciculata var. fasciculata leaves. Withanolides are naturally occurring C-28 steroidal lactone triterpenoids with cytotoxic and anticancer properties, among other relevant pharmacological activities.

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Background: Sporothrix brasiliensis is the causative agent of zoonotic cases of sporotrichosis in Brazil and is associated with atypical and severe presentations in cats, dogs, and humans. Sporotrichosis treatment is usually time- and cost-consuming, sometimes with poor response and host toxicity. Schinus terebinthifolius has proven efficacy against bacteria and fungi of clinical interest.

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The species are a recognized botanical source of a broad structural diversity of lignans and its derivatives. For the first time, Kunth is presented as a promising natural source of the bioactive (-)-grandisin. Phytochemical analyses of extracts from its leaves, branches and inflorescences showed the presence of the target compound in large amounts, with leaf extracts found to contain up to 52.

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is a semiaquatic plant native to Brazil and belongs to the Alismataceae family. Infusion preparations of the leaves of this plant are often used due to its diuretic, blood pressure lowering, and anti-inflammatory properties. Our aim was to investigate the effects of chronic treatment with the crude hydroalcoholic extract of on central and peripheral microvascular changes induced in a model of hypertension and diabetes.

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Article Synopsis
  • - Snake envenomation is a significant global health concern, and current antivenoms often fail to effectively neutralize local toxins.
  • - A study focused on the plant Schwartzia brasiliensis, which showed promise in inhibiting various toxic effects of Bothrops jararaca and B. jararacussu venoms, including coagulant and hemolytic activities.
  • - The extract from S. brasiliensis was found to be non-toxic to mice and red blood cells, suggesting its potential as an alternative treatment to enhance current antivenom therapy for snakebites.
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Background: In Brazil, the Bothrops genus accounts for 87% of registered snakebites, which are characterized by hemorrhage, tissue necrosis, hemostatic disturbances, and death. The treatment recommended by governments is the administration of specific antivenoms. Although antivenom efficiently prevents venom-induced lethality, it has limited efficacy in terms of preventing local tissue damage.

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Leishmaniasis is the generic denomination to the neglected diseases caused by more than 20 species of protozoa belonging to the genus . The toxic and parenteral-delivered pentavalent antimonials remain to be the first-line treatment. However, all the current used drugs have restrictions.

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Cancer is one of the leading causes of death worldwide (approximately 8.2 million cases/year) and, over the next two decades, a 70% increase in new cancer cases is expected. Through analysis of the available drugs between the years of 1930 and 2014, it was found that 48% were either natural products or their derivatives.

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Background/aims: Severe dengue fever is a result of exacerbated immune responses and no specific treatments are available. We evaluated the antiviral and immunomodulatory effects of Norantea brasiliensis Choisy.

Methods: Human adherent monocytes infected in vitro with dengue virus (DENV)-2 were incubated with the crude ethanol extract from leaves (NB1) or 3 derived fractions: dichloromethane (NB3), ethyl acetate (NB5), and butanolic (NB6) partitions.

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Echinodorus grandiflorus (Cham. & Schltdl.) Micheli is a native Brazilian species used in traditional practices for the treatment of several conditions such as inflammatory diseases, arthritis and hypertension.

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Ethnopharmacological Relevance: Schinus terebinthifolius is a species of plant from the Anacardiaceae family, which can be found in different regions of Brazil. Schinus is popularly known as aroeirinha, aroeira-vermelha, or Brazilian pepper. In folk medicine, S.

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Benzophenone derivatives are special metabolites that arouse great scientific interest. The Clusiaceae family is known for producing large amounts of benzophenone derivatives with several isoprene residues on their structures, which are responsible for the observed complexity and structural variety in this class of substances, and also contribute to their biological activities. Clusia is an important genus belonging to Clusiaceae, with 55 different polyisoprenylated benzophenones identified so far.

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Plumbago scandens L. is a Brazilian tropical/subtropical species that occurs along the coast. Chemically it is mainly represented by naphthoquinones, flavonoids, terpenoids and steroids.

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Different species of the family Clusiaceae, including Rheedia longifolia, are used in folk medicine to treat inflammatory diseases. This family is largely distributed in tropical and subtropical areas of Brazil, but their chemical and pharmacological properties have been the subject of a few studies. In previous studies, we found that the aqueous extract from R.

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Recently, the P2X(7) receptor has been reported to be associated with chronic inflammatory and neuropathic pain. Because Rheedia longifolia extract has analgesic and anti-inflammatory activity, we evaluated the in vitro inhibitory potential of methanol extract and fractions from its leaves on the P2X(7) purinergic receptor. The activity of P2X(7) was studied with a dye uptake assay and with the whole-cell patch clamp technique in mouse peritoneal macrophages treated with methanol extract of R.

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Introduction: Limonoids are tetranortriterpenoids of considerable interest due to their structural varieties and biological activities, such as insecticidal, antibacterial, antifungal, antimalarial, anticancer and antiviral. They contain oxygen atoms that confer a moderate polarity and are responsible for the difficulties in their separation by traditional chromatographic methods. High-speed countercurrent chromatography (HSCCC) is a versatile liquid-liquid separation technique, in which the sample is distributed between two non-miscible phases to achieve separation.

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Schinus is a genus of the Anacardiaceae family and contains Schinus terebinthifolius, the Brazilian pepper tree that is widely used in folk medicine. We investigate the anti-allergic activity of the ethyl acetate fraction of S. terebinthifolius Raddi (ST fraction).

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The antihypertensive action of a crude ethanolic extract (EEEG) from leaves of Echinodorus grandiflorus (Alismataceae) was investigated in spontaneously hypertensive rats. The intraperitoneal injection of increasing doses of EEEG (300-1000 mg/kg) elicited dose-dependent reductions in mean arterial pressure (MAP) that were paralleled by reductions of cardiac output and systemic vascular resistance, reaching the maximum of 23 +/- 5%, 13 +/- 3% and 18 +/- 4%, respectively (n = 5, P < 0.05).

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Rheedia longifolia Planch et Triana belongs to the Clusiaceae family. This plant is widely distributed in Brazil, but its chemical and pharmacological properties have not yet been studied. We report here that leaves aqueous extract of R.

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We investigated the vascular effects of a crude aqueous extract (AEEG) of Echinodorus grandiflorus (Alismataceae) using the in vitro experimental models of the rabbit isolated aorta and perfused kidney. Echinodorus grandiflorus, a native semi-aquatic plant widely distributed in Brazil, has been extensively used in Brazilian folk medicine for the treatment of high blood pressure and inflammatory diseases. The bolus injection of AEEG (0.

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