Jackson Nunes e Vasconcelos

Estudo químico e biológico de Tephrosia toxicaria Pers.

The ethanol extracts from leaves, stems, pods and roots were assayed against the 3rd instar Aedes aegypti larvae and the highest activity was observed in the roots extracts (LC50 47.86 ppm). This extract was submitted to partition with hexane, chloroform, ethyl acetate and methanol. The respective fractions were bioassayed and the best larvicidal activities were identified in the hexane (LC50 23.99 ppm) and chloroform (LC50 13.80 ppm) fractions. Antioxidant activity (DDPH method) was observed in the ethanol extract (IC50 276 µg/mL) from roots of T. toxicaria. Fractions from this extract were also tested and the highest antioxidant activity (IC50 89 µg/mL) was found in the methanol fraction. The flavonoids iso-obovatin (1), obovatin (2), 6a,12a-dehydro-β-toxicarol (3), 6a,12a-dehydro-α-toxicarol (4) and α-toxicarol (5) were isolated and bioassayed against A. aegypti. The flavonoid 5 showed the best larvicidal activity (LC50 24.55 ppm). The antioxidant activity of 2 was investigated and showed IC50 3.370 µg/mL. The antioxidant and larvicidal activities of Tephrosia toxicaria are reported for the first time.

Tephrosia toxicaria Pers. reduces temporomandibular joint inflammatory hypernociception: The involvement of the HO‐1 pathway

We investigated both the efficacy and the sub‐chronic toxicity of Tephrosia toxicaria Pers. in the zymosan‐induced temporomandibular joint (TMJ) inflammatory hypernociception in rats evaluating the possible role of heme oxygenase‐1 (HO‐1).

Rotenoids from Tephrosia toxicaria with larvicidal activity against Aedes aegypti, the main vector of dengue fever

In the search for new larvicides from plants, we have investigated the potential activity of the rotenoids deguelin (1), 12a-hydroxy-α-toxicarol (2) and tephrosin (3), isolated from the bioactive ethanol extract of roots of Tephrosia toxicaria Pers., against Aedes aegypti, the main vector of dengue. The absolute configuration of these compounds was determined by circular dichroism (CD) spectra. The LC50 values of the compounds evaluated justify the potential of T. toxicaria as a new natural larvicide.

Zanthoxylum articulatum Engler (Rutaceae) Essential Oil: Chemical Composition and Larvicidal Activity

Abstract The leaves of Zanthoxylum articulatum Engler (Rutaceae), collected in Jacobina-Bahia, Northwest of Brazil, was subjected to hydrodistillation and its essential oil was characterized by GC/MS. Twelve compounds were identified representing 90.4% of the oil. Oxygenated sesquiterpenes (65.4%) were the major constituents with viridiforol (35.4%), spathulenol (9.9%), elemol (9.7%) and globulol (6.5%) being the main compounds. The oil was examined with respect to its larvicidal properties against the larvae of a mosquito (Aedes aegypti) and showed LC50 77.62 ± 0.64 ppm.

Tephrosia purpurea: A Source of Larvicidal Compounds Against Aedes Aegypti

Tephrosia purpurea (L.) Pers., a member of the Fabaceae family, is a shrub popularly known in northeastern Brazil as “anil-bravo.” The species is reported to have various biological properties, such as hepatoprotective, laxative, deobstruent, and diuretic activities. The plant is useful for treating bronchitis, bilious febrile attacks, and obstructions of the liver, spleen, and kidneys, and a decoction of its roots is used as a nematicide 1–3 . In addition to its wound-healing, antileishmanial, anticarcinogenic, antimicrobial, and anti-lipid peroxidative effects, the potential use of T. purpurea for the treatment of polycystic ovary syndrome has been recently reported 4–6]. The genus Tephrosia, which is distributed in tropical and subtropical regions of the world, is noted for the presence of flavonoids, especially rotenoids. The latter group is an interesting class of compounds showing primarily fish-poisoning, insecticidal, and antimicrobial activities [7–10]. The aim of the present study was to evaluate the activities of essential oil from T. purpurea stems, extracts from its leaves, roots, pods, and stems, and isolated compounds lanceolatin B, pongamol, and rotenone against third-instar Aedes aegypti larvae. Aedes aegypti is one of the mosquito species responsible for transmission of dengue fever and dengue hemorrhagic fever. These diseases emerged in the second half of the twentieth century as a major public health concern in many of the world’s tropical and sub-tropical regions. In addition to their association with high mortality levels, these diseases cause great economic losses and social disruption, both in Brazil and elsewhere [11]. Because no effective drug or vaccine currently exists against dengue, the only method of prevention is control of its host [12]. The synthetic insecticides applied for vector eradication are hazardous to handle and are harmful to humans, other mammals, and the environment. Several plants from different families have been reported to exert mosquitocidal activity, and their extracts and essential oils have been evaluated as biological agents against A. aegypti [13]. In this manner, alternatives to chemical pesticides can be discovered. In the study reported here, we investigated the chemical composition and larvicidal activity of T. purpurea from northeastern Brazil [8, 10] as part of an attempt to find ecological and economically feasible alternative insecticides for controlling dengue. Essential oil was obtained from T. purpurea fresh stems (450 g) by hydrodistillation using a modified Clevenger-type apparatus. GC/FID and GC/MS analyses of the essential oil allowed the identification of 90.1% of its constituents (Table 1). The quantitative analysis was performed on a Shimadzu GC-17A model gas chromatograph equipped with a flame ionization detector (FID) and a non-polar DB-5 fused silica capillary column (30 m 0.25 mm i.d.; 0.25 m film thickness). Hydrogen was used as the carrier gas at a flow rate of 1 mL/min, with a split ratio of 1:30 and an injection volume of 1 L.

Composition of the Essential Oil of Guarea macrophylla Vahl. ssp. tuberculata (Meliaceae) from Northeast of Brazil

Abstract The essential oils obtained from fresh leaves of Guarea macrophylla Vahl. ssp. tuberculata Vellozo (Meliaceae) were analyzed by GC and GC/MS. Fourteen volatile compounds were identified in the leaf oil. The major components of the leaf oil were γ-eudesmol (15.3%), α-ylangene (15.1%), δ-cadinene (13.2%), γ-muurolene (11.4%) and β-caryophyllene (10.0%).

The semi-synthetic molecule [4″,5″] dihydro-obovatin isolated from Tephrosia Toxicaria pers reduces zymosan-induced temporomandibular joint inflammatory hypernociception in rats

Arthritis possesses inflammatory components and flavonoids of well-known structures exert anti-inflammatory activity. Here, we aim to evaluate the effects of [4″,5″] dihydro-obovatin and three structurally-defined flavonoids from Tephrosia toxicaria Pers roots on the zymosan-induced temporomandibular joint inflammatory hypernociception in rats as well as their toxicity. Rats were pretreated with the flavonoids (1 and 10 mg/kg) and [4″,5″] dihydro-obovatin (0.1 and 1.0 mg/kg) 1 h before intra-articular zymosan injection (2 mg, 40 μL). Von Frey test was used to evaluate the nociceptive threshold at the 4th hour after zymosan injection. Six hours after zymosan injection, synovial lavage was collected for total cell counting. Acute toxicity assay for [4″,5″] dihydro-obovatin (1, 10, and 100 mg/kg) were performed along with the subchronic toxicity assay by administering [4″,5″] dihydro-obovatin (0.01 mg/kg) or saline solution for 14 consecutive days and the rota-rod test was carried out to determine whether [4″,5″] dihydro-obovatin would impair motor functions. The tested flavonoids and [4″,5″] dihydro-obovatin increased nociceptive threshold and reduced the cell counting in the synovial lavage in the temporomandibular joint compared with the zymosan group. [4″,5”] dihydro-obovatin did not induce toxic effects as well as did not alter the motor function in the rota-rod test. The flavonoids and [4″,5″] dihydro-obovatin exerted antinociceptive and anti-inflammatory effects on the zymosan-induced temporomandibular joint inflammatory hypernociception in rats and the latter did not show significant toxic effects. Therefore, [4″,5″] dihydro-obovatin would be a promising anti-inflammatory and antinociceptive agent.

Chemical composition and antioxidant activity of Indigofera suffruticosa

Indigofera suffruticosa Mill. (Fabaceae), popularly known as “anil,” is an endemic shrub, which is distributed in tropical America [1]. This plant species is used as a source of indigo dye, and its leaves and roots are popularly used against urinary tract disease, disorders of the nervous system, joint pain and neuralgic, epilepsy, spasm, fever, nose bleeding, acute inflammation of the skin, hepatitis, scabies, and gonococcal urethritis [2]. The literature points to studies on its several biological activities [3–8], and chemical investigations have been made previously [9–11] on this species; nevertheless, to the best of our knowledge, only one report has appeared concerning the volatile chemistry of this genus [12]. Restrictions on the use of synthetic antioxidants are being imposed because of their potential carcinogenicity [13]. Therefore, the purpose of this study was to assess the antioxidant activity (Table 1) and the chemical composition of its pods. The presence of gallic acid, which is known to be a powerful antioxidant [14], seems to be responsible for its radical scavenging activity (1.55·10–2 3.0·10–4 mg/mL), as shown by the ethanol extract of pods of I. suffruticosa. Successive chromatographic treatments of the ethanol extract of the air-dried pods of I. suffruticosa afforded sitosterol and gallic acid. The structures of these compounds were established based on the comparison of 1H and 13C NMR data with the literature [15, 16]. The essential oil from the leaves of I. suffruticosa was analyzed by CG/MS to determine their constituents. Thirteen constituents were identified in the oil of I. suffruticosa leaves representing 96.8% of the total oil fraction, and the major constituents were phytol (75.8%) and methyl linoleate (9.1%) (Table 2). The results indicated that I. suffruticosa essential oil was characterized mainly by a large amount of a linear diterpene (78.5%), the esters of fatty acids (12.8%) and aliphatic compounds (8.2%), and by the lack of monoand sesquiterpenes. To the best of our knowledge, the only study on the essential oil of Indigofera genus in the literature is on I. microcarpa [12] and shows no similarities between the oils. The oil of I. microcarpa has the sesquiterpenes -caryophyllene and -humulene as the main constituents but no diterpenes and fatty acids. This fact suggests the chemical variability among the oils of the genus Indigofera.

Constituents of the Essential Oil of Pluchea quitoc DC

Abstract The essential oil obtained from fresh leaves of Pluchea quitoc DC (Compositae) was analyzed by GC and GC/MS. Twenty-four compounds are identifed, of which δ-cadinene (25.3%) and 1,8-cineole (17.3%) were the major constituents.