Márcio Galdino dos Santos

Chemical constituents of the bark of Dipteryx alata vogel, an active species against Bothrops jararacussu venom.

The effect of four sub-extracts prepared from the lyophilized hydroalcoholic bark of Dipteryx alata (Leguminosae-Papilionoideae) dissolved in a methanol-water (80:20) mixture through a liquid-liquid partition procedure has been investigated against the neuromuscular blockade of the venom of the snake Bothrops jararacussu. The active CH2Cl2 sub-extract has been extensively analyzed for its chemical constituents, resulting in the isolation of four lupane-type triterpenoids: lupeol (1), lupenone (2), 28-hydroxylup-20(29)-en-3-one (3), betulin (4), nine isoflavonoids: 8-O-methylretusin (5), 7-hydroxy-5,6,4’-trimethoxyisoflavone (6), afrormosin (8), 7-hydroxy-8,3’,4’-trimethoxyisoflavone (9), 7,3’-dihydroxy-8,4’-dimethoxyisoflavone (10), odoratin (11), 7,8,3’-trihydroxy-4’-methoxyisoflavone (13), 7,8,3’-trihydroxy-6,4’-dimethoxyisoflavone (15), dipteryxin (17), one chalcone: isoliquiritigenin (7), one aurone: sulfuretin (14) and three phenolic compounds: vanillic acid (12), vanillin (16), and protocatechuic acid (18). Their chemical structures were elucidated on the basis of spectroscopic analysis, including HRMS, 1D- and 2D-NMR techniques.

In Vitro Antiophidian Properties of Dipteryx alata Vogel Bark Extracts

Extracts from Dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with Bothrops jararacussu (Bjssu, 40 μg/mL) and Crotalus durissus terrificus (Cdt, 15 μg/mL) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. Cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of Bjssu venom were decreased by the methanolic extract. This inhibition appears to be augmented by tannins. Dichloromethane bark extract inhibited ~40% of Bjssu venom effects and delayed blockade induced by Cdt. The methodology used to determine which extract was active allows inferring that: (i) phenolic acids and flavonoids contained in the methanolic extract plus tannins were responsible mostly for neutralization of Bjssu effects; (ii) terpenoids from the dichloromethane extract may participate in the anti-Cdt and anti-Bjssu venom effects; (iii) a given extract could not inhibit venoms from different species even if those belong to the same family, so it is improper to generalize a certain plant as antiophidian; (iv) different polarity extracts do not present the same inhibitory capability, thus demonstrating the need for characterizing both venom pharmacology and the phytochemistry of medicinal plant compounds.

The Triterpenoid Betulin Protects against the Neuromuscular Effects of Bothrops jararacussu Snake Venom In Vivo

We confirmed the ability of the triterpenoid betulin to protect against neurotoxicity caused by Bothrops jararacussu snake venom in vitro in mouse isolated phrenic nerve-diaphragm (PND) preparations and examined its capability of in vivo protection using the rat external popliteal/sciatic nerve-tibialis anterior (EPSTA) preparation. Venom caused complete, irreversible blockade in PND (40 μg/mL), but only partial blockade (~30%) in EPSTA (3.6 mg/kg, i.m.) after 120 min. In PND, preincubation of venom with commercial bothropic antivenom (CBA) attenuated the venom-induced blockade, and, in EPSTA, CBA given i.v. 15 min after venom also attenuated the blockade (by ~70% in both preparations). Preincubation of venom with betulin (200 μg/mL) markedly attenuated the venom-induced blockade in PND; similarly, a single dose of betulin (20 mg, i.p., 15 min after venom) virtually abolished the venom-induced decrease in contractility. Plasma creatine kinase activity was significantly elevated 120 min after venom injection in the EPSTA but was attenuated by CBA and betulin. These results indicate that betulin given i.p. has a similar efficacy as CBA given i.v. in attenuating the neuromuscular effects of B. jararacussu venom in vivo and could be a useful complementary measure to antivenom therapy for treating snakebite.

Mutagenicity induced by the hydroalcoholic extract of the medicinal plant Plathymenia reticulata Benth

Plathymenia reticulata Benth has an anti-inflammatory effect and is capable of neutralizing the neuromuscular blockade induced by Bothrops jararacussu or Crotalus durissus terrificus venoms, probably by precipitating venom proteins (an effect caused by plant tannins). The present study aimed to evaluate the mutagenic activity of P. reticulata by using the Salmonella mutagenicity assay (Ames test) and the micronucleus test in CHO-K1 cells. P. reticulata extract concentrations of 2.84, 5.68, 11.37, and 19.90 mg/plate were assayed by the Ames test using TA97a, TA98, TA100 and TA102 bacterial strains, with (+S9) and without (-S9) metabolic activation. Concentrations of 5, 1.6 and 0.5 μg/mL of P. reticulata extract were used for the micronucleus test. P. reticulata extract was mutagenic to TA98 (-S9) and showed signs of mutagenic activity in TA97a and TA102 (both -S9) strains. Micronucleus test CBPI values showed that the endogenous metabolic system increased the number of viable cells when compared to the non-activated samples and the micronucleus frequency increased when the cells were treated in the absence of S9. We concluded that P. reticulata extract may present direct mutagenic properties.

Assessment of Cytotoxicity, Fetotoxicity, and Teratogenicity of Plathymenia reticulata Benth Barks Aqueous Extract

Scientific assessment of harmful interactions of chemicals over the entire reproductive cycle are divided into three segments based on the period: from premating and mating to implantation (I), from implantation to major organogenesis (II), and late pregnancy and postnatal development (III). We combined the segments I and II to assess Plathymenia reticulata aqueous extract safety. In order to investigate reproductive toxicity (segment I), pregnant rats received orally 0.5 or 1.0 g/kg of extract, daily, during 18 days. These concentrations were determined by a preliminary in vitro LD50 test in CHO-k1 cells. A control group received deionized water. The offspring was removed at the 19th day, by caesarean, and a teratology study (segment II) was carried out. The corpora lutea, implants, resorptions, live, and dead fetuses were then counted. Placenta and fetuses were weighted. External and visceral morphology were provided by the fixation of fetuses in Bouin, whereas skeletal analysis was carried out on the diaphanizated ones. The increase in the weights of placenta and fetuses was the only abnormality observed. Since there was no sign of alteration on reproduction parameters at our experimental conditions, we conclude that P. reticulata aqueous extract is safe at 0.5 to 1.0 g/kg and is not considered teratogenic.

Neutralising ability of Terminalia fagifolia extract (Combretaceae) against the in vitro neuromuscular effects of Bothrops jararacussu venom

Abstract The ability of Terminalia fagifolia hydroalcoholic extract (Tf-HE) to neutralise the paralysis and myotoxicity induced by Bothrops jararacussu venom was assayed using mouse phrenic nerve-diaphragm (PND) preparation and two varieties of chick biventer cervicis (BC) preparations. Tf-HE 100 μg/mL and 500 μg/mL were tested against 40 and 200 μg of venom/mL in PND and BC preparations, respectively, using pre- and post-venom incubation treatments. The effects of Tf-HE against the myotoxicity caused by venom were evaluated via histological analysis (PND) and creatine kinase (CK) release (BC). Tf-HE was able to reverse the venom paralysis in both preparation types. The contractures to exogenous ACh in BC preparations showed that Tf-HE may act on extrinsic, preserving those intrinsic postsynaptic receptors. There was a positive correlation between CK and morphological changes. The high non-hemolytic saponin content can explain the Tf-HE efficacy against the toxic effects of B. jararacussu venom in vertebrate neuromuscular preparations.

Efeitos alelopáticos de extratos vegetais de Hancornia speciosa, Gomes na germinação de Lactuca sativa L.

Hancornia speciosa Gomes (Apocynaceae) e uma fruteira, conhecida como mangabeira, com ampla distribuicao no Brasil e muito utilizada na medicina popular, por suas propriedades anti-inflamatorias, anti-hipertensivas, antidiabeticas e antimicrobianas. Entretanto, nenhum estudo foi realizado com objetivo de avaliar o potencial alelopatico dessa especie. Nesse sentido, esse estudo objetivou investigar a atividade alelopatica de H. speciosa , a partir do extrato aquoso de folhas secas sobre a germinacao de sementes de Lactuca sativa L. O experimento foi conduzido no municipio de Porto Nacional, Tocantins, Brasil, no periodo de agosto/2015 a julho/2016. Folhas de mangabeira coletadas em tres areas de Cerrado foram trituradas, ate obter-se um po que posteriormente foi diluido em agua destilada, resultando no extrato aquoso com concentracoes de 10%, 7,5%, 5,0%, e 2,5% m/v, sendo a agua destilada utilizada como testemunha. Utilizou-se o delineamento inteiramente casualizado, apos a analise do delineamento, nos efeitos dose, local e interacao dose versus local, os graus de liberdade de dose foram desdobrados em polinomios ortogonais. Pode-se verificar que o extrato aquoso de folhas de H. speciosa apresentou efeito alelopatico negativo sobre as sementes de L. sativa , pois retardou a germinabilidade e aumentou o tempo medio de germinacao, enquanto que o indice de sincronia nao foi fortemente influenciado.

Hemoglobinas de origem africana em comunidades quilombolas do estado do Tocantins, Brasil

Verificar la incidencia de hemoglobinas de herencia africana en comunidades quilombolas del Estado de Tocantins, Brasil. MATERIALES Y METODOS: Se recolecto sangre de quilombolas en 14 comunidades del Estado; la seleccion se hizo en electroforesis de acetato de celulosa (pH 8,6), y las de patron alterado fueron sometidas a la cromatografia liquida de alta eficiencia (CLAE), registrandose el genero y la edad de las personas del muestreo. RESULTADOS: El analisis de los resultados demostro que, de los 822 quilombolas investigados, 95 presentaron hemoglobinas anormales, siendo 0,5% con enfermedad falciforme (HbSS); 5,7% trazo para hemoglobina S (HbAS); 4,9% trazo para hemoglobina C (HbAC); 0,2% con hemoglobina fetal aumentada; 0,1% con hemoglobina A2 aumentada; y 88,4% con hemoglobina normal (HbAA). La enfermedad falciforme se observo en la franja etaria infantil y adolescente y el trazo para HbS y HbC en todas las franjas etarias. En relacion al sexo, no fue posible sugerir el efecto materno para HbS debido al mayor numero de personas del sexo masculino con esa informacion genetica. CONCLUSION: En este estudio, la incidencia de las HbS y HbC, observada en las comunidades quilombolas, estuvo dentro de lo esperado para la Region Norte de Brasil. Sin embargo, se destaca la elevada prevalencia de la enfermedad falciforme y la elevada frecuencia de trazos falciformes en algunas de las comunidades estudiadas, con especial atencion para la region sur del Estado. De ese modo, los resultados aqui presentados senalan riesgo inminente para el aumento de la incidencia de la enfermedad en Tocantins