Phytotoxic potential of young leaves from Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae) / Potencial fitotóxico de folhas jovens de Blepharocalyx salicifolius (Kunth) O. Berg

Abstract The loss of leaves by plant species found in the Cerrado (Brazilian savanna) is an energetically expensive process due to adverse environmental conditions and predation by herbivory. The mature leaves have adaptations which minimize these events. However, the young individuals lack these structures and produce high leaf concentrations of secondary metabolites as a form of protection. These compounds can be used in bioprospection of natural herbicides. Thus, this study aimed to evaluate the phytotoxicity of hexane, ethyl acetate and aqueous extracts of young leaves from Blepharocalyx salicifolius (Kunth) O. Berg on the elongation of wheat coleoptiles (Triticum aestivum L.) and evaluate the potential phytotoxic of ethyl acetate extract on germination, growth and cell size of metaxylem of sesame (Sesamum indicum L.) seedlings. The hexane and ethyl acetate extracts inhibited the elongation of wheat coleoptiles at all concentrations; however, the most promising results were observed in coleoptile fragments treated with the ethyl acetate extract. This treatment changed the mean germination time and the synchrony of sesame seeds, inhibited the growth of shoots and roots, reduced the dry weight of seedlings, led to abnormalities in the seedlings and reduced the length of the metaxylem cells in the sesame seedlings. These results demonstrated the phytotoxic potential of young leaf extracts of B. salicifolius and the high phytotoxicity of the ethyl acetate extract in the initial development of S. indicum.

Resumo A perda das folhas pelas plantas do Cerrado é um processo energeticamente custoso devido às condições ambientais adversas e intensa predação por herbivoria. As folhas maduras possuem adaptações que minimizam esses eventos. Entretanto, os indivíduos jovens carecem dessas estruturas e produzem elevadas concentrações foliares de metabólitos secundários como forma de proteção. Esses compostos podem ser utilizados na bioprospecção de herbicidas naturais. Dessa forma, objetivamos com este estudo avaliar a fitotoxicidade dos extratos hexânico, acetato etílico e aquoso de folhas jovens de Blepharocalyx salicifolius (Kunth) O. Berg sobre o alongamento de coleóptilos estiolados de Triticum aestivum L. (trigo) e avaliar o potencial fitotóxico do extrato acetato etílico sobre a germinação, crescimento e comprimento das células do metaxilema de Sesamum indicum (gergelim). Os extratos hexânico e acetato etílico inibiram o alongamento dos coleóptilos em todas as concentrações testadas, entretanto os resultados mais promissores foram observados nos fragmentos submetidos ao extrato acetato etílico. Este extrato alterou o tempo médio de germinação e a sincronia das sementes de gergelim, inibiu o crescimento da parte aérea e subterrânea com redução da massa seca das plântulas, levou ao surgimento acentuado de anomalias e causou redução no comprimento médio das células do metaxilema de plântulas de gergelim. Assim, ficou comprovado o potencial fitotóxico dos extratos de folhas jovens de B. salicifolius e a acentuada fitotoxicidade do extrato acetato etílico sobre o desenvolvimento inicial de S. indicum.

Histological investigation of the effect of soybean (Glycine max) extracts on the collagen layer and estrogen receptors in the skin of female rats

OBJECTIVES: The purpose of this study was to analyze the effects of soybean extracts obtained using different extraction methods on the skin of female rats. METHOD: A total of 64 female Sprague-Dawley rats were divided into 8 equal groups. Various extracts were administered to the female rats by oral gavage for one month. The groups comprised carboxymethyl cellulose-free control, carboxymethyl cellulose-plus control, 100-mg/kg n-hexane extract, 200-mg/kg n-hexane extract, 100-mg/kg ethyl acetate extract, 200-mg/kg ethyl acetate extract, 100-mg/kg ethanol extract and 200-mg/kg ethanol extract groups. The thickness of the collagen layer and the number of estrogen receptor-positive cells were evaluated. RESULTS: All the extract-treated groups showed a statistically significant decrease in the number of estrogen receptor-positive cells compared with the control groups. Regarding the thickness of the collagen layer, only the 200-mg/kg ethyl acetate extract-treated group showed a significant increase compared with the control groups (p<0.05). CONCLUSIONS: Our data suggest that oral intake of three different total soybean extracts might have positive estrogenic effects on the skin and that only a high-dose ethyl acetate extract can increase the expression of collagen, which may prove to be beneficial for postmenopausal facial skin. ...

Actividad antimicrobiana de extractos de Psidium friedrichsthalianum L., Pterocarpus hayesii L., Tynanthus guatemalensis L. y Spondias purpurea L / Antimicrobial activity of Psidium friedrichsthalianum L., Pterocarpus hayesii L., Tynanthus guatemalensis L. and Spondias purpurea L. extracts

There is not much information on antimicrobial activity presented by several species traditionally used as medicinal plants in Tabasco. Antimicrobial activity of ethanolic and hexanic extracts from leaf and bark of guayaba agria (Psidium friedrichsthalianum L.), palo de sangre (Pterocarpus hayesii L.) chichimecate (Tynanthus guatemalensis L.) and ciruela (Spondias purpurea L.) was evaluated for against Staphylococcus aureus ATCC 25923, Salmonella typhimurium ATCC 14028 and Bacillus cereus ATCC 11778 by the use of agar diffusion method. Results indicate that the hexanic extract of every one of the plant species presented antimicrobial activity on at least one of the evaluated microorganisms meanwhile bark hexanic extracts did not present activity against the three microorganisms tested. The extracts that presented a Minimal Inhibitory Concentration (MIC) of < 7.50 mg mL-1 against B. cereus were both leaf ethanolic of P. friedrichsthalianum and S. purpurea and the T. guatemalensis leaf hexanic extract as well as P. friedrichsthalianum bark hexánico extract against S. aureus and S. typhimurium.

Existe poca información sobre la actividad antimicrobiana que pueden presentar varias plantas que han sido reportadas con uso medicinal tradicional en el Estado de Tabasco. Se evaluó la actividad antimicrobiana de los extractos etanólico y hexánico de hoja y corteza de cuatro plantas utilizadas como medicinales: guayaba agria (Psidium friedrichsthalianum L.), palo de sangre (Pterocarpus hayesii L.), chichimecate (Tynanthus guatemalensis L.) y ciruela (Spondias purpurea L.). La actividad antimicrobiana se evaluó contra Staphylococcus aureus ATCC 25923, Salmonella typhimurium ATCC 14028 y Bacillus cereus ATCC 11778 mediante el método de difusión en agar. Los resultados indican que el extracto hexánico de cada una de las plantas presentaron actividad antimicrobiana al menos en uno de los microorganismos evaluados mientras que los extractos hexánicos de corteza no presentaron actividad contra ninguno de los tres microorganismos ensayados. Los extractos que presentaron una Concentración Mínima Inhibitoria (CMI) igual o menor de 7.50 mg mL-1 contra B. cereus fueron los etanólicos de hoja de P. friedrichsthalianum y S. purpurea y el hexánico de hoja de T. guatemalensis así como el extracto hexánico de corteza de P. friedrichsthalianum contra S. aureus y S. typhimurium.

Relaxant effects of different fractions from Tymus vulgaris on guinea-pig tracheal chains

In previous studies, the relaxant effect of Tymus vulgaris has been demonstrated on guinea pig tracheal chains. Therefore, in the present study, the relaxant effects of n-hexane, dichloromethane, methanol and aqueous fractions of Tymus vulgaris on tracheal chains of guinea pigs were examined. The relaxant effects of four cumulative concentrations of each fraction (0.4, 0.8, 1.2 and 1.6 g%) in comparison to saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6 and 0.8 mM) were examined for their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1) and 10 ìÌ methacholine (group 2, n = 7 for each group). In group 1, all concentrations of the n-hexane fraction and theophylline and three last concentrations (0.8, 1.2 and 1.6 g%) of dichloromethane and two higher concentrations (1.2 and 1.6 g%) of methanol fractions showed significant relaxant effects compared to that of saline (p<0.05 to p<0.001). In group 2, all concentrations of theophylline, n-hexane and dichloromethane fractions and three concentrations (0.8, 1.2 and 1.6 g%) of methanol and two higher concentrations (1.2 and 1.6 g%) of aqueous fractions showed significant relaxant effects compared to that of saline (p<0.05 to p<0.001). In addition, with group 1, the relaxant effect of all concentrations of all fractions except the n-hexane fraction, were significantly less than those of theophylline (p<0.05 to p<0.001). The n-hexane fraction showed higher relaxant effect than theophylline. The relaxant effect of all concentrations of the n-hexane fraction and the three last concentrations (0.8, 1.2 and 1.6 g%) of dichloromethane and aqueous fractions were significantly greater in group 2 than in group 1 (p<0.05 to p<0.001). There were significant positive correlations between the relaxant effects and concentrations for theophylline and all fractions (except aqueous fraction in group 1) in both groups, but a negative correlation for the aqueous fraction in group 1 (p<0.05 to p<0.001). These results showed a potent relaxant effect for n-hexane and weaker relaxant effect for other fractions from Tymus vulgaris on tracheal chains of guinea pigs.

Atividade hepatoprotetora dos extratos etanólico e hexânico das folhas de Momordica charantia / Hepatoprotective activity of hexane and ethanol extracts from Momordica charantia L. leaves

Momordica charantia L. (Cucurbitaceae) é empregada na medicina popular pelas diversas propriedades biológicas e farmacológicas. Neste trabalho, objetivou-se avaliar a atividade hepatoprotetora dos extratos hexânico (EH) e etanólico (EE) das folhas de M. charantia no modelo de lesão hepática aguda induzida pelo etanol. Em ambos os extratos foram detectados esteróides; EH apresentou atividade antioxidante mais marcante que EE. O pré-tratamento de camundongos (Swiss, machos) por via oral por três dias consecutivos com 25, 50 ou 100 mg Kg-1 de EH preveniu o aumento tanto de AST quanto de ALT (p<0,05) enquanto o pré-tratamento com EE preveniu apenas o aumento de ALT (p<0,05). Ambos os extratos reduziram a atividade das enzimas hepáticas, contudo EH apresentou efeito mais relevante, caracterizando potencial hepatoprotetor, possivelmente associado ao seu potencial antioxidante.

Momordica charantia L. (Cucurbitaceae) has been used in folk medicine based on its several biological and pharmacological properties. The aim of this work was to evaluate the hepatoprotective activity of hexane (HE) and ethanol (EE) extracts from M. charantia leaves on the acute liver injury model induced by ethanol. Steroids were detected in both extracts, and EH had higher antioxidant activity than EE. Oral pretreatment of male Swiss mice for three consecutive days with 25, 50 or 100 mg kg-1 HE prevented the increase in AST and ALT (p<0.05), whereas pretreatment with EE only prevented ALT increase (p<0.05). Both extracts reduced the activity of hepatic enzymes; however, HE had a more relevant effect, characterizing hepatoprotective potential, likely associated with its antioxidant potential.

Antimicrobial activity of wax and hexane extracts from Citrus spp. peels

Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin) from C. limon.