Larvicidal Effect of Hyptis suaveolens (L.) Poit. Essential Oil Nanoemulsion on Culex quinquefasciatus (Diptera: Culicidae).

Mosquitoes can be vectors of pathogens and transmit diseases to both animals and humans. Species of the genus Culex are part of the cycle of neglected diseases, especially Culex quinquefasciatus, which is an anthropophilic vector of lymphatic filariasis. Natural products can be an alternative to synthetic insecticides for vector control; however, the main issue is the poor water availability of some compounds from plant origin. In this context, nanoemulsions are kinetic stable delivery systems of great interest for lipophilic substances. The objective of this study was to investigate the larvicidal activity of the Hyptis suaveolens essential oil nanoemulsion on Cx. quinquefasciatus. The essential oil showed a predominance of monoterpenes with retention time (RT) lower than 15 min. The average size diameter of the emulsions (sorbitan monooleate/polysorbate 20) was ≤ 200 nm. The nanoemulsion showed high larvicidal activity in concentrations of 250 and 125 ppm. CL50 values were 102.41 (77.5253−149.14) ppm and 70.8105 (44.5282−109.811) ppm after 24 and 48 h, respectively. The mortality rate in the surfactant control was lower than 9%. Scanning micrograph images showed changes in the larvae's integument. This study achieved an active nanoemulsion on Cx. quinquefasciatus through a low-energy-input technique and without using potentially toxic organic solvents. Therefore, it expands the scope of possible applications of H. suaveolens essential oil in the production of high-added-value nanosystems for tropical disease vector control.

A herbal oil in water nano-emulsion prepared through an ecofriendly approach affects two tropical disease vectors

ABSTRACT Lippia alba (Mill.) N.E.Br. ex Britton & P. Wilson, Verbenaceae, is considered a great source of a bioactive volatile oil. Due to the wide range of known chemotypes, its chemical analysis is very important. Among the several activities of this volatile oil, a potential larvicidal action against Culicidae species is highlighted. However, the low water miscibility of volatile oils limits their application in aqueous media. Oil in water nano-emulsions are in the spotlight of novelty to solve this main problem. Thus, the aim of the present study was to obtain this nanostructured system with L. alba volatile oil (citral chemotype) and evaluate its larvicidal activity against Aedes aegypti and Culex quinquefasciatus larvae. The major compounds were geranial (30.02%) and neral (25.26%). Low mean droplet size (117.0 ± 1.0 nm) and low polydispersity index (0.231 ± 0.004) were observed and no major changes were observed after seven days of storage. LC50 values against C. quinquefasciatus and A. aegypti third-instar larvae were respectively 38.22 and 31.02 ppm, while LC90 values were, respectively, 59.42 and 47.19 ppm. The present study makes use of a low energy, solvent-free and ecofriendly method with reduced costs. Thus, this paper contributes significantly to phyto-nanobiotechnology of larvicidal agents, opening perspectives for the utilization of L. alba volatile oil in integrated practices of vector control.

Preparation of aqueous nanodispersions with annatto (Bixa orellana L.) extract using an organic solvent-free and low energy method.

The seeds of Bixa orellana L. is widely used in food industry as a natural colorant. A major technological challenge for its utilization on aqueous food products is the low water solubility. Therefore, the present study aimed to obtain aqueous nanodispersions using this natural raw material by using a simple organic solvent-free and low energy method. Bixin and geranylgeraniol were found on the extract. The nanodispersions were prepared by addition of water on a mixture of extract and surfactant (s). The effect of the surfactants and dilution on the nanodispersions were also evaluated. Best results were achieved using polysorbate 80/sorbitan monooleate (HLB 13) (diluted in water, 1:10). The results shows the potential of this ecofriendly approach, in contrast to common methods that make use of potentially toxic organic solvents and high input of energy, which elevate the costs for further industrialization.

Preparation of a Nanoemulsion with Carapa guianensis Aublet (Meliaceae) Oil by a Low-Energy/Solvent-Free Method and Evaluation of Its Preliminary Residual Larvicidal Activity.

Andiroba (Carapa guianensis) seeds are the source of an oil with a wide range of biological activities and ethnopharmacological uses. However, few studies have devoted attention to innovative formulations, including nanoemulsions. The present study aimed to obtain a colloidal system with the andiroba oil using a low-energy and organic-solvent-free method. Moreover, the preliminary residual larvicidal activity of the nanoemulsion against Aedes aegypti was evaluated. Oleic and palmitic acids were the major fatty acids, in addition to the phytosterol ß-sitosterol and limonoids (tetranortriterpenoids). The required hydrophile-lipophile was around 11.0 and the optimal nanoemulsion was obtained using polysorbate 85. The particle size distribution suggested the presence of small droplets (mean diameter around 150 nm) and low polydispersity index (around 0.150). The effect of temperature on particle size distribution revealed that no major droplet size increase occurred. The preliminary residual larvicidal assay suggested that the mortality increased as a function of time. The present study allowed achievement of a potential bioactive oil in water nanoemulsion that may be a promising controlled release system. Moreover, the ecofriendly approach involved in the preparation associated with the great bioactive potential of C. guianensis makes this nanoemulsion very promising for valorization of this Amazon raw material.

Utilization of dynamic light scattering to evaluate Pterodon emarginatus oleoresin-based nanoemulsion formation by non-heating and solvent-free method

Abstract Pterodon emarginatus Vogel, Fabaceae, is a great source of bioactive compounds. The most known and studied herbal derivative from this species is an ambar-colored oleoresin that contains vouacapane diterpenes and volatile terpenoids, such as β-caryophyllene. Some recent papers aimed to generate nanoemulsions using this oleoresin for biological applications. However, they used high-energy methods that elevate costs of the process or heating procedures, which offer the disadvantage of possible volatile substances loss. Thus, as part of our ongoing studies with nanobiotechnology of natural products, especially regarding preparation of nanoemulsions with promising plant-based oils by low cost and low energy methods, we decided to evaluate the ability of non-heating and solvent-free method to generate P. emarginatus oleoresin-based nanoemulsions. Two non-ionic surfactants were used to generate the nanoemulsions by a simple homogenization method with vortex stirrer. Low mean droplet size (<180 nm) and low polydispersity index (<0.200) were observed even after one day of preparation. The low coefficient of variation for the analyzed parameters of different batches and similar profile for droplet size distribution suggested reproducibility of the method. After 30 days, some degree of droplet growth was observed on nanoemulsion prepared with polyethyleneglycol 400 monooleate, while almost no alteration was observed for nanoemulsion prepared with polysorbate 85. Programmed temperature ramp analysis revealed that no major effects on droplet size and polydispersity index were observed, suggesting the robustness of formed nanoemulsions. Thus, the present study shows for the first time the formation of sucupira-based nanoemulsions by a simple, low cost and ecofriendly method. This study opens new perspectives for bioactive evaluation of this novel nano-product.

Effect of the treatment with Euterpe oleracea Mart. oil in rats with Triton-induced dyslipidemia.

OBJECTIVES: Dyslipidemias are defined as changes in lipid metabolism that have abnormal concentrations of lipids or lipoproteins in the bloodstream. Chronic increase in triglyceride and low-density lipoprotein (LDL-c) levels are known as risk factors for the atherogenesis process as well as other cardiovascular diseases (CVDs). The magnitude of the problems caused by dyslipidemias impels research by new agents that act in the prevention and control. Thus, products from the Amazonian biodiversity, such as Euterpe oleracea oil (OFEO), rich in unsaturated fatty acids (UFAs), constitutes a study source for the treatment of alterations in lipid metabolism. METHODS: The present study aims to investigate the effect of OFEO treatment in rats with Triton-induced dyslipidemia (Tyloxapol WR1339). RESULTS: The physicochemical and chromatographic results confirmed the chemical composition of OFEO with a predominance of UFAs (67.83%), with Oleic acid being the majority (54.32%). At Triton-induced dyslipidemia, the animals treated with OFEO and Simvastatin showed a significant reduction in total cholesterol levels, with values ​​of 121.7±29.5 (p<0.01) and 96.6±17.6mg/dL (p<0.001), respectively. OFEO also significantly reduced LDL-c levels (p<0.01) and triglycerides (p<0.001). OFEO and Simvastatin improved the lipid profile by significantly increasing (p<0.05) the high-density lipoprotein (HDL) values. CONCLUSIONS: Therefore, it is concluded that the OFEO treatment used in the conditions of this study had a beneficial effect on dyslipidemia, acting as antihypercholesterolemic and antihypertriglyceridemic, thus possibly contributing as a preventive agent for CVDs.

Pterodon emarginatus oleoresin-based nanoemulsion as a promising tool for Culex quinquefasciatus (Diptera: Culicidae) control.

BACKGROUND: Preparation of nanoformulations using natural products as bioactive substances is considered very promising for innovative larvicidal agents. On this context, oil in water nanoemulsions develop a main role, since they satisfactorily disperse poor-water soluble substances, such as herbal oils, in aqueous media. Pterodon emarginatus, popularly known as sucupira, has a promising bioactive oleoresin. However, to our knowledge, no previous studies were carried out to evaluate its potential against Culex quinquefasciatus, the main vector of the tropical neglected disease called lymphatic filariasis or elephantiasis. Thus, we aimed to investigate influence of different pairs of surfactants in nanoemulsion formation and investigate if a sucupira oleoresin-based nanoemulsion has promising larvicidal activity against this C. quinquefasciatus. We also evaluated morphological alteration, possible mechanism of insecticidal action and ecotoxicity of the nanoemulsion against a non-target organism. RESULTS: Among the different pairs of surfactants that were tested, nanoemulsions obtained with polysorbate 80/sorbitan monooleate and polysorbate 80/sorbitan trioleate presented smallest mean droplet size just afterwards preparation, respectively 151.0 ± 2.252 and 160.7 ± 1.493 nm. They presented high negative zeta potential values, low polydispersity index (<0.300) and did not present great alteration in mean droplet size and polydispersity index after 1 day of preparation. Overall, nanoemulsion prepared with polysorbate 80/sorbitan monooleate was considered more stable and was chosen for biological assays. It presented low LC50 value against larvae (34.75; 7.31-51.86 mg/L) after 48 h of treatment and some morphological alteration was observed. The nanoemulsion did not inhibit acetylcholinesterase of C. quinquefasciatus larvae. It was not toxic to green algae Chlorella vulgaris at low concentration (25 mg/L). CONCLUSIONS: Our results suggest that optimal nanoemulsions may be prepared with different surfactants using a low cost and low energy simple method. Moreover, this prototype proved to be effective against C. quinquefasciatus, being considered an ecofriendly novel nanoproduct that can be useful in integrated control programs of vector control.

Development and Characterization of Cassia grandis and Bixa orellana Nanoformulations.

Cassia grandis and Bixa orellana are important plant species with folk use and great potential for phytopharmaceuticals. Nanodispersions are disperse systems of insoluble or immiscible substances in a liquid medium that may be prepared with or without coating polymers. To our knowledge, no studies were carried in order to achieve coating-polymer free nanoformulations using B. orellana extract or any C. grandis-based nanoformulations. Thus, on the present study we aimed to develop C. grandis nanoformulations using three different coating polymers (Eudragit® L 100 55, PEG 4000 and Kollicoat®), while B. orellana nanodispersions were obtained using different surfactants (polysorbate 80, polysorbate 20, polyethylene glycol 400 monooleate, polyethylene glycol 600 monooleate, polyethylene glycol 400 dioleate and polyethylene glycol 600 dioleate) as coating polymer-free nanoformulations. Characterization of nanoformulations was performed by different parameters, including particle size, polydispersity index and zeta-potential. Our results suggested that some optimal nanoformulations were obtained for both plant species. Moreover, possible stable behavior was observed during storage period for C. grandis (30 days) and B. orellana (21 days). On this context, the present study contributes to nanobiotechnology development of phytopharmaceuticals, allowing achievement of novel nano-delivery systems with two important folk medicinal plant extracts and making them potential products for innovative phytopharmaceuticals.

Development of Quercetin Based Nanodispersions.

Polyphenols are a large group of structurally diverse natural products, including flavonoids. One of the most bioactive compounds of this class is the flavonol quercetin, a recognized antioxidant. Despite several studies were carried out aiming to develop nanoformulations with secondary metabolites, to our knowledge, quercetin was not used as raw material for nanodispersion production without coating polymers. This type of nanosize formulation is often prepared using organic solvents and quercetin nanodispersions were prepared by emulsification evaporation technique, using 1(6).2(2) experimental factorial design, ("surfactant type" evaluated at 6 levels, "surfactant amount" and "stirring speed" evaluated at 2 levels). Variance analysis, after one day of nanodispersions preparation, revealed that only the surfactant type was statistically significant on particle size, while none of factors presented statistically significant effect on polydispersity index. Variance analysis after seven days of nanodispersions preparation revealed that either surfactant type and surfactant amount presented significant effect on particle size, while only surfactant type influenced polydispersity index. Some nanodispersions presented small diameter and narrow size distribution, suggesting potential stability of these systems. Special attention was given to nanodispersion prepared with 3 % (w/w) of polyethylene glycol 400 monooleate (expressed as function of surfactant concentration at aqueous phase). It presented mean droplet size of 129.4 ± 0.5 nm and polydispersity index of 0.173 ± 0.018, after 7 days of preparation. Low polydispersity index indicates a high homogeneity concerning particle size distribution and suggests stability of the system. Moreover, absence of coating polymers and utilization of a low energy method would be an advantage in terms of reducing costs for industrial application, without any nanosize impairment.

Development of a Larvicidal Nanoemulsion with Pterodon emarginatus Vogel Oil.

Pterodon emarginatus Vogel is a Brazilian species that belongs to the family Fabaceae, popularly known as sucupira. Its oil has several biological activities, including potent larvicidal property against Aedes aegypti. This insect is the vector of dengue, a tropical disease that has been considered a critical health problem in developing countries, such as Brazil. Most of dengue control methods involve larvicidal agents suspended or diluted in water and making active lipophilic natural products available is therefore considered a technological challenge. In this context, nanoemulsions appear as viable alternatives to solve this major problem. The present study describes the development of a novel nanoemulsion with larvicidal activity against A. aegypti along with the required Hydrophile Lipophile Balance determination of this oil. It was suggested that the mechanism of action might involve reversible inhibition of acetylcholinesterase and our results also suggest that the P. emarginatus nanoemulsion is not toxic for mammals. Thus, it contributes significantly to alternative integrative practices of dengue control, as well as to develop sucupira based nanoproducts for application in aqueous media.

Development of a larvicidal nanoemulsion with Copaiba (Copaifera duckei) oleoresin

Copaiba (Copaifera duckei Dwyer, Fabaceae) oleoresin is an important Amazonian raw material. Despite its insecticidal potential, poor water solubility remains a challenge for the development of effective and viable products. Nanotechnology has emerged as a promising area to solve this problem, especially oil-in-water nanoemulsions. On this context, the aim of the present study was to develop oil-in-water nanoemulsions using copaiba oleoresin dispersed through a high internal phase; and evaluate its potential insecticidal action against Aedes aegypti larvae. Overall, 31 formulations were prepared, ranging from 11.5 ± 0.2 to 257.3 ± 4.1 nm after one day of manipulation. Some of them reached small mean droplet sizes (< 200 nm) and allowed achievement of a nanoemulsion region. The formulation consisted of 5% (w/w) of copaiba oil, 5% (w/w) of surfactant and 90% (w/w) of water, which presented mean droplet size of 145.2 ±0.9 nm and polidispersity of 0.378 ± 0.009 after one day of manipulation, and these were evaluated for larvicidal potential. According to mortality level (250 ppm - 93.3 after 48 h), this nanoemulsion was classified as a promising insecticidal agent against Aedes aegypti larvae. The present study allowed the development of low-cost ecofriendly green natural-based nanoformulations with potential larvicidal activity, using a nanobiotechnology approach.

Triterpene esters and biological activities from edible fruits of Manilkara subsericea (Mart.) Dubard, Sapotaceae.

Manilkara subsericea (Mart.) Dubard (Sapotaceae) is popularly known in Brazil as "guracica." Studies with Manilkara spp indicated the presence of triterpenes, saponins, and flavonoids. Several activities have been attributed to Manilkara spp such as antimicrobial, antiparasitic and antitumoral, which indicates the great biological potential of this genus. In all, 87.19% of the hexanic extract from fruits relative composition were evaluated, in which 72.81% were beta- and alpha-amyrin esters, suggesting that they may be chemical markers for M. subsericea. Hexadecanoic acid, hexadecanoic acid ethyl ester, (E)-9-octadecenoic acid ethyl ester, and octadecanoic acid ethyl ester were also identified. Ethanolic crude extracts from leaves, stems, and hexanic extract from fruits exhibited antimicrobial activity against Staphylococcus aureus ATCC25923. These extracts had high IC50 values against Vero cells, demonstrating weak cytotoxicity. This is the first time, to our knowledge, that beta- and alpha-amyrin caproates and caprylates are described for Manilkara subsericea.

Essential oils from fruits with different colors and leaves of Neomitranthes obscura (DC.) N. Silveira: an endemic species from Brazilian Atlantic forest.

Neomitranthes obscura (DC.) N. Silveira is an endemic plant of Brazilian Atlantic Forest and widely spread in the sandbanks of "Restinga de Jurubatiba" National Park. It is popularly known by local population as "camboim-de-cachorro" or "cambuí-preto" and recognized by its black ripe fruits. However, specimens with yellow ripe fruits were localized in the "Restinga de Jurubatiba" National Park. The aim of the present study was to evaluate chemical composition of essential oils obtained from leaves and fruits of N. obscura specimens with different fruit color (black and yellow) by GC and GC-MS. Essential oils from leaves of specimens with black and yellow fruits indicated a predominance of sesquiterpenes (81.1% and 84.8%, resp.). Meanwhile, essential oil from black fruits presented a predominance of monoterpenes (50.5%), while essential oil from yellow fruits had sesquiterpenes (39.9%) as major substances. Despite previous studies about this species, including essential oil extraction, to our knowledge this is the first report on N. obscura fruits with different colors. Our results suggest the occurrence of unless two different varieties for this species.

Effect of Artemisia annua L. leaves essential oil and ethanol extract on behavioral assays / Efeito do extrato etanólico bruto e óleo essencial das folhas de Artemisia annua em modelos comportamentais

Artemisia annua has been used as a traditional plant for the treatment of malaria and fever in China because of the presence of its active compound, artemisinin. The present study evaluated the central activity of the essential oil and the crude ethanol extract of A. annua L. in animals as a part of a psychopharmacological screening of this plant. The extract was prepared in ethanol (AEE) and the essential oil (AEO) obtained by hydrodistillation, both with fresh leaves. Induced immobility, the forced swimming test (FST) and the open-field test (OFT) are well-known animal models to study drug-induced depression. The administration of A. annua essential oil or crude ethanol extract increased the immobility time in the FST and decreased other activities (ambulation, exploration, rearing and grooming) in the OFT in animals. Both AEO and AEE prolonged pentobarbital-induced sleep as well, but the essential oil had a marked effect. Observing these results, it is possible to suggest that A. annua crude ethanol extract and essential oil could act as depressors on the Central Nervous System (CNS).

Artemisia annua tem sido utilizada tradicionalmente para o tratamento de malária e febre na China devido à presença do princípio ativo, artemisinina. O presente trabalho avaliou a atividade central de do óleo essencial obtido por hidrodestilação e do extrato etanólico bruto de folhas frescas de A. annua em modelo in vivo como parte de um screening farmacológico dessa espécie. Sono induzido por pentobarbital, nado forçado e o ensaio de campo aberto são modelos de estudo conhecidos para o estudo de fármacos sobre depressão induzida. A administração do óleo essencial ou extrato bruto etanólico de A. annua aumentaram o tempo de imobilidade no teste do nado forçado. Por outro lado, diminuíram outros parâmetros no campo aberto, como ambulação, exploração, o ato de lamber as patas ou se lamber. Ambos produtos aumentaram o tempo de sono induzido por pentobarbital, com o óleo essencial apresentando um efeito superior ao do extrato. Pela análise dos resultados, é possível sugerir que tanto o extrato bem como o óleo essencial podem atuar como depressores do Sistema Nervoso Central (SNC).

Antiulcerogenic activity of crude extract, fractions and populnoic acid isolated from Austroplenckia populnea (Celastraceae).

Many plant crude extracts and their isolated compounds are the most attractive sources of new drugs and show promising results for the treatment of gastric ulcers. Austroplenckia populnea is commonly known as "marmelinho-do campo, mangabeira-brava, mangabarana and vime" and it has been used in folk medicine as anti-dysenteric and anti-rheumatic. Powdered bark wood (3.25 kg) was macerated with aqueous ethanol (96%) and the extract was concentrated under reduced pressure to yield 406 g of crude hydralcoholic extract. The hydralcoholic extract was suspended in aqueous methanol and partitioned with hexane, chloroform and ethyl acetate (EtOAc) in sequence, yielding 8.0 g, 9.5 g and 98.17 g of crude extracts, respectively. Chromatography of the hexane extract over a silica gel column led to the isolation of the triterpene populnoic acid. The oral administration of hydralcoholic, hexane, chloroform and EtOAc extracts (200 mg/kg) decreased the ulcer lesion index (ULI) by 83.15%, 46.87%, 32.2%, 68.12%, respectively. Oral administration of populnoic acid (100 mg/kg) diminished the ULI by 55.29%. All the obtained results were significant in comparison with the negative control, with exception of the chloroform extract.

Efeito da administração de cogumelo tibetano, um consórcio microbiano, sobre a peristalse intestinal em ratos / Effect of the administration of Tibetan mushroom, a microbial consortium, on the intestinal peristalsis in rats

O cogumelo tibetano (CT) é uma bebida probiótica fermentada por um grande conjunto de bactérias e leveduras, algumas das quais de conhecida atividade antimicrobiana, imunomodulatória, pró-digestiva e auxiliar da peristalse intestinal. Neste sentido, este trabalho teve como objetivo avaliar a possível ação da suspensão produzida pelo CT sobre a motilidade intestinal de ratos. Foram utilizados grupos de animais (ratos Wistar albinos machos, n = 6/grupo) pesando 200 ± 20 g. Os diferentes grupos foram tratados v.o. durante 15 dias (1,5 mL/animal de fermentado de 24 h de CT em cultivo contínuo em 50 g/l de açúcar mascavo comercial em água destilada), e os demais grupos tratados com água destilada (1,5 mL/animal). Após 15 dias os animais foram mantidos em jejum por 24 hs, e tratados com suspensão de CT (1,5 mL/animal/v.o), água destilada (controle, 1,5mL/animal/v.o), acetilcolina (1mg/kg/s.c.) e atropina (1mg/kg/i.m.). Após 30 min, os animais receberam uma suspensão de carvão ativo 10 por cento (0,1 mL/10 g, v.o), seguindo-se eutanásia após 45 min, excisão da porção do piloro até o início do ceco, e determinação da distância percorrida pelo carvão. A administração da suspensão de CT aumentou o trânsito intestinal em 68,7 por cento e os demais tratamentos apresentaram as seguintes percentagens: atropina 20,2 por cento, acetilcolina 78,7 por cento e controle 42,9 por cento (p < 0,05, ANOVA seguido de teste de Tukey-Kramer). Esses resultados mostraram que a suspensão de CT estimulou o peristaltismo nos animais, o que sugere um efeito positivo na digestão e absorção alimentar para o consórcio microbiano.

The Tibetan mushroom (CT) is a probiotic beverage fermented by a big group of bacteria and yeasts, some of which of well-known anti-bacterial activity, immunomodulatory, pro-digestive and to aid of the intestinal peristalsis. In this sense, this work had the aim of evaluating the possible action of the suspension produced by CT on the peristalsis intestinal of rats. Animal groups weighing 200 ± 20 g were used (Wistar rats (male, n = 6/group)). The different groups were treated v.o. for 15 days (1,5 mL/animal of 24h fermented of CT in continuously cultured into molasses solutions (50 g/l)), and the other groups treated with distilled water (1,5 mL/animal). After 15 days the animals were maintained in fast for 24h, and treated with suspension CT (1,5 mL/animal/v.o), distilled water (control, 1,5mL/animal/v.o), acetylcholine (1mg/kg/s.c) and atropine (1mg/kg/i.m). After 30 min, the animals received a suspension of active coal 10 percent (0,1 mL/10g, v.o), after the euthanasia, excision of the portion of the pylorus to the beginning of the cecum, and determination of the distance traveled by the coal. The administration of the CT suspension increased the intestinal peristalsis in 68,7 percent and the other treatments presented the following percentages: atropine 20,2 percent, acetylcholine 78,7 percent and control 42,9 percent (p < 0,05, ANOVA followed by Tukey-Kramer test). Those results showed that the CT suspension stimulated the peristalsis in the animals, what suggests a positive effect in the digestion and alimentary absorption for the microbial consortium.

Anti-inflammatory and analgesic properties of water-ethanolic extract from Pothomorphe umbellata (Piperaceae) aerial parts.

Anti-inflammatory and analgesic activities as well as the median lethal dose (LD50) of water-ethanolic extract (PHE) of the aerial parts of Pothomorphe umbellata were evaluated in animal models. The ED(50) (oral) for the inhibition of carrageenan-induced rat paw edema assay was determined to be 550 mg/kg, while the LD(50) was higher than 2.0 g/kg. At a dose of 550 mg/kg, PHE inhibited the inflammatory process by 48.7% (P < 0.05) on the third hour of the assay (edema peak) when compared to the untreated control. Indomethacin, the positive control used in this test, inhibited the edema by 58.6% at a dose of 10 mg/kg, when compared to the untreated control (P < 0.05). All three fractions--hexane, methylene chloride and ethyl acetate--obtained by partition of PHE with respective solvents also showed inhibition of the edema induced by carrageenan over a period of 4h but the methylene chloride fraction showed the best activity. The activity shown by the methylene chloride fraction at 200 mg/kg was comparable to that exhibited by indomethacin at a dose of 10mg/kg. The number of writhings induced by a 0.6% acetic acid solution intraperitoneal injection was decreased by 22% (P < 0.05) in the group treated orally with Pothomorphe umbellata crude extract. PHE also inhibited the granulomatous tissue formation in rats by 6.2% (P < 0.05). In the same assay, topically applied dexamethasone decreased the granuloma formation by 14.2%. The above results suggest that Pothomorphe umbellata crude extract has analgesic and anti-inflammatory properties supporting its folkloric use for the treatment of these conditions.

Synthesis and biological activity evaluation of lignan lactones derived from (-)-cubebin.

The anti-inflammatory and analgesic effects of three dibenzylbutyrolactone lignans, (-)-hinokinin (2), (-)-6,6'-dinitrohinokinin (3), and (-)-6,6'-diaminohinokinin (4), obtained by partial synthesis from (-)-cubebin (1), were investigated using different animal models. It was observed that compounds (1) and (2) inhibited the edema formation in the rat paw edema assay at the same level and that all responses were dose dependent. Also, at the dose of 30 mg/kg, compounds 1, 2, 3, and 4 inhibited the edema formation by 53%, 63%, 54%, and 82%, respectively, at the third hour of the experiment. In the acetic acid-induced writhing test in mice, compounds 2 and 4 produced inhibition levels of 97% and 92%, respectively, while 3 displayed lower effect (75%), which was still higher than 1. The assayed compounds neither displayed activity in the cell migration test nor in the hot plate test.

Toxicity of a subchronic treatment with hydroalcoholic crude extract from Solanum grandiflorum (Ruiz et Pav) in rats.

The toxic effect of the hydroalcoholic crude extract (HACE) from the fruits of the Solanum grandiflorum was evaluated following subchronic treatment (p.o.) in Wistar rats for 65 days using the dose of 2 mg/kg. The LD(50) in mice was 50 mg/kg (p.o.). At the end of treatment, the consumption of water remained within the normal patterns. On the other hand, the consumption of food had 40% reduction in the period between the 18th and the 40th day after the beginning of the study. The diuresis showed a wide variation in volume which started at the 8th day of treatment until the end of the study. This finding was correlated with macroscopic observations of the kidneys which presented nephromegaly (70%) when compared to the control group. Moreover, for the histopathological study, it was observed degeneration and glomerular necrosis (100%), tubular lesions (80%), and hypercellular lesions (100%) in the treated group. The ponderal development of the treated group was increased compared to the control group. The weight of some of the organs, including kidneys, lungs, and pancreas, was also increased in the treated group (P<0.05, Student "t" test). These data suggest a nephrotoxicity following a subchronic treatment of the hydroalcoholic crude extract from Solanum grandiflorum.