Assessment of the chemical profile, polyphenol content and antioxidant activity in extracts of Psidium Guajava L. fruits

Fruits and vegetables that are rich in polyphenolic compounds, especially flavonoids, may be used to benefit human health by reducing the incidence of cancers and cardiovascular diseases. Previous studies have demonstrated the antioxidant activity of guava, a fruit widely available in Brazil, possibly due to the presence of these polyphenolic compounds. The aim of this study was to analyze the total phenolic and flavonoid contents of various guava extracts, assay their antioxidant activity and record the chromatographic profiles of these extracts, to determine a simple and low way of extracting these compounds efficiently from guava. The results confirmed the presence of polyphenols in guava, including flavonoids, and its antioxidant activity. Furthermore, it was demonstrated that the 70% ethanol (by volume) was the most effective solvent to extract these compounds from the fruit, among those tested.

Avaliação da resposta tecidual de extratos de araçá (Psidium Cattleianum) associado ao hidróxido de cálcio: análise edemogênica e histológica em ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Absence of mutagenicity effects of Psidium cattleyanum Sabine (Myrtaceae) extract on peripheral blood and bone marrow cells of mice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Synergism between plant extract and antimicrobial drugs used on Staphylococcus aureus diseases

Searches for substances with antimicrobial activity are frequent, and medicinal plants have been considered interesting by some researchers since they are frequently used in popular medicine as remedies for many infectious diseases. The aim of this study was to verify the synergism between 13 antimicrobial drugs and 8 plant extracts - guaco (Mikania glomerata), guava (Psidium guajava), clove (Syzygium aromaticum), garlic (Allium sativum), lemongrass (Cymbopogon citratus), ginger (Zingiber officinale), carqueja (Baccharis trimera), and mint (Mentha piperita) - against Staphylococcus aureus strains, and for this purpose, the disk method was the antimicrobial susceptibility test performed. Petri dishes were prepared with or without dilution of plant extracts at sub-inhibitory concentrations in Mueller-Hinton Agar (MHA), and the inhibitory zones were recorded in millimeters. In vitro anti-Staphylococcus aureus activities of the extracts were confirmed, and synergism was verified for all the extracts; clove, guava, and lemongrass presented the highest synergism rate with antimicrobial drugs, while ginger and garlic showed limited synergistic capacity.

Evaluation of antidiarrhoeal effects of Psidium guajava L. (Myrtaceae) aqueous leaf extract in mice

A crude aqueous extract of the leaves of the guava tree, Psidium guajava L. (Myrtaceae), were studied for antidiarrhoeal effects, to place one of its traditional medical uses. The extract induced a decrease in the propulsive movements of the intestinal contents in mice. These findings suggested that an aqueous extract of guava leaves may be used as an effective treatment for non-specific diarrhoea in folk medicine.

Acute lethal and sublethal effects of neem leaf extract on the neotropical freshwater fish Prochilodus lineatus

The aim of this study was to determine the toxicity of the aqueous extract of neem leaves, a product extensively used in fish-farms as alternative for the control of fish parasites and fish fry predators, for the neotropical fish Prochilodus lineatus. The 24 It LC(50) of neem leaf extract for juveniles P lineatus was estimated as 4.8 g L(-1); the fish were then exposed for 24 h to 2.5, 5.0 and 7.5 g L(-1) or only clean water (control). Plasma glucose levels were higher in fish exposed to 2.5 g L(-1) and 5.0 g L(-1) neem extract, relative to control, indicating a typical stress response. Neem extract did not interfere with the osmoregulating capacity of the fish, as their plasma sodium, chloride, total protein and osmolarity did not change. The presence of the biopesticide interfered with the antioxidant defense system of P. lineatus, as there was a decrease in liver catalase activity at all neem concentrations and the detoxifying enzyme glutathione-S-transferase was activated in fish exposed to 5.0 g L(-1). Fish exposed to all neem extract concentrations exhibited damaged gill and kidney tissue. These results indicate that although neem extract is less toxic to P. lineatus than other synthetic insecticides used in fish-farming it does cause functional and morphological changes in this fish species. (c) 2006 Elsevier B.V. All rights reserved.

Effect of Aloe vera extract on the improvement of the respiratory activity of leukocytes of matrinxã during the transport stress

This study evaluated the effect of extract of Aloe vera in the transport water of matrinxã (Brycon amazonicus) fish on stress response and leukocyte respiratory activity. Fish was transported for 4 h in water containing Aloe at levels 0; 0.02; 0.2 and 2 mg/L, and sampled before transport 2, 4, 24 and 96 h after for determination of plasma glucose and respiratory activity of leukocytes. An additional in vitro assay was conducted with another fish species, pacu (Piaractus mesopotamicus), to test the respiratory burst of leukocytes exposed to Aloe extract (0.0, phosphate-buffered saline (PBS) only) at 0.1, 0.2, 0.5 and 1 mg/L). Plasma glucose increased after 2 and 4 h of transport and returned to control levels within 24 h, but the addition of Aloe in the transport water did not affect the level of blood glucose. However, at 2 h of transport, Aloe enhanced the respiratory activity of leukocytes in a dose-dependent way. The highest value of respiratory burst activity of leukocytes was observed in the fish transported in water containing Aloe at 2 mg/L. The enhancing effect of the plant extract on the production of oxygen radicals was confirmed in vitro in leukocytes of pacu incubated in Aloe at concentrations 0.1 and 0.2 mg/L. The results suggest that Aloe vera is a modulator of the immune system in fish improving the innate immune response tested.

The extract of the jellyfish Phyllorhiza punctata promotes neurotoxic effects

Phyllorhiza punctata (P. punctata) is a jellyfish native to the southwestern Pacific. Herewith we present the biochemical and pharmacological characterization of an extract of the tentacles of P. punctata. The tentacles were subjected to three freezethaw cycles, homogenized, ultrafiltered, precipitated, centrifuged and lyophilized to obtain a crude extract (PHY-N). Paralytic shellfish poisoning compounds such as saxitoxin, gonyautoxin-4, tetrodotoxin and brevetoxin-2, as well as several secretory phospholipase A2 were identified. PHY-N was tested on autonomic and somatic neuromuscular preparations. In mouse vas deferens, PHY-N induced phasic contractions that reached a peak of 234 +/- 34.7% of control twitch height, which were blocked with either 100 mu m of phentolamine or 1m m of lidocaine. In mouse corpora cavernosa, PHY-N evoked a relaxation response, which was blocked with either L-NG-Nitroarginine methyl ester (0.5 m m) or 1m m of lidocaine. PHY-N (1, 3 and 10 mu g ml(-1)) induced an increase in tonus of the biventercervicis neuromuscular preparation that was blocked with pre-treatment of galamine (10 mu m). Administration of 6 mg kg(-1) PHY-N intramuscularly produced death in broilers by spastic paralysis. In conclusion, PHY-N induces nerve depolarization and nonspecifically increases neurotransmitter release. Copyright (C) 2011 John Wiley & Sons, Ltd.

Inhibition of the myotoxic activity of Bothrops jararacussu venom and its two major myotoxins, BthTX-I and BthTX-II, by the aqueous extract of Tabernaemontana catharinensis A. DC. (Apocynaceae)

Partial neutralization of the myotoxic effect of Bothrops jararacussu venom (BV) and two of its myotoxins [bothropstoxin-I (BthTX-I), catalytically inactive, and II (BthTX-II), showing low PLA(2) activity], by the lyophilized aqueous extract of Tabernaemontana catharinensis (AE), was studied in rat isolated soleus muscle preparations (in vitro) and through i.m. injection in the gastrocnemius muscle (in vivo) by determination of creatine kinase (CK) activity and histopathological analysis. Incubation of soleus muscle for 1 h with BV or toxins (20 mug/ml) plus AE (400 mug/ml) added immediately after BV, BthTX-I or BthTX-II reduced CK levels by 53%, 37% and 56%, respectively. The myonecrotic effects of BV (20 mug/ml) upon soleus muscle was reduced 24%, 35% and 36% when AE (400 mug/ml) was added 1 h after BV and CK was evaluated 30 min, 1 and 2 h later, respectively. For BthTX-I these values were 46%, 48% and 47%, while for BthTX-II no inhibitory effect was detected. Histological analysis of soleus muscle after incubation with AE (400 mug/ml, I h) did not reveal any change in muscle fibers, but severe necrosis induced by -BV or toxins (20 mug/ml) was clearly in evidence, and decreased significantly when soleus muscle was protected by AE. This protection was also observed when AE was administered 1 h after BV or BthTX-I, but not after BthTX-II. AE did not inhibit the catalytic PLA(2), activity of BthTX-II or BV and did not change the PAGE pattern of BV, BthTX-I or BthTX-II. In vivo assays were performed in 100-g rats and maximal CK release was attained at a dose of 100 mug of BV, 3 h after injection. AE was not effective when injected 20 s after BV or toxins. However, injecting BV or toxins (100 mug), which were pre-incubated with AE (2 mg) caused an inhibition of 57%, 59% and 51%, respectively, with zero time pre-incubation, but was less effective with I h pre-incubation. This plant represents a potential source of promising myotoxin inhibitors. (C) 2004 Elsevier GmbH. All rights reserved.

Effects of the Ottonia martiana Miq. (Piperaceae) extract on dog's ocular surface

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Larvicidal activity of the water extract of Moringa oleifera seeds against Aedes aegypti and its toxicity upon laboratory animals

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of neem extract on the cotton aphid

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Yeast extract and prebiotic in pre-initial phase diet for broiler chickens raised under different temperatures

Objetivou-se nesta pesquisa avaliar o desempenho, o rendimento de carcaça e a morfometria intestinal de frangos de corte criados em diferentes temperaturas e que receberam na fase pré-inicial ração contendo ou não extrato de leveduras e prebiótico. Foram utilizados 1.440 pintos machos de 1 dia de idade, criados em diferentes câmaras climáticas. As rações, acrescidas ou não de extrato de leveduras e prebiótico, foram oferecidas somente na fase pré-inicial (1 a 7 dias). A partir do oitavo dia, todas as aves receberam a mesma ração, reajustada de acordo com as recomendações usuais. Adotou-se o delineamento experimental inteiramente casualizado em arranjo fatorial 3 × 2 × 2, composto de três temperaturas de criação (calor, conforto e frio) e dois níveis de extrato de leveduras (com ou sem) e prebiótico (com ou sem). O desempenho das aves foi avaliado considerando o ganho de peso, o consumo de ração, a conversão alimentar e a viabilidade aos 42 dias de idade. Também foram avaliados o rendimento de carcaça e a morfometria intestinal. O calor ambiente prejudicou o desempenho e o rendimento de carcaça. A inclusão de prebiótico na ração pré-inicial aumentou o ganho de peso e melhorou a conversão alimentar das aves criadas no calor. A inclusão dos produtos na ração de frangos de corte criados em ambiente de calor e no frio tem efeito benéfico sobre as vilosidades das aves.

Liming and quality of guava fruit cultivated in Brazil

An experiment was conducted on guava trees Psidium guajava L. (cv. Paluma) grown in the Experimental Citrus Culture Station of Bebedouro, SP, on dystrophic, acid Typical Hapludox in order to assess the effects of application of increasing lime doses to the soil on the quality of guava fruits on the basis of the physicochemical changes observed in the fruits after harvesting. The treatments consisted of increasing lime doses applied before planting, considering 0, 1.85, 3.79, 5.56 and 7.41 t ha(-1), applied in August 1999. Leaf calcium content was assessed at flowering time. After fruit harvesting, calcium content in the pulp, total weight, transverse diameter, length, pulp weight, % pulp, Brix degrees (degrees Brix), titratable acidity, and fruit ratio were determined. Loss of fruit fresh mass, firmness and color were determined daily during a period of 8 days of storage. Lime application to an acid Red Latosol before guava tree planting did not affect the physical characteristics of the fruits but provided a lower loss of fresh matter and greater fruit firmness when the fruits presented Ca levels close to 0.99 g kg(-1). It is important to conduct new studies of the effects of liming on guava fruit quality under different edaphic-climatic conditions and on different guava tree genotypes. (c) 2005 Elsevier B.V. All rights reserved.

Balancing guava nutrition with liming and fertilization

A resposta da goiabeira à calagem e à adubação pode ser monitorada por análises de tecido vegetal. O perfil nutricional é definido em relação a padrões de teores de nutrientes. No entanto, os teores de nutrientes-padrão são constantemente criticados por não considerarem as interações que ocorrem entre nutrientes e por gerarem tendências numéricas, decorrentes da redundância dos dados, da dependência de escala e da distribuição não normal. As técnicas de análise composicional de dados podem controlar esses dados tendenciosos, equilibrando os grupos de nutrientes, tais como os envolvidos na calagem e na adubação. A utilização das relações log isométricas (ilr) ortonormais, sequencialmente dispostas, evita tendências numéricas inerentes aos dados de composição. Os objetivos do trabalho foram relacionar o balanço de nutrientes dos tecidos vegetais com a produção de goiabeiras em pomares de 'Paluma' diferentemente corrigidos e adubados, e ajustar os atuais padrões de nutrientes com a faixa de equilíbrio das goiabeiras mais produtivas. Um experimento de calagem de sete anos e três, experimentos de três anos com doses de N, P2O5 e K2O, foram conduzidos em pomares de goiabeiras 'Paluma' em um Latossolo Vermelho-Amarelo. Os teores de N, P, K, Ca e Mg na planta foram monitorados anualmente. Selecionaram-se os balanços [N, P, K | Ca, Mg], [N, P | K], [N | P] e [Ca | Mg] para separar os efeitos da calagem (Ca-Mg) e dos fertilizantes (N-K) nos balanços de macronutrientes. Os balanços foram mais influenciados pela calagem do que pela fertilização. A produtividade das goiabeiras e seu balanço nutricional permitiram a definição de faixas de equilíbrio de nutrientes e sua validação com as faixas de concentrações críticas atualmente utilizadas no Brasil e combinadas em coordenadas ilr.